Uniform performance of high-efficiency room-temperature GaInAsSb/GaSb photodiodes for 1.75 < lambda < 2.2 mum.
A group of 126 experimental, packaged, backilluminated, 1.75-2.2-microm wavelength, GaInAsSb mesa (~85-microm diameter) photodetectors have been assembled and evaluated. Average room-temperature properties were peak quantum efficiency, 86%; zero-bias capacitance, 3.9 pF; dark current at -0.5-V bias, 7.4 microA.
2.2 μm GaInAsSb/AlGaAsSb injection lasers with low threshold current density
Double heterostructure 2.2 μm wavelength lasers were fabricated from Ga0.84In0.16As0.15Sb0.85/ AlxGa1−xAs0.04Sb0.96 wafers grown by liquid phase epitaxy. These structures were grown with Al‐rich confinement layers (x=0.4) for optical confinement and thin intermediate cladding layers (x=0.34) to relieve the strain resulting from the lattice mismatch of the Al‐rich confinement layers with respect to the substrate and the active layer. A threshold current density as low as 1.7 kA/cm2 was obtained at room temperature.
InGaAsP/InP double-heterostructure lasers: Simple expressions for wave confinement, beamwidth, and threshold current over wide ranges in wavelength (1.1-1.65 µm)
For InGaAsP/InP devices emitting in the wavelength range of 1.1-1.65 \mu m, we present novel and accurate analytical approximations of the crucial parameters in laser design: the radiation confinement factor \Gamma ; the effective refractive index N eff ; and the transverse beamwidth \theta_{\perp} . It is found that \Gamma is independent of wavelength or step-index difference and \theta_{\perp} becomes independent of wavelength as the active layer thicknesses d decreases below 0.15 μm. An explicit analytical expression is derived for the threshold current density J th . The new linear gain-current relationship g (cm-1) = 28.5 (J/d) - 50 is deduced from a critical assessment of recent experimental data. A theoretical framework is provided to explain experimental observations such as: the J th versus d curve is independent of wavelength, the threshold has a negligible variation over the 0.1-0.3 \mu m active-layer thickness range, and the normalized threshold current density ( J_{th}/d , for d \geq 0.5 \mu m) varies strongly (3-5 kA/cm2/μm) with cavity length.