| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an amplification method of wavelength division multiplexed (WDM) signal light capable of suppressing the deviation in the optical output level over the entire wavelength band of the WDM signal light to the fluctuations in the input level of the WDM signal light to a minimum with a simple constitution, and also provide an optical amplifier having a low cost. <P>SOLUTION: An optical amplifier 1 of the present invention divides WDM signal light into N by a demultiplexer 11, and then amplifies it by each of optical amplifier sections 12<SB>1</SB>to 12<SB>N</SB>. The output light level at each of the optical amplifier sections 12<SB>1</SB>to 12<SB>N</SB>is controlled to a fixed level by each of control circuits 25<SB>1</SB>to 25<SB>N</SB>and multiplexed by a multiplexer 13. At this time, the demultiplexer 11 is designed so that the bandwidth of the signal light output from each of output ports P<SB>1</SB>to P<SB>N</SB>has a different value in such a manner that the deviation between the wavelengths of the optical output levels generated at each of the optical amplifier sections 12<SB>1</SB>to 12<SB>N</SB>falls within a preset range. Moreover, the constant output control of each of the control circuits 25<SB>1</SB>to 25<SB>N</SB>is performed by individually adjusting the gain of each of the optical amplifier sections 12<SB>1</SB>to 12<SB>N</SB>to the fluctuations in power level without the channel number change of the WDM signal light input to the demultiplexer 11. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
