Polarization‐independent liquid crystal‐based refractive index sensor

A polarization-independent refractive index (RI) sensor with a sensitivity of 50 nm/RIU is demonstrated. The proposed RI sensor simply consists of a liquid crystal (LC) polymeric polarization grating film and one glass substrate. The wavelength shift over the RI of the surrounding medium is investigated through anisotropic rigorous coupled-wave analysis. Such an LC-based polarization-independent RI sensor not only enables the usage of an unpolarized light source but also manifests a high sensitivity, offering great potential for the integration with display systems.