Study On Solid-state Laser Amplifier For High Gain And High Extraction Efficiency

Master oscillator power amplification technology of one micrometer has been widely used in industry application.And Nd:YVO4 crystal has a wide application for excellent laser performance.This paper launched research for high gain and high extraction efficiency 1.06?m solid-state laser amplifier with gain medium of Nd:YVO4 crystal.Firstly,according to laser amplification theory,by studying amplification process of light signal in laser medium,gain and extraction efficiency was analyzed with different condition for providing laser design with theory result.Then,establishing the steady state heat conduction model,crystal parameters were analyzed for the influence of thermal distribution of crystal,which calculated thermal focal length.According to the results of thermal simulation,parameters of resonator and cavity type were discussed for influence of beam coupling.In the design of amplification,analyzing gain and ABCD matrix,designing stage coupling with thermal lens effect and linear polarization rotation way for double-pass,coaxial double-pass amplifier was achieved with Nd:YVO4 crystal.Light signal source with plane convex cavity was accomplished with single pulse output energy of 118.3?J,during 25.5ns pulse width,at the repetition frequency of 100 kHz.In the single-pass amplifier,coupling ratio and pumped power was tested for the influence of output characteristics.Based on the result of above experiments,double-pass amplification configuration was built and,injecting pulse signal of average power of 12 W,output power of 36.9W was obtained with extraction efficiency of 44.5%.On the same condition,output power of 38.5W was achieved with c.w.signal of 13 W,corresponding to the extraction efficiency of 45.2%.