CWDM multi/demultiplexer consisting of stacked dielectric interference filters and off-axis diffractive lenses

A compact coarse wavelength-division multi/demultiplexer based on a stack of dielectric interference filters and an array of off-axis diffractive lenses is reported. The prototype optical system was packaged in the volume of 6.4 (width) * 2.5 (height) * 8.2 mm (depth). The optical system is interfaced via a multichannel connector with single-mode fiber ribbons. Optical insertion losses are better than 5 dB. The worst channel crosstalk was -19 dB.