Sound waves used to advance optical communication

Source: Xinhua| 2018-01-23 05:39:46|Editor: Mu Xuequan
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CHICAGO, Jan. 22 (Xinhua) -- Researchers at the University of Illinois (UI) have successfully used sound waves to produce ultraminiature optical diodes that are tiny enough to fit onto a computer chip.

These devices, called optical isolators, may help solve major data capacity and system size challenges for photonic integrated circuits, the light-based equivalent of electronic circuits, which are used for computing and communications.

The new device is only 200 by 100 microns in size, about 10,000 times smaller than a centimeter squared, and is made of aluminum nitride, a transparent material that transmits light and is compatible with photonics foundries.

"Sound waves are produced in a way similar to a piezoelectric speaker, using tiny electrodes written directly onto the aluminum nitride with an electron beam. It is these sound waves that compel light within the device to travel only in one direction. This is the first time that a magnetless isolator has surpassed gigahertz bandwidth," said UI graduate student and lead author Benjamin Sohn.

The researchers are now looking for ways to increase bandwidth or data capacity of these isolators and are confident that they can overcome this hurdle. Once perfected, they envision transformative applications in photonic communication systems, gyroscopes, GPS systems, atomic timekeeping and data centers.

"Data centers handle enormous amounts of internet data traffic and consume large amounts of power for networking and for keeping the servers cool," said mechanical science and engineering professor and co-author of the study Gaurav Bahl. "Light-based communication is desirable because it produces much less heat, meaning that much less energy can be spent on server cooling while transmitting a lot more data per second."

Aside from the technological potential, the researchers can't help but be mesmerized by the fundamental science behind this advancement.

The study has been published in the journal Nature Photonics.