Nanolaser Created on Silicon at Technical University of Munich

Researchers at the Technical University of Munich (TUM) have created a nanolaser on a silicon chip. According to the researchers, the minuscule nanolaser is a thousand times thinner than a human hair. The researchers say that the process that they used to fabricate the nanolaser may make it possible to produce high-performance photonics components cost-effectively. In the future such lasers might be used in optically based processing and computers.

Moore’s Law predicted the doubling of the number of transistors in integrated circuits every two years, and the computing industry has since met that prediction for decades. However, the physics of semiconductor electronics has run into physical limits. Clock speeds of processors have only improved marginally in recent years.

One method theorized to improve performance of processors is to use photons instead of conventional silicon electronics
Scientists at the TU Munich have taken a step in the direction of optical computing.

The scientists solved the inherent lattice mismatch problem by depositing freestanding nanowires on silicon. Because the footprints of the nanowires are merely a few square nanometers, the scientists could preclude the emerging of defects in the GaAs material.

 The top and bottom ends of the wire needed to reflect and amplify the light until it reaches the threshold for lasing.
The used a 200 nm thick silicon oxide layer evaporated onto the silicon to form the mirror layer. Then they etched tiny holes in the mirror layer and used epitaxy to grow nanowires out of the holes.

“The work is an important prerequisite for the development of high-performance optical components in future computers,” Finley said. “We were able to demonstrate that manufacturing silicon chips with integrated nanowire lasers is possible.”