Lightwave Communication

Abstract

Lightwave communication has been developed extensively in these years. One of the potentialities of thelightwave is its high-speed or broad-band property. Present communication system, however, utilizes only partsof this feature. The possibility of higher-speed systems, several or even several tens gigabits per second, is discussed.
Another interesting development towards next century is the repeater-less long-haul transmission. The key element is the ultra-low-loss infrared fiber with one-to-two order small attenuation constant compared with ordinary silica fiber.
Finally, lightwave transmission through outer space, e. g. inter-satellite link, is described. In this case, short wavelength of the lightwave yields the extremely sharp light beam with the radiator much smaller than the radio-wave antenna.