1.3 μm lasers on GaAs(111)B employing ordered (InAs) 1(GaAs) 1 quantum wells for high frequency response applications

Abstract

We propose a novel laser active region design that employs a strained and ordered ([nAs) 1(GaAs) 1 quantum well on a GaAs(111)B substrate for 1.31 μm high-speed applications. The increased Matthevvs-Blakeslee critical thickness for this orientation as compared to the (001) case allows for wider wells with higher indium compositions. In the In 0.5Ga 4.5As case, however, the bandgap is not significantly affected by the reduced quantum confinement because an increase in the hydrostatic strain component of the Hamiltonian for the (111)-orientation approximately negates any narrowing effects. By using an alternate monolayer superlattice active region to replace the alloy, we find that wavelengths well beyond 1.3 μm can be achieved. We also discuss some of the adBANtages of moving to the (111)-orientation that indicate higher modulation bandwidths are possible using this material system over conventional 1.3 μm laser diodes on InP substrates.