Dynamic phase-change metafilm absorber for strong designer modulation of visible light

Nanophotonics

article

Sun-Je Kim¹  Chulsoo Choi¹  Jongwoo Hong¹  Yong Wook Lee²  Byoungho Lee¹  Hansik Yun¹  Sungwook Choi²  Jeong-Geun Yun¹  Kyungsoo Park²  Sun Jae Jeong²  Seung-Yeol Lee³  Yohan Lee¹  Jangwoon Sung¹ 

[1] Inter-University Semiconductor Research Center and School of Electrical and Computer Engineering, Seoul National University;Interdisciplinary Program of Biomedical Mechanical & Electrical Engineering and School of Electrical Engineering, Pukyong National University;School of Electronics Engineering, College of IT Engineering, Kyungpook National University

关键词: coupled mode theory;    effective medium theory;    metafilm;    phase-change material;    vanadium dioxide;    visible light modulation;   

DOI  :  10.1515/nanoph-2020-0264

学科分类：社会科学、人文和艺术（综合）

来源: De Gruyter

【 摘 要 】

Effective dynamic modulation of visible light properties has been significantly desired for advanced imaging and sensing technologies. In particular, phase-change materials have attracted much attention as active material platforms owing to their broadband tunability of optical dielectric functions induced by the temperature-dependent phase-changes. However, their uses for visible light modulators are still limited to meet multi-objective high performance owing to the low material quality factor and active tunability in the visible regime. Here, a design strategy of phase-change metafilm absorber is demonstrated by making the use of the material drawbacks and extending design degree of freedom. By engineering tunability of effective anisotropic permittivity tensor of VO 2 -Ag metafilm around near-unity absorption conditions, strong dynamic modulation of reflection wave is achieved with near-unity modulation depth at desired wavelength regions without sacrificing bandwidth and efficiency. By leveraging effective medium theory of metamaterial and coupled mode theory, the intuitive design rules and theoretical backgrounds are suggested. It is also noteworthy that the dynamic optical applications of intensity modulation, coloring, and polarization rotation are enabled in a single device. By virtue of ultrathin flat configuration of a metafilm absorber, design extensibility of reflection spectrum is also verified. It is envisioned that our simple and powerful strategy would play a robust role in development of miniaturized light modulating pixels and a variety of photonic and optoelectronic applications.

【 授权许可】

CC BY