{"id":2389,"date":"2021-05-11T02:55:56","date_gmt":"2021-05-11T02:55:56","guid":{"rendered":"https:\/\/fclatbz2dc.wpdns.site\/?p=2389"},"modified":"2024-01-22T01:34:05","modified_gmt":"2024-01-22T01:34:05","slug":"what-is-the-laser-resonator","status":"publish","type":"post","link":"https:\/\/mydery.com\/es\/what-is-the-laser-resonator\/","title":{"rendered":"\u00bfQu\u00e9 es el resonador l\u00e1ser?"},"content":{"rendered":"<p class=\"yoast-reading-time__wrapper\"><span class=\"yoast-reading-time__icon\"><\/span><span class=\"yoast-reading-time__descriptive-text\">Tiempo de lectura estimado:  <\/span><span class=\"yoast-reading-time__reading-time\">37<\/span><span class=\"yoast-reading-time__time-unit\"> minuto<\/span><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">El instrumento que produce una fuente de luz l\u00e1ser se llama resonador l\u00e1ser, que incluye l\u00e1ser de gas, l\u00e1ser l\u00edquido, l\u00e1ser de estado s\u00f3lido, dispositivo \u00f3ptico semiconductor y otros l\u00e1seres. Entre ellos, los l\u00e1seres m\u00e1s t\u00edpicos son CO<sub>2 <\/sub>l\u00e1seres de gas, l\u00e1seres semiconductores, l\u00e1seres de estado s\u00f3lido YAG y l\u00e1seres de fibra.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"h-basic-composition-and-development-of-laser\">Composici\u00f3n b\u00e1sica y desarrollo del l\u00e1ser.<\/h3>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"h-the-basic-composition-of-laser\">La composici\u00f3n b\u00e1sica del l\u00e1ser.<\/h4>\n\n\n\n<p class=\"wp-block-paragraph\">Aunque existen muchos tipos de l\u00e1seres, todos producen l\u00e1seres mediante excitaci\u00f3n y radiaci\u00f3n estimulada. Por lo tanto, la composici\u00f3n b\u00e1sica de los l\u00e1seres es fija, generalmente compuesta por materiales de trabajo (es decir, medios de trabajo que pueden producir inversi\u00f3n de poblaci\u00f3n despu\u00e9s de ser excitados), fuentes de excitaci\u00f3n (la energ\u00eda que puede hacer que la sustancia de trabajo invierta el n\u00famero de part\u00edculas, tambi\u00e9n conocida como la fuente de la bomba) y la cavidad resonante \u00f3ptica se componen de tres partes.<\/p>\n\n\n\n<h5 class=\"wp-block-heading\" id=\"h-working-substance\">Sustancia de trabajo<\/h5>\n\n\n\n<p class=\"wp-block-paragraph\">La producci\u00f3n del l\u00e1ser debe elegir un material de trabajo adecuado, que puede ser gas, l\u00edquido, s\u00f3lido o semiconductor. En este medio, el n\u00famero de part\u00edculas se puede invertir para crear las condiciones necesarias para obtener luz l\u00e1ser. La existencia de niveles de energ\u00eda metaestables es muy beneficiosa para la realizaci\u00f3n de la inversi\u00f3n de la poblaci\u00f3n. Hay casi mil tipos de materiales de trabajo y las longitudes de onda del l\u00e1ser que se pueden generar cubren una amplia gama de bandas ultravioleta de vac\u00edo a bandas de infrarrojo lejano.<\/p>\n\n\n\n<h5 class=\"wp-block-heading\" id=\"h-excitation-source\">Fuente de excitaci\u00f3n<\/h5>\n\n\n\n<p class=\"wp-block-paragraph\">Para hacer que el n\u00famero de part\u00edculas en la sustancia de trabajo se invierta, se debe adoptar un cierto m\u00e9todo para excitar el sistema de part\u00edculas y aumentar el n\u00famero de part\u00edculas a altos niveles de energ\u00eda. El m\u00e9todo de descarga de gas puede utilizar electrones con energ\u00eda cin\u00e9tica para excitar la sustancia de trabajo, lo que se denomina excitaci\u00f3n el\u00e9ctrica; La fuente de luz de pulso tambi\u00e9n se puede usar para irradiar la sustancia de trabajo para producir excitaci\u00f3n, que se llama excitaci\u00f3n \u00f3ptica; hay excitaci\u00f3n t\u00e9rmica, excitaci\u00f3n qu\u00edmica, etc. Varios m\u00e9todos de incentivo se denominan v\u00edvidamente bombeo o bombeo. Para obtener continuamente la salida del l\u00e1ser, debe bombearse continuamente para mantener el n\u00famero de part\u00edculas en el estado excitado.<\/p>\n\n\n\n<h5 class=\"wp-block-heading\" id=\"h-optical-cavity\">Cavidad \u00f3ptica<\/h5>\n\n\n\n<p class=\"wp-block-paragraph\">Con un material de trabajo y una fuente de excitaci\u00f3n adecuados, se puede lograr la inversi\u00f3n de la poblaci\u00f3n, pero la intensidad de la radiaci\u00f3n estimulada generada de esta manera es muy baja y no se puede aplicar. Entonces, la gente pens\u00f3 que se podr\u00eda usar una cavidad resonante \u00f3ptica para amplificar la radiaci\u00f3n estimulada. La cavidad de resonancia \u00f3ptica est\u00e1 compuesta por dos espejos con una determinada forma geom\u00e9trica y caracter\u00edsticas de reflexi\u00f3n \u00f3ptica combinadas de una manera espec\u00edfica. Sus principales funciones son las siguientes.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Proporcionar la capacidad de retroalimentaci\u00f3n \u00f3ptica para hacer que los fotones de emisi\u00f3n estimulados vayan y retrocedan en la cavidad varias veces para formar una oscilaci\u00f3n continua coherente.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Limite la direcci\u00f3n y frecuencia del rayo oscilante en la cavidad para asegurarse de que el l\u00e1ser de salida tenga una cierta direccionalidad y monocromaticidad.<\/p>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"h-the-development-of-lasers\">El desarrollo de los l\u00e1seres<\/h4>\n\n\n\n<p class=\"wp-block-paragraph\">El l\u00e1ser es uno de los componentes b\u00e1sicos indispensables en los sistemas de procesamiento l\u00e1ser modernos. Con el desarrollo de la tecnolog\u00eda de procesamiento l\u00e1ser, los l\u00e1seres tambi\u00e9n avanzan constantemente y han aparecido muchos l\u00e1seres nuevos.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Los primeros l\u00e1seres de procesamiento de fuente l\u00e1ser eran principalmente CO de alta potencia<sub>2<\/sub>, l\u00e1seres de gas y l\u00e1seres de estado s\u00f3lido YAG con bombeo de l\u00e1mpara. Desde la perspectiva de la historia del desarrollo de la tecnolog\u00eda de procesamiento l\u00e1ser, el CO de alta capitalizaci\u00f3n<sub>2 <\/sub>y los l\u00e1seres que aparecieron a mediados de la d\u00e9cada de 1970 han desarrollado CO enfriado por difusi\u00f3n<sub>2<\/sub> l\u00e1seres. La Tabla 2.1 muestra el estado de desarrollo de CO<sub>2<\/sub> l\u00e1seres.<\/p>\n\n\n\n<figure class=\"wp-block-table\"><table><tbody><tr><td class=\"has-text-align-center\" data-align=\"center\">Tipo de l\u00e1ser &nbsp;<\/td><td class=\"has-text-align-center\" data-align=\"center\">Tipo sellado<\/td><td class=\"has-text-align-center\" data-align=\"center\">Tipo de flujo axial lento<\/td><td class=\"has-text-align-center\" data-align=\"center\">Tipo de flujo cruzado<\/td><td class=\"has-text-align-center\" data-align=\"center\">Tipo de flujo axial r\u00e1pido<\/td><td class=\"has-text-align-center\" data-align=\"center\">Turbo ventilador Flujo axial r\u00e1pido &nbsp;<\/td><td class=\"has-text-align-center\" data-align=\"center\">Tipo de enfriamiento por difusi\u00f3n SLAB &nbsp;<\/td><\/tr><tr><td class=\"has-text-align-center\" data-align=\"center\">Edad de aparici\u00f3n &nbsp;<\/td><td class=\"has-text-align-center\" data-align=\"center\">Mediados de la d\u00e9cada de 1970<\/td><td class=\"has-text-align-center\" data-align=\"center\">Principios de la d\u00e9cada de 1980<\/td><td class=\"has-text-align-center\" data-align=\"center\">Mediados de la d\u00e9cada de 1980<\/td><td class=\"has-text-align-center\" data-align=\"center\">Finales de la d\u00e9cada de 1980<\/td><td class=\"has-text-align-center\" data-align=\"center\">Principios de la d\u00e9cada de 1990<\/td><td class=\"has-text-align-center\" data-align=\"center\">Mediados de los 90 del siglo XX &nbsp;<\/td><\/tr><tr><td class=\"has-text-align-center\" data-align=\"center\">Potencia \/ W<\/td><td class=\"has-text-align-center\" data-align=\"center\">500 &nbsp;<\/td><td class=\"has-text-align-center\" data-align=\"center\">1000 &nbsp;<\/td><td class=\"has-text-align-center\" data-align=\"center\">20000 &nbsp;<\/td><td class=\"has-text-align-center\" data-align=\"center\">5000 &nbsp;<\/td><td class=\"has-text-align-center\" data-align=\"center\">10000 &nbsp;<\/td><td class=\"has-text-align-center\" data-align=\"center\">5000<\/td><\/tr><tr><td class=\"has-text-align-center\" data-align=\"center\">Calidad del haz (M<sup>2<\/sup> factor &nbsp;<\/td><td class=\"has-text-align-center\" data-align=\"center\">Inestable<\/td><td class=\"has-text-align-center\" data-align=\"center\">1.5<\/td><td class=\"has-text-align-center\" data-align=\"center\">10<\/td><td class=\"has-text-align-center\" data-align=\"center\">5<\/td><td class=\"has-text-align-center\" data-align=\"center\">2.5<\/td><td class=\"has-text-align-center\" data-align=\"center\">1.2<\/td><\/tr><tr><td class=\"has-text-align-center\" data-align=\"center\">Calidad del haz (K<sub>F<\/sub>\/ mm \u2022 mrad)<\/td><td class=\"has-text-align-center\" data-align=\"center\">&nbsp;Inestable<\/td><td class=\"has-text-align-center\" data-align=\"center\">5<\/td><td class=\"has-text-align-center\" data-align=\"center\">35<\/td><td class=\"has-text-align-center\" data-align=\"center\">17<\/td><td class=\"has-text-align-center\" data-align=\"center\">9<\/td><td class=\"has-text-align-center\" data-align=\"center\">4.5<\/td><\/tr><\/tbody><\/table><figcaption>Tabla 2.1 Estado de desarrollo del CO<sub>2<\/sub> l\u00e1ser<\/figcaption><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">CO temprano<sub>2 <\/sub>Los l\u00e1seres tend\u00edan a desarrollarse en la direcci\u00f3n de aumentar la potencia del l\u00e1ser, pero cuando la potencia del l\u00e1ser alcanz\u00f3 un cierto requisito, se prest\u00f3 atenci\u00f3n a la calidad del rayo del l\u00e1ser y el desarrollo del l\u00e1ser se desplaz\u00f3 para mejorar la calidad del rayo. Recientemente, la losa de CO enfriada por difusi\u00f3n<sub>2<\/sub> El l\u00e1ser, que est\u00e1 cerca del l\u00edmite de difracci\u00f3n, tiene una buena calidad de haz y ha sido ampliamente utilizado una vez que se lanz\u00f3, especialmente en el campo del corte por l\u00e1ser, y es el preferido de muchas empresas.