In order to complement future tera-scale computers, optical interconnects are needed to provide high speed delivery of massive chunks of data either between racks, boards or even between chips. As the industry begins to meet technological limits at the copper level, Intel is investing in a somewhat unique approach to bring optical connectivity at the silicon chip level.
Today, Intel revealed yet another silicon photonics breakthrough. Working with a research team at UCSB (University of California Santa Barbara), Intel unveiled the first electrically pumped hybrid silicon laser.
The hybrid silicon laser is achieved by coupling an indium phosphide laser with a silicon waveguide. Since both indium phosphide and silicon are largely different types of material, these two components were 'glued' together by growing a thin 25 atom thick oxide layer using an oxygen plasma process and then fused together through a low temperature process. This simple processing method makes volume manufacturing of silicon lasers possible since both materials are separately processed. Previous attempts by other researchers to directly grow indium phosphide on silicon have been unsuccessful as the largely different material properties caused crystal lattice mismatch and poor lasing performance.
Now that an electrically pumped hybrid laser has been proven as a viable option, Intel looks set to integrate all the other components (e.g. modulators, waveguides, multiplexors/demultiplexors) into a single silicon chip.
Intel expects this breakthrough to be a stepping stone to future silicon based optical devices manufactured at high volumes and available at low cost. It is also an Intel vision to integrate optics into future tera-scale computers by using low cost optical interconnects on a board-to-board level (like in a blade application) or even between high performance multi-core chips.