Materials roadmap for inscription of nanogratings inside transparent dielectrics using ultrafast lasers

20 years ago, volume nanogratings were discovered in silica glass upon ultrafast laser irradiation. Since then, these extraordinary self-organised and birefringent structures have been observed in a wide range of transparent materials, including crystals and glasses. In the latter, the role of glass composition and chemistry drastically impact the overall nanostructuring, properties, and morphologies of the fabricated nanogratings, but there still is no global understanding of the origin of various observed discrepancies. Consequently, this work aims to provide a materials roadmap to stimulate the development and selection of glass materials for nanogratings imprinting, depending on the final application, and intends to comprehensively pinpoint the differences existing between glasses. A critical overview of the discovery of nanogratings in multicomponent glasses is presented from 2003 to 2023, and general aspects of the nanogratings formation mechanisms are provided. Then, principal nanograting characteristics are collected, summarized, and discussed (e.g., periodicity, nanopore size) along with useful "technical performances" (e.g., nanogratings energy window, maximum retardance, nanogratings power consumption) that are discussed in the light of chemical composition effects. Finally, a summary of the main optical applications based on nanogratings is given, such as birefringent or geometric phase optics, optical data storage, micro/nanofluidic devices, third harmonic generation and optical fiber sensors.