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">El co<sub>2<\/sub> El resonador l\u00e1ser tiene las desventajas de un gran volumen, una estructura compleja y un mantenimiento dif\u00edcil. El metal no puede absorber bien el l\u00e1ser con una longitud de onda de 10,6 m, no puede usar fibra \u00f3ptica para transmitir el l\u00e1ser, y el plasma inducido por el tiempo de soldadura tiene graves y otras deficiencias. M\u00e1s tarde, el l\u00e1ser de estado s\u00f3lido YAG con una longitud de onda de 1.06 \u0447m compens\u00f3 las deficiencias del CO<sub>2<\/sub> l\u00e1ser hasta cierto punto. Los primeros l\u00e1seres de estado s\u00f3lido de YAG utilizaban m\u00e9todos de bombeo de l\u00e1mparas, que ten\u00edan problemas como la baja eficiencia del l\u00e1ser (aproximadamente 3%) y la mala calidad del haz. Con el avance continuo de la tecnolog\u00eda l\u00e1ser, los l\u00e1seres de estado s\u00f3lido YAG continuaron progresando y aparecieron muchos l\u00e1seres nuevos. El estado de desarrollo de los l\u00e1seres de estado s\u00f3lido YAG se muestra en la Tabla 2.2.<\/p>\n\n\n\n<figure class=\"wp-block-table aligncenter\"><table><tbody><tr><td class=\"has-text-align-center\" data-align=\"center\">Tipo de l\u00e1ser &nbsp;<\/td><td class=\"has-text-align-center\" data-align=\"center\">L\u00e1mpara bombeada<\/td><td class=\"has-text-align-center\" data-align=\"center\">Bombeo de diodo<\/td><td class=\"has-text-align-center\" data-align=\"center\">Fibra bombeada &nbsp;<\/td><td class=\"has-text-align-center\" data-align=\"center\">DISCO de escamas &nbsp;<\/td><td class=\"has-text-align-center\" data-align=\"center\">Semiconductor bombeado por el extremo<\/td><td class=\"has-text-align-center\" data-align=\"center\">l\u00e1ser de fibra &nbsp;<\/td><\/tr><tr><td class=\"has-text-align-center\" data-align=\"center\">Edad de aparici\u00f3n &nbsp;<\/td><td class=\"has-text-align-center\" data-align=\"center\">Decenio de 1980<\/td><td class=\"has-text-align-center\" data-align=\"center\">Finales de la d\u00e9cada de 1980 &nbsp;<\/td><td class=\"has-text-align-center\" data-align=\"center\">Mediados de la d\u00e9cada de 1990 &nbsp;<\/td><td class=\"has-text-align-center\" data-align=\"center\">Mediados de la d\u00e9cada de 1990 &nbsp;<\/td><td class=\"has-text-align-center\" data-align=\"center\">Finales de la d\u00e9cada de 1990 &nbsp;<\/td><td class=\"has-text-align-center\" data-align=\"center\">Principios del siglo XXI &nbsp;<\/td><\/tr><tr><td class=\"has-text-align-center\" data-align=\"center\">Potencia \/ W<\/td><td class=\"has-text-align-center\" data-align=\"center\">6000 &nbsp;<\/td><td class=\"has-text-align-center\" data-align=\"center\">4400 &nbsp;<\/td><td class=\"has-text-align-center\" data-align=\"center\">2000 &nbsp;<\/td><td class=\"has-text-align-center\" data-align=\"center\">4000 \uff08prototipo\uff09 &nbsp;<\/td><td class=\"has-text-align-center\" data-align=\"center\">200 &nbsp;<\/td><td class=\"has-text-align-center\" data-align=\"center\">10000<\/td><\/tr><tr><td class=\"has-text-align-center\" data-align=\"center\">Calidad del haz (M<sup>2<\/sup> factor)<\/td><td class=\"has-text-align-center\" data-align=\"center\">70<\/td><td class=\"has-text-align-center\" data-align=\"center\">35<\/td><td class=\"has-text-align-center\" data-align=\"center\">35<\/td><td class=\"has-text-align-center\" data-align=\"center\">7<\/td><td class=\"has-text-align-center\" data-align=\"center\">1.1<\/td><td class=\"has-text-align-center\" data-align=\"center\">70<\/td><\/tr><tr><td class=\"has-text-align-center\" data-align=\"center\">Calidad del haz (K<sub>F<\/sub>\/ mm \u2022 mard)<\/td><td class=\"has-text-align-center\" data-align=\"center\">25<\/td><td class=\"has-text-align-center\" data-align=\"center\">12<\/td><td class=\"has-text-align-center\" data-align=\"center\">12<\/td><td class=\"has-text-align-center\" data-align=\"center\">2.5<\/td><td class=\"has-text-align-center\" data-align=\"center\">0.35<\/td><td class=\"has-text-align-center\" data-align=\"center\">25<\/td><\/tr><\/tbody><\/table><figcaption>Tabla 2.2 El estado de desarrollo de los l\u00e1seres de estado s\u00f3lido YAG<\/figcaption><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">Puede verse en la Tabla 2.1 y la Tabla 2.2 que adem\u00e1s de mejorar continuamente la potencia del l\u00e1ser, otro aspecto importante del desarrollo del l\u00e1ser es mejorar continuamente la calidad del rayo del l\u00e1ser. La calidad del rayo l\u00e1ser a menudo juega un papel m\u00e1s importante en el proceso de procesamiento del l\u00e1ser que la potencia del l\u00e1ser.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">El desarrollo de la fabricaci\u00f3n de l\u00e1ser con <a href=\"https:\/\/mydery.com\/es\/more-knowledge-to-improving-laser-cutting-machine\/\">l\u00e1ser<\/a> La potencia y la calidad del haz se muestran en la Figura 2.1.<\/p>\n\n\n\n<figure class=\"wp-block-image size-large\"><img decoding=\"async\" width=\"800\" height=\"482\" src=\"https:\/\/mydery.com\/wp-content\/themes\/woodmart\/images\/lazy.svg\" data-src=\"http:\/\/mydery.com\/wp-content\/uploads\/2021\/05\/The-development-of-manufacturing-lasers-with-laser-power-and-beam-quality.jpg\" alt=\"The development of manufacturing lasers with laser power and beam quality\" class=\"wd-lazy-fade wp-image-2393\" title=\"\" srcset=\"\" data-srcset=\"https:\/\/mydery.com\/wp-content\/uploads\/2021\/05\/The-development-of-manufacturing-lasers-with-laser-power-and-beam-quality.jpg 800w, https:\/\/mydery.com\/wp-content\/uploads\/2021\/05\/The-development-of-manufacturing-lasers-with-laser-power-and-beam-quality-500x301.jpg 500w, https:\/\/mydery.com\/wp-content\/uploads\/2021\/05\/The-development-of-manufacturing-lasers-with-laser-power-and-beam-quality-700x422.jpg 700w, https:\/\/mydery.com\/wp-content\/uploads\/2021\/05\/The-development-of-manufacturing-lasers-with-laser-power-and-beam-quality-300x181.jpg 300w, https:\/\/mydery.com\/wp-content\/uploads\/2021\/05\/The-development-of-manufacturing-lasers-with-laser-power-and-beam-quality-768x463.jpg 768w\" sizes=\"(max-width: 800px) 100vw, 800px\" \/><figcaption>Figura 2.1 El desarrollo de la fabricaci\u00f3n de l\u00e1seres con potencia l\u00e1ser y calidad de haz<\/figcaption><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">A principios del siglo XXI, apareci\u00f3 otro nuevo tipo de l\u00e1ser semiconductor l\u00e1ser. En comparaci\u00f3n con el CO tradicional de alta potencia<sub>2<\/sub> Resonador de l\u00e1seres y l\u00e1seres de estado s\u00f3lido YAG, los l\u00e1seres semiconductores tienen ventajas t\u00e9cnicas obvias, como tama\u00f1o peque\u00f1o, peso ligero, alta eficiencia, bajo consumo de energ\u00eda, larga vida \u00fatil y alta tasa de absorci\u00f3n de l\u00e1seres de metal a semiconductores. Con el continuo desarrollo de la tecnolog\u00eda l\u00e1ser de semiconductores, se han desarrollado r\u00e1pidamente otros l\u00e1seres de estado s\u00f3lido basados en l\u00e1seres de semiconductores, como los l\u00e1seres de fibra, los l\u00e1seres de estado s\u00f3lido bombeados por semiconductores y los l\u00e1seres de l\u00e1minas. Entre ellos, los l\u00e1seres de fibra se est\u00e1n desarrollando r\u00e1pidamente, especialmente los l\u00e1seres de fibra dopados con tierras raras, que se han utilizado ampliamente en comunicaciones de fibra, detecci\u00f3n de fibra, procesamiento de materiales con l\u00e1ser y otros campos.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">De CO<sub>2<\/sub> l\u00e1ser de gas a l\u00e1ser de fibra<\/h3>\n\n\n\n<h4 class=\"wp-block-heading\">CO<sub>2<\/sub> l\u00e1ser de gas<\/h4>\n\n\n\n<p class=\"wp-block-paragraph\">Un l\u00e1ser que usa CO<sub>2<\/sub> ya que la principal sustancia de trabajo se llama CO<sub>2<\/sub> l\u00e1ser. Una peque\u00f1a cantidad de N<sup>2<\/sup> y debe agregarse a su sustancia de trabajo para mejorar la ganancia, la eficiencia de la resistencia al calor y la potencia de salida del l\u00e1ser. CO<sub>2<\/sub> El l\u00e1ser tiene las siguientes caracter\u00edsticas.<\/p>\n\n\n\n<ul class=\"wp-block-list\"><li>La potencia de salida es grande. El CO general de tubo cerrado<sub>2<\/sub> El l\u00e1ser puede tener una potencia de salida continua de decenas de vatios, que es mucho m\u00e1s que otros l\u00e1seres de gas. El flujo lateral de CO excitado el\u00e9ctricamente<sub>2<\/sub> El l\u00e1ser puede tener una salida continua de decenas de kilovatios.<\/li><li>Alta eficiencia de conversi\u00f3n de energ\u00eda. La eficiencia de conversi\u00f3n de energ\u00eda del CO<sub>2<\/sub> los l\u00e1seres pueden alcanzar 30% ~ 40%, que supera a otros l\u00e1seres de gas.<\/li><li>El co<sub>2<\/sub> El l\u00e1ser utiliza la transici\u00f3n entre los niveles de energ\u00eda del CO<sub>2<\/sub> vibraci\u00f3n molecular y tiene un espectro relativamente rico. Hay docenas de l\u00edneas de espectro en la salida del l\u00e1ser cerca de la longitud de onda de 10 \u0447m. El CO de alta presi\u00f3n<sub>2<\/sub> El l\u00e1ser desarrollado en los \u00faltimos a\u00f1os puede lograr una salida sintonizable de forma continua de 9 a 10 \u0447m.<\/li><li>La banda de salida del CO<sub>2 <\/sub>el l\u00e1ser es exactamente la ventana atmosf\u00e9rica (es decir, la transparencia de la atm\u00f3sfera a esta longitud de onda es relativamente alta)<\/li><li>Adem\u00e1s, CO<sub>2<\/sub> Los l\u00e1seres tambi\u00e9n tienen las ventajas de una alta calidad de haz de salida, buena coherencia, ancho de l\u00ednea estrecho, funcionamiento estable, etc., por lo que se han utilizado ampliamente en la industria y la defensa nacional.<\/li><\/ul>\n\n\n\n<h5 class=\"wp-block-heading\">La estructura de CO<sub>2<\/sub> l\u00e1ser<\/h5>\n\n\n\n<p class=\"wp-block-paragraph\">Un t\u00edpico CO excitado el\u00e9ctricamente longitudinalmente sellado<sub>2<\/sub> <a href=\"https:\/\/youtu.be\/jAmrj9dkzd0\" target=\"_blank\" rel=\"noopener\">l\u00e1ser<\/a> El resonador consta de un tubo l\u00e1ser, electrodos y una cavidad resonante (Figura 2.2). El componente m\u00e1s cr\u00edtico es un tubo l\u00e1ser hecho de vidrio duro, que generalmente adopta una estructura de manga en capas. La capa m\u00e1s interna es un tubo de descarga, la segunda capa es un tubo de revestimiento refrigerado por agua y la capa m\u00e1s externa es un tubo de almacenamiento de gas.