A light emitting device including an array of light emitters to emit first light pulses. Each of the light emitters includes a saturable absorber and a waveguide having an electrically pumped gain region to emit the first light pulses. At least one reflector structure reflects the first light pulses into a nonlinear crystal by changing the direction of the first light pulses by an angle that is in a range of 70 to 110 degrees. The reflector structure includes a sub-wavelength grating structure to change the polarization of the first light pulses. A nonlinear crystal generates second light pulses such that the optical frequency of the second light pulses is two times the optical frequency of the first light pulses.