| 摘要 |
PURPOSE:To reduce the waveform distortion of transmitted light due to singularity in low band characteristics by a method wherein an optical amplifier is composed by non-excitedly connecting, to an optical amplifier output end using rare earth ion doped filter, an optical circuit containing the same rare earth element ions. CONSTITUTION:When a waveform distorted optical signal outputted from an excitation accelerating stage 2 is inputted in an optical circuit containing non- excited rare earth element ions, the front end of a packet pulse line rapidly excites Er<+3> ions so that the ions may absorb the light to be brought into saturated state. By this action, the front end of the packet pulse line is to be flattened to be consumed for the saturation with the Er<+3> ions. Thus, the succeeding pulse lines in relatively narrow width pass through only slightly attenuated by the absorptive saturation. Accordingly, the wavelength distortion of transmitted light due to the peculiarity in low region characteristics can be reduced thereby enabling the title optical amplifier applicable in a saturated region to be provided by applying the optical transmission system delivering the packet in a burst mode. |
