The Optimization Research On Multi-pass Yb:YAG Thin Disk Laser

Diode-pumped solid-state lasers(DPSSL)have been developing for a long time,occupying a large amount of the laser markets with its excellent performance.The high-power LDPSSL has two hot research major directions,including the thin disk laser(TDL)and the fiber laser(FL).The TDL has the advantages of smaller thermal lens effect,higher output power,better beam quality,higher optical-to-optical conversion efficiency,and lower power series expansion.The TDL has an important application prospect in industry,national defense,and medical and so on.For the 24 multi-pass TDL with independent research and development.It is impossible to realize high-power pump light injection due to the limitation of pump light spatial distribution,multi-pass coupling cavity modulation,crystal amplified spontaneous emission(ASE)and the output power can't be raised.Aiming at the technology issues above,this paper concentrates on the research of the system optimization of the 24 multi-pass TDL and has realized the high-power continuous laser output.As well as satisfying the demand of needs practical processing and scientific application.Based on the Lambert-Beer law,the absorption efficiency of the pump light relationship with the multi-pass and the crystal thin are calculated.Based on the ABCD matrix,the pump spot size and the focal length of the collimation system change law are calculated.The uniformity of the pump light is achieved by homogenizing rod shaping,and the energy of the coupled pump spot on the disk crystal is uniform.Then on the basis of these,a 24 multi-pass uniform pumped high power Yb:YAG TDL was developed.The experiments show that the 24 multi-pass TDL is optimized and its light output is optimized.The feasibility of the optimization scheme is verified.Finally,the multimode continuous laser came out with center wavelength of 1030 nm and power is 219.9W.The optical-to-optical conversion efficiency is 33.4% and the slope efficiency is 40%.The experimental results show that the single or more TDLs,laid the theoretical and experimental basis.