High gain fiber-solid hybrid double-passing end-pumped Nd:YVO4 picosecond amplifier with high beam quality  

作　　者：Xueyan Dong Pingxue Li Shun Li Dongsheng Wang 董雪岩;李平雪;李舜;王东生(Institute of Laser Engineering,Beijing University of Technology,Beijing 100124,China)

机构地区：[1]Institute of Laser Engineering,Beijing University of Technology,Beijing 100124,China

出　　处：《Chinese Physics B》2020年第5期273-281,共9页中国物理B（英文版）

基　　金：Project supported by the National Natural Science Foundation of China(Grant Nos.61675009 and 61325021);Key Program of Beijing Municipal Natural Science Foundation,China(Grant No.KZ201910005006).

摘　　要：We propose a fiber-solid hybrid system which consists of a semiconductor saturable absorber mirror(SESAM)modelocked fiber seed with a pulse width of 10.2 ps and a repetition rate of 18.9 MHz,a two-level fiber pre-amplifier and a double-passing end-pumped Nd:YVO4 amplifier.In the solid-state amplifier,to enhance the gain and the extraction efficiency,a specially designed structure in which the seed light passes through the gain medium four times and makes full use of population inversion is used as the double-passing amplifier.Besides,the beam filling factor(the ratio of the seed light diameter to the pump light diameter)and the thermal lens effect of the double-passing amplifier are considered and its optical-to-optical conversion efficiency is further improved.To preserve the beam quality of the double-passing amplifier,a new method of spherical-aberration self-compensation based on the principles of geometrical optics is used and discussed.Our system achieves a maximum average power of 9.5Wat the pump power of 28W,corresponding to an optical-to-optical efficiency of 27%.And the beam quality factor M^2 reaches 1.3 at the maximum output power.

关 键 词：picosecond fiber-solid hybrid double-passing amplifier high beam quality spherical-aberration self-compensation 

分 类 号：TN253[电子电信—物理电子学] TN722