| 摘要 |
PROBLEM TO BE SOLVED: To realize a wavelength filter, which reduces the measurements of cost and physical size, accompanying the increase of channel number for treated WDM signals. SOLUTION: The wavelength filter for filtering WDM signals is composed of a demultiplexer, a multiplexer, and a control array that connects the demultiplexer to the multiplexer. Then, at least one element of the control array functions on a plurality of channels for the WDM signals. One of the embodiments is the wavelength filter that filters the WDM signals. Each of the demultiplexer and multiplexer is a grating having free spectral range(FSR) narrower than a wavelength channel span. When the FSR is narrower than the wavelength channel span, the control array treates the wavelength channel in the WDM signals as a set. This generally reduces the physical minimum size that the wavelength filter is asked for. |
