| 摘要 |
A power equalising optical amplifier 630 comprises an optical amplifier 631, for amplifying wavelength division multiplexed signals, a band pass filter 632, and a chirped fibre grating 633, which reflects signals of different wavelengths at different positions. Preferably the fibre grating 633 attenuates signals passing along it, thereby attenuating different wavelength signals by different amounts and equalising their powers. To avoid dispersing signals passing along it, the fibre 633 may comprise two identical gratings chimed in opposite directions. Preferably the amplifier 631 is also lossy, being doped wit samarium. |
