OREANDA-NEWS. Fujitsu Laboratories Limited announced the development of a four-wavelength integrated silicon laser for optical transceivers that use silicon photonics, a step toward faster data communications between processors.

One effective way to increase the capacity of data transfers is to carry multiple signals, each at a different wavelength, over the same optical fiber (multiplexing). Typically, in silicon photonics there would be different sized ring resonators to generate optical signals for each wavelength. However, maintaining precise spacing between each wavelength is problematic due to variations in manufacturing processes as well as temperature fluctuations. Also, high-power signals are needed to compensate for losses that occur when multiplexing and demultiplexing signals. Fujitsu Laboratories has succeeded in making use of the periodic transparency of ring resonators to generate wide and uniform wavelength spacing of laser light. Also, mounting technologies that precisely connect multiple silicon waveguides and optical amplifiers on the silicon reduce connection loss between waveguides and achieves a higher power output. The resulting integrated silicon laser has been proven to generate four wavelengths consistently with a wide spacing of 12±0.5 nm and high output of +5 dBm.

This technology helps pave the way toward faster inter-processor communications, which will be a key element in future high-performance computers, such as exaflops-class supercomputers and high-end servers.