High efficiency second harmonic generation vertical external cavity surface emitting laser

A vertical external cavity surface emitting laser (VECSEL) comprising:

• a laser chip for generating laser light at a predetermined wavelength;
• a first etalon filter layer formed on the laser chip and configured to filter wavelengths outside of a first predetermined mode of the laser light;
• a second etalon filter layer that is formed on the first etalon filter layer, has a different refractive index than the first etalon filter layer, and is configured to filter wavelengths outside of a second predetermined mode of the laser light, the first and second etalon filter layers being configured to reduce a full-width at half maximum (FWHM) of the laser light;
• a first mirror separated from and disposed obliquely to the laser chip;
• a second mirror for reflecting the laser light reflected from the first mirror back to the first mirror to form a cavity with the laser chip;
• and
• a second harmonic generation (SHG) crystal that is disposed along an optical path between the first mirror and the second mirror and configured to double the frequency of the laser light generated in the laser chip.