<\/p>\n\n\n\n<figure class=\"wp-block-image size-large\"><img decoding=\"async\" width=\"800\" height=\"418\" src=\"https:\/\/mydery.com\/wp-content\/themes\/woodmart\/images\/lazy.svg\" data-src=\"http:\/\/mydery.com\/wp-content\/uploads\/2021\/05\/Schematic-diagram-of-CO2-laser-structure.jpg\" alt=\"Schematic diagram of CO2laser structure\" class=\"wd-lazy-fade wp-image-2394\" title=\"\" srcset=\"\" data-srcset=\"https:\/\/mydery.com\/wp-content\/uploads\/2021\/05\/Schematic-diagram-of-CO2-laser-structure.jpg 800w, https:\/\/mydery.com\/wp-content\/uploads\/2021\/05\/Schematic-diagram-of-CO2-laser-structure-500x261.jpg 500w, https:\/\/mydery.com\/wp-content\/uploads\/2021\/05\/Schematic-diagram-of-CO2-laser-structure-700x366.jpg 700w, https:\/\/mydery.com\/wp-content\/uploads\/2021\/05\/Schematic-diagram-of-CO2-laser-structure-300x157.jpg 300w, https:\/\/mydery.com\/wp-content\/uploads\/2021\/05\/Schematic-diagram-of-CO2-laser-structure-768x401.jpg 768w\" sizes=\"(max-width: 800px) 100vw, 800px\" \/><figcaption>Figura 2.2 Diagrama esquem\u00e1tico de CO<sub>2<\/sub>estructura l\u00e1ser<\/figcaption><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">El tubo de descarga est\u00e1 ubicado en el \u00e1rea de la columna positiva de la descarga luminiscente en la descarga de gas. Esta regi\u00f3n es rica en part\u00edculas portadoras de energ\u00eda, como electrones, iones, part\u00edculas metaestables y fotones, que es la regi\u00f3n de ganancia del l\u00e1ser. Por esta raz\u00f3n, existen ciertos requisitos para el di\u00e1metro, la longitud, la redondez y la rectitud del tubo de descarga. La mayor\u00eda de los equipos por debajo de 100 W est\u00e1n hechos de vidrio duro. Los dispositivos de potencia media (100 ~ 500 W) suelen estar hechos de tubos de vidrio de cuarzo para garantizar la estabilidad de la potencia o la frecuencia. El di\u00e1metro del tubo es generalmente de unos 10 mm y la longitud del tubo puede ser un poco m\u00e1s gruesa.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Hay una camisa de agua fr\u00eda al lado del tubo de descarga, su funci\u00f3n es reducir la temperatura del gas de trabajo en el tubo, para asegurar que el dispositivo se d\u00e9 cuenta de la distribuci\u00f3n de inversi\u00f3n de poblaci\u00f3n y para evitar que el tubo de descarga se caliente y agriete durante el proceso de excitaci\u00f3n de descarga. El prop\u00f3sito de agregar una carcasa refrigerada por agua es enfriar el aire y el gas para que la potencia de salida permanezca estable. El tubo de descarga est\u00e1 conectado al tubo de almacenamiento de gas en ambos extremos. Un extremo del tubo de almacenamiento de gas tiene un peque\u00f1o orificio que se comunica con el tubo de descarga, y el otro extremo est\u00e1 conectado al tubo de descarga a trav\u00e9s del tubo de retorno en espiral para que el gas pueda circular en el tubo de descarga y el tubo de almacenamiento de gas. El gas de la tuber\u00eda se puede intercambiar con el gas de la tuber\u00eda de almacenamiento de gas en cualquier momento.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">La funci\u00f3n del tubo de almacenamiento de gas m\u00e1s externo es reducir el cambio de la composici\u00f3n y presi\u00f3n del gas de trabajo durante el proceso de descarga y mejorar la estabilidad mec\u00e1nica del tubo de descarga.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">El tubo de retorno de aire es un tubo en espiral delgado que conecta los dos espacios del c\u00e1todo y el \u00e1nodo, lo que puede mejorar la distribuci\u00f3n desequilibrada de la presi\u00f3n entre los electrodos causada por el fen\u00f3meno de la electroforesis. El valor del di\u00e1metro y la longitud de la tuber\u00eda de retorno es muy importante. No solo permite que el gas en el c\u00e1todo fluya r\u00e1pidamente hacia el \u00e1rea del \u00e1nodo para lograr una distribuci\u00f3n uniforme del gas, sino que tambi\u00e9n evita el fen\u00f3meno de descarga en la tuber\u00eda de retorno.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Los electrodos se dividen en \u00e1nodo y c\u00e1todo. El material del c\u00e1todo requiere la capacidad de emitir electrones, una baja tasa de pulverizaci\u00f3n cat\u00f3dica y la capacidad de reducir el CO<sub>2<\/sub>. En la actualidad, la mayor\u00eda de CO<sub>2<\/sub> y los resonadores l\u00e1ser usan electrodos de n\u00edquel, y el \u00e1rea del electrodo est\u00e1 determinada por el di\u00e1metro interno del tubo de descarga y la corriente de trabajo. La electrodeposici\u00f3n es coaxial con el tubo de descarga. El tama\u00f1o del \u00e1nodo puede ser el mismo que el del c\u00e1todo o puede ser un poco m\u00e1s peque\u00f1o.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">La cavidad resonante est\u00e1 compuesta por un espejo total y un espejo de salida. Los espejos de reflexi\u00f3n total de CO de media y baja potencia<sub>2<\/sub> El resonador l\u00e1ser generalmente usa espejos de vidrio chapados en oro, porque la pel\u00edcula de oro tiene una alta reflectividad de luz de 10,6 \u0447m y es qu\u00edmicamente estable. Sin embargo, los espejos de sustrato de vidrio tienen mala conductividad t\u00e9rmica, por lo que el CO de alta potencia<sub>2<\/sub> Los l\u00e1seres a menudo usan espejos de metal, como espejos de cobre o espejos de molibdeno, o espejos recubiertos con oro y una pel\u00edcula diel\u00e9ctrica sobre un sustrato de acero inoxidable de cobre sin ox\u00edgeno pulido. El espejo de salida generalmente utiliza un material que puede transmitir una longitud de onda de 10,6um como sustrato, y se coloca una pel\u00edcula multicapa sobre \u00e9l para controlar una cierta transmitancia y lograr la mejor salida de acoplamiento. Los materiales com\u00fanmente utilizados son cloruro de potasio, cloruro de sodio, aluminio, ars\u00e9nico, seleniuro de zinc, telururo de cadmio, etc.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">La cavidad resonante del CO<sub>2<\/sub> El l\u00e1ser suele ser plano y c\u00f3ncavo. El espejo total est\u00e1 hecho de vidrio \u00f3ptico K8 o cuarzo \u00f3ptico, que se procesa en un espejo c\u00f3ncavo con un gran radio de curvatura. La superficie del espejo est\u00e1 recubierta con una pel\u00edcula de metal de alta reflectividad, una pel\u00edcula chapada en oro, a una longitud de onda de 10. 6 \u0447m La reflectividad en el lugar alcanza 98.8%, y las propiedades qu\u00edmicas son estables. <\/p>\n\n\n\n<p class=\"wp-block-paragraph\">La luz emitida por el di\u00f3xido de carbono es luz infrarroja, por lo que los espejos de reflexi\u00f3n total deben usar materiales que transmitan luz infrarroja. Debido a que el vidrio \u00f3ptico ordinario no es transparente a la luz infrarroja, se requiere abrir un peque\u00f1o orificio en el centro del espejo total y luego sellar una pieza de material infrarrojo que puede transmitir l\u00e1seres de 10,6 \u0447m para sellar el gas, lo que hace que el l\u00e1ser se la cavidad resonante separada es una salida del peque\u00f1o orificio fuera de la cavidad para formar un rayo de luz l\u00e1ser o un cuchillo de luz.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">La corriente de descarga del CO sellado<sub>2<\/sub> El resonador l\u00e1ser es relativamente peque\u00f1o. Se utiliza el electrodo fr\u00edo y el c\u00e1todo est\u00e1 hecho de una hoja de molibdeno o una hoja de n\u00edquel en forma cil\u00edndrica. La corriente de trabajo es de 30 ~ 40MA, el \u00e1rea del cilindro del c\u00e1todo es de 500 cm.<sup>2<\/sup>, para no contaminar la lente, se agrega una barrera de luz entre el c\u00e1todo y la lente. La bomba se excita mediante una fuente de alimentaci\u00f3n continua de CC.<\/p>\n\n\n\n<h5 class=\"wp-block-heading\">Caracter\u00edsticas de salida de CO<sub>2<\/sub> sistema laser<\/h5>\n\n\n\n<p class=\"wp-block-paragraph\">CO de flujo cruzado<sub>2<\/sub> resonador l\u00e1ser. El flujo de gas es perpendicular al eje de la cavidad. El co<sub>2<\/sub> El l\u00e1ser con esta estructura tiene una calidad de haz de luz baja y se usa principalmente para el tratamiento de superficies de materiales, y generalmente no se usa para cortar. Comparado con otros CO<sub>2<\/sub> l\u00e1seres, CO de flujo cruzado<sub>2<\/sub> Los l\u00e1seres tienen alta potencia de salida, calidad de haz de luz baja y precios bajos.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">CO de flujo cruzado<sub>2 <\/sub>Los l\u00e1seres pueden usar excitaci\u00f3n de corriente continua (CC) y excitaci\u00f3n de alta frecuencia (HF), y los electrodos se colocan a ambos lados de la zona de plasma paralelos al eje de la cavidad. El voltaje de encendido y funcionamiento del plasma es bajo, el gas fluye a trav\u00e9s de la zona de plasma perpendicular al haz y el paso del gas que fluye a trav\u00e9s del sistema de electrodos es muy amplio, por lo que la resistencia al flujo es muy peque\u00f1a, el enfriamiento del el plasma es muy eficaz y la potencia del l\u00e1ser no es demasiado grande. Muchas restricciones. <\/p>\n\n\n\n<p class=\"wp-block-paragraph\">La longitud de este tipo de l\u00e1ser es inferior a 1 m, pero puede generar 8KW de potencia. Sin embargo, debido al flujo lateral de gas a trav\u00e9s del plasma, este tipo de l\u00e1ser expulsa el plasma del circuito de descarga principal, lo que hace que el \u00e1rea del plasma en la secci\u00f3n del haz se desv\u00ede m\u00e1s o menos en un tri\u00e1ngulo, la calidad del haz no es alta , y aparecen los modos de orden superior. Si se utiliza un orificio circular para limitar el modo, la simetr\u00eda de la viga se puede mejorar hasta cierto punto.