Single axial mode, 2 mJ pulses from a gain-switched Cr:forsterite laser

Summary form only given. Single axial mode, pulsed, tunable lasers and OPOs are used in a range of applications in remote sensing and applied spectroscopy. The widely-used grazing incidence configuration has been successfully implemented for single axial mode operation of Ti:sapphire lasers and OPOs. However, efficiencies are typically low with a high pump threshold energy, often close to the damage levels of cavity components. In fact with BBO OPOs and with low gain/high passive loss vibronic laser materials such as Cr:forsterite, similar laser and damage thresholds mean that the grazing incidence cavity is, at best, a marginal approach. Consequently, single axial mode operation of Cr:forsterite has, to our knowledge, only been obtained using a complex cavity with 4-prism beam expander, etalon and diffraction grating. Pump threshold fluence was low (0.3 Jcm/sup -2/), but damage limitations restricted output pulse energy to 300 mJ. We report the design, modeling and single frequency laser performance of two coupled-cavity Cr:forsterite lasers optimized for lower threshold, higher energy operation.