A single growth facetless semiconductor laser platform for photonic integration

InP based optical and electronic devices have been extensively studied for their enabling properties in modern telecommunication systems. There is considerable demand to further improve the performance of lasers and in particular to integrate the lasers with additional optical components such as detectors, waveguides, amplifiers, splitters, interferometers, modulators and multiplexers to realize optical chips with advanced functionality. This is hindered by the dominating costs associated with integrating these devices. On-chip integration is an attractive solution but one which requires the use of complex technologies (electron beam lithography and epitaxial overgrowth) that are generally proprietary and not compatible with foundry manufacture. In this talk, we report on a novel alternative approach to integration using a single epitaxial growth stage and conventional optical lithography. A tuneable laser with an integrated optical amplifier is demonstrated but the technology can be extended to integration of modulators and other optical functions. This device is enabled by the realization of a reflective mirror using etched slots thus freeing the laser designer from the absolute requirement of the cleaved facet and the associated crystal orientation of all semiconductor lasers. The integration of multiple components on a single chip will provide a platform for photonics that can be implemented in a foundry and this mimics the approach of the silicon electronics industry.