Widely tunable optical filter with variable bandwidth based on the thermal effect on cholesteric liquid crystals

A widely tunable optical filter with variable bandwidth has been demonstrated based on the thermal effect on cholesteric liquid crystals. The central wavelength can be widely tuned from 826 to 517 nm and the bandwidth can be varied from 10 to 70 nm. It will have potential applications in many fields, especially in telecommunications and multi-spectral/hyper-spectral imaging systems.