Photonic Switches – High-Speed Data Transmission

Researchers’ experimental photonic switches show promise toward the goal of fully optical, high-capacity switching for future high-speed data transmission networks, demonstrating previously unseen capabilities. The researchers will present the results of a successful scale-up of a 240×240 integrated silicon photonic switch.

The device’s name comes from the fact that it accepts 240 optical communication input channels and sends them to 240 output channels. The experimental switches kept the signal loss lower than any previously reported technology.

Lithography tools etch the required geometric patterns on the silicon wafers (integrated chip base). Due to the tools’ limitations the physical size of a silicon photonic chip has been limited to 2 to 3 cm.

Researchers overcame this limitation by stitching together nine 80×80 switch blocks in a 3×3 array, with three input and three output coupler blocks, to create a wafer-scale 240×240 silicon photonic switch. The photonic switches use grating couplers to couple light coming in and out of the chip. Electrical probes activated the switch cells. The resulting switch area was 4 cm x 4 cm, nearly doubling the size of currently available silicon photonic switches.

The technology applies to any silicon photonics applications that require ultra-large-scale devices such as programmable photonic processors.

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