Work

A 10-mJ-level regenerative amplifier based on an Yb:CaGdAlO 4 single crystal with spectral shaping for gain narrowing suppression

Year: 2026

Type: article

Abstract: In this work, we demonstrate a high-energy regenerative amplifier based on a single Yb:CaGdAlO 4 (Yb:CALGO) crystal, delivering a pulse energy of 11.2 mJ at a 1 kHz repetition rate. To the best of our knowledge, this represents the highest pulse energy directly obtained from an Yb:CALGO single-crystal regenerative amplifier to date. To mitigate the severe gain narrowing typically associated with high-energy amplification, a specially designed polarization-spectral filter was integrated into the system to pre-shape the seed spectrum, enabling an amplified full width at half maximum spectral bandwidth of 10.1 nm. As a result, the amplified pulses were able to be compressed to a pulse duration of 198 fs without any pedestal. The output power stability, measured over 200 minutes, exhibited a root mean square fluctuation of 0.27%, and the beam quality factors were M x 2 = 1.08 and M y 2 = 1.17.

Source: High Power Laser Science and Engineering

DOI: 10.1017/hpl.2026.10173