Tittle: Topology-Optimized Dielectric Metasurface Cavities for Enhanced Valley Polarized Excitonic Light Emission from WSe<sub>2</sub>

POSTER

Abstract

Plasmonic cavities have been extensively studied for their ability to localize optical modes via strong confinement by metallic structures, advancing light-matter interactions such as exciton-photon coupling and Purcell enhancement. However, their performance is limited by non-radiative decay. Dielectric cavities offer a promising alternative with significantly lower losses. Photonic inverse design and topology optimization further enable dielectric cavities with sub-diffraction mode volumes and high quality factors (Q), making them ideal for Purcell enhancement and lifetime shortening. This spatial control over Purcell enhancement is crucial for applications in on-chip quantum photonics, nanolasers, and valleytronics.

We leverage topology-optimized silicon metasurface cavities to enhance photon-exciton coupling in few-layer WSe2, achieving transverse mode sizes of 20-30 nm while minimizing losses. This leads to significant photoluminescence (PL) enhancement and exciton lifetime shortening, consistent with expected Purcell enhancement. Additionally, we observe enhanced valley polarization in WSe2 due to localized modes, opening opportunities for valleytronic devices and quantum computing. Our design allows nanoscale-precision cavity placement, enabling efficient photonic integration with 2D van der Waals materials like WSe2 for potential applications.

*This work was supported by the Office of Naval Research (ONR) (Grant No. 13001182), and the U.S. Department of Energy (DOE), Office of Science through the Quantum Science Center (QSC), a National Quantum Information Science Research Center.

Presenters

  • Vahagn Mkhitaryan

    • Elmore Family School of Electrical and Computer Engineering, Birck Nanotechnology Center,Purdue University
    • Elmore Family School of Electrical and Computer Engineering, Purdue Quantum Science and Engineering Institute, Birck Nanotechnology Center, Purdue University

Authors

  • Vahagn Mkhitaryan

    • Elmore Family School of Electrical and Computer Engineering, Birck Nanotechnology Center,Purdue University
    • Elmore Family School of Electrical and Computer Engineering, Purdue Quantum Science and Engineering Institute, Birck Nanotechnology Center, Purdue University

  • Owen Matthiessen

    • Elmore Family School of Electrical and Computer Engineering, Birck Nanotechnology Center,Purdue University
    • Purdue University

  • Davide Cassara

    • Harvard John A. Paulson School of Engineering and Applied Sciences

  • Brandon Triplett

    • Elmore Family School of Electrical and Computer Engineering,Birck Nanotechnology Center,Purdue University

  • Ömer Yesilyurt

    • Elmore Family School of Electrical and Computer Engineering,Birck Nanotechnology Center, Purdue University

  • Karthik Pagadala

    • Purdue University
    • Elmore Family School of Electrical and Computer Engineering,Birck Nanotechnology Center, Purdue University

  • Colton Fruhling

    • Elmore Family School of Electrical and Computer Engineering,Birck Nanotechnology Center, Purdue University
    • Purdue University

  • Vladimir M Shalaev

    • Purdue University
    • Elmore Family School of Electrical and Computer Engineering,Birck Nanotechnology Center, Purdue University
    • Elmore Family School of Electrical and Computer Engineering, Purdue Quantum Science and Engineering Institute,Birck Nanotechnology Center, Purdue University

  • Federico Capasso

    • Harvard John A. Paulson School of Engineering and Applied Sciences, Harvard University
    • Harvard University

  • Alexandra Boltasseva

    • Purdue University
    • Elmore Family School of Electrical and Computer Engineering,Birck Nanotechnology Center, Purdue University
    • Elmore Family School of Electrical and Computer Engineering, Purdue Quantum Science and Engineering Institute,Birck Nanotechnology Center, Purdue University