SBIR-STTR Award

Significant research and development is being conducted in near infrared and infrared lasers with an emphasis on Q-switched pulsed lasers. This presents an opportunity to investigate the feasibility of three new Q-switch devices for lasers operating in the one to three micron region. Three new devices will be investigated. First, is a new Brewster window "Zig Zag" acousto-optic Q-switch device suitable for multi-wavelength laser operation which can be inserted into the laser cavity without requiring major realignment. The second Q-switch device also works in the Zig Zag configuration, but utilizes the grating electrooptic effect for ultra fast (up to a few nanoseconds) switching at a much lower drive voltage than conventional electrooptic Q-switches. The third Q-switch device allows a very simple single frequency laser cavity which produces an extremely stable and low noise output beam.The potential commercial application as described by the awardee: Potential applications are medical surgery LIDAR systems, and frequency doubling with very low noise for applications in semiconductor materials processing.

Several key results were obtained in the Phase I study of an efficient acousto-optic resonator for GHz laser mode locking. The results indicate that lithium niobate is one of the best resonator materials. We believe that fabrication techniques can limit resonator gain at the higher frequencies. This study also verified the closed loop electronic driver approach which worked well for lamp pumped lasers with cavity frequency below 200 MHz. The diode pumped laser mode locking pulse width produced varied from 8 to 13 picoseconds and appeared to be more stable when the cavity is shortened. Phase II of the study will continue the work begun in Phase I. We have improved our fabrication techniques and will construct a higher gain resonator. The electronic driver concept will also be implemented at the higher frequency. Through joint activities with laser companies, we will determine the most stable cavity length of mode locked diode pumped lasers. At the conclusion of this study, working mode locked systems that can provide stable pulses less than 10 picoseconds wide will be completed for diode pumped lasers and for tunable solid state lasers