High-speed Laser with Ultralow Energy Consumption for Silicon Photonics

This project aims to investigate and demonstrate a novel laser structure that appears as a very promising high-speed, ultralow-energy-consumption light source for silicon photonics. The laser structure differs from conventional designs in that the active material (III-V semiconductor) is incorporated into one of the mirrors, a so-called high-index-contrast grating mirror, which provides very strong field confinement within the grating. This allows ultra-small lasers with very efficient energy conversion of electrons to photons simultaneously with a high modulation bandwidth. At the same time, the laser can be integrated onto a silicon chip, allowing the realization of the long-time dream of integrating photonics and electronics on the same chip. In this integrated chip, one can exploit the properties of electrons for processing data and the properties of photons for transmitting data. This vision of silicon photonics is being actively pursued by companies like IBM and Intel, but the light source remains the critical component. Considerable interest shown by several companies reflects the potential of this innovative laser structure. The novel structure that we wish to investigate, however, has some fundamental challenges. Thus, a good understanding of the mode properties, the electrical transport and the thermal issues is needed. Also, the technology for integrating the active material (buried heterostructure) within the grating mirror needs to be developed. The project will thus rely on a close interaction between theory, design, fabrication and characterization. The knowledge gained in this project can form the background for research and development of a new class of ultra-small and highly-integrated photonic devices.