Near-perfect terahertz wave amplitude modulation enabled by impedance matching in VO2 thin films

Zhu, Huabing; Du, Liang-Hui; Li, Jiang; Shi, Qiwu; Peng, Bo; Li, Zeren; Huang, Wanxia; Zhu, Li-Guo

doi:10.1063/1.5020930

Cited by 57 publications

(30 citation statements)

References 41 publications

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“…The proposed Au NP layer stacks can not only be employed as optical switches as described in this paper but also for developing optical modulators. [30][31][32] In this article, we demonstrate experimentally and theoretically a higher switchability-a higher extinction ratio upon phase transition of VO 2 -than what has been shown earlier in the spectral regions less than or %1000 nm. [19] We have defined the two states of the plasmonic switch corresponding to the low-temperature (LT) state (i.e., at 25 C) and high-temperature (HT) state (i.e., at 90 C) of the VO 2 material.…”

supporting

confidence: 51%

Large‐Area Plasmonic Switches Based on Crystalline Au Nanoparticles Between VO₂ Layers for Enhanced Switching in Visible–Near‐Infrared Regime

Agrawal

Das

Gupta

et al. 2022

Advanced Photonics Research

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Vanadium dioxide (VO 2 ) is a phase change material that undergoes a reversible semiconductor-to-metal transition that can be triggered thermally, electrically, or optically. VO 2 exhibits this sharp first-order phase transition at a temperature of %68 C. [1,2] This phase transformation from monoclinic phase to rutile metallic phase leads to a considerable change in the electrical and optical properties of VO 2 thin films and nanostructures, primarily in the infrared (IR) and near-infrared regime (NIR) spectral range. As this phase transition is reversible, occurs near room temperature, and can occur at ultrafast speeds, [3][4][5][6] several applications of VO 2 films and nanostructures have emerged, such as temperature-dependent sensors, [7] optoelectronics, [2] optical switches, [8,9] and smart windows. [10,11] In recent years, there have been several studies on the plasmonic behavior of VO 2 nanostructures. [9,12,13] The temperaturedependent variation of the refractive index of VO 2 enables thermally induced modulation of plasmon resonance wavelengths in the VO 2 nanostructures. [12] More recently, composite materials consisting of metallic thin films or nanostructures of plasmonically active metals (such as gold and silver) either embedded in or surrounded by VO 2 have gained importance, as greater tunability of the plasmon resonances can be achieved in these composite structures. [14][15][16] Tunable plasmon resonances have been studied in VO 2 -Au nanocomposites, with gold plasmon resonance wavelengths blueshifting with an increase in temperature. [17] Devices with nanoparticles of Au present on top of thin films of VO 2 have also been studied. [18] More recently, a VO 2 /Au/ VO 2 thermochromic structure was studied in which the thermochromic characteristics of the structure were dependent on the gold deposition thickness. [19] Metamaterials based on VO 2 /Au lamellar stacks have also been reported, [20] such that their optical dispersion phase changes upon semiconductor-to-metal transition of the VO 2 layers. A VO 2 /Au/VO 2 sandwich structure was proposed for smart windows such that the color of the windows could be attained by controlling the gold thickness. [21] More recently, several lithography-based techniques have been employed-such as electron beam lithography, [14,15] focused ion beam (FIB) milling, [22] and nanosphere lithography-for the fabrication of the composite materials consisting of plasmonic nanostructures and VO 2 . Modulation of optical transmission in the NIR spectral regime was reported with subwavelength nanohole arrays in a metal-VO 2 double-layer film. [22] Plasmonic switches based on a combination of electron beam lithography (EBL)-fabricated aluminum nanohole arrays and VO 2 have also been reported for use in the C, L, and U optical communication bands. [23] Although precise nanostructures could be fabricated using electron-beam lithography and FIB milling, large-area fabrication of plasmonic switching devices using these methods is time-consuming and expensive. Patterned VO 2 n...

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supporting

confidence: 51%

Large‐Area Plasmonic Switches Based on Crystalline Au Nanoparticles Between VO₂ Layers for Enhanced Switching in Visible–Near‐Infrared Regime

Agrawal

Das

Gupta

et al. 2022

Advanced Photonics Research

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“…This electrical–mechanical behavior for the TPU/Ni conductive polymer composite would be quite suitable for application in dynamic electronic devices. Particularly, due to the sensitivity of the THz wave to the resistivity of the transmission medium, , variation in the resistivity of this conductive polymer composite may be monitored by THz technology. Compared to the previous methods for detecting the dynamic resistivity of a conductive polymer, the THz method is contactless and may provide a more convenient application potential.…”

Section: Resultsmentioning

confidence: 99%

Flexible and Giant Terahertz Modulation Based on Ultra-Strain-Sensitive Conductive Polymer Composites

Shi

Tian

Zhu

et al. 2020

ACS Appl. Mater. Interfaces

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Dynamic tuning of terahertz (THz) wave has a great potential application as smart THz devices, such as switches, modulators, sensors, and so on. However, the realization of flexible THz modulation with high efficiency is rarely observed, which is nearly absent from the booming development and demands on flexible electronics. Here, we report a flexible THz modulation based on conductive polymer composites composed of thermoplastic polyurethane (TPU) and conductive particles (Ni). By designing the additive content of Ni particles, such a flexible layer exhibits resistivity change of 6–7 orders under tensile strain due to the formation of an electron-transport channel provided by the in situ evolution of the Ni network. It could be used to dynamically control the THz transmission with a giant modulation depth of around 96%, at a high strain operation (up to around 58.5%). Moreover, these characteristics are demonstrated to be available for highly tension sensitive THz spectroscopy and imaging. This work opens up a connection between flexible polymer-based composites and THz dynamic devices. It proposes an unprecedented flexible THz modulation with giant tuning efficiency and provides a scheme for contactless and passive tension sensors.

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“…More importantly, the modulation depth of VO 2 film is highly tuneable due to the phase coexistence phenomenon during the IMT. Multistate THz response can be realized in VO 2 film through tuning the strength of external stimuli, promoting its applications in fields such as antireflection coating [ 90 ], impedance matching [ 137 , 138 ] and multistate optical memorizers [ 33 , 35 ].…”

Section: Dynamically Tuneable Thz Devices Based On Vo 2 mentioning

confidence: 99%

Dynamic Manipulation of THz Waves Enabled by Phase-