HIGHLY EFFICIENT 3rd HARMONIC GENERATION IN Nd: YAG LASER

A method comprising:

• providing a laser comprising:
• a laser resonator comprising a back reflection mirror, an output optical coupler and multiple resonator branches, the laser resonator further comprises:
• one or more gain components in a first branch of the three resonator branches configured to generate a first wavelength radiation;
• a first non-linear optical component in a second branch of the multiple resonator branches configured to generate a second wavelength radiation related to the first optical frequency radiation in a predefined manner;
• a second non-linear optical component in a third branch of the multiple resonator branches configured to generate a third wavelength radiation related to one or more of the first and second wavelength radiations in a further predefined manner;
• a first meniscus lens located between the first and second branches and configured to transmit the first wavelength radiation and to reflect the second wavelength radiation, and configured to focus the first wavelength radiation on the first non-linear optical component;
• and
• a second meniscus lens located between the second and third branches and configured to transmit the first and the second wavelength radiations, and to reflect the third wavelength radiation, and configured to focus the first and second wavelength radiations on the second non-linear optical component,
• wherein the output optical coupler is configured to reflect at least the first and second wavelength radiations and to transmit the third wavelength radiation;
• providing an optical power pumping to the one or more gain components and generating the first wavelength radiation in the laser resonator;
• and
• generating the third wavelength radiation in the third branch of the laser resonator using one or more of the generated first and second wavelength radiations in the corresponding first and second branches and providing the third wavelength radiation by the laser through the output optical coupler.

An apparatus, comprising:

• a laser resonator comprising a back reflection mirror, an output optical coupler and multiple resonator branches between the back reflection minor and the output optical coupler, the laser resonator further comprises:
• one or more gain components in a first branch of the multiple resonator branches configured to generate a first wavelength radiation;
• one or more non-linear optical elements, each of the one or more non-linear optical elements is located in a corresponding branch of the multiple resonator branches, where each corresponding branch comprises only one of the one or more non-linear optical elements, and wherein each of the one or more non-linear optical elements is configured to generate a corresponding wavelength radiation related to the first wavelength radiation in a predefined manner and having a wavelength different from wavelengths of radiation generated by any other of the one or more non-linear optical elements;
• one or more meniscus lenses, each located in between two branches of the multiple resonator branches, where each meniscus lens is configured to focus an optical radiation on a corresponding non-linear optical component of the one or more non-linear optical components, and further configured to transmit radiation of one or more wavelengths generated in the laser resonator and to reflect radiation of other one or more wavelengths generated in the laser resonator based on a predetermined criterion,
• wherein the output optical coupler is configured to transmit a wavelength generated in one branch of the multiple resonator branches, the one branch comprises the output optical coupler, and to reflect all other radiations having one or more wavelengths generated in the laser resonator.