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Combining Switchable Phase‐Change Materials and Phase‐Transition Materials for Thermally Regulated Smart Mid‐Infrared Modulators
Author(s) -
Lyu Xinrui,
Heßler Andreas,
Wang Xiao,
Cao Yunzhen,
Song Lixin,
Ludwig Alfred,
Wuttig Matthias,
Taubner Thomas
Publication year - 2021
Publication title -
advanced optical materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.89
H-Index - 91
ISSN - 2195-1071
DOI - 10.1002/adom.202100417
Subject(s) - materials science , optical switch , optoelectronics , amorphous solid , absorption (acoustics) , reflection (computer programming) , infrared , thermal , layer (electronics) , phase (matter) , phase transition , transmission (telecommunications) , optics , nanotechnology , composite material , telecommunications , computer science , chemistry , physics , organic chemistry , quantum mechanics , meteorology , programming language
Phase‐change materials (PCMs) and phase‐transition materials (PTMs) both show a large contrast in their respective optical properties upon switching, enabling compact optical components with diverse functionalities like sensing, thermal imaging, and data recording. However, their switching properties differ significantly, that is, the switching is non‐volatile for PCMs while volatile for PTMs. Here, new‐generation smart mid‐infrared modulators with switchable transmission, reflection, and absorption are demonstrated conceptually and experimentally, which combine one PCM (Ge 3 Sb 2 Te 6 or In 3 SbTe 2 ) with one PTM (VO 2 ) as two active layers. The bottom VO 2 layer is employed as a thermally regulated (modulated) dynamic mirror, facilitating the switching of transmission between “on” state (using VO 2 in its semiconducting state at temperatures below its phase transition temperature T c ) and “off” state (metallic VO 2 at temperatures above T c ). The PCM layer on top of the metallic VO 2 layer is used either for continuously adjusting the absorption peak spectrally (by up to 1.8 µm using different phases of Ge 3 Sb 2 Te 6 ) or for switching between absorption mode ( A = 0.99 with amorphous In 3 SbTe 2 ) and reflection mode ( R = 0.85 with crystalline In 3 SbTe 2 ). The presented concept of merging static, non‐volatile thermal switching (via PCMs) with dynamic, volatile thermal modulation (via PTMs) empowers a new generation of optical devices for smart optical switching, for example in spectrally tunable safety optical switches.