BROAD BAND CIRCULATOR USING OPTICAL FILTER AND NARROW BAND CIRCULATOR

摘要

A broadband circulator using a filter and a narrowband circulator is provided to implement a CWDM(Coarse Wavelength Division Multiplexing) full band bi-directional communication facility at a low price and improve isolation characteristics. BPFs(Band Pass Filters) or edge filters(2,4,6) filter a desired band of WDM signal. Narrowband circulators(8,10) include a plurality of regions and provide a signal flow related to a wavelength within the band of the WDM signal which has passed through the BPFs or edge filters(2,4,6). The WDM signal is a signal of a CWDM 18-channel band.