Patent ID: 6751373
Filing Date: 2004-06-15
Classification: G02B,H04J

Abstract:
An apparatus for demultiplexing an input optical signal carrying a plurality of channels, comprising:a splitting device for dividing the input optical signal into a plurality of distinct free-space sub-beams, each sub-beam also carrying said plurality of channels; and for each sub-beam, a distinct narrow band reflective filter array, said narrow band reflective filter array comprising a plurality of narrow band reflective filters linearly disposed along an optical axis extending in a direction of propagation of said sub-beam, each narrow band reflective filter reflecting a distinct one of said plurality of channels and being tilted with respect to said optical axis such that the reflected channel is directed away from the optical axis to an output, each narrow band reflective filter being substantially transparent to the remaining channels of the sub-beam and allowing a remainder of the sub-beam to proceed therethrough along said optical axis, said optical device being robust against tilt variations in said narrow band reflective filters because said tilt variations have minimal impact on the direction of said remainder of the sub-beam passing therethrough.