Femtosecond laser direct writing is a powerful technique for fabricating micro‐nano devices as it can modify the interior of transparent optical materials in a spatially selective manner through nonlinear multi‐photon absorption. In this context, laser‐induced nanogratings, i.e., a sub‐wavelength assembly of nanolayers (≈20 nm in width, ≈200 nm period), are ultrashort self‐organized structures created by light in the bulk of transparent materials. These have been intensively explored over the last two decades opening a novel era of micro photonic devices due to their unique physicochemical properties, like orientable form birefringence, anisotropic light scattering, highly selective chemical etching, optical chirality, and extraordinary thermal stability. This review provides a throughout overview of the advances in this field, specifically focused on the formation of nanogratings, optical properties that can be exploited in various transparent solids, and the related main applications. Also, the fundamental characteristics, formation mechanism, tuning methods of nanogratings are reviewed.

中文翻译：

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超快激光直写纳米光栅及其在透明材料中的工程


飞秒激光直写是一种用于制造微纳米器件的强大技术，因为它可以通过非线性多光子吸收以空间选择性的方式修改透明光学材料的内部。在这种情况下，激光诱导纳米光栅，即纳米层的亚波长组件（宽度约20纳米，周期约200纳米），是由光在大量透明材料中产生的超短自组织结构。由于其独特的物理化学性质，如可定向双折射、各向异性光散射、高选择性化学蚀刻、光学手性和非凡的热稳定性，在过去二十年中人们对其进行了深入的探索，开启了微光子器件的新时代。这篇综述全面概述了该领域的进展，特别关注纳米光栅的形成、可在各种透明固体中利用的光学特性以及相关的主要应用。并对纳米光栅的基本特征、形成机制、调谐方法等进行了综述。