ADVANCED III-NITRIDE-BASED STRUCTURES FOR HIGH-PERFORMANCE ULTRAVIOLET LASERS

"This proposal addresses the development of practical designs for semiconductor injection lasers fabricated from III-V nitride materials operating in the ultraviolet spectral regions with potential for high efficiency operation for use in chemical andbiological warfare agent sensor and secure communication system applications. Many biological molecules of interest fluoresce in the UV spectral region and can be detected by using a laser-induced fluorescence (LIF) technique. LIF typically employsillumination of the bio-molecules of interest with a high-intensity UV photon pulse in the 260-290 nm spectral range that causes the bioagent to fluoresce in the l~300-400 nm wavelength regime. Furthermore, UV emitters in the 280nm spectral range can beused as sources in secure communications systems to be developed for a variety of applications. The major tasks of this program involve the analysis and modeling of InAlGaN/GaN heterojunction structures and the development of improved injection laserdevices operating in the UV. We propose to design (Phase I) and produce (Phase II) small, efficient UV sources for these important systems. This work is closely synergistic with the existing DARPA-sponsored UV emitter work being carried out in Dupuis?Group at UT-Austin under the SUVOS program. Improvements in the performance of nitride-based optoelectronic devices, especially injection lasers, will have a immediate broad impact in many important