Single-frequency Q-switched Ho:YLF High-Power Laser

A single-frequency Q-switched 2064 nm Ho:YLF laser system was developed at the National Laser Centre of the CSIR Pretoria (South Africa). It consists of a fibre-laser-pumped ring laser that emits 70 mJ at 50 Hz with a diffraction-limited beam and a Ho:YLF slab amplifier that is pumped by a Tm:YLF slab laser. With its single-frequency pulses of 330 mJ at 50 Hz this system to date holds the world record for single-frequency pulsed 2 µm lasers and has a significantly better performance than a comparable laser with which NASA will be measuring wind from space.