Monolithic tunable GaSb-based lasers at 3.3 μm

Widely-tunable monolithic two-section lasers emitting at around 3.3 m have been developed. The devices are based on GaInAsSb quantum wells with quinary AlGaInAsSb barrier layers. Tuning is achieved by adjusting the currents injected into two segments with lateral binary superimposed gratings. Counter-directional current-tuning of the segments resulted in wavelength channel switching, co-directional current-tuning in wavelength tuning of a channel. The typical tuning range of the devices is around 23 nm. High-sensitivity measurements indicate that sidemode suppression ratios are usually around 45 dB.