Tunable optical add/drop multiplexer

A tunable optical add/drop module (TOADM) comprising:

• an input/output port for inputting an input optical beam with a plurality of optical wavelength channels, and for outputting an output optical beam with at least one of the plurality of optical wavelength channels;
• an add/drop port for outputting a drop beam with at least one of the optical wavelength channels;
• a tiltable mirror rotatable about a rotation axis to one of a plurality of tilt angles for directing the optical beam along one of a plurality of different paths;
• a fixed thin film filter (TFF) positioned to receive the input optical beam along any one of the plurality of different paths for splitting the optical beam into a transmittance beam, which includes the at least one drop channel, and a reflection beam, which includes at least one of the plurality of optical channels in the output beam, wherein each one of the plurality of different paths corresponds to a different wavelength channel to be dropped;
• a first general retro-reflector means for reflecting said transmitted beam back with a lateral shift in position to the add/drop port via the thin film filter and the tiltable mirror;
• and
• a second general retro-reflector means for reflecting said reflected beam back to the input/output port via the thin film filter and the tiltable mirror.