| 摘要 |
<p>A multi-wavelength optical filtering device for optical signal transmission, capable for functioning as a multiplexer or a demultiplexer. The device has at least one (first) optical circulator having at least four ports including an input port and a plurality of sequential ports, the last of said sequential ports being an output port, and an in-fiber Bragg grating (wavelength selective means) coupled to each of said sequential ports except said output port. The circulator may be branched off to a number of other circulators, the number depending on the number of the sequential ports of the first circulator, through the Bragg grating rather than through the output port of the first circulator. The other circulators, which are preferably also at least four-port circulators with wavelength selective means at the sequential ports, can also be branched off in an analogous manner as the first circulator. The device allows a reduction of signal losses in optical signal transmission due to the passing of a signal between circulator ports.</p> |
