Contents 1. Introduction
Network traffic is increasing worldwide. There are also demands for the efficient use of energy. Therefore, there is a strong need for low-power communication systems. The power consumption of laser modules can be greatly reduced by removing the light source temperature controller and suppressing the rise in the drive current at high temperature. With this aim, InGaAlAs material, GaInNAs, and quantum dots have been studied as a replacement for the conventional InGaAsP material. Another choice is to use metamorphic growth technology, which increases the flexibility when choosing lattice constants and band offsets. Several lasers have been reported with lattice constants between GaAs and InP using metamorphic growth technology [1]–[3]. A metamorphic laser operates at high temperature, however, the characteristic temperature still needs to be increased. In this paper, we report the improved temperature characteristic of a laser on an InGaAs metamorphic buffer with an increased conduction band offset between the p-cladding layer and separately confined hetero-structure (SCH) that we achieved by inserting an electron stopper layer.
