Massive Optical Switches Assembled on Inexpensive Silicon
Optical switches that have been shown to greatly enhance throughput in data centers can also be assembled in massive numbers on inexpensive silicon, according to research conducted at the Center for Integrated Access Networks (CIAN), an NSF-funded Engineering Research Center (ERC) with headquarters at the University of Arizona.
CIAN research had earlier shown that increasing the size or number of optical switches can lead to even greater benefits than was shown by using the optical switches in data centers. Developing the crossbar switch on silicon means achieving high speed and port counts on a chip with potentially low cost, power, and size for use in data centers.
The CIAN ERC has realized a record 50x50 port optical switch fabricated in silicon—the same low-cost, high-volume platform used for electronic chips. The switch has 50 input ports, 50 through ports, and 50 drop ports to send communication signals in different directions and a total of 2,500 Micro-Electrical-Mechanical-Systems (MEMS) cantilever switches.
The switch is fabricated using the standard silicon photonics technology at Berkeley Marvell Nanolab. Leveraging on silicon photonics technology, the switch can be mass-produced at low cost as it requires only three photomasks for the current process. Performance was excellent, as well, with the time response measured out to 0.4 MHz, which corresponds to a switching speed of roughly 2.4 micro-seconds. That is more than three orders of magnitude faster than existing, commercial optical switches that have 50 ports or more.