Development of High Repetition LD-Pumped Solid-State Laser

Abstract

In the Leading Project of MEXT from 2003, Japan, high average power LD-pumped YAG lasers are being developed with specifications of > 1 J, > 5 kHz, and 1-10-ns pulse. All fiber front end system consists of cw 40-mW Yb doped fiber laser (YbDFL) with a fiber Bragg grating cavity, a pulse shaper of LiNbO3, and three stages of YbDFL amplifiers, delivering 2-mW average power of 1-20 ns pulses in 5-kHz repetition rate. The design and test of 500-W class LD-pumped booster amplifier head is discussed. Some key elements of technology for high-peak and high-average power system are reviewed such as a ten-cm silica laser material, a repetitive work of stimulated Brillouin scattering phase conjugate mirror for 10-kW capability, a ceramic material for Faraday rotator for high-average power level, so on.