Hello,
I have been trying to figure out the fundamental difference between WDM Add/Drop and and a combination of FBG with Coupler in OptiSystem.
Of all that I have read, OADM (Optical Add Drop Multiplexers) is used in WDM systems for combining several optical signals. It has functionality for adding/dropping select wavelengths and usually consists of an FBG and circulators.
I read that in the OptiSystem Documentation that the WDM Add Block consists of filters followed by a combiner while the WDM Drop consists of a splitter followed by filters. In a certain application that I am trying to simulate I am splitting several optical components generated by an MZM through WDM Drop blocks and then recombining select components using WDM Add blocks. I then replaced the WDM Drop Blocks by an FBG (with Optical Rectangular Filter to limit the undesired components). The WDM Add Blocks were replaced by Optical Couplers. I expected the response in both the cases to be the same. However they differ greatly. Am I making a fundamental mistake? Or is there something that I have missed?
Thank you.
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