| 摘要 |
<p>PURPOSE: A wavelength multiplexing optical transmission system is provided to reduce the non-linear degradation and S/N degradation of a wavelength-multiplexed optical signal when the number of channels are varied. CONSTITUTION: In the device, an optical amplifying apparatus, the positioning of the first part(1000) and the second part(2000) are essentially switched. Therefore, a wavelength-multiplexed optical signal is controlled to have a constant power level by second part(2000), and is then controlled by first part(1000) to have a constant gain. More specifically, an input wavelength-multiplexed optical signal is transmitted to optical attenuator(64). The wavelength-multiplexed optical signal output from optical attenuator(64) is transmitted to rare-earth-doped optical fiber(521) via optical isolator(551) and optical wavelength multiplexing coupler(561). The amplified wavelength-multiplexed optical signal is output via optical isolator(552) and optical branching coupler(542).</p> |
