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Carrier heating in GaAs/AlGaAs quantum wells (QWs) under optical interband pumping in the spontaneous-emission mode has been studied. The electron temperature was determined as a function of the pumping intensity. The effect of the electric field on the photoluminescence spectrum was examined. The change in the carrier concentration with the drive current in the spontaneous- and stimulated-emission modes in InGaAsSb/InAlGaAsSb QWs was determined from electroluminescence spectra. The rise in the temperature of hot carriers, which results in the increase in the carrier concentration with the drive current, was roughly estimated. [ABSTRACT FROM AUTHOR]

The vacuum pocket retaining molecular beam epitaxial regrowth of the nano-patterned GaSb surface was demonstrated. The high contrast 2D photonic crystal layer was incorporated into the test 2 μm emitting laser heterostructure. The photonic dispersion determined from angleresolved electroluminescence experiment showed four well-resolved bands corresponding to the model predictions for the square lattice. The single-mode lasing near 2 μm has been observed at the temperature corresponding to the alignment of the photonic crystal bandedge states and the quantum well gain peak. The reference devices without the photonic crystal layer emitted trivial spectra and did not lase at any temperature. [ABSTRACT FROM AUTHOR]

GaSb-based type-I quantum-well diode lasers emitting at 3.36 μm at 12 °C with 15 mW of continuous wave output power are reported. Devices with two or four InGaAsSb compressively strained quantum wells and AlInGaAsSb quinternary barriers were fabricated and characterized. It was shown that increase in the quantum-well number led to improved laser differential gain and reduced threshold current. [ABSTRACT FROM AUTHOR]

Improvement of the output parameters of 2.3 µm GaSb-based laser diodes was observed with increase of the quantum-well compressive strain. A continuous-wave (CW) power of 1.15 W and quasi-CW power of 1.4 W were obtained at room temperature from 2 mm-long single emitters with a 100 µm-aperture. [ABSTRACT FROM AUTHOR]

GaSb-based type-I quantum wells cascade diode lasers with nearly diffraction limited output beam were fabricated using methane-hydrogen dry etching plasma process. Rapid thermal annealing was shown to be a necessary step to reverse the effect of hydrogen plasma on conductivity of AlGaAsSb cladding alloy. Annealed two-step narrow ridge lasers confined both optical field and current in lateral direction and demonstrated operating voltage, threshold current density and slope efficiency comparable to those of reference wide ridge devices. [ABSTRACT FROM AUTHOR]

Cascade type-I quantum well GaSb-based laterally coupled distributed feedback diode lasers emitting near 2.9 μm were designed and fabricated. Second order index grating with period of 825 nm was defined by e-beam lithography and etched on both sides of 4-μmwide shallow ridge waveguide. Anti-/neutral reflection coated 2-mmlong devices that were solder-mounted epitaxial side-up demonstrated stable single frequency operation in a wide temperature range with output power of 13 mW at 20°C. Bragg wavelength temperature tuning rate was ~0.32 nm/K. [ABSTRACT FROM AUTHOR]

GaSb-based type-I quantum well laterally coupled distributed feedback diode lasers emitting in the methane absorption band near 3.27 µm were designed and fabricated. The first-order index grating with a period of 480 nm was defined by e-beam lithography and etched on both sides of 6 µm-wide shallow ridge waveguide. Coated 2 mmlong devices demonstrated stable continuous-wave single-frequency operation in a wide temperature range with an output power of 15 mW at +17°C and 40 mW at -20°C. The Bragg wavelength temperature tuning rate was ~0.27 nm/K. [ABSTRACT FROM AUTHOR]

Single spatial mode GaSb-based type-I quantum well diode lasers operating near 3 μm at room temperature were designed and fabricated by chlorine-free dry etching technique. The etching profile was optimised to minimise the optical loss. The 5.5 μm-wide ridge lasers demonstrated the same slope efficiency as that of 100 μm-wide multimode devices and generated 37 mW of continuous-wave output power at 17°C. [ABSTRACT FROM AUTHOR]

Ridge waveguide type-I quantum-well GaSb-based diode lasers operating at room temperatures in the spectral region near 3.15 µm have been designed and fabricated. The laser active region comprises three InGaAsSb quantum-wells embedded into quinary AlInGaAsSb barrier material to promote carrier confinement. Lasers generate 9 mW of continuous-wave output power at 3.16 µm in a diffraction limited beam at 20°C. Devices operate in continuous-wave regime up to 40°C producing above 1 mW of power at wavelength above 3.2 µm. [ABSTRACT FROM AUTHOR]