# A Versatile Materials Class for Solution‐Processed Optics and Photonics Based On Titanium Oxide Hydrates and Polyalcohols: A Perspective

## TL;DR

This paper introduces a new class of optical materials made from titanium oxide hydrates and polyalcohols that can be used in various light-based technologies.

## Contribution

The paper presents a novel solution-processable class of optical materials with tunable refractive index and low optical loss.

## Key findings

- The materials can be processed into thin films and photonic structures.
- They offer tunable refractive index and low optical loss through composition and post-deposition treatments.
- They have potential applications in optics, photonics, and quantum devices.

## Abstract

The ability to propagate light within a structure comprising a controlled spatial distribution of the refractive index n prompted the telecommunications revolution of the 20th century. More recently, progress with exploiting the flow of light has led to a broad range of light‐ and heat‐management tools, as well as novel quantum devices. This perspective discusses a new versatile class of optical materials based on molecular hybrids of metal oxide hydrates and commodity polymers, such as poly(vinyl alcohol). These fascinating, easy‐to‐produce materials are examined, and their processing into useful architectures such as photonic crystals is reviewed, with a focus on thin‐film optics. Their potential in other areas is also assessed, for instance, for the fabrication of optical microcavities that allow the formation of exciton‐polaritons, enabling studies on strong light‐matter interactions. Generally, these molecular hybrids open future opportunities in applications like optics, photonics, quantum devices, catalysis, and beyond.

A new, solution‐processable class of optical materials based on molecular hybrids of metal oxide hydrates and commodity polymers is discussed here, including their synthesis, processing into thin films, patterning, and photonic structures realized to date. Due to their low optical loss and tunable refractive index through composition and post‐deposition treatments, this library of materials expands the capabilities to control light.