Patent ID: 8175428

Claim:
An optical communications system operable with a mixed input signal comprising: an optical beam separator having means for separating said mixed input optical beam into a separated optical channel and a remainder beam; a block add unit optically coupled to said separator to receive said separated optical channel and producing as an output a controllably modified separated optical channel in response thereto or an added input optical signal, said block add unit including at least one switch unit comprising: a planar surface disposed to allow light from a first source to illuminate a first detector in a first position thereof, said planar surface being mounted for rotation about an axis along an edge of said planar surface thereof from said first position, at which light from said first source is unimpeded, to a second position, at which said light is blocked by said planar surface, at least one side of said planar surface being reflective and effective to block light from a first source with respect to a first detector in said second position and reflect light from a second source to said detector in said second position and means for selectively actuating said surface between said first and second positions; and an optical beam combiner coupled to receive said controllably modified separated optical channel or said added input optical channel from said block add unit and combine said remainder beam therewith as an output beam.