Moorhouse, T. orcid.org/0000-0001-7319-9549 and Raistrick, T. orcid.org/0000-0002-6227-6550 (2024) Sub-Micron Diffractive Optical Elements Facilitated by Intrinsic Deswelling of Auxetic Liquid Crystal Elastomers. Advanced Optical Materials, 12 (24). 2400866. ISSN 2195-1071
Abstract
Diffractive optical elements (DOEs) enable precise control over the direction and filtering of light, making them common components in spectrometers, waveguides, and sensors. There is great interest in tunable and sub-micron diffractive optical elements in flexible photonics and for responsive structural colors. Here this study presents sub-micron tunable diffraction gratings produced by patterning a liquid crystal elastomer (LCE). The intrinsic anisotropic deswelling of the liquid crystal elastomer enables sub-micron (707 nm) pitch structures to be produced from a micron-scale (1040 nm) surface relief grating. Using atomic force microscopy (AFM) and diffraction measurements, a thermal pitch tunability is demonstrated of +212 nm (+31%) or −322 nm (−33%) over a temperature range of 215 °C depending on grating orientation. A mechanical pitch tunability is demonstrate of +1110 nm by applying strains of up to 157% to the liquid crystal elastomer. The height of the diffraction grating is preserved over strain due to the negative Poisson-ratio, or “auxetic”, behavior exhibited by this chosen family of the liquid crystal elastomers. This report opens the possibility of using LCEs to facilitate flexible sub-micron diffractive optical elements, with a high degree of tunability for sensing and structural color applications.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2024 The Author(s). This is an open access article, under the terms of the Creative Commons Attribution License (CC-BY 4.0), which permits unrestricted use, distribution and reproduction in any medium, provided the original work is properly cited. |
Keywords: | anisotropic deswelling, diffractive optical elements, liquid crystal elastomers, sub-micron features |
Dates: |
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Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Engineering & Physical Sciences (Leeds) > School of Physics and Astronomy (Leeds) > Soft Matter Physics (Leeds) |
Depositing User: | Symplectic Publications |
Date Deposited: | 12 Jul 2024 09:14 |
Last Modified: | 21 Oct 2024 14:15 |
Status: | Published |
Publisher: | Wiley |
Identification Number: | 10.1002/adom.202400866 |
Related URLs: | |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:214189 |