Patent ID: 7039271

Claim:
An optical add and drop multiplexer (OADM), comprising: a ferrule having an input side and an output side, and an opening formed therethrough; an input fiber, an output fiber, an add fiber and a drop fiber positioned within the opening of the ferrule; a collimating lens positioned on the output side of the ferrule, the collimating lens operable to receive optical signals from the input and add fibers and operable to transmit optical signals to the output and drop fibers; a filter having a first side and a second side, the first side of the filter optically coupled to the collimating lens and operable to reflect optical signals from the input fiber having one or more particular wavelengths in the filter's reflection band back through the collimating lens to the output fiber and to transmit a drop signal from the input fiber and an add signal from the add fiber having one or more particular wavelengths in the filter's transmission band through the filter to a reflector; and the reflector optically coupled to the second side of the filter and at an angle to the filter such that optical signals transmitted through the filter from the input and add fibers are reflected back through the filter and collimating lens to the drop and output fibers, respectively.