Development of compact laser system with 1-J, 300-Hz by using high peak power laser-diode pumped Nd:YAG amplifiers for novel laser application

摘要

A laser-diode (LD) pumped Nd:YAG compact laser system that is capable of generating 1064-nm, 1-J output pulses inseveral tens of nanoseconds pulse duration at 300-Hz repetition rate (300-W average power) was developed. A conceptof this laser system is based on a ubiquitous machine that is easy to transport and process test rapidly in laboratory. Afootprint is 1.2-m in width and 2.4-m in length. This laser system is a master-oscillator power-amplifier (MOPA)architecture that allows for increasing the output energy by adding amplifiers. It consisted of an acousto-optic QswitchedNd:YAG oscillator, a ϕ3-mm Nd:YAG preamplifier and three ϕ12-mm Nd:YAG main amplifiers. Theoscillator generated 6-mJ pulse energy at 37-ns pulse duration that could be adjusted by changing the cavity length. Themain amplifier had a small-signal gain (SSG) of 9 by laser diodes (LDs) pumping with maximum 27-kW peak power.The beam size and divergence were adjusted to compensate for thermal lens effect in each amplifier. Single-passamplification by three main amplifiers increased the pulse energy to 1 J. The pumping repetition rate was fixed to obtainthermally stable condition. However, the output repetition rate is variable from single shot to 300 Hz by controlling theoscillator for the experiment usability.