Generation of high-contrast, joule-level pulses based on Nd:glass chirped pulse amplification laser

Xiaoming Lu,Yanyan Li,Xinliang Wang,Xiaoyang Guo,Yuxin Leng,Yi Xu,Yujie Peng

doi:10.1017/hpl.2016.39

Abstract

We demonstrate a high-contrast, joule-level Nd:glass laser system operating at 0.5 Hz repetition rate based on a double chirped pulse amplification (CPA) scheme. By injecting high-contrast, high-energy seed pulses into the Nd:glass CPA stage, the pulse energy is amplified to 1.9 J through two optical parametric CPA stages and two Nd:glass amplifiers. The temporal contrast of compressed pulse is measured down to the level of$10^{-8}$at tens of ps, and$10^{-10}$near 200 ps before the main pulse, respectively.

Highlights

Since the 1980s, chirped pulse amplification (CPA)[1] technique has been used to generate high-peak-power pulses by many laboratories and the focused intensity has reached at a level of 1020 W cm−2 or more
The temporal contrast which is defined as the ratio of the intensity of the prepulses or noise background to the peak intensity of the main pulse has become a key parameter for highpeak-power laser system
To generate 1053 nm high-contrast seed pulses, many groups used optical parametric amplification (OPA) pumped by high-contrast psduration pulses which shared the same seed with the signal pulses[3,4,5,6,7]

Summary

Introduction

Since the 1980s, chirped pulse amplification (CPA)[1] technique has been used to generate high-peak-power pulses by many laboratories and the focused intensity has reached at a level of 1020 W cm−2 or more. For some kinds of solid target experiments, the temporal noise intensity of a focused pulse on target should be kept below 1012 W cm−2 to avoid destroying the experimental conditions[2]. The contrast enhancement methods for high-peak-power pulse have been developed. The general method is based on the high-contrast, high-energy seed-pulse injection to suppress the amplified spontaneous emission (ASE) in the amplification progress. With high-contrast seed injection, the contrast of the amplified pulse in the Nd:glass CPA systems had been improved, respectively[5,6,7,8]. In the past several years, we have developed a new pulse cleaning device which combines three cascaded fs-OPAs

Laser setup

Contrast measurement

Conclusion