2.2-2.5 /spl mu/m InGaAsSb/AlGaAsSb QW diode laser with extraordinarily wide (/spl Delta//spl lambda/ = 300 nm) optical gain spectrum

Summary form only given. Spectroscopy and environmental monitoring are among the prospective applications of mid-infrared diode lasers. Achievement of the widest tuning range for these lasers is highly desirable. The typical tuning range of commercially available external cavity tunable lasers is below 100 nm in the 2-/spl mu/m range. To expand this range it is necessary to employ a gain media with a wider optical gain spectrum. The switching of the laser emission wavelength between the ground n = 1 and the first excited n = 2 states in a quantum well has previously been reported in for GaAs/AlGaAs QW lasers. We suggest involving the first excited states into the light amplification in order to expand the gain spectrum bandwidth. In this work we determined the structural design and experimental conditions for GaSb-based lasers in order to attain the widest gain spectrum (the full-width at half-maximum was /spl Delta//spl lambda/ = 300 nm) at reasonable gain flatness: for the structure with quantum well width of 200 A at near-room temperature the depth of the valley between gain peaks did not exceed 10 cm/sup -1/.