A 52-mJ Ho:YAG Master Oscillator and Power Amplifier with Kilohertz Pulse Repetition Frequency

We report on a high energy, high repetition rate Ho:YAG master oscillator and power amplifier (MOPA), resonantly dual-end-pumped by Tm:YLF lasers at room temperature. At the pulse repetition frequency of 1 kHz, we demonstrate a maximum energy of 30 mJ per pulse with a 28.2 ns pulse width in a Ho:YAG oscillator system resonantly double-end-pumped by Tm:YLF lasers. A maximum energy of 52 mJ per pulse with a 30.5 ns pulse width is achieved in the Ho:YAG amplifier, corresponding to a peak power of approximately 1.7 MW. The output wavelength is at 2090.6 nm and 2096.9 nm, and a beam quality factor of M²～2.1 is achieved.