High power confocal-to-concentric diode pumped laser - has diode pump source supplying pump beam to laser crystal which has strong thermal focussing properties, producing thermal lens in crystal

摘要

The laser comprises at least one resonator mirror (38) and an output coupler (42). A laser crystal (43) with strong thermal focussing properties is positioned in the resonator along a resonator optical axis. At least one diode pump source supplies a pump beam (46) to the laser crystal, producing a thermal lens in the laser crystal. The combination of the laser crystal, thermal lens, resonator mirrors and output coupler create a confocal-to concentric resonator, generating an output beam which may be polarized. Pref. a Q-switch is positioned in the resonator, particularly when the laser crystal is Nd:YAG. The resonator can have a multiple Rayleigh range, and an optical slope efficiency in a TEM00 mode of greater than about 40 percent. The laser may have an optical efficiency of greater than about 25 percent, and a ratio of a TEM00 mode dia. of the laser crystal to a pump beam dia. in the crystal is about less than 1.0 to 0.83.