Monday, March 4, 2019

UC Berkeley develops 240x240 silicon photonics switch

Researchers at the University of California, Berkeley have demonstrated an experimental, silicon photonics switch with 240 inputs and 240 outputs.

In a paper presented at OFC, researchers Tae Joon Seok and colleagues will report the successful scale up of a 240x240 integrated silicon photonic switch.

The switch was manufactured at the Marvell Nanofabrication Laboratory at UC Berkeley using a process known as lithography stitching, creating a wafer-scale 240x240 silicon photonic switch by stitching together nine 80x80 switch blocks in a 3x3 array, with three input and three output coupler blocks.

The research team demonstrated signal loss lower than any previously reported, said Seok, who is assistant professor at the Gwangju Institute of Science and Technology in South Korea and a visiting scholar at UC Berkeley. The on-chip loss to port-count ratio  was measured at 0.04 dB/port.

"Recently, many research groups competitively reported silicon photonic switches with large input/output port counts," said Seok. However, the physical size of a silicon photonic chip has been limited to 2 to 3 cm because of the limitations of the lithography tools necessary to etch the required geometric patterns on the silicon wafers used as a base for the integrated chips.