We report external cavity Raman lasers using a 9.5-mm-long low-loss CVD diamond pumped by a 35 W q-switched
Nd:YVO<sub>4</sub> laser with approximately 22 ns pulses at 36 kHz pulse repetition frequency. Two systems were investigated.
The first demonstrated first and second Stokes simultaneously with more than 14.5 W of combined optical power. For an
output coupler optimized for second Stokes only output (1485 nm), 11.1 W at 38% conversion efficiency was obtained.
This output power is comparable to the maximum output powers reported for competing pulsed eye-safe technologies
such as optical parametric oscillators and Er:YAG lasers.
We present the results of an investigation of the spectroscopic properties of Ce<sup>3+</sup>:BaY<sub>2</sub>F<sub>8</sub> (BYF), which is a potential laser
material with an emission wavelength range from 320 nm to 360 nm. We have employed a time-resolved pump-probe
technique to investigate the polarization-dependent absorption and emission properties, and the dynamic color centre
formation process. We observe strong absorption from colour centres with millisecond and second lifetimes that will
certainly prevent laser action with the crystals used here. Evidence suggests that there may be potential gain in this crystal
if long-lived colour centres can be reduced.
Ultraviolet (UV) miniature cerium fluoride lasers have been demonstrated using a low cost, frequency-quadrupled microchip Nd:YVO<sub>4</sub> pump laser. The concept of miniature configuration of the cavities was shown to improve the laser performance in the low pump power region. Using a 10 μJ, 266nm pump pulse, we have obtained output energies of 3.5μJ at 287nm and 0.65 μJ at 311nm. The slope efficiencies were 45% and 35%, and the pump thresholds 2 μJ and 0.8 μJ respectively. Tunable operation of these lasers provides a simple compact wavelength converter from 266 nm to 282-333 nm.