Fiber optics: Single-mode cables and long-wavelength transmission are seen as requisite for next-generation systems

New fiberoptic technology in the laboratory promises to provide users a long-wavelength option to supplement existing short-wavelength systems. Last year U.S., Canadian, and European telephone companies continued to tie fiber-optic systems operating at the 800-to-900-nanometer-region into existing copper transmission networks. At the same time, engineers were pushing development of fiber-optic components and cables for systems that are expected to transmit at 1300 and 1500 nm. Attempts are being made to perfect methods that would allow fiber-optic components to operate at the longer wavelengths. Separate research in single-mode fibers is also being done. These fibers can transmit light over long distances due to the low loss at the longer wavelengths. Hence single-mode, long-wavelength systems can accommodate a larger bandwidth than multimode, short-wavelength systems.