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Flujo axial r\u00e1pido CO<sub>2<\/sub> resonador l\u00e1ser. La estructura se muestra en la Figura 2.3. El flujo de gas l\u00e1ser de este tipo de CO<sub>2<\/sub> el l\u00e1ser est\u00e1 a lo largo del eje del resonador. La potencia de salida de CO<sub>2<\/sub> El l\u00e1ser con esta estructura var\u00eda desde cientos de vatios hasta 20KW. La calidad del haz de salida es mejor y es la estructura principal que se utiliza actualmente en el corte por l\u00e1ser.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Flujo axial r\u00e1pido CO<sub>2<\/sub> Los l\u00e1seres pueden utilizar excitaci\u00f3n de corriente continua (CC) y excitaci\u00f3n de radiofrecuencia (RF). La forma del plasma entre los electrodos es una columna delgada. Para evitar que el plasma se disperse en el \u00e1rea circundante, este tipo de \u00e1rea de descarga se encuentra a menudo en un tubo de vidrio cil\u00edndrico hueco o un tubo de cer\u00e1mica. El plasma se puede encender y mantener en ambos extremos de los dos electrodos de anillo. El voltaje de encendido y funcionamiento depende del electrodo. El voltaje m\u00e1ximo utilizado en aplicaciones pr\u00e1cticas es 20 ~ 30KV.<\/p>\n\n\n\n<figure class=\"wp-block-image size-large\"><img decoding=\"async\" width=\"800\" height=\"350\" src=\"https:\/\/mydery.com\/wp-content\/themes\/woodmart\/images\/lazy.svg\" data-src=\"http:\/\/mydery.com\/wp-content\/uploads\/2021\/05\/Fast-axial-flow-CO2-laser.jpg\" alt=\"\" class=\"wd-lazy-fade wp-image-2395\" title=\"\" srcset=\"\" data-srcset=\"https:\/\/mydery.com\/wp-content\/uploads\/2021\/05\/Fast-axial-flow-CO2-laser.jpg 800w, https:\/\/mydery.com\/wp-content\/uploads\/2021\/05\/Fast-axial-flow-CO2-laser-500x219.jpg 500w, https:\/\/mydery.com\/wp-content\/uploads\/2021\/05\/Fast-axial-flow-CO2-laser-700x306.jpg 700w, https:\/\/mydery.com\/wp-content\/uploads\/2021\/05\/Fast-axial-flow-CO2-laser-300x131.jpg 300w, https:\/\/mydery.com\/wp-content\/uploads\/2021\/05\/Fast-axial-flow-CO2-laser-768x336.jpg 768w\" sizes=\"(max-width: 800px) 100vw, 800px\" \/><figcaption>Figura 2.3 CO de flujo axial r\u00e1pido<sub>2<\/sub> l\u00e1ser<\/figcaption><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">El enfriamiento del gas circulante adopta la forma de flujo axial r\u00e1pido. Para garantizar una conducci\u00f3n de calor eficaz, los sopladores Roots o los ventiladores de rueda ajustables se utilizan com\u00fanmente para lograr este flujo de alta velocidad, pero la resistencia al flujo de esta forma geom\u00e9trica es relativamente alta y la potencia del l\u00e1ser de salida est\u00e1 sujeta a ciertas limitaciones, como la salida del l\u00e1ser de s\u00f3lo unos pocos cientos de vatios del excitador de CC. La potencia de salida del l\u00e1ser es limitada, por lo que a menudo se conectan varios tubos de descarga de enfriamiento de flujo axial en forma \u00f3ptica para proporcionar suficiente potencia de l\u00e1ser.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Dado que la potencia de salida del CO<sub>2<\/sub> El resonador l\u00e1ser depende principalmente de la entrada de energ\u00eda el\u00e9ctrica por unidad de volumen, la excitaci\u00f3n de RF es mayor que la excitaci\u00f3n de CC y la densidad del plasma es mayor. El l\u00e1ser de flujo axial de excitaci\u00f3n de RF en el que se conectan varios tubos de descarga de enfriamiento axial en forma \u00f3ptica, continua La potencia de salida puede alcanzar los 20KW. CO axial<sub>2<\/sub> Los l\u00e1seres, debido a la simetr\u00eda axial del plasma, son f\u00e1ciles de operar en el modo fundamental y producen un haz de alta calidad.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Refrigeraci\u00f3n por difusi\u00f3n tipo lama CO<sub>2<\/sub> l\u00e1ser. CO enfriado por difusi\u00f3n<sub>2<\/sub> lasers are similar to the early sealed-off CO<sub>2 <\/sub>lasers. The working gas of the sealed-off CO<sub>2<\/sub> laser is enclosed in a discharge tube and cooled by heat conduction. Although the outer wall of the discharge tube is effectively cooled, the discharge tube can only generate 50W of laser energy per meter, and it is impossible to make a compact, high-energy laser. Diffusion-cooled CO<sub>2<\/sub> lasers also use gas-enclosed methods, but the lasers are compact structures, the gas discharge excited by radiofrequency occurs between two copper electrodes with a larger area. The electrodes can be cooled by water cooling, and the narrow gap between the two electrodes can dissipate heat from the discharge cavity as much as possible so that a relatively high output power density can be obtained.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The diffusion-cooled CO<sub>2<\/sub> laser resonator adopts a stable resonant cavity composed of cylindrical mirrors. Since the optically unstable cavity can easily adapt to the geometry of the excited laser gain medium, the slab-type diffusion-cooled CO<sub>2<\/sub> laser can produce high-power-density laser beams, and the laser beam quality High, but the original output beam of this type of laser is rectangular, and a water-cooled reflected beam shaping device is required to shape the rectangular beam into a circular symmetrical laser beam. At present, the output power range of this type of laser is 1~5KW.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Compared with gas flow CO<sub>2<\/sub> lasers, slab diffusion cooling CO<sub>2 <\/sub>lasers have the characteristics of compact and sturdy structure and have an outstanding advantage, that is, in practical applications, they do not need to be fresh as gas flow CO<sub>2<\/sub> lasers. Laser working gas, but a small about 10L cylindrical container is installed in the laser head to store the laser working gas. This can be achieved through an external laser working gas supply device and a water permanent gas tank exchanger. This kind of executive agency has been working for more than one year.<\/p>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"h-a-semiconductor-laser\">A semiconductor laser<\/h4>\n\n\n\n<p class=\"wp-block-paragraph\">Semiconductor laser refers to a type of laser with semiconductor as its working material. Compared with other lasers, semiconductor lasers have the advantages of small size, high efficiency, simple and robust structure, and direct modulation. Semiconductor lasers have important applications in communications, ranging and information processing.<\/p>\n\n\n\n<h5 class=\"wp-block-heading\" id=\"h-semiconductor-foundation\">Semiconductor foundation<\/h5>\n\n\n\n<p class=\"wp-block-paragraph\">Pure semiconductors without impurities are called intrinsic semiconductors. If impurity atoms are doped into intrinsic semiconductors, impurity levels are formed below the conduction band and above the valence band, which are called donor level and acceptor level, respectively. Figure 2.4 shows the impurity levels of Si single crystal semiconductors.<\/p>\n\n\n\n<div class=\"wp-block-image\"><figure class=\"aligncenter size-large\"><img decoding=\"async\" width=\"600\" height=\"595\" src=\"https:\/\/mydery.com\/wp-content\/themes\/woodmart\/images\/lazy.svg\" data-src=\"http:\/\/mydery.com\/wp-content\/uploads\/2021\/05\/Impurity-level-of-Si-single-crystal-semiconductor.jpg\" alt=\"Impurity level of Si single crystal semiconductor\" class=\"wd-lazy-fade wp-image-2473\" title=\"\" srcset=\"\" data-srcset=\"https:\/\/mydery.com\/wp-content\/uploads\/2021\/05\/Impurity-level-of-Si-single-crystal-semiconductor.jpg 600w, https:\/\/mydery.com\/wp-content\/uploads\/2021\/05\/Impurity-level-of-Si-single-crystal-semiconductor-300x298.jpg 300w, https:\/\/mydery.com\/wp-content\/uploads\/2021\/05\/Impurity-level-of-Si-single-crystal-semiconductor-150x149.jpg 150w, https:\/\/mydery.com\/wp-content\/uploads\/2021\/05\/Impurity-level-of-Si-single-crystal-semiconductor-12x12.jpg 12w\" sizes=\"(max-width: 600px) 100vw, 600px\" \/><figcaption>Figure 2.4 Impurity level of Si single crystal semiconductor<\/figcaption><\/figure><\/div>\n\n\n\n<p class=\"wp-block-paragraph\">Semiconductor materials are mostly crystalline structures. When a large number of atoms are regularly and tightly combined into a crystal, those valence electrons in the crystal are all in the crystal energy band. When an external electric field is applied, the electrons in the valence band transition to the conduction band, and can move freely in the conduction band to conduct electricity. The loss of an electron in the valence band is equivalent to the appearance of a positively charged hole, which can also conduct electricity under the action of an external electric field. Therefore, the holes in the valence band and the electrons in the conduction band have a conductive effect, which is collectively called carriers.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">A semiconductor with a donor level is called an n-type semiconductor; a semiconductor with an acceptor level is called a p-type semiconductor. At room temperature, most of the donor atoms of n-type semiconductors are ionized by thermal energy, and electrons are excited to the conduction band and become free electrons. Most of the acceptor atoms of p-type semiconductors capture electrons in the valence band and form holes in the valence band. Therefore, n-type semiconductors are mainly conducted by electrons in the conduction band; p-type semiconductors are mainly conducted by holes in the valence band.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">In a piece of semiconductor material, the sudden change from the p-type region to the n-type region is called the p-n junction. A space charge zone is formed at the interface. The electrons in the conduction band of the n-type semiconductor diffuse to the p region, and the holes in the valence band of the p-type semiconductor diffuse to the n region. The n-type region near the junction region is positively charged because it is a donor, and the p-type region near the junction region is negatively charged because it is an acceptor. At the interface, an electric field directed from the n zone to the p zone is formed, which is called the built-in electric field (or self-built electric field). This electric field prevents the continued diffusion of electrons and holes.