The goal of this project is to use molecular beam epitaxy (MBE) of PbSnTe and PbEuSeTe on PbTe substrates to develop and fabricate buried heterostructure (BH) tunable single-mode diode lasers emitting in the 15um to 28um spectral region with operation temperature in excess of 20 K. The BH diode lasers should deliver single mode output power in the range of 0.1-1.OmW. Threshold currents at 20 K and 80 K should not exceed 2 ma and 11 mA respectively. Temperature tuning rates should be between 3 cm-1/K to 4 cm-1/K (a fixed Pb salt material property) and current tuning rate should be minimized to values below 1800 Mhz/mA, thus directly satisfying NASA requirements for local oscillators for heterodyne detection. In addition, these lasers should also exhibit longer mode tuning in the range of 1.5-4 cm-1 per mode, and high temperature continuous wave (cw) operation in excess of 80 K. In phase I of this program the cladding layer composition, the doping profile and the active layer thickness for a diode laser emitting at 15um will be determined. Two working devices satisfying the above conditions will be delivered for evaluation.Present areas of application include noninvasive medical diagnostics, environmental/atmospheric monitoring, trace analysis of electronic processing gases, plasma etching diagnostics, and impurity analysis of Si and GaA1As wafers. Development of buried heterostructure diode lasers should substantially reduce system costs and complexity, resulting insignificantly greater commercial applicability in the environmental and medical areas.single-mode buried heterostructure tunable diode laserSTATUS: Phase I Only
