External Cavity Stabilized LWIR QCL [7275-200]

78057S Lasers based on quantum cascade (QC) gain media represent a powerful new tool for optical detection in the infrared spectral region, needed to help detect the proliferation of weapons of mass destruction. They have been demonstrated to be reliable, compact, efficient, bright sources of spectrally narrow radiation in midwave-, longwave-, and far-infrared. The ultimate utility of QC lasers, however, will be greatly enhanced if their tuning range can be increased. This project will apply previous experience with quantum cascade (QC) lasers and external cavity stabilization to demonstrate a broadly tunable QC laser source. Phase I will focus on designing and demonstrating a broadly tunable external cavity QC laser device near 8 ¿m. The evaluation tests of the prototype device will include output power, tuning range, tunability (i.e., the presence of mode-hops or discontinuities in the tuning range), and spectral purity. From these results, an improved concept for a reliable, robust, and compact, package will be designed for Phase II, in which the properties of the laser will be optimized, and the laser will engineered into a robust package. Commercial Applications and Other Benefits as described by the awardee: The broadly tunable quantum cascade laser source should meet an unfilled need for narrow bandwidth spectroscopic systems in the 8 to 14 micron spectral region. Systems employing these versatile lasers will be used for high-precision spectroscopy to detect trace amounts of gaseous molecules. Customers will include the Department of Energy Laboratories, university-based research teams, and industrial companies developing advanced sensors for hazardous gas leak detection, process monitoring, and human breath analysis.