| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an optical amplifier a gain of which is flattened, and to provide a wavelength division multiplex optical transmission system using the same. <P>SOLUTION: The optical amplifier 140 is a two-stage type, comprising a first stage 210 containing a flat waveguide 214 having a region doped with fluorescence material, and a second stage 220 containing an optical fiber 223 doped with the fluorescence material at the first and second stages. The pump light from light sources 212 and 221 are coupled with optical couplers 213 and 222. Optical isolators 211 and 216 prevent the natural emission light generated at the optical amplifier from returning to a previous stage. An optical filter 215 prevents the pump light of the first stage from being propagated to the second stage. <P>COPYRIGHT: (C)2008,JPO&INPIT |
