2.05 μm single-frequency fiber-solid hybrid amplification laser pumped by Tm: YAP

In this manuscript, we present a high energy, high beam quality 2.05 μm single-frequency laser based on fiber-solid hybrid amplification scheme, a compact and high optical-to-optical efficiency Ho: YLF amplifier is achieved by employing a linearly polarized Tm: YAP pump laser which matches the polarization characteristics of Ho: YLF. The laser utilizes a 5 mW distributed feedback (DFB) diode single-frequency seed laser with linewidth <3 MHz, which is pre-amplified through three stages continuous fiber amplifier, then shaped by an acousto-optic modulator (AOM), followed by one stage fiber amplifier and a single-pass Ho: YLF amplifier. The laser delivers an adjustable pulse repetition frequency from 1 kHz to 50 kHz, achieves 6.2 mJ pulse energy at 1 kHz and 1.86 mJ pulse energy at 5 kHz, with a pulse width of about 700 ns, a linewidth of 2.74 MHz, and beam quality M 2 of 1.20 and 1.17 in x and y directions, respectively. The laser integrates high energy, excellent beam quality, and a compact structure, making it an ideal laser source for lidar applications.