Angle insensitive filters based on Fabry–Pérot resonance structures

Filters based on plasmon resonance suffer from low efficiency due to inevitable metal loss. Moreover, their operational limitations, particularly their inability to function effectively at large incident angles, significantly restrict their practical applications. To address these challenges, we propose an all-dielectric filter characterized by relatively small Ohmic loss and remarkably high efficiency, even at wide incident angles. The filter is based on Fabry–Pérot cavity resonance, with narrow bandwidth and high transmittance. The transmittance in the near-infrared band is as high as 99%, and the transmittance in the shortwave band is highly suppressed. This filter offers ease of manufacture coupled with exceptional efficiency. It is expected to gain application prospects in different fields such as liquid crystal displays, optical communications, sensor detection, and imaging.