| 摘要 |
PROBLEM TO BE SOLVED: To execute selective drop and/or insert of a wavelength division multiplexing channel by especially minimizing the loss. SOLUTION: The subject optical filtering device includes n-sets of block filters (F1-Fn) and also a switch means (K) provided with a set (Gk) of waveguide paths, which have (n+1) sets of output ports (S1 to Sn+1) of ranks 1 to (n+1), (n+1) sets of input ports (E0 to En) of ranks 0 to n and selectively connects each output (Sk) to any input port (Ei) of a lower order rank. Each filter is provided with 1st and 2nd ports (Pe, Ps) opposed to each other, and these ports are respectively connected to the related output port (Sk) and the related input port (Ek) of the same rank. |
