Optical Fiber : Progress in half a century and recent trend

Abstract

In 1970, Kapron et. al. reported an optical fiber with a transmission loss of 20 dB/km, and a semiconductor laser continuously oscillating at room temperature was demonstrated as well. After then, technology development for optical fiber communication started in full swing. Optical fibers have been evolutionally advanced and, now, optical networks are indispensable life lines for human society.　In this report, the progress of optical fibers in half a century is reviewed, and a recent trend is also introduced.