Abstract

Titanium doped sapphire (Ti:SAP) is an attractive solid state alternative to near IR dyes because of its broad tuning range (662-1178 run)^1,2 and high quantum efficiency. Single frequency pulsed Ti:SAP sources, pumped by 532-nm light from a Nd:YAG laser, are attractive for numerous uses. We describe a simple approach based on injection seeding a pulsed Ti:SAP oscillator using a cw seed laser. This takes advantage of the precise frequency control afforded by the seed laser to select the frequency of the high power pulsed oscillator. Our simple three-mirror resonator, shown in Fig. 1, has no unidirectional or spectral control elements. When seeded with about a milliwatt, the oscillator produces 2 mJ of single-mode (longitudinal and transverse) output with >99.9% of the energy at the seed wavelength. Seeding forces almost completely unidirectional oscillation, doubling the energy in the forward beam while reducing the energy in the reverse beam by at least a factor of 10.

© 1990 Optical Society of America