摘要 |
<P>PROBLEM TO BE SOLVED: To provide an optical amplifier, used for a wavelength multiplex optical communications system, capable of extending or removing an exciting light source stably, according to the increase and the decrease in the number of channels of signal light, even while the optical communications system is in operation. <P>SOLUTION: The optical amplifier has an optical fiber 17 for amplifier to which a rare-earth element, into which a plurality of optical signals, having different wavelength are inputted, is doped. The optical amplifier can increase/decrease the number of exciting light sources 20 and 21 for supplying the exciting light to the optical fiber 17 for amplifier, according to the number of optical signals to be inputted. <P>COPYRIGHT: (C)2006,JPO&NCIPI |