Optical interferometer for demultiplexing an optical signal

A method for processing an input optical signal, comprising:

• receiving an input signal at an incidence angle;
• separating the input signal into a first beam having a first optical path length and a second beam having a second optical path length, wherein the difference between the first optical path length and the second optical path length is based at least in part upon the incidence angle of the input signal;
• interfering the first beam with the second beam to produce a first output signal and a second output signal, the first output signal comprising a first subset of wavelength channels from the input signal and the second output signal comprising a second subset of wavelength channels from the input signal.

An optical system, comprising a demultiplexer network operable to demultiplex an input WDM signal into a plurality of wavelength channels, the demultiplexer network comprising:

• a tunable optical element operable to receive an intermediate input signal at an incidence angle and to separate the intermediate input signal into a first beam having a first optical path length and a second beam having a second optical path length, wherein the difference between the first optical path length and the second optical path length is based at least in part upon the incidence angle of the intermediate input signal;
• and
• a reflective element operable to reflect the first beam and the second beam such that the first beam interferes with the second beam to produce a first intermediate output signal and a second intermediate output signal, the first intermediate output signal comprising a first subset of wavelength channels from the intermediate input signal and the second output signal comprising a second subset of wavelength channels from the intermediate input signal.