IBM scientists today took another significant advance towards sending information inside a computer chip by using light pulses instead of electrons by building the world’s tiniest nanophotonic switch with a footprint about 100X smaller than the cross section of a human hair (40×12 microns).

The IBM team demonstrated that their switch has several critical characteristics that make it ideally suited to on-chip applications:

The switch is extremely compact. As many as 2000 would fit side-by-side in an area of one square millimeter, easily meeting integration requirements for future multi-core processors.

The device is able to route a huge amount of data, since many different wavelengths of light can be switched simultaneously. With each wavelength carrying data at up to 40 Gb/s, it is possible to switch an aggregate bandwidth exceeding 1 Tb/s — a requirement for routing large messages between distant cores.

IBM scientists showed for the first time that their optical switch is capable of operating within a realistic on-chip environment, where the temperature of the chip itself can change dramatically in the vicinity of “hot-spots,” which move around depending upon the way the processors are functioning at any given moment. The IBM scientists believe this temperature-drift tolerant operation to be one of the most critical requirements for on-chip optical networks.