Efficient Yellow and Green Lasers Generation in Lithium Niobate Micro-Waveguides

With a balance between optical loss and conversion efficiency, the generation of yellow lasers and green lasers by sum-frequency generation (SFG) and second-harmonic generation (SHG) is demonstrated in 16-mm-long periodically poled lithium niobate (PPLN) micro-waveguides. The waveguides exhibit low insertion losses of 4.3 dB in SFG and 4.4 dB in SHG. For nonlinear conversion performance measurement, high device efficiencies of 1037%/W and 1465.6%/W are achieved in SFG and SHG, respectively.