Design and simulation of omnidirectional reflective color filters based on metal-dielectric-metal structure

Abstract

We propose omnidirectional reflective color filters based on metal-dielectric-metal subwavelength grating structure. By particle swarm optimization, the structural parameters of three color filters (yellow, magenta, cyan) are obtained. The optimized filters can present the same perceived specular color at unpolarized illumination for a broad range of incident angles. The reflectance curves at different incident angles keep almost invariable and the color difference is less than 6 in CIEDE2000 formula up to 45°. Angle-insensitive properties including the incident angular tolerance, azimuthal angular tolerance and the polarization effect are investigated thoroughly to construct a real omnidirectional color filter. Through the analysis of the magnetic field, the physical origin is verified that the total absorption band at specific wavelength results from the localized surface plasmon resonance responsible for the angle insensitive spectral filtering.

Compact Multilayer Film Structure for Angle Insensitive Color Filtering

“…Color filter, which is a common kind of bandpass filter, displays various colors by selectively transmitting or reflecting a specific wavelength in the visible region. In recent years, color filters have been extensively studied for its wide range of application, e.g., display3456, colorful decoration7, and anti-counterfeiting8910. Generally, color filter can be grouped into two categories in terms of the principle of the color filtering feature: optical color filter and chemical color filter.…”

Free-standing plasmonic metal-dielectric-metal bandpass filter with high transmission efficiency

“…However, most of the single layer plasmonic filters are very sensitive to the incident angle, which is not suitable for the applications that require a large field of view. To overcome the drawbacks of poor angular tolerance, an effective approach is to employ the coupling between two metallic layers to design the filter 18–22 . In addition, almost all reported plasmonic filters are incorporating thick substrate, which not only severely restricts the device’s critical thickness and functionality in the ultra-compact integrated optical systems, but also reduces the device’s performance due to asymmetric coupling occurring between the top and bottom interfaces 23–26 .…”

Angular- and polarization-independent structural colors based on 1D photonic crystals

“…Besides, most of the previously reported studies utilize the one‐dimensional (1D) grating structure that works for only one polarization . Furthermore, the most widely used geometries are metal–dielectric–metal (MDM) designs that involve an optically thick bottom metal layer, thus resulting in a color only from the illumination direction . Unless such bottlenecks are addressed, it is extremely difficult to use these designs as an alternative to the conventional color filters.…”