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">If a forward bias is applied to the semiconductor material that forms the p-n junction, the p area is connected to the positive electrode and the n area is connected to the negative electrode. The electric field of the forward voltage is opposite to the built-in electric field of the p-n junction, which weakens the built-in electric field&#8217;s hindrance to the diffusion of electrons in the crystal so that the free electrons in the n-zone are constantly under the action of the forward voltage. <\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Diffusion to the p region through the p-n junction. When there are a large number of electrons in the conduction band and holes in the valence band at the same time in the junction zone, they recombine in the injection zone. When the electrons in the conduction band transition to the valence band, the excess energy are emitted in the form of light. come out. This is the mechanism of semiconductor electroluminescence, and this spontaneous recombination luminescence is called spontaneous emission.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">To make the p-n junction generate laser light, a particle inversion distribution must be formed in the junction area, a heavily doped semiconductor material must be used, and the current injected into the p-n junction must be large enough (such as 30KA\/cm<sup>2<\/sup>). In this way, in the local area of \u200b\u200bthe p-n junction, a reversed distribution state of more electrons in the conduction band than holes in the valence band can be formed, thereby generating stimulated radiation and emitting laser light.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The optical resonant cavity of a semiconductor laser resonator is composed of a cleavage plane (110 faces) perpendicular to the p-n junction plane. It has a reflectivity of 35%, which is enough to cause laser oscillation. If it is necessary to increase the reflectivity, a layer of SiO<sub>2<\/sub> can be plated on the crystal surface, and then a layer of metallic silver film can be plated to obtain a reflectivity of more than 95%.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Once a forward bias is applied to the semiconductor laser, the population inversion occurs in the junction area and recombination occurs.<\/p>\n\n\n\n<h5 class=\"wp-block-heading\" id=\"h-conditions-for-semiconductor-stimulated-emission\">Conditions for semiconductor stimulated emission<\/h5>\n\n\n\n<p class=\"wp-block-paragraph\">Semiconductor lasers work by injecting carriers, and emitting lasers must meet the following three basic conditions.<\/p>\n\n\n\n<ul class=\"wp-block-list\"><li>It is necessary to produce sufficient population inversion distribution, that is, the number of particles in the high-energy state is sufficiently larger than the number of particles in the low-energy state.<\/li><li>There is a suitable resonant cavity that can play a feedback role so that the photons of the stimulated radiation are proliferated to produce laser oscillation.<\/li><li>A certain threshold condition must be met to make the photon gain equal to or greater than the photon loss.<\/li><\/ul>\n\n\n\n<h5 class=\"wp-block-heading\" id=\"h-injection-type-homojunction-semiconductor-laser\">Injection type homojunction semiconductor laser<\/h5>\n\n\n\n<p class=\"wp-block-paragraph\">The injection-type homojunction GaAs semiconductor laser resonator is the first semiconductor laser to be successfully developed. Homogeneous junction refers to a p-n junction composed of p-type and n-type semiconductors of the same matrix material (such as GaAs), and injection type refers to a pumping method that directly energizes the semiconductor laser and injects current to excite the working substance.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Figure 2.5 (a) shows the typical appearance structure of this laser. There is a small window on the tube shell to output the laser, and the electrode at the lower end of the tube is used for the external power supply. Inside the shell is the laser die, as shown in Figure 2.5(b). There are many shapes of the die, Figure 2.5(c) is a schematic diagram of the structure of the mesa-shaped die. The thickness of the p-n junction is only tens of microns. Generally, a thin layer of p-type GaAs is grown on the bottom of the n-type GaAs village to form the p-n junction.<\/p>\n\n\n\n<div class=\"wp-block-image\"><figure class=\"aligncenter size-large\"><img decoding=\"async\" width=\"500\" height=\"265\" src=\"https:\/\/mydery.com\/wp-content\/themes\/woodmart\/images\/lazy.svg\" data-src=\"http:\/\/mydery.com\/wp-content\/uploads\/2021\/05\/2.6-Typical-structure-of-homojunction-GaAs-semiconductor-laser.jpg\" alt=\"2.6 Typical structure of homojunction GaAs semiconductor laser\" class=\"wd-lazy-fade wp-image-2476\" title=\"\" srcset=\"\" data-srcset=\"https:\/\/mydery.com\/wp-content\/uploads\/2021\/05\/2.6-Typical-structure-of-homojunction-GaAs-semiconductor-laser.jpg 500w, https:\/\/mydery.com\/wp-content\/uploads\/2021\/05\/2.6-Typical-structure-of-homojunction-GaAs-semiconductor-laser-300x159.jpg 300w\" sizes=\"(max-width: 500px) 100vw, 500px\" \/><figcaption>Figure 2.5 Typical structure of homo junction GaAs semiconductor laser<\/figcaption><\/figure><\/div>\n\n\n\n<p class=\"wp-block-paragraph\">The resonant cavity of the laser generally directly utilizes two end faces perpendicular to the p-n junction. The refractive index of GaAs is 3.6, and the reflectivity of light perpendicular to the end surface is 32%. In order to increase the output power and reduce the operating current, one of the reflective surfaces is generally plated with gold.<\/p>\n\n\n\n<h5 class=\"wp-block-heading\" id=\"h-heterojunction-semiconductor-laser\">Heterojunction semiconductor laser<\/h5>\n\n\n\n<p class=\"wp-block-paragraph\">Studies have shown that it is difficult for homojunction semiconductor lasers to obtain low threshold currents and achieve continuous operation at room temperature. Therefore, people have developed heterojunction lasers on this basis. Heterojunction lasers are also single heterojunction (SH) lasers and double heterojunction (SH) lasers. Mass junction (DH) laser.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Single heterojunction semiconductor laser. Figure 2.6 shows the structure of a single heterojunction laser (GaAs-P-Ga<sub>1-x<\/sub>Al<sub>x<\/sub>As) and a schematic diagram of the energy band change, refractive index change, and light intensity distribution of each region. It can be seen that after adding the heterogeneous material GaAs-P-Ga<sub>1-x<\/sub>Al<sub>x<\/sub>As to the P-GaAs side, the interface electron energy barrier makes the electrons injected into P-GaAs from N-GaAs can only be confined in the P zone to recombine and generate photons. Because of the change of refractive index at the interface of P-GaAs and P-Ga<sub>1-x<\/sub>Al<sub>x<\/sub>As, the photons generated by the recombination in the active area are reflected and confined in the P-GaAs layer. <\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The confinement effect of the heterojunction on electrons and photons reduces their loss so that the threshold current density of the single heterojunction laser at room temperature is reduced to 8KA\/cm<sup>2<\/sup>.<\/p>\n\n\n\n<div class=\"wp-block-image\"><figure class=\"aligncenter size-large\"><img decoding=\"async\" width=\"400\" height=\"538\" src=\"https:\/\/mydery.com\/wp-content\/themes\/woodmart\/images\/lazy.svg\" data-src=\"http:\/\/mydery.com\/wp-content\/uploads\/2021\/05\/2.7-Energy-band-refractive-index-and-light-intensity-distribution-of-GaAs-P-Ga1-xAlxAs-single-heterojunction.jpg\" alt=\"Energy band, refractive index and light intensity distribution of GaAs- P-Ga1-xAlxAs single heterojunction\" class=\"wd-lazy-fade wp-image-2477\" title=\"\" srcset=\"\" data-srcset=\"https:\/\/mydery.com\/wp-content\/uploads\/2021\/05\/2.7-Energy-band-refractive-index-and-light-intensity-distribution-of-GaAs-P-Ga1-xAlxAs-single-heterojunction.jpg 400w, https:\/\/mydery.com\/wp-content\/uploads\/2021\/05\/2.7-Energy-band-refractive-index-and-light-intensity-distribution-of-GaAs-P-Ga1-xAlxAs-single-heterojunction-223x300.jpg 223w\" sizes=\"(max-width: 400px) 100vw, 400px\" \/><figcaption>Figure 2.6 Energy band, refractive index, and light intensity distribution of GaAs- P-Ga1-xAlxAs single heterojunction<\/figcaption><\/figure><\/div>\n\n\n\n<p class=\"wp-block-paragraph\">In a single heterojunction laser source, the heterojunction plays a role in limiting the diffusion of carriers, but it is not used for injection, so the value of x is generally chosen to be relatively large, such as 0.3&lt;x&lt;0.5. In a semiconductor laser resonator, the thickness d of the active region is critical. If d is too large, it will lose the meaning of carrier limitation, and if d is too small, it will increase the loss. In single heterojunction lasers, d\u22482\u0447m is generally adopted.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Double heterojunction semiconductor laser source. Liquid phase epitaxy was used to sequentially grow N-Ga<sub>1-x<\/sub>Al<sub>x<\/sub>As, P-GaAs, P-Ga<sub>1-x<\/sub>Al<sub>x<\/sub>As, As single crystal thin layers on the N-GaAs village bottom. There are N- Ga<sub>1-x<\/sub>Al<sub>x<\/sub>As, as layers and P- Ga<sub>1-x<\/sub>Al<sub>x<\/sub>As as layers on both sides of the active area P-GaAs, forming N-Ga<sub>1-x<\/sub>Al<sub>x<\/sub>As \/P-GaAs and P-GaAs\/P-Ga<sub>1-x<\/sub>Al<sub>x<\/sub>As two heterojunctions of N-Ga<sub>1-x<\/sub>Al<sub>x<\/sub>As and P-Ga<sub>1-x<\/sub>Al<sub>x<\/sub>As are shown in Figure 2.7.