Semiconductors for Long Wavelength Optical Communications
11 October 1988
Tremendous progress has been made in optical communications technology over the past two decades. The transmission losses of silica fibers have been reduced to levels of only a few tenths of a decibel, and semiconductor sources and detectors have been advanced from research laboratory novelties to reliable products in commercial communication systems. The first optical transmission, or lightwave, systems were based on injection laser or light-emitting diode sources fabricated from the GaAs/AlGaAs materials system, and operating at a wavelength near 0.87microns. These sources initially suffered from serious reliability problems, but major improvements in both their reliability and performance was achieved through the 1970s.