2.3 micron High Power Continuous Wave Diode Laser Arrays

For phase I of this STTR, we propose the design, fabrication, and characterization of an electrically-pumped GaSb-based one-dimensional semiconductor laser array emitting at 2.3 microns. The laser array is expected to produce 5 watts of continuous-wave power from a single room-temperature 1 cm long laser bar by the end of phase I, and will be optimized to produce 10-15 watts per bar by the end of phase II. The lasers will be liquid cooled with micro-channel heatsinks for efficient heat removal. The proposed lasers will be based on SUNY Stony Brook's record setting 1 watt continuous wave power 2.5 micron GaSb based lasers. These lasers employ an optimized doping of the cladding layers resulting in a very low electrical series resistance while simultaneously minimizing free-carrier losses. A broadened waveguide further decreases free carrier losses by minimizing the interaction between the optical mode and the cladding layers. The design of the 2.3 micron In(Al)GaAsSb multiple quantum well active region will be carried out using extensive modeling guided by the experience of the Power Photonic team. Carrier transport, thermal distribution, optical mode configuration and band offsets will all be calculated and/or simulated using both established and novel techniques. The high-power 2.3 micron diode laser arrays proposed in this STTR have important military and civilian applications. The foremost application is for infrared countermeasures (IRCM); either directly as a light source or indirectly as excitation for optically pumped semiconductor lasers emitting near 4 microns. With the advent of the war on terrorism, there is an increased need for IRCM. While the military has always needed state-of-the-art IRCM, it is increasingly likely that IRCM will be widely deployed in the civilian aircraft fleet. This civilian application of IRCM will require the low-cost, low-maintenance, low-weight, and high reliability capabilities that the proposed laser array can provide.