Thermal tunability of photonic bandgaps in liquid crystal infiltrated microstructured polymer optical fibers

We demonstrate the photonic bandgap effect and the thermal tunability of bandgaps in microstructured polymer optical fibers infiltrated with liquid crystal. Two liquid crystals with opposite sign of the temperature gradient of the ordinary refractive index (E7 and MDA-00-1444) are used to demonstrate that both signs of the thermal tunability of the bandgaps are possible. The useful bandgaps are ultimately bounded to the visible range by the transparency window of the polymer.