Optical amplifying apparatus and optical transmission system

摘要

An optical amplifying apparatus that amplifies a wavelength-division multiplexed (WDM) optical signal includes an input section, a laser light source, a double-clad optical fiber, a gain equalizer, and a residual pump light attenuating section that attenuates a residual pump light outputted from the double-clad optical fiber. The residual pump light attenuating section is disposed such that the residual pump light of the laser light is incident on the residual pump light attenuating section before being incident on an isolator.

主权项

1. An optical amplifying apparatus that amplifies a wavelength-division multiplexed optical signal, comprising:
an input section whereto the wavelength-division multiplexed optical signal is inputted; a laser light source that generates multimode laser light; a double-clad optical fiber having a cladding portion whereto the multimode laser light is inputted and a core portion doped with a rare-earth element whereto the wavelength-division multiplexed optical signal is inputted, the double-clad optical fiber amplifying optical signals of a plurality of wavelengths in the wavelength-division multiplexed optical signal by a stimulated emission by the multimode laser light; a gain equalizer that flattens a gain characteristic of the wavelength-division multiplexed optical signal that has been amplified by the double-clad optical fiber; an output section that outputs the amplified wavelength-division multiplexed optical signal; and a residual pump light attenuating section that attenuates a residual pump light outputted from the double-clad optical fiber, the residual pump light attenuating section being disposed in such a manner that the residual pump light of the multimode laser light which has propagated through the double-clad optical fiber is incident on the residual pump light attenuating section before being incident on an isolator, the residual pump light attenuating section including a residual pump light leakage portion that causes the residual pump light which has propagated through the cladding portion to leak out of the cladding portion, and a thermal conversion portion that converts a part of the leaked-out residual pump light into heat, a part of the residual pump light being outputted from the residual pump light attenuating section to be incident on the isolator.