Abstract

A novel photothermal process to spatially modulate the concentration of sub-wavelength, high-index nanocrystals in a multicomponent Ge-As-Pb-Se chalcogenide glass thin film resulting in an optically functional infrared grating is demonstrated. The process results in the formation of an optical nanocomposite possessing ultralow dispersion over unprecedented bandwidth. The spatially tailored index and dispersion modification enables creation of arbitrary refractive index gradients. Sub-bandgap laser exposure generates a Pb-rich amorphous phase transforming on heat treatment to high-index crystal phases. Spatially varying nanocrystal density is controlled by laser dose and is correlated to index change, yielding local index modification to ≈+0.1 in the mid-infrared.

Department(s)

Materials Science and Engineering

Publication Status

Full Access

Comments

U.S. Department of Defense, Grant FA8650-12-C-7225

Keywords and Phrases

achromatic microlenses; chalcogenide glass; gradient refractive index; optical nanocomposites; photothermal process

International Standard Serial Number (ISSN)

1521-4095; 0935-9648

Document Type

Article - Journal

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 2023 Wiley, All rights reserved.

Publication Date

26 Sep 2018

PubMed ID

30101495

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