Distributed Feedback Interband Cascade Lasers

In this program, we propose to develop single-mode distributed feedback (DFB)interband cascade lasers based on type-II InAs/Ga(In)Sb/AlSb quantum wells. Thesesemiconductor diode lasers will emit in the 3-5 micron mid-IR wavelength region andoperate in quasi-CW mode. The DFB interband cascade lasers retain the advantagesof cascade injection and emission wavelength tailoring, while circumventing thephonon scattering losses that are present in intersubband lasers. These featuresmake them excellent candidates for compact, reliable, efficient, mid-infrared lightsources for a wide range of commercial and military applications, such as chemicalsensing, communications, land-mine detection, and industrial process control.The recent demonstration of interband cascade lasers with record-high powerefficiencies (>18% in pulsed mode and >14% in cw mode at 80 K) clearly shows theirpotential to fulfill the necessary requirements for practical mid-IR applications.The phase I effort will be directed towards the design, MBE growth, characterization,and optimization of type-II InAs/GaInSb/AlSb DFB interband cascade lasers todemonstrate their feasibility for chemical sensing applications. High performancemid-IR DFB IC lasers will be developed in Phase II.If successful, the proposed effort will lead to the first DFB single-mode interbandcascade laser that can operate under cw conditions at ambient temperatures. Thiswould enable several commercially viable products in several fields including thebroad field of chemical sensing. This research should considerably accelerate therealization and commercialization of efficient semiconductor mid-infrared lasers tomeet the demand for defense and commercial applications.