Electrically Controlled Non-Polarizing Optical Bandpass Filtering in Liquid Crystal Planar Waveguide

This letter proposes an electrically controlled non-polarizing optical bandpass filter based on prism coupled planar optical waveguide (POW) structure that incorporates a liquid crystal layer, which works in the electrically controlled birefringent (ECB) mode and makes the central wavelength for TM passband tunable. The measured passband of TM wave, tuned from 526 nm to 599 nm, overlaps with that of the TE wave at 582 nm under driving voltage of about 3.70 V.