RESUMO
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.
RESUMO
A novel coupled resonator was developed for narrow-bandwidth, tunable, solid-state lasers. Stable, single-longitudinal-mode, gain-switched titanium:sapphire pulses were obtained across a 130-nm operating range limited by the cavity optics. The low threshold fluence of 0.7 Jcm(-2) makes the cavity attractive for other tunable laser media, particularly when gain is low or parasitic loss is high. A model has been developed that can be used to predict the mode structure of the coupled cavity and for optimization at specific wavelength regions.