<\/p>\n\n\n\n<figure class=\"wp-block-image size-large\"><img decoding=\"async\" width=\"800\" height=\"339\" src=\"https:\/\/mydery.com\/wp-content\/themes\/woodmart\/images\/lazy.svg\" data-src=\"http:\/\/mydery.com\/wp-content\/uploads\/2021\/05\/Schematic-diagram-of-double-heterojunction-laser-structure.jpg\" alt=\"\" class=\"wd-lazy-fade wp-image-2431\" title=\"\" srcset=\"\" data-srcset=\"https:\/\/mydery.com\/wp-content\/uploads\/2021\/05\/Schematic-diagram-of-double-heterojunction-laser-structure.jpg 800w, https:\/\/mydery.com\/wp-content\/uploads\/2021\/05\/Schematic-diagram-of-double-heterojunction-laser-structure-500x212.jpg 500w, https:\/\/mydery.com\/wp-content\/uploads\/2021\/05\/Schematic-diagram-of-double-heterojunction-laser-structure-700x297.jpg 700w, https:\/\/mydery.com\/wp-content\/uploads\/2021\/05\/Schematic-diagram-of-double-heterojunction-laser-structure-300x127.jpg 300w, https:\/\/mydery.com\/wp-content\/uploads\/2021\/05\/Schematic-diagram-of-double-heterojunction-laser-structure-768x325.jpg 768w\" sizes=\"(max-width: 800px) 100vw, 800px\" \/><figcaption>Figure 2.7 Schematic diagram of double heterojunction laser structure<\/figcaption><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">Figure 2.8 shows the energy band, refractive index, and light intensity distribution of a double heterojunction laser. The active region P-GaAs is sandwiched between two wide-bandgap Ga<sub>1-x<\/sub>Al<sub>x<\/sub>As layers. For this structure, due to its symmetry, it is no longer limited to only electron injection. The double-heterojunction structure allows both electron injection and hole injection to be effectively utilized. If the width of the active region is smaller than the diffusion length of carriers, most of the carriers can diffuse to the active region before recombination. When they reach the heterojunction, they are repelled by the potential barrier and stay in the active region. If the thickness d of the active region is much smaller than the diffusion length of the carriers, the carriers will evenly fill the active region. For this kind of laser, recombination occurs almost uniformly in the active region.<\/p>\n\n\n\n<div class=\"wp-block-image\"><figure class=\"aligncenter size-large\"><img decoding=\"async\" width=\"400\" height=\"524\" src=\"https:\/\/mydery.com\/wp-content\/themes\/woodmart\/images\/lazy.svg\" data-src=\"http:\/\/mydery.com\/wp-content\/uploads\/2021\/05\/2.9-GaAs-Ga1-xAlxAs-energy-band-refractive-index-and-light-intensity-distribution-of-double-heterojunction.jpg\" alt=\"\" class=\"wd-lazy-fade wp-image-2478\" title=\"\" srcset=\"\" data-srcset=\"https:\/\/mydery.com\/wp-content\/uploads\/2021\/05\/2.9-GaAs-Ga1-xAlxAs-energy-band-refractive-index-and-light-intensity-distribution-of-double-heterojunction.jpg 400w, https:\/\/mydery.com\/wp-content\/uploads\/2021\/05\/2.9-GaAs-Ga1-xAlxAs-energy-band-refractive-index-and-light-intensity-distribution-of-double-heterojunction-229x300.jpg 229w\" sizes=\"(max-width: 400px) 100vw, 400px\" \/><figcaption>Figure 2.8 GaAs-Ga<sub>1-x<\/sub>Al<sub>x<\/sub>As, energy band, refractive index, and light intensity distribution of double hetero junction<\/figcaption><\/figure><\/div>\n\n\n\n<p class=\"wp-block-paragraph\">Because both sides of the active area are broadband materials, the effective refractive index jumps in the hierarchy, so that the photons are confined in the active area, and the distribution of the light field is also symmetrical. The double heterojunction can effectively limit the carriers and photons, so the threshold current density of the laser is significantly reduced, and the continuous operation of the laser at room temperature is realized.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">After the double heterojunction laser achieves continuous operation at room temperature, the outstanding problem is how to improve the life of the device, which can start from solving the problem of active area structure and heat dissipation. With the different requirements, there are multiple structures of double heterojunction lasers, the more typical one is the bar double heterojunction (DH) laser. In GaAs\/ Ga<sub>1-x<\/sub>Al<sub>x<\/sub>As DH lasers, the bandgap of GaAs corresponds to a laser wavelength of about 0.89um. InP\/InGaAsP DH lasers cover a range of 0.92~1.65\u0447m. Since the lowest loss of optical fiber is 1.3~1.6\u0447m, InP\/InGaAsP DH lasers have important applications for long-distance optical fiber communication systems, while GaAs\/ Ga<sub>1-x<\/sub>Al<sub>x<\/sub>As DH lasers are often used in short-distance optical fiber communication systems.<\/p>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"h-yag-solid-state-laser\">YAG solid-state laser<\/h4>\n\n\n\n<p class=\"wp-block-paragraph\">The core of the laser emission is the laser working substance (that is, the working substance containing the metastable energy level) in the laser that can realize the population inversion, such as the laser whose working substance is crystalline or glass, which is called crystal laser and glass laser, respectively. Usually, these two types of lasers are collectively referred to as solid-state lasers. Among the lasers, the solid-state laser was the first to develop. This kind of laser has a small size, high output power, and convenient application. There are three main working materials for solid-state lasers; neodymium-doped yttrium aluminum garnet (Nd: YAG), with an output wavelength of 1.06 \u0447m, which is white and blue; neodymium glass, with an output wavelength of 1.06 \u0447m, which is purple-blue; ruby, the output wavelength is 0.694\u0447m, which is red.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">YAG lasers are the most common type of solid-state lasers. YAG lasers came out later than ruby \u200b\u200band neodymium glass lasers. In 1964, YAG crystals were successfully developed. After several years of hard work, the optical and physical properties of YAG crystal materials have been continuously improved, and the preparation process of large-size YAG crystals has been overcome. By 1971, large-size Nd: YAG crystals with a diameter of 40mm and a length of 200mm were able to be drawn, which provided high-quality crystals at a moderate cost for the development of YAG lasers, and promoted the development of the YAG lasers. <\/p>\n\n\n\n<p class=\"wp-block-paragraph\">In the 1970s, the development of lasers ushered in an upsurge in the research and application of YAG lasers. Research institutions in many industrially developed countries invested a lot of manpower and financial resources to study how to improve the efficiency, power, and reliability of YAG lasers and solve engineering problems. Some application results have been achieved in the fields of laser ranging, laser radar, laser industrial processing, and laser medical treatment. For example, the YAG Laser Precision Tracking Radar (PATS system) was successfully used in the missile measurement range in 1971 by Silvania Company of the United States. In the 1980s, the research and application of YAG lasers have matured and entered a period of rapid development, becoming the mainstream of the development and application of various lasers.<\/p>\n\n\n\n<h5 class=\"wp-block-heading\" id=\"h-the-structure-of-yag-laser\">The structure of YAG laser<\/h5>\n\n\n\n<p class=\"wp-block-paragraph\">Generally speaking, the YAG laser refers to the Nd: YAG laser doped with trivalent Nd<sup>3+<\/sup> in the yttrium aluminum garnet (YAG) crystal. It emits a near-infrared laser source of 1.06 \u0447m and is a solid-state laser that can work continuously at room temperature. In the small and medium-power pulsed lasers, Nd: YAG lasers are currently used in quantities far more than other lasers. The single pulse power emitted by this laser can reach 107W or higher, which can process materials at extremely high speeds. YAG lasers have high energy, high peak power, compact structure, firmness and durability, reliable performance, safe processing, simple control, etc. Features, it is widely used in industry, national defense, medical treatment, scientific research, and other fields. Nd: YAG crystal has excellent thermal properties and is very suitable for making continuous and repetitive laser devices.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">YAG laser includes YAG laser source rod, xenon lamp, condenser cavity, Q switch, polarizer, total mirror, semi-feedback, etc., the structure is shown in Figure 2.9<\/p>\n\n\n\n<div class=\"wp-block-image\"><figure class=\"aligncenter size-large\"><img decoding=\"async\" width=\"700\" height=\"267\" src=\"https:\/\/mydery.com\/wp-content\/themes\/woodmart\/images\/lazy.svg\" data-src=\"http:\/\/mydery.com\/wp-content\/uploads\/2021\/05\/YAG-laser-structure-1.jpg\" alt=\"\" class=\"wd-lazy-fade wp-image-2491\" title=\"\" srcset=\"\" data-srcset=\"https:\/\/mydery.com\/wp-content\/uploads\/2021\/05\/YAG-laser-structure-1.jpg 700w, https:\/\/mydery.com\/wp-content\/uploads\/2021\/05\/YAG-laser-structure-1-500x191.jpg 500w, https:\/\/mydery.com\/wp-content\/uploads\/2021\/05\/YAG-laser-structure-1-300x114.jpg 300w\" sizes=\"(max-width: 700px) 100vw, 700px\" \/><figcaption>Figure 2.9 YAG laser structure<\/figcaption><\/figure><\/div>\n\n\n\n<p class=\"wp-block-paragraph\">The working medium of the YAG micro-optical device is Nd: YAG rod, the sides are roughened, the two ends are ground into a plane, and the antireflection coating is plated. The frequency doubling crystal adopts potassium tetany oxide (KTP) crystal with an anti-reflection coating on both sides. The laser spectroscopy cavity adopts a plano-concave stable cavity, the cavity length is 530mm, and the radius of curvature of the plano-concave total mirror is 2m. Please use high-transmittance and high-reflection quartz lenses for the galvanometer mirror, and the modulation frequency of the Q switch device is adjustable.