Understanding all-dielectric periodically modulated coatings for normal-incidence polarization control

TL;DR

This paper presents an analytical, numerical, and experimental study of an all-dielectric ultracompact polarizer using Fano resonances in nanostructured thin films, achieving high polarization contrast and damage resistance.

Contribution

It introduces a novel all-dielectric thin-film polarizer based on Fano resonances with demonstrated high contrast and durability at normal incidence.

Findings

Achieved polarization contrast ratios of up to 1:1000.

Confirmed high damage resistance with nanosecond laser pulses.

Validated device performance through experimental measurements.

Abstract

An ultracompact thin-film polarizer for normal-incidence (0{\deg} angle of incidence, AOI) applications is analytically and experimentally investigated. The device is based on Fano resonances in periodically nanostructured dielectric thin films, enabling polarization selective reflection and transmission due to polarization dependent resonance frequencies. The operating principle is analyzed both analytically and numerically, and the optimized structure is fabricated and experimentally characterized. Measurements demonstrate polarization contrast ratios of up to approximately 1:1000 at normal incidence. Laser-induced damage threshold measurements using nanosecond laser pulses further confirm the high damage resistance of the all-dielectric polarizer.