High efficiency GaInSbAs/GaSb type-II quantum well continuous wave lasers

Narrow ridge GaInSbAs/GaSb! type-II QW lasers emitting at 2,37-2.4 mu m hav e been fabricated. The lasers operated in the cw regime at room temperature with the output optical power up to 20 mW/facet. The internal quantum effi ciency of the lasers was. found to be 89% and the power efficiency reached 20%. The lasers emitted in the fundamental spatial mode and exhibited singl e frequency operation in a large range of currents and temperatures. The em ission wavelength could be continuously tuned by current over 0.7-1.2 MI. T he single longitudinal mode behaviour was explained by the photorefractive effect due to DX centres in the Te-doped GaAlSbAs cladding layer acting as a saturable absorber.