The output optical power and spectra of a 975 nm semiconductor laser diode (SLD) were measured and analyzed when the SLD was operated with different current in the temperature range of -10°C—65°C. The results showed that the output center wavelength of the SLD shifts in the direction of long wavelength as the operation current and temperature rises. The slopes were approximately 0.24nm/100mA and 0.36nm/°C, respectively. Furthermore, the Conversion efficiency of the SLD was higher when the temperature was low. The reasons for the red shift of SLD was theoretical analyzed.

122mW green emission at 532.3nm with a conversion efficiency of 1.2% was measured by single-pass second-harmonic generation in a 10mm long periodically poled MgO:LiNbO3 (MgO:PPLN) crystal is reported. A continuous-wave Yb-doped fiber laser operating at 1064.6nm with narrow bandwidth of 0.1nm is used as pumping source. The experimental temperature acceptance bandwidth ΔT=4.6°C is a little higher than the simulation data of 4°C. Output power instabilities or variations of the green beam pattern were not observed during experiments. In this work, the optimized efficiency was achieved when the waist located at the center of MgO:PPLN and Rayleigh length equal to its length, and the lens’ location in the system was calculated.