Strained Layer Mid-IR Lasers Based on Ternary Substrates

Present day strained layer multi-quantum well (SLMQW) lasers are limited in wavelength to about 2.1 um. Longer wavelengths require thin layers whose "critical thickness" for dislocation-free strain begin to approach atomic dimensions due to the use of a binary (e.g. InP) substrate. We propose to use bulk ternary InAsyP1-y substrates which have larger atomic spacing thus allowing longer wavelength operation. In Phase I we will deposit strained layers of InGaAs and InAsP upon a bulk grown InAs .1P.9 substrate and demonstrate and deliver a ridge-waveguide laser at 2.3 um. In Phase II we will work with Crystallod, Inc., (a new substrate manufacturer) to fabricate InAsyP1-y (Y + 0.4) and InzGa1-zSb (.1 < z < .3) substrates to push the wavelength of strained layer antimonide-based lasers out past 3 microns. Dr. Ramon U. Martinelli of SRI David Sarnoff Research Center will consult. A Phase I extension option is included.