Photo-thermo-refractive glass: a promising photonics material [Review]

Subject of study. Photo-thermo-refractive (PTR) glass is a multifunctional material in high demand today in the photonics market, which has great potential as a holographic, luminescent, ion-exchange, and laser medium. It is promising for creating high-performance elements and devices of a new generation of photonics. Objective. This study attempts to generalize and demonstrate, through a review, the wide possibilities of PTR glasses for photonics problems, including recording volume holographic optical elements. Methodology. The review includes an analysis of Russian and foreign literary sources (original and review articles, conference proceedings, patents, monographs, and dissertations). Main results. The review includes a historical note on the creation of PTR glasses, a mechanism for changing the refractive index during photo-thermally induced crystallization of PTR glass used to record phase holograms. The review considers the properties of PTR glasses and holograms based on them, including their advantages and disadvantages, as well as technologies for modifying PTR glasses. The review contains several graphic materials illustrating the covered topics. Practical value. Examples of the use of holographic optical elements based on PTR glass in Russia and abroad are given. The prospects for using holographic optical elements based on PTR glasses to create a new generation of laser technology are shown.