• High Power Laser Science and Engineering
  • Vol. 8, Issue 4, 04000e35 (2020)
Huijun He1、2, Jun Yu1, Wentao Zhu1, Xiaoyang Guo1、*, Cangtao Zhou1、*, and Shuangchen Ruan1、2、*
Author Affiliations
  • 1Center for Advanced Material Diagnostic Technology, and College of Engineering Physics, Shenzhen Technology University, Shenzhen518118, China
  • 2College of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen518060, China
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    Abstract

    This study develops a Yb:KGW dual-crystal based regenerative amplifier. The thermal lensing and gain-narrowing effects are compensated by the dual-crystal configuration. Sub-nanojoule pulses are amplified to 1.5 mJ with 9 nm spectral bandwidth and 1 kHz repetition rate using chirped pulse amplification technology. Consequently, 1.2 mJ pulses with a pulse duration of 227 fs are obtained after compression. Thanks to the cavity design, the output laser was a near diffraction limited beam with M2 around 1.1. The amplifier has the potential to boost energy above 2 mJ after compression and act as a front end for a future kilohertz terawatt-class diode-pumped Yb:KGW laser system.

    1 Introduction

    Ultra-intense, ultrafast lasers[1] are widely used in strong field physics, such as laser wakefield acceleration[2,3], high harmonic generation[4,5] and terahertz radiation[6]. These lasers are currently generated from a Ti:sapphire-based chirped pulse amplification (CPA) system[79] or nonlinear crystal-based optical parametric chirped pulse amplification (OPCPA) system[1012]. Due to the short storage time, Ti:sapphire is typically pumped by frequency-doubled Nd:YAG or Nd:glass solid-state lasers, which results in a bulky and complicated system with high cost. Compared with conventional CPA laser systems, the OPCPA system can obtain a shorter pulse duration and a higher peak power. Its pump laser needs a short pulse duration, a low time jitter, and smooth temporal and spatial distributions because of the intrinsic instantaneous process. Thus, the OPCPA system is more complicated and expensive.