Engineered refractive and diffractive optical composites via photo-thermal processes

Abstract

Oxide and non-oxide glass with tailored morphology or microstructure induced by photo-exposure and subsequent heat treatment can result in new materials with unique optical functions. Spatial control of where this local modification occurs can result in optical materials with refractive or diffractive behavior different from those found in homogeneous optical materials. We review the use of such strategies to introduce such unique optical function to commercially developed oxide and prototype chalcogenide glass ceramic media that have yielded a range of performance attributes that make them unique in applications requiring reduced size, weight, power and cost (SWAP-C). We summarize how these materials have been designed and created to yield components that combine multiple functions in a single optical element, resulting in unique performance solutions for a variety of optical systems, highlighting the future potential these materials offer.

Photochemically Engineered Large‐Area Arsenic Sulfide Micro‐Gratings for Hybrid Diffractive–Refractive Infrared Platforms

“…A curved or predefined trajectory of electromagnetic waves passing through a GRIN medium decreases ROE's spectral aberrations. [22][23][24][25] However, practical challenges in manufacturing, such as spatial resolution and complexity of GRIN profiles in a 3D volume of ROEs, limit the extent to which chromatic aberrations can be removed. Micro-gratings as a category of thin DOEs can offer unique opportunities as an alternative to these issues.…”

“…Chalcogenide glasses have been attractive target materials for the DLW process due to their unique sub-ablation laser-matter interactions, which can be utilized to convert them into spatially ordered structures with novel properties. [22][23][24][25][26] Near-bandgap laser exposure of target chalcogenide glasses often induces the excitation of their lone-pair electrons or in some cases defects, which in turn leads to the reorganization of atomic bond structures. [22][23][24][25][26] The resulting material modification has been shown to be composition and form specific (bulk, films, or fibers), and is dictated largely by the type of bonding present in the irradiated material.…”

“…[22][23][24][25][26] Near-bandgap laser exposure of target chalcogenide glasses often induces the excitation of their lone-pair electrons or in some cases defects, which in turn leads to the reorganization of atomic bond structures. [22][23][24][25][26] The resulting material modification has been shown to be composition and form specific (bulk, films, or fibers), and is dictated largely by the type of bonding present in the irradiated material. The types of atomic reorganization observed in a laser-exposed volume of chalcogenide glasses typically include severing and/or cross-linking of bonds over an interatomic length scale and the migration of atoms, which can result in phase separation over a relatively longer length scale.…”

“…The types of atomic reorganization observed in a laser-exposed volume of chalcogenide glasses typically include severing and/or cross-linking of bonds over an interatomic length scale and the migration of atoms, which can result in phase separation over a relatively longer length scale. [22][23][24][25][26] The laser-induced cross-linking, sometimes called polymerization, of atomic bonds in chalcogenide glasses was first reported in pioneering work by Zoubir et al, [26] in which the unique phenomenon was further utilized to create waveguide structures embedded in As 2 S 3 chalcogenide glasses through spatially controlled DLW process. This work was further extended by Schwarz and coworkers who aimed to make metastructures in the form of pillars in As 2 S 3 films.…”

Modeling of laser beam shaping by volume holographic phase masks

“…Thus, it enables a high tolerance to ultrashort laser pulses. This high laser damage threshold allows the use of PTR diffractive elements in optical systems with any type of high-power pulsed lasers.. Due to this wide transparency window, PTR glass is used to produce volume Bragg gratings (VBG) for the visible and near infrared regions 5 .…”