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

Abstract

<jats:title>Abstract</jats:title><jats:p>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<jats:sub>2</jats:sub>-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.</jats:p>

Trilayered Gires–Tournois Resonator with Ultrasensitive Slow-Light Condition for Colorimetric Detection of Bioparticles

“…Highly absorbent photonic structures have recently received much attention due to their potential applications in solar cells [ 20 , 21 , 22 ], electro-optic detectors [ 23 , 24 ], and heat emitters [ 25 , 26 , 27 , 28 ]. In particular, Gires–Tournois (GT) resonators composed of thin films on a reflective metal mirror have been successfully demonstrated to promote ultrahigh absorption and strong light–matter interactions with multibeam interference and a slow-light effect [ 29 , 30 , 31 , 32 , 33 , 34 , 35 ]. This geometry exhibits numerous advantages, such as simple fabrication, facile spectral tuning, omnidirectional strong absorption, and the possibility of active modulation of absorption.…”

“…This geometry exhibits numerous advantages, such as simple fabrication, facile spectral tuning, omnidirectional strong absorption, and the possibility of active modulation of absorption. Based on these promising properties, considerable studies have been conducted to explain optical properties, such as the conditions for the ultrahigh absorption of these systems using impedance or admittance matching analysis or assuming a constant tangential electric or magnetic field [ 33 , 34 , 36 ]. Recently, GT resonators using nonlinear effective phase change have been widely studied as planar metasurfaces, including dynamic phase change absorbers, achromatic surface clocking and lenses, and colored perovskite solar cells [ 32 , 33 , 34 , 35 , 37 ].…”

MoS2-based absorbers with whole visible spectrum coverage and high efficiency

“…Higher efficiencies of optoelectronic components are directly related to the amount of light which is absorbed in them. Photovoltaic cells, photodetectors, and modulators are few examples of these components which are widely used in the field of green energy production and telecommunication 1 – 3 . Apart from the absorption quantity, the absorption bandwidth is also a deterministic parameter in absorbers, especially in photovoltaic applications within the visible range 4 , 5 .…”

Gires–Tournois Immunoassay Platform for Label‐Free Bright‐Field Imaging and Facile Quantification of Bioparticles

“…[28] Previously reported slow-light-based bio-/ single-molecular platforms mainly utilized nanovolume-scale structures for the preparation of slow light, such as nanocavities in the surface-enhanced Raman scattering substrates. [29][30][31] Meanwhile, as a simple structure for effectively controlling light, Gires-Tournois (GT) resonators have been recently studied as flat metasurfaces including dynamic phase-change absorbers, [32] achromatic surface cloaking and lensing, [33] and colored perovskite solar cells. [34] However, despite the recent emphasis on multiscale biointerfaces design, [35] these strong designable modulators have not yet been optimized for bioimaging requiring low-index viral particle detection.…”