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The laser resonant cavity is a three-mirror folded cavity with 1.3mm spectral line resonance, including two semiconductor laser pump modules, each module is composed of 20W continuous-wave semiconductor laser arrays (LD) with a center wavelength of 808nm, and the total spectral line width Less than 3nm, the laser crystal is 3mm\u00d775mm Nd: YAG, the doping concentration is 1.0%, and a 1.319nm laser 90\u00b0 quartz rotator is inserted between the two LD pump modules to compensate for the thermally induced birefringence effect. <\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The stable areas of the resonant cavity of the radially polarized light and the radially polarized light overlap each other, which is beneficial to increase the output power and improve the beam quality. The acousto-optic Q switch with high diffraction loss is used to generate Q-switched pulse output, and the repetition frequency can be adjusted in the range of 1~50kHz. The designed resonant cavity produces a real focus on the folded arm to increase the power density, which is beneficial to nonlinear frequency conversion.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Plano mirror M<sub>1<\/sub> is coated with 1319nm, 659. 4nm double high-reflection film system, plano-concave mirror M<sub>2<\/sub> is an output coupling mirror, and plano-concave mirror M<sub>3<\/sub> is 1319nm, 659nm, 440nm three-wavelength high-reflection film. Since the 1064nm spectral line intensity of the Nd: YAG crystal is three times that of the 1319nm wavelength, the M<sub>1<\/sub>, M<sub>2<\/sub>, M<sub>3<\/sub>, cavity mirror design requires the transmittance of the 1064nm wavelength to be greater than 60%, which is very important to suppress the 1064nm laser oscillation. of. <\/p>\n\n\n\n<p class=\"wp-block-paragraph\">In order to reduce the insertion loss in the cavity, all components in the cavity should be coated with an anti-reflection coating. The semiconductor laser does not add any shaping measures or optical imaging components, and the Nd: YAG crystal is pumped from the adjacent 120\u00b0 directions. By optimizing the pumping parameters, a relatively uniform and Gauss-like gain profile can be obtained. This design is simple, compact, and practical, and can be better matched with the Eigenmode of the resonator, which is beneficial to improve the energy extraction efficiency and beam quality.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Because lithium tribemate (LBO) crystal has a high damage threshold, low absorption of fundamental frequency light, and frequency-doubled light, it can achieve 1319nm double frequency and triple frequency phase matching and has the advantages of suitable effective nonlinear coefficients, so choose two LBO crystals are used as crystals for intracavity frequency doubling and intracavity sum-frequency.<\/p>\n\n\n\n<h5 class=\"wp-block-heading\" id=\"h-output-characteristics-of-yag-laser\">Output characteristics of YAG laser<\/h5>\n\n\n\n<ul class=\"wp-block-list\"><li>Lamp-pumped Nd: YAG laser. The structure is shown in Figure 2.10 and Figure 2.11. The gain medium Nd: YAG is rod-shaped, and it is often placed on the focal line of the double-sugar circle reflection condenser cavity. The two pump lamps are located on the two outer focal lines of the double ellipse, and the cooling water flows between the pump lamp and the laser rod with a glass tube sleeve.<\/li><li>In high-power lasers, the thermal effect of the laser rod limits the maximum output power of each laser rod. The heat inside the laser rod and the cooling of the surface of the laser rod cause the temperature gradient of the crystal so that the maximum power of the pump must be lower than to cause damage. The stress limit. The effective power range of a single rod Nd: YAG laser is 50~800W. Higher power Nd: YAG lasers can be obtained by connecting Nd: YAG laser rods in series.<\/li><li>Diode-pumped Nd: YAG laser. The structure of a diode-pumped Nd: YAG laser is shown in Figure 2.12, and a GaAlAs semiconductor laser is used as the pump light source.<\/li><li>Using a semiconductor laser as the pump source increases the life of the components and eliminates the requirement of regular replacement of the pump lamp when using lamp pumping. The diode-pumped Nd: YAG laser has higher reliability and longer working time.<\/li><li>The high conversion efficiency of the diode-pumped Nd: YAG laser comes from the good spectral matching between the emission spectrum of the semiconductor laser and the absorption of Nd: YAG. GaAIAs semiconductor laser emits a narrow-band wavelength. By precisely adjusting the Al content, it can emit light at 808nm, which is in the absorption band of Nd<sup>3+<\/sup> particles. The electro-optical conversion efficiency of semiconductor lasers is approximately 40%-50%, which is the reason that diode-pumped Nd; YAG lasers can achieve a conversion efficiency of more than 10%. While the lamp is excited to produce white light, the Nd: YAG crystal only absorbs a small part of the spectrum, which leads to its low efficiency.<\/li><\/ul>\n\n\n\n<div class=\"wp-block-image\"><figure class=\"aligncenter size-large\"><img decoding=\"async\" width=\"600\" height=\"357\" src=\"https:\/\/mydery.com\/wp-content\/themes\/woodmart\/images\/lazy.svg\" data-src=\"http:\/\/mydery.com\/wp-content\/uploads\/2021\/05\/Pump-lamp-and-laser-rod-of-laser-1.jpg\" alt=\"\" class=\"wd-lazy-fade wp-image-2503\" title=\"\" srcset=\"\" data-srcset=\"https:\/\/mydery.com\/wp-content\/uploads\/2021\/05\/Pump-lamp-and-laser-rod-of-laser-1.jpg 600w, https:\/\/mydery.com\/wp-content\/uploads\/2021\/05\/Pump-lamp-and-laser-rod-of-laser-1-300x179.jpg 300w, https:\/\/mydery.com\/wp-content\/uploads\/2021\/05\/Pump-lamp-and-laser-rod-of-laser-1-18x12.jpg 18w, https:\/\/mydery.com\/wp-content\/uploads\/2021\/05\/Pump-lamp-and-laser-rod-of-laser-1-150x89.jpg 150w\" sizes=\"(max-width: 600px) 100vw, 600px\" \/><figcaption>Figure 2.10 Pump lamp and laser rod of laser<\/figcaption><\/figure><\/div>\n\n\n\n<div class=\"wp-block-image\"><figure class=\"aligncenter size-large\"><img decoding=\"async\" width=\"600\" height=\"293\" src=\"https:\/\/mydery.com\/wp-content\/themes\/woodmart\/images\/lazy.svg\" data-src=\"http:\/\/mydery.com\/wp-content\/uploads\/2021\/05\/Multi-laser-rod-resonator-fiber-output-kilowatt.jpg\" alt=\"\" class=\"wd-lazy-fade wp-image-2492\" title=\"\" srcset=\"\" data-srcset=\"https:\/\/mydery.com\/wp-content\/uploads\/2021\/05\/Multi-laser-rod-resonator-fiber-output-kilowatt.jpg 600w, https:\/\/mydery.com\/wp-content\/uploads\/2021\/05\/Multi-laser-rod-resonator-fiber-output-kilowatt-500x244.jpg 500w, https:\/\/mydery.com\/wp-content\/uploads\/2021\/05\/Multi-laser-rod-resonator-fiber-output-kilowatt-300x147.jpg 300w\" sizes=\"(max-width: 600px) 100vw, 600px\" \/><figcaption>Figure 2.11 Multi-laser rod resonator fiber output kilowatt Nd: YAG laser<\/figcaption><\/figure><\/div>\n\n\n\n<div class=\"wp-block-image\"><figure class=\"aligncenter size-large\"><img decoding=\"async\" width=\"600\" height=\"256\" src=\"https:\/\/mydery.com\/wp-content\/themes\/woodmart\/images\/lazy.svg\" data-src=\"http:\/\/mydery.com\/wp-content\/uploads\/2021\/05\/diode-pumped-laser-structure-diagram-7.jpg\" alt=\"\" class=\"wd-lazy-fade wp-image-2502\" title=\"\" srcset=\"\" data-srcset=\"https:\/\/mydery.com\/wp-content\/uploads\/2021\/05\/diode-pumped-laser-structure-diagram-7.jpg 600w, https:\/\/mydery.com\/wp-content\/uploads\/2021\/05\/diode-pumped-laser-structure-diagram-7-500x213.jpg 500w, https:\/\/mydery.com\/wp-content\/uploads\/2021\/05\/diode-pumped-laser-structure-diagram-7-300x128.jpg 300w\" sizes=\"(max-width: 600px) 100vw, 600px\" \/><figcaption>Figure 2. 12 Diode pumped Nd: YAG laser structure diagram<\/figcaption><\/figure><\/div>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"h-fiber-laser\">Fiber laser<\/h4>\n\n\n\n<h5 class=\"wp-block-heading\" id=\"h-classification-of-fiber-lasers\">Classification of fiber lasers<\/h5>\n\n\n\n<p class=\"wp-block-paragraph\">Fiber lasers are lasers that use optical fibers as the laser source medium. According to the incentive mechanism, it can be divided into the following four categories.<\/p>\n\n\n\n<ul class=\"wp-block-list\"><li>Rare-earth-doped fiber laser source, through doping different rare-earth ions in the fiber matrix material to obtain the laser output of the required wavelength band.<\/li><li>Fiber lasers made using the nonlinear effects of fibers, such as stimulated Raman scattering (SRS), etc.<\/li><li>Single-crystal fiber lasers, including ruby \u200b\u200bsingle-crystal fiber lasers, Nd: YAG single product fiber lasers, etc.<\/li><li>Dye fiber laser, by filling the plastic core or cladding with dye to realize laser output.<\/li><\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">Among these types of fiber lasers, fiber lasers and amplifiers doped with rare-earth ions are the most important and have the fastest development. They have been applied in the fields of fiber communication, fiber sensing, and laser material processing, this type of laser.<\/p>\n\n\n\n<h5 class=\"wp-block-heading\" id=\"h-waveguide-principle-of-fiber-laser\">Waveguide principle of fiber laser<\/h5>\n\n\n\n<p class=\"wp-block-paragraph\">The geometric structure of a single-layer fiber laser source is shown in Figure 2.13. Compared with solid-state lasers source, fiber lasers have at least one free beam path formed in the laser resonator, and beam formation and introduction into fiber lasers are realized in optical waveguides. Generally, these optical waveguides are based on rare-earth-doped optoelectronic dielectric materials. For example, silicon, phosphate glass, and fluoride glass materials show an attenuation of about 10dB\/km, which is several orders of magnitude less than solid-state laser crystals. Compared with crystalline solid materials, the absorption and emission bands of rare-earth ions show a broadened spectrum. This is because the interaction of the glass substrate reduces the frequency stability and the required width of the pump light source. Therefore, it is necessary to choose a laser diode pump source with a suitable wavelength for fiber lasers.