| 摘要 |
PROBLEM TO BE SOLVED: To provide a variable channel optical drop filter which has high performance and high stability and contributes to the reduction of a circuit scale, the drastic reduction of the number of optical semiconductor amplifiers and the reduction of a cost by combining the input and output ports of array waveguide gratings. SOLUTION: A pass wavelength is λ1 if, for example, the input port 6 and the output port 9 are assumed to be used. Next, the pass wavelength is λ2 if the input port 6 and the output port 10 are assumed to be used. The pass characteristics of the same 12 wavelengths as the wavelengths of the prior art are obtd. with 7 pieces of the input and output ports smaller than 13 pieces of the input ports which are heretofore indispensable with the prior art if the input ports 4, 6, 8 and the output ports 3, 4, 9, 10 are used in combination by using one piece of the 3×4 array waveguide gratings in such a manner. Further, the arbitrary wavelength multiplex signal group may be dropped from the wavelength multiplex signals of the same 12 wavelengths as the wavelengths of the prior art with 7 pieces of the optical switches fewer than 13 pieces of the optical switches which are heretofore necessary with the prior art if the optical switches are respectively connected to these input and output ports to be passed by the respective wavelength and are driven. |
