High-repetition-rate single-frequency Ho:YAG MOPA system

A stable, 2.09 μm single-frequency Ho:YAG master oscillator and power amplifier (MOPA) system at a pulse repetition frequency of 1.25 kHz is demonstrated. The maximum output energy of the single-frequency injection-seeded laser is 13.76 mJ, and the corresponding pulse width is 178.9 ns. The seed laser is a continuous-wave Ho:YAG non-planar ring oscillator laser. The half-width of the pulse spectrum is measured to be 2.65 MHz by using the heterodyne technique, which is about 1.06 times Fourier transform limited.