Optical apparatus with faraday rotator, static gain flattening filter and variable optical attenuator

摘要

An optical apparatus for transmitting an optical signal includes a static filter, a Faraday rotator and a reflector. The Faraday rotator makes a first change in polarization of an optical signal in a first direction, and a second change in polarization of the optical signal received from the reflector in a second direction. This produces a polarization of the optical signal that is substantially orthogonal to an initial polarization state of the optical signal.