Theoretical And Experimental Study Of Dual-end-pumped Traveling Wave Amplifier

Compared with other kinds of lasers,all-solid-state continuous-wave(cw)single frequency lasers with high output power have been widely employed in non-classical optical field,cold atomic physics,high precision measurement and so on owing to their intrinsic advantages including perfect beam quality,narrow linewidth,low noise and high stability.In order to increase the output power of the single-frequency lasers,the most popular method is amplifying the power of the seed laser by using a master oscillation power amplifier.However,the serious thermal effects and gain saturation due to the uniform temperature and gain distribution in crystal of the block amplifier can lead to degradation of output beam quality,decrease of the conversion efficiency and limitation of the output power.Therefore,developing a block amplifier with high power,high conversion efficiency,high beam quality is an important topic in the current field.For this purpose,we designed and established dual-end-pumped master oscillation power amplifier to increase the output power and conversion efficiency of the cw single-frequency laser.The main content is as follows:1.The thermal model of master oscillation power amplification is established and analyzed.The steady state heat conduction equation in the crystal was used to establish the model,and the heat distribution in the crystal of the dual-end-pumped amplifier was compared with that of the single-end-pumped amplifier,and it is concluded that the thermal distribution of crystal for the dual-end-pumped scheme was more uniform than that for the single-end-pumped scheme.2.A dual-end-pumped traveling wave amplifier was established by using a high power seed source.In order to achieve high extraction efficiency,a 50 W solid-state continuous single frequency laser was firstly constructed and used as a high power seed source.Then,a two-stage dual-end-pumped traveling wave amplifier was successfully constructed and used to amplify the power of the seed source.Lastly,the laser output power of 125.2 W was obtained,and the conversion efficiency was as high as 43.3%,and the beam quality was better than 1.28.Finally,the relationship between the gain of the amplifier and the seed power was simulated,which further verified that the improvement of seed source output power plays a crucial role in the improvement of amplifier power and conversion efficiency.