1.55 micron in-plane lasers with p-Al0.7Ga0.3As cladding layers

Semiconductor lasers operating at 1.55 μm are important components for long haul fiber-optic communications. However, their strong temperature sensitivity requires that thermoelectric coolers be used to control the device parameters as the temperature changes. Two parameters are the main focus of this work: the change in threshold current (measured by T₀) and slope efficiency with temperature. Modeling shows that both a reduction in Auger recombination and carrier overflow are needed to improve the temperature performance of 1.55 μm lasers significantly. To this end, we propose a novel laser structure with increased carrier confinement at 1.55 μm This novel structure use a p-Al_0.7Ga_0.3As cladding layer instead of p-InP. Since Al_0.7Ga_0.3As has a lower index of refraction at 1.55 μm than InP, it is possible, in this design, to use a higher barrier in the active region with no decrease in optical confinement when compared to a typical structure using InP. In addition, the large band gap of Al_0.7Ga_0.3 As allows for carrier leakage out of the active region to be reduced significantly. To obtain a p-Al_0.7Ga_0.3As layer on a GaInAsP active region, direct wafer bonding is used which combines two dissimilar materials without threading dislocation formation