Development of Intra-Cavity-Injection Mid-IR Interband Cascade Laser

70109 Monitoring the development and proliferation of nuclear materials and weapons is an important national objective. Several gases are emitted during the processing of nuclear materials, and their presence at trace levels at a given location essentially establishes that nuclear materials are being processed there. However, presently available semiconductor lasers do not have the operating characteristics that would allow remote sensing units to covertly identify these gases. This project will develop the required semiconductor laser transmitter and then a highly compact, single-person-portable sensor unit capable of covertly and remotely detecting the presence of a nuclear material processing site from a modest range (~100 m to1km). In Phase I, mid-infrared type-II interband cascade lasers, using intra-cavity-injection and improved lower optical cladding materials, will be developed. Performance characteristics will include the capability to operate under continuous wave conditions at ambient temperatures (or temperatures accessible with thermoelectric coolers) and output power in excess of several milliwatts. Phase I also will identify and test detection strategies and sensitivities for one or more target species and develop a conceptual design for a sensor unit to be assembled and field tested during Phase II. Commercial Applications and Other Benefits as described by the awardee: The semiconductor diode lasers should enable not only a sensor system for detecting nuclear materials processing facilities but also a wide array of commercial products in several application areas. These areas include other chemical sensing applications (e.g., industrial process controls, medical diagnostics, explosives and bio-agent detection, etc.), free-space communications, and several military applications including infrared countermeasures.