Tiny Lasers Show Way to Light-Based Computing Era

The fabrication of microscopically small lasers directly on silicon by Prof Kei May Lau, Fang Professor of Engineering and Chair Professor of Electronic and Computer Engineering, and her group has given the prospect of light-based computing a major boost. The breakthrough, impossible to achieve for over 30 years, saw the integration of subwavelength cavities onto silicon, enabling high-density on-chip light-emitting elements to be created and demonstrated.

The advance represents an exciting step forward for the semiconductor industry. Prof Lau, who worked in collaboration with scientists from the University of California, Santa Barbara, Sandia National Laboratories and Harvard University, said such lasers could increase microprocessor capabilities and allow the microprocessors to use much less power, moving photonics and electronics integration on a silicon platform closer to reality and potentially providing a key solution for next-generation green information technology. The lasers used measure just one micron in diameter, and are 1,000 times shorter in length and one million times smaller in area than those currently used for commercial applications.

Photonics has long been the most energy-efficient and cost-effective method to transmit large volumes of data over long distances. With the new silicon-based integrated lasers, photonics may be able to be used for short-distance data transmission as well. “These whispering gallery mode lasers are an extremely attractive light source for on-chip optical communications, data processing and chemical sensing applications,” Prof Lau said.

The research was published as the cover story in Applied Physics Letters and further highlighted by online media.