Monolithic light source with integrated optics based on nonlinear frequency conversion

A visible light source including an array of semiconductor light sources, each semiconductor light source in the array of semiconductor light sources comprising:

• a substrate;
• a first set of semiconductor layers forming a first mirror;
• and a second set of semiconductor layers forming a second mirror, the second mirror and the first mirror forming a resonant cavity, wherein the resonant cavity is on the substrate;
• a light emitting region positioned between the first set of semiconductor layers and the second set of semiconductor layers and configured to emit light in a first wavelength;
• a third mirror between the resonant cavity and the substrate, having an area larger than the second mirror;
• a nonlinear crystal configured to convert the light in the first wavelength and focused by the planar lens into light in a second wavelength that is a half of the first wavelength, wherein the planar lens and the nonlinear crystal are positioned such that the planar lens focuses the light in the first wavelength emitted by the light emitting region into an area of the nonlinear crystal to increase a light intensity at the area of the nonlinear crystal;
• and
• a selective reflection layer on the nonlinear crystal and configured to:
• reflect the light in the first wavelength back into the resonant cavity to form an external cavity;
• and
• transmit the light in the second wavelength out of the semiconductor light source.