Influence of GaSb and AlGaInAsSb as Barrier Material on $\sim$2.8-$\mu$m GaSb-Based Diode Laser Properties

GaSb-based diode lasers emitting at a wavelength of 2.8 μm have been grown. The devices feature GaSb or Al
_0.21
Ga
_0.58
In
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As
_0.20
Sb
_0.80
barrier layers for the quantum wells, respectively. The transparency current density, modal gain, internal absorption, and characteristic temperature have been investigated on both devices. Since the barrier layers serve at the same time as waveguide for the laser light, the optical properties and the impact on device performance have been determined. The refractive index for Al
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Ga
_0.58
In
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As
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Sb
_0.80
has been estimated to be 3.26.