SPLIT-BAND DEPRESSED-PROFILE AMPLIFIER AND SYSTEM

摘要

An optical split-band amplifier (212) amplifying at least a portion of the S-band and the C- and/or L-band. The amplifier composed of a first (212A) and a second section (212B) for amplifying long and short wavelength bands respectively. The second section (212B) comprises a short-pass fiber (10), a core (12) doped with an active material (18) such as erbium; a depressed inner cladding (14) and an outer cladding (16). The refractive index profile of the second amplifier results in losses comparable to the high gain in the long wavelength band and substantially smaller than the positive gains in the s-band.