HK scientist develops small lasers that enhance light-based computing

Researchers at The Hong Kong University of Science and Technology (HKUST) have fabricated microscopically-small lasers directly on silicon, enabling the future-generation microprocessors to run faster and less power-hungry.

The innovation was made by Kei-may Lau, chair professor of the Department of Electronic and Computer Engineering of HKUST, in collaboration with the University of California, Santa Barbara, and Sandia National Laboratories, and Harvard University.

Silicon forms the basis of everything from solar cells to the integrated circuits at the heart of our modern electronic gadgets. However, the crystal lattice of silicon and of typical laser materials could not match up, making it impossible to integrate the two materials.

Now, Lau's group managed to integrate subwavelength cavities - the essential building blocks of their tiny lasers - onto silicon, allowing them to create and demonstrate high-density on-chip light-emitting elements.

"These whispering gallery mode lasers are extremely attractive light source for on-chip optical communications, data processing and chemical sensing applications," Lau said.

"Putting lasers on microprocessors boosts their capabilities and allows them to run at much lower powers -- a big step towards photonics and electronics integration on the silicon platform and a key solution to the next-generation green information technology."

For years, photonics had been the most energy-efficient and cost-effective method to transmit large volumes of data over long distances, now with these new silicon-based integrated lasers, photonics may be able to use for short-distance data transmission as well, which is set to greatly enhance the speed of data communication.

The finding was recently published as the cover story on Applied Physics Letters. Endit