A dense wavelength division multiplexer for separating an optical signal into optical channels comprising:
- means for inputting an optical signal, the optical signal comprising a plurality of optical channels;
- means for separating one or more of the plurality of optical channels by introducing a phase difference between at least two of the plurality of optical channels,
- wherein the separating means is at least partially based on the polarity of the plurality of optical channels,
- wherein the separating means comprises a polarization beam splitter optically coupled to the lenses, and at least two nonlinear interferometers optically coupled to the polarization beam splitter,
- wherein the nonlinear interferometers (b) each comprise a first glass plate optically coupled to a second glass plate, forming a cavity;
- a first reflective coating residing inside the cavity and on the second glass plate;
- a second reflective coating residing inside the cavity and on the first glass plate;
- and a waveplate residing inside the cavity between the first and second glass plates;
- and
- means for outputting the separated plurality of optical channels along a plurality of optical paths.