Traffic on the Internet as much as quadruples every year, whereas plain old voice calls chug along at 8 to 13 percent annual growth. That wasn't true just a few years back. The multiplexer sends laser light of different wavelengths down a single optical fiber. DWDM systems work in concert with optical amplifiers that can boost the strength of many wavelengths at once without having to convert the wave back into an electrical signal.
Most current equipment tops out at about a tenth of a terabit.
Lucent Technologies's Bell Laboratories will attempt an experiment next year that would transmit 1,000 wavelengths on a fiber, in an effort to test the maximum capacity an individual fiber can accommodate. Multiplexers create the lanes on optical superhighways. But these pathways move only from point A to point B. To channel traffic from New York to either Los Angeles or Seattle, a switching interchange may be needed in Chicago. So companies have dusted off 1980s-era research on switching optical signals. Photonics has even become a basis for regional economic development.