# Polarization-sensitive diffractive optics and metasurfaces: “Past is Prologue”

## TL;DR

This paper reviews how modern metasurfaces offer new polarization control compared to older diffractive optics.

## Contribution

Clarifies functional differences between modern metasurfaces and past diffractive optics in polarization control.

## Key findings

- Metasurfaces enable more advanced polarization control than traditional diffractive optics.
- The paper distinguishes new capabilities from those previously available in diffractive technologies.

## Abstract

Polarization control and switchability are among the most unique features of “metasurfaces” as compared with diffractive optics technologies of the past. Here, we review how the polarization control afforded by the advent of present-day metasurfaces compares to diffractive elements of previous decades, clarifying from a functional perspective what is new, and what is not.