Title: Broadband Liquid Crystal Tunable Metasurfaces in the Visible: Liquid Crystal Inhomogeneities Across the Metasurface Parameter Space

Abstract

Optical metasurfaces—planar nanostructured devices that can arbitrarily tailor the wavefront of light—may be reconfigured by changing their dielectric environment. The application of external stimuli to liquid crystals is a particularly promising means of tuning the optical properties of embedded metasurfaces because of liquid crystals' large and broadband optical anisotropy. However, the detailed behavior of liquid crystals immediately adjacent to the nanostructured meta-atoms elements is often overlooked, despite the optics of the device depending sensitively on this behavior (e.g., the spectral position of the meta-atom resonances). This is of increasing concern as the wavelength of operation further approaches the short-wavelength end of the visible spectrum and, therefore, the length scale of the inhomogeneities in the liquid crystal director field. In this manuscript, we undertake a fully comprehensive study, across the metasurface geometrical parameter space, of broadband (450-700 nm) all-dielectric liquid crystal tunable metasurfaces operating in the visible. Here, through combined experimental characterization, liquid crystal modeling, and optical simulations, we reveal and quantify the improved accuracy with which the optical properties of the liquid crystal tunable metasurfaces may be described, and identify the underlying physical mechanism: the three-dimensional spatial overlap of the liquid crystal director field and metasurface optical near fields inmore » the vicinity of the meta-atoms.« less

Authors:

Dolan, James A.  ^[1];

• Search DOE PAGES for author "Dolan, James A."
• Search DOE PAGES for ORCID "0000-0001-5019-1544"

Cai, Haogang  ^[2];

• Search DOE PAGES for author "Cai, Haogang"
• Search DOE PAGES for ORCID "0000-0003-1700-2531"

Delalande, Lily ^[3]; Li, Xiao  ^[4];

• Search DOE PAGES for author "Li, Xiao"
• Search DOE PAGES for ORCID "0000-0003-3456-1933"

Martinson, Alex F.  ^[5];

• Search DOE PAGES for author "Martinson, Alex F."
• Search DOE PAGES for ORCID "0000-0003-3916-1672"

de Pablo, Juan J.  ^[1];

• Search DOE PAGES for author "de Pablo, Juan J."
• Search DOE PAGES for ORCID "0000-0002-3526-516X"

López, Daniel ^[6]; Nealey, Paul F.  ^[1]

• Search DOE PAGES for author "Nealey, Paul F."
• Search DOE PAGES for ORCID "0000-0003-3889-142X"

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+ Show Author Affiliations

1. Univ. of Chicago, IL (United States); Argonne National Lab. (ANL), Argonne, IL (United States)
2. New York Univ. (NYU), NY (United States)
3. Univ. of Chicago, IL (United States)
4. Univ. of North Texas, Denton, TX (United States)
5. Argonne National Lab. (ANL), Argonne, IL (United States)
6. Pennsylvania State Univ., University Park, PA (United States)

Publication Date:

Fri Jan 15 00:00:00 EST 2021

Research Org.:

Argonne National Lab. (ANL), Argonne, IL (United States)

Sponsoring Org.:

USDOE Office of Science (SC), Basic Energy Sciences (BES)

OSTI Identifier:

1840554

Grant/Contract Number:  

AC02-06CH11357

Resource Type:

Accepted Manuscript

Journal Name:

ACS Photonics

Additional Journal Information:

Journal Volume: 8; Journal Issue: 2; Journal ID: ISSN 2330-4022

Publisher:

American Chemical Society (ACS)

Country of Publication:

United States

Language:

English

Subject:

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; Huygens' metasurfaces; inhomogeneity; liquid crystals; optical metasurfaces; tunable