Specialty Optical Fibers Handbook

in the early 1980s. Most manufacturers offer standard specifications optimized

for 488–532 nm in the blue and green, 633–680 nm in the red, 780–850 nm in the

first telecommunications window, 940–1100 nm for YAG, YLF, and semicon-

ductor EDFA pump lasers, 1310–1550 nm in the second and third telecommu-

nications windows, and 1530–1610 nm for the so-called S-, C-, and L-bands.

All of the basic rules that apply to conventional telecommunications fibers

also apply to PM fibers. Progressively fewer modes are supported as the cutoff

wavelength is approached, reducing to only a single mode when cutoff is

reached. The fiber will then continue to support this one remaining mode,

usually for at least 200 nm beyond cutoff. This single-mode waveband will

increase ...