Researchers at Bell Communications Research, the laboratory in Livingston, New Jersey jointly owned by the Baby Bells, are developing a system that switches different wavelengths from one part of an optical fibre cable to another. The system – called the Integrated Acousto-optic Filter – is claimed to be the first such multiplexing device, and can extract one or more wavelength channels from one optical fibre simultaneously and independently, and divert all or part of each signal to a second fibre. The new system is claimed to combine the miniaturisation techniques of integrated optics technology with surface acoustic wave electronics; it uses the physical properties of light and sound to sort and distribute wavelengths electronically. In addition to expanding signal-carrying capacity beyond the current single-wavelength optical transmission systems, the new product is claimed to be able to process incoming and outgoing wavelengths around 1,000 times faster than with current optical multiplexing technologies. It is also claimed to have a lower power consumption, representing under 0.01W, compared with the current figure of over 1W. Bellcore says that the technology is particularly suitable for telephone company main exchanges with high-volume switching requirements, enabling them to send or receive signals between exchanges and remote switching sites. Bellcore says that it has filed design and fabrication patents on the technique.
