Single Frequency Diode Pumped Solid State Lasers.

Our original project goal was to develop a 1.06 micron, 5 watt single frequency, injection-locked laser. Both CW and Q-switched operation were required and we anticipated that Pound-Drever-Hall stabilization could be used for both tasks. A portion of the master oscillator used for injection locking was needed as a low-power frequency reference for LIDAR work. We expected that we might optimistically be able to obtain about 25 slope efficiency using diode pumping which implied a required pump power of at least 20 watts. Earlier we had built some linear oscillators that consisted of a multiple-bounce optical path within a single block of NdYAG. Each bounce point required an individual diode pump and coupling optics. We anticipated that this architecture would not be easily scaled to high powers much above the 5 watt level so we decided to commit to an architecture that might utilize the recently available high power 10 to 20 watts diode arrays. We decided to couple these arrays to one or more active NdYAG elements using optical fibers.