| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical node that extracts light with a desired wavelength from a wavelength multiplexed light at a low cost and with low loss. SOLUTION: A branch filter section 15 in this optical node 11 branches wavelength multiplexed lights λ1-λ16 into branched lights with two or more wavelengths, the channel interval of which are coarser than that of the multiplexed lights λ1-λ16, and then each of reflected wavelength variable gratings 1711-1744 reflects or transmits the lights with wavelengths included in each branched light. Thus, the number of the reflected wavelength variable gratings is typically sufficient if it equals the number of the channels of the wavelength multiplexed lights, which is different from a conventional technology. Furthermore, number of the reflected wavelength variable gratings, through which the light with one wavelength is transmitted, can be decreased. |
