Widely tunable filter based on side-polished polarisation-maintaining fibre coupled with thermo-optic polymer overlay

A wide wavelength tunable filter based on a side-polished polarisation-maintaining fibre in contact with a polymer planar waveguide overlay is proposed and demonstrated. The good thermo-optic effect of the polymer waveguide induced by a micro-strip heater leads to a wide tunable wavelength range of 230 nm with an applied electrical power of 0.76 W.