Tunable F-P filter with dual transmission peaks suitable for demultiplexing in mm-wave radio-on-fibre dense WDM systems

A tunable Fabry-Perot (F-P) filter that has a transmission spectrum with periodic dual-peaks is successfully demonstrated. The filter consists of a birefringent waveguide sandwiched between highly reflective dielectric coatings. Preliminary results showing the performance of the filter at a dual-peak frequency spacing of about 50 GHz and an FSR of 160 GHz are presented. This filter has potential applications in communication systems, including millimetre (mm)-wave single-sideband modulation and channel selection in mm-wave radio-on-fibre dense WDM systems.