Absorbing Backside Anti-reflecting Layers for high contrast imaging in fluid cells

TL;DR

This paper investigates absorbing backside anti-reflecting layers for high contrast imaging in fluid cells, providing a generalized solution for their design applicable to various absorption levels.

Contribution

It introduces a generalized approach to designing absorbing anti-reflecting layers for non-absorbing media, extending classical lambda/4 solutions to absorbing materials.

Findings

Derived conditions for optimal absorbing layers based on index and thickness.

Applicable to ultrathin layers with potential for high contrast imaging.

Provides a theoretical framework for designing AR layers with absorption.

Abstract

The single Anti-Reflecting (AR) layer is a classical problem in optics. When all materials are pure dielectrics, the solution is the so-called lambda/4 layer. Here we examine the case of absorbing layers between non absorbing media. We find a solution for any layer absorption coefficient provided that the light goes from the higher towards the lower index medium, which characterizes backside layers. We describe these AR absorbing (ARA) layers through generalized index and thickness conditions. They are most often ultrathin, and have important applications for high contrast imaging in fluid cells.