Single-mode lightwave technology has rapidly evolved to where it is now the standard technology for telephone transmission. With this advance, several basic single-mode fiber designs have evolved, each of which has certain advantages and weaknesses. The two main classes of single-mode fiber are the so-called standard fiber, which is optimized for use at a wavelength of 1.31 μm, and the dispersion shifted fiber, which is optimized for use at 1.55 μm. Within each of these classes the two basic designs are the (a) matched cladding fibers, which have a cladding with a constant index of refraction, and the (b) depressed cladding fibers, which have an inner cladding with an index lower than that of the outermost cladding. Although the terms matched and depressed historically have referred to the cladding index relative to SiO2, this general definition includes fibers with both GeO2 and SiO2 cores.
© 1988 Optical Society of AmericaPDF Article