Kawasaki, Japan--A compact silicon photonics light source to be integrated in an optical transceiver has been developed by Fujitsu Laboratories Limited. The new design introduces mechanism that automatically keeps the wavelength of the light source and the operating wavelength of the optical modulator in sync, allowing the device to be smaller and more energy efficient. In addition to shrinking the size of communications transceiver components, these small light sources could be mounted directly in computer central processing units (CPUs) to create high-density optical interconnects between CPUs for exaflop-class supercomputers and high-speed, high-end servers.
The Fujitsu light source is comprised of a silicon mirror and a semiconductor optical amplifier. The silicon mirror is itself composed of a ring resonator and Bragg reflector that control the lasing wavelength. The sizes of the ring resonators introduced into both the light source and the optical modulator are exactly the same, so that shifts in the lasing wavelength of the light source and the modulator caused by CPU heating should match, eliminating the need for thermal control and reducing the transceiver footprint.
The transmitter component can be shrunk to less than 1 mm in length and an array of these components should be able to produce an optical transceiver for a large-capacity optical interconnect that is small enough to be mounted on a CPU module.
SOURCE: Fujitsu Laboratories; www.fujitsu.com/global/news/pr/archives/month/2011/20110916-01.html
