Near‐infrared tuneable filter based on polymer dispersed liquid crystals

Abstract Dynamic filtering is crucial in various applications, including imaging, communication, and biological detection. With advancements in micro‐nano device fabrication, there is a growing demand for enhanced filtering performance. This paper presents a near‐infrared single‐wavelength tuneable filter that utilizes polymer‐dispersed liquid crystal combined with a Fabry–Perot resonant cavity. The device achieves a transmittance of 99% at 927 nm with a 24 nm full width at half maximum. Utilizing the electro‐optical tuneable properties of dielectric layer, the transmission wavelength can be tuned from 913 to 969 nm by altering external voltage to it, resulting in a wavelength shift of 56 nm while maintaining high transmittance. This structure provides a reference for the dynamic control of light sensors and near‐infrared dynamic imaging.