Analysis On Noise Characteristic Of Intr-Cavity Sum-Frequency Laser

Low-noise solid-state laser has important application in laser material processing, color display, analytical instrument, optical metrology, interferometry, experimental study etc. In this paper, the theoretical analysis and experimental study on noise resource and characteristic of intra-cavity sum-frequency laser were presented.Form rate equation, the threshold laser in the four-level system was reduced. After inserting nonlinear crystal, the dual-wavelength rate equation was added accordingly and the optimal sum-frequency efficiency was analyzed. Besides, the theoretical analysis and experimental test on noise resource with three wave couple equation and jones matrix were made.In respect of experiment,1064nm and1342nm dual-wavelength operation have been realized when2W and3W LD pumped Nd:YV04respectively by using one plan-curved cavity, the experiments and analyses show low current is high noise operation. Then high noise of593.5nm laser with KTP nonlinear crystal Ⅱ phase matching was observed when current is more than1.5A. The noise of593.5nm laser get higher with current increasing, analysis from dual-wavelength oscillation and longitudinal modes couple was made. In the end, based on selecting frequency of etalon, low noise single longitudinal mode of KTP sum-frequency laser was realized.