Electrically driven reprogrammable phase-change metasurface reaching 80% efficiency

Nature Communications, vol. 13, pp. 1696

Abstract

Abstract Phase-change materials (PCMs) offer a compelling platform for active metaoptics, owing to their large index contrast and fast yet stable phase transition attributes. Despite recent advances in phase-change metasurfaces, a fully integrable solution that combines pronounced tuning measures, i.e., efficiency, dynamic range, speed, and power consumption, is still elusive. Here, we demonstrate an in situ electrically driven tunable metasurface by harnessing the full potential of a PCM alloy, Ge 2 Sb 2 Te 5 (GST), to realize non-volatile, reversible, multilevel, fast, and remarkable optical modulation in the near-infrared spectral range. Such a reprogrammable platform presents a record eleven-fold change in the reflectance (absolute reflectance contrast reaching 80%), unprecedented quasi-continuous spectral tuning over 250 nm, and switching speed that can potentially reach a few kHz. Our scalable heterostructure architecture capitalizes on the integration of a robust resistive microheater decoupled from an optically smart metasurface enabling good modal overlap with an ultrathin layer of the largest index contrast PCM to sustain high scattering efficiency even after several reversible phase transitions. We further experimentally demonstrate an electrically reconfigurable phase-change gradient metasurface capable of steering an incident light beam into different diffraction orders. This work represents a critical advance towards the development of fully integrable dynamic metasurfaces and their potential for beamforming applications.

Authors 14

1. Sajjad Abdollahramezani

   Georgia Institute of Technology

   Affiliation as printed

   School of Electrical and Computer Engineering, Georgia Institute of Technology, Atlanta, GA, 30332, USA

2. Omid Hemmatyar

   Georgia Institute of Technology

   Affiliation as printed

   School of Electrical and Computer Engineering, Georgia Institute of Technology, Atlanta, GA, 30332, USA

3. Mohammad Taghinejad

   Georgia Institute of Technology

   Affiliation as printed

   School of Electrical and Computer Engineering, Georgia Institute of Technology, Atlanta, GA, 30332, USA

4. Hossein Taghinejad

   Georgia Institute of Technology

   Affiliation as printed

   School of Electrical and Computer Engineering, Georgia Institute of Technology, Atlanta, GA, 30332, USA

5. Alex Krasnok

   City University of New York · Florida International University · CUNY Advanced Science Research Center

   Affiliation as printed

   Department of Electrical and Computer Engineering, Florida International University, Miami, FL, 33174, USA

   Photonics Initiative, Advanced Science Research Center, City University of New York, New York, NY, 10031, USA

6. Ali Asghar Eftekhar

   Georgia Institute of Technology

   Affiliation as printed

   School of Electrical and Computer Engineering, Georgia Institute of Technology, Atlanta, GA, 30332, USA

7. Christian Teichrib Aachen Physikalisches Institut IA

   RWTH Aachen University

   Affiliation as printed

   Physikalisches Institut IA, RWTH Aachen, 52074, Aachen, Germany

8. Sanchit Deshmukh

   Stanford University

   Affiliation as printed

   Department of Electrical Engineering, Stanford, CA, 94305, USA

9. Mostafa A. El‐Sayed

   Georgia Institute of Technology

   Affiliation as printed

   Laser Dynamics Laboratory, School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, GA, 30332, USA

10. Eric Pop

    Stanford University

    Affiliation as printed

    Department of Electrical Engineering, Stanford, CA, 94305, USA

    Department of Materials Science and Engineering, Stanford University, Stanford, CA, 94305, USA

    Precourt Institute for Energy, Stanford University, Stanford, CA, 94305, USA

11. Matthias Wuttig Aachen Physikalisches Institut IA

    RWTH Aachen University

    Affiliation as printed

    Physikalisches Institut IA, RWTH Aachen, 52074, Aachen, Germany

12. Andrea Alù

    The Graduate Center, CUNY · City University of New York · CUNY Advanced Science Research Center

    Affiliation as printed

    Photonics Initiative, Advanced Science Research Center, City University of New York, New York, NY, 10031, USA

    Physics Program, Graduate Center, City University of New York, New York, NY, 10016, USA

13. Wenshan Cai

    Georgia Institute of Technology

    Affiliation as printed

    School of Electrical and Computer Engineering, Georgia Institute of Technology, Atlanta, GA, 30332, USA

    School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, GA, 30332, USA

14. Ali Adibi corresponding

    Georgia Institute of Technology

    Affiliation as printed

    School of Electrical and Computer Engineering, Georgia Institute of Technology, Atlanta, GA, 30332, USA. ali.adibi@ece.gatech.edu

    School of Electrical and Computer Engineering, Georgia Institute of Technology, Atlanta, GA, 30332, USA