<\/p>\n\n\n\n<div class=\"wp-block-image\"><figure class=\"aligncenter size-large\"><img decoding=\"async\" width=\"500\" height=\"373\" src=\"https:\/\/mydery.com\/wp-content\/themes\/woodmart\/images\/lazy.svg\" data-src=\"http:\/\/mydery.com\/wp-content\/uploads\/2021\/05\/The-geometry-of-a-single-layer-fiber-laser-2.jpg\" alt=\"The geometry of a single-layer fiber laser source\" class=\"wd-lazy-fade wp-image-2522\" title=\"\" srcset=\"\" data-srcset=\"https:\/\/mydery.com\/wp-content\/uploads\/2021\/05\/The-geometry-of-a-single-layer-fiber-laser-2.jpg 500w, https:\/\/mydery.com\/wp-content\/uploads\/2021\/05\/The-geometry-of-a-single-layer-fiber-laser-2-300x224.jpg 300w\" sizes=\"(max-width: 500px) 100vw, 500px\" \/><figcaption>Figure 2.13 The geometry of a single-layer fiber laser source<\/figcaption><\/figure><\/div>\n\n\n\n<p class=\"wp-block-paragraph\">The optical fiber contains a rare-earth-doped active core with a refractive index of n<sub>1<\/sub>, usually surrounded by a layer of pure silica glass cladding, and the refractive index of the cladding is n<sub>2<\/sub>&lt;n<sub>1<\/sub>. Therefore, based on the total reflection inside the interface between the core and the cladding, the waveguide is generated in the core layer. For pump radiation and laser radiation, the core layer of the fiber laser is both an active medium and a waveguide. The entire optical fiber is protected from external influences by a polymer outer layer.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">For optically excited fiber lasers, the pump radiation is coupled to the laser core through the fiber surface. However, if it is axially pumped, the pump radiation must be coupled into a waveguide of only a few microns. Therefore, a highly transparent pump radiation source must be used to excite the multi-mode fiber, and the current output power of the radiation source is limited to about 1W. In order to amplify the pump power proportionally, it is necessary to match the beam parameters of the large-opening fiber with the high-power semiconductor laser array. However, the enlarged fiber active core allows higher transverse mode oscillations, which will result in reduced beam quality. At present, a double-clad design is used, that is, an isolated core layer is used to pump and emit lasers, and good results can be obtained.<\/p>\n\n\n\n<h5 class=\"wp-block-heading\" id=\"h-double-clad-fiber-laser\">Double-clad fiber laser<\/h5>\n\n\n\n<p class=\"wp-block-paragraph\">Double-clad doped fiber consists of four parts: core, inner cladding, outer cladding and protective layer.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The function of the fiber core is to absorb the incoming pump light and confine the radiated laser light in the core; as a waveguide, confine the laser light to transmit in the core and control the mode.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The role of the inner cladding layer is to wrap the core and confine the radiated laser light within the core; as a waveguide, the multimode transmission of the pump light coupled to the inner cladding layer makes it reflect back and forth between the inner cladding layer and the outer cladding layer. Pass through the single-mode fiber core and be absorbed<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">For double-clad fiber lasers, the pump radiation is not directly emitted to the active core layer, but into the surrounding multimode core layer. The pump core layer is also like the cladding layer. In order to realize the optical waveguide characteristics of the pump core layer to the active core layer, the surrounding coating must have a small refractive index. Usually, fluorine-doped silica glass or a highly transparent polymer with a low refractive index is used. The typical diameter of the pump core is several hundred microns, and its numerical aperture NA\u22480.32~0.7, as shown in Figure 2.14.<\/p>\n\n\n\n<div class=\"wp-block-image\"><figure class=\"aligncenter size-large\"><img decoding=\"async\" width=\"500\" height=\"368\" src=\"https:\/\/mydery.com\/wp-content\/themes\/woodmart\/images\/lazy.svg\" data-src=\"http:\/\/mydery.com\/wp-content\/uploads\/2021\/05\/2.15-Double-clad-fiber-laser-4.jpg\" alt=\"\" class=\"wd-lazy-fade wp-image-2488\" title=\"\" srcset=\"\" data-srcset=\"https:\/\/mydery.com\/wp-content\/uploads\/2021\/05\/2.15-Double-clad-fiber-laser-4.jpg 500w, https:\/\/mydery.com\/wp-content\/uploads\/2021\/05\/2.15-Double-clad-fiber-laser-4-300x221.jpg 300w\" sizes=\"(max-width: 500px) 100vw, 500px\" \/><figcaption>Figure 2.14 Double-clad fiber laser<\/figcaption><\/figure><\/div>\n\n\n\n<p class=\"wp-block-paragraph\">The radiation emitted to the pump core is coupled into the laser core over the entire length of the fiber, where it is absorbed by the rare-earth ions, and all high-level light is excited. Using this technology, multi-mode pump radiation can be effectively converted from high-power semiconductor lasers into laser radiation, and it has excellent beam quality.<\/p>\n\n\n\n<h5 class=\"wp-block-heading\" id=\"h-technical-characteristics-of-fiber-laser-source\">Technical characteristics of fiber laser source<\/h5>\n\n\n\n<p class=\"wp-block-paragraph\">Fiber lasers provide the possibility to overcome the limitation of the calibrated output power of solid-state lasers while maintaining the beam quality. The quality of the final laser beam depends on the refractive index profile of the fiber, and the refractive index profile of the fiber ultimately depends on the geometric size and the numerical aperture of the activated waveguide. When the fundamental mode is propagated, the laser oscillation has nothing to do with external factors. This means that compared with other (even semiconductor pumped) solid-state lasers, fiber lasers do not have thermo-optical effects.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The prism effect caused by heat and the birefringence effect caused by pressure in the active zone will cause the beam quality to decrease. When the pump energy is transported, the fiber laser does not observe a decrease in efficiency even at high power.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">For fiber laser source, the thermal load caused by the pumping process will expand to a longer area. Because of the larger surface area to volume ratio, the thermal effect is easier to eliminate. Therefore, the temperature rise of the fiber laser core is small compared to solid semiconductor pump lasers. Therefore, when the laser is working, the quantum efficiency is attenuated due to the increasing temperature, which plays a secondary role in fiber lasers.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Taken together, fiber lasers source have the following main advantages.<\/p>\n\n\n\n<ul class=\"wp-block-list\"><li>Optical fiber as a guided wave medium has high coupling efficiency, small core diameter, high power density is easily formed in the core, and can be easily connected to the current optical fiber communication system efficiently, and the formed laser has high conversion efficiency and low laser threshold., The output beam quality is good and the line width is narrow.<\/li><li>Because the optical fiber has a large surface-to-volume ratio, the heat dissipation effect is good, and the ambient temperature is allowed to be between -20~+70\u2103, without a huge water cooling system, only simple air cooling.<\/li><li>It can work in harsh environments, such as high impact, high vibration, high temperature, and dusty conditions.<\/li><li>Because the optical fiber has excellent flexibility, the laser can be designed to be small and flexible, compact in appearance, easy to system integration, and cost-effective.<\/li><li>Tiene bastantes par\u00e1metros ajustables y selectividad. Por ejemplo, una rejilla de fibra de Bragg con la longitud de onda y la transmitancia adecuadas se escribe directamente en ambos extremos de una fibra de doble revestimiento para reemplazar la cavidad resonante formada por la reflexi\u00f3n del espejo. El l\u00e1ser Raman totalmente de fibra est\u00e1 compuesto por un anillo de fibra unidireccional, una cavidad de gu\u00eda de ondas circular. La se\u00f1al en la cavidad es amplificada directamente por la luz de la bomba sin inversi\u00f3n de poblaci\u00f3n.<\/li><\/ul>\n\n\n\n<p class=\"wp-block-paragraph\"><\/p>","protected":false},"excerpt":{"rendered":"<p>El instrumento que produce una fuente de luz l\u00e1ser se llama resonador l\u00e1ser, que incluye l\u00e1ser de gas, l\u00e1ser l\u00edquido, l\u00e1ser de estado s\u00f3lido, dispositivo \u00f3ptico semiconductor y otros l\u00e1seres. Entre ellos, los l\u00e1seres m\u00e1s t\u00edpicos son los l\u00e1seres de gas CO2, l\u00e1seres semiconductores, l\u00e1seres de estado s\u00f3lido YAG y l\u00e1seres de fibra.<\/p>","protected":false},"author":4,"featured_media":2408,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[887,888,889,886,890],"class_list":["post-2389","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-laser-cutting-machine","tag-co2-laser","tag-cold-water","tag-discharge-tube","tag-electrode","tag-pump-source"],"jetpack_featured_media_url":"https:\/\/mydery.com\/wp-content\/uploads\/2021\/05\/LASER-SYSTEM-1.png","_links":{"self":[{"href":"https:\/\/mydery.com\/es\/wp-json\/wp\/v2\/posts\/2389","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/mydery.com\/es\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/mydery.com\/es\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/mydery.com\/es\/wp-json\/wp\/v2\/users\/4"}],"replies":[{"embeddable":true,"href":"https:\/\/mydery.com\/es\/wp-json\/wp\/v2\/comments?post=2389"}],"version-history":[{"count":0,"href":"https:\/\/mydery.com\/es\/wp-json\/wp\/v2\/posts\/2389\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/mydery.com\/es\/wp-json\/wp\/v2\/media\/2408"}],"wp:attachment":[{"href":"https:\/\/mydery.com\/es\/wp-json\/wp\/v2\/media?parent=2389"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/mydery.com\/es\/wp-json\/wp\/v2\/categories?post=2389"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/mydery.com\/es\/wp-json\/wp\/v2\/tags?post=2389"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}