ECM - École Centrale de Marseille : UMR7249 (Pôle de l'étoile - Technopole de Château-Gombert - 38 rue Frédéric Joliot-Curie - 13013 Marseille - France)
Abstract : We experimentally demonstrate a very large dynamic optical reflection modulation from a simple unpatterned layered stack of phase-change materials ultrathin films. Specifically, we theoretically and experimentally demonstrate that properly designed deeply sub-wavelength GeSbTe (GST) films on a metallic mirror produce a dynamic modulation of light in the near-infrared from very strong reflection (R > 80%) to perfect absorption (A > 99, 97%) by simply switching the crystalline state of the phase-change material. While the amplitude of modulation can lead to an optical contrast up to 10 6 , we can also actively "write" intermediate levels of reflection in between extreme values, corresponding to partial crystallization of the GST layer. We further explore several layered system designs and provide guidelines to tailor the wavelength efficiency range, the angle of operation and the degree of crystallization leading to perfect absorption.
https://hal-amu.archives-ouvertes.fr/hal-02996004
Contributor : Julien Lumeau <>
Submitted on : Monday, November 9, 2020 - 2:20:16 PM Last modification on : Saturday, February 13, 2021 - 3:29:04 AM Long-term archiving on: : Wednesday, February 10, 2021 - 7:04:38 PM