Scientists have created micro lasers to make processors faster and lower power consumption

- 2022-03-01-

A group of scientists from the Hong Kong University of science and technology, the University of California Santa Barbara, Sandia National Laboratory and Harvard University were able to directly manufacture micro lasers on silicon, which became a huge breakthrough in the semiconductor industry.


For more than 30 years, silicon lattice and special laser materials cannot match, and it is only now possible to integrate the two materials. Just like the research group, which publishes an article in the annual Applied Physics express, the integrated subwavelength cavity is an essential component of a tiny laser, which can create and display high-density light-emitting elements on a chip on silicon.

In order to achieve this goal, researchers must solve the defect points of silicon lattice, which are consistent with those grown on gallium arsenide (GaAs) substrates matched with the lattice. Create a nano mode on silicon, make the GaAs template on silicon almost free of defects, and the quantum confinement of electrons in quantum dots grows on this template, making laser possible.

The research team then uses optical pumping to process lasers, rather than electronic currents, low-energy photons in atoms or molecules, and "pump" them to higher energy levels to make the device work like a laser.

"Allowing lasers on microprocessors to improve their capabilities so that they can operate at lower energy levels is a big step towards photonic and electronic integration on the silicon platform," said Kei may Lau, a professor of electronic computer engineering at the Hong Kong University of science and technology.

Traditionally, lasers used in commercial applications, usually 1mm x 1mm, are very large. Smaller lasers have large image loss.

But the researchers say they have overcome this challenge by using tiny echo corridor mode lasers, which are only 1 micron in diameter, 1000 times shorter in length and 1 million times smaller than those currently used.

Echo corridor mode laser is a very attractive light source, which is used in optical communication, data processing and chemical sensing applications on chip.

"Our lasers, with very low threshold and small volume, can be integrated into microprocessors," Lau pointed out. "These small high-performance lasers can be grown directly on silicon wafers, which is the raw material for most integrated circuits (semiconductor chips)."


In terms of application, this micro laser is very suitable for high-speed data communication.

"Photons are the most energy efficient and economical solution for transmitting large amounts of data over long distances. So far, the laser sources for these applications are" off chip "and lost from the components," Lau explained. "Our research is to integrate the chip with the laser, a relatively independent component relative to other silicon photons and microprocessors."


The researchers hope to apply the technology to the market within 10 years. Next, the research team will use microelectronic technology to work for electrically excited lasers.