Pulse amplification of a single-frequency cr:forsterite laser

Stable single-longitudinal-mode operation of a tunable gain-switched Cr:forsterite oscillator-amplifier system is reported. A novel coupled-cavity oscillator configuration provides a low-threshold fluence of 0.3 J cm(-2), making the system attractive for laser media with low gain or high parasitic loss. Nearly transform-limited pulses with instrument-limited bandwidths of 150 MHz have been obtained across a 100-nm wavelength range, limited by the cavity optics. A range of forsterite crystals with Cr(4+) concentration in the 3-21 x 10(18)-cm(-3) range has been used for investigation of amplifier performance in single- and double-pass configurations.