Excited Light

Silicon laser is hot these days. Researchers at the University of California, Santa Barbara, John Bowers and his students, Alex Fang and Hyundai Park have developed a novel laser by bonding optical gain layers directly to a silicon laser cavity. This hybrid laser offers an alternative to silicon Raman lasers and is an order of magnitude shorter. The laser is optically pumped, operates in continuous wave mode, and only needs 30 mW of input pump power.

In the media announce, they also explained why silicon laser is important.

This evanescent silicon laser demonstration is the first step toward an electrically pumped hybrid silicon laser. Increasingly, the performance of microelectronic systems will depend more on the connections between chips and devices than on the characteristics of the chips and devices themselves. As semiconductor systems get smaller, interconnect capacity and power dissipation will limit their performance. Optical interconnects could alleviate these limitations but the challenge has been to create a semiconductor laser that can be fully integrated with silicon microelectronics.

They uses InAlGaAs quantum wells to provide optical amplification, with is evanescently coupled to the silicon cavity.