High-repetition-rate and high-power picosecond regenerative amplifier based on a single bulk Nd:GdVO4 crystal

Jie Guo,Hua Lin,Xiaoyan Liang,Wei Wang

doi:10.1017/hpl.2019.16

Abstract

We report on a high-repetition-rate, high-power continuously pumped Nd:GdVO4regenerative amplifier. Numerical simulations successfully pinpoint the optimum working point free of bifurcation instability with simultaneous efficient energy extraction. At a repetition rate of 100 kHz, a maximum output power of 23 W was obtained with a pulse duration of 27 ps, corresponding to a pulse energy of$230~\unicode[STIX]{x03BC}\text{J}$. The system displayed an outstanding stability with a root mean square power noise as low as 0.3%. The geometry of the optical resonator and the pumping scheme enhanced output power in the$\text{TEM}_{00}$mode with a single bulk crystal. Accordingly, nearly diffraction-limited beam quality was produced with$M^{2}\approx 1.2$at full pump power.

Highlights

Compact, stable and high-power diode-pumped shortpulse laser amplifier systems with excellent spatial quality are ideal sources for high-power optical parametric chirped pulse amplification (OPCPA) and efficient laser processing[1,2,3,4,5]
A maximum output power of 28 W was achieved at 66 W absorbed pump power, which corresponds to 42% optical efficiency
The moderate efficiency was due to losses caused by the insertion of the Pockels cell (PC), as the output power increased to 33 W once the PC was removed

Summary

Introduction

Stable and high-power diode-pumped shortpulse laser amplifier systems with excellent spatial quality are ideal sources for high-power optical parametric chirped pulse amplification (OPCPA) and efficient laser processing[1,2,3,4,5]. Regenerative amplifiers (RAs) are routinely used to enhance the output of mode-locked oscillators because of their ability to provide gains of several orders of magnitude and a resonator structure that maintains the spatial quality of the seed[6,7,8,9]. Nubbemeyer et al employed a Kerrlens mode-locked thin-disk oscillator to seed two stages of regenerative amplifiers, including a thin-disk preamplifier and a main amplifier comprising two thin-disk modules, generating >200 mJ pulses at a 5 kHz repetition rate and >100 mJ at a 10 kHz repetition rate[10]. The cryogenic cooling technique offered another alternative to obtain a high pulse energy at a 1 kHz repetition rate, measures were necessary to mitigate the reduced gain bandwidth[11]

Methods

Results

Conclusion