Electrically driven reprogrammable phase-change metasurface reaching 80% efficiency

Sajjad Abdollahramezani; Omid Hemmatyar; Mohammad Taghinejad; Hossein Taghinejad; Alex Krasnok; Ali A Eftekhar; Christian Teichrib; Sanchit Deshmukh; Mostafa A El-Sayed; Eric Pop; Matthias Wuttig; Andrea Alù; Wenshan Cai; Ali Adibi

doi:10.1038/s41467-022-29374-6

Electrically driven reprogrammable phase-change metasurface reaching 80% efficiency

Nat Commun. 2022 Mar 30;13(1):1696. doi: 10.1038/s41467-022-29374-6.

Authors

Sajjad Abdollahramezani¹, Omid Hemmatyar¹, Mohammad Taghinejad¹, Hossein Taghinejad¹, Alex Krasnok^{2

3}, Ali A Eftekhar¹, Christian Teichrib⁴, Sanchit Deshmukh⁵, Mostafa A El-Sayed⁶, Eric Pop^{5

7

8}, Matthias Wuttig⁴, Andrea Alù^{2

9}, Wenshan Cai^{1

10}, Ali Adibi¹¹

Affiliations

¹ School of Electrical and Computer Engineering, Georgia Institute of Technology, Atlanta, GA, 30332, USA.
² Photonics Initiative, Advanced Science Research Center, City University of New York, New York, NY, 10031, USA.
³ Department of Electrical and Computer Engineering, Florida International University, Miami, FL, 33174, USA.
⁴ Physikalisches Institut IA, RWTH Aachen, 52074, Aachen, Germany.
⁵ Department of Electrical Engineering, Stanford, CA, 94305, USA.
⁶ Laser Dynamics Laboratory, School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, GA, 30332, USA.
⁷ Department of Materials Science and Engineering, Stanford University, Stanford, CA, 94305, USA.
⁸ Precourt Institute for Energy, Stanford University, Stanford, CA, 94305, USA.
⁹ Physics Program, Graduate Center, City University of New York, New York, NY, 10016, USA.
¹⁰ School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, GA, 30332, USA.
¹¹ School of Electrical and Computer Engineering, Georgia Institute of Technology, Atlanta, GA, 30332, USA. ali.adibi@ece.gatech.edu.

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, Ge₂Sb₂Te₅ (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.

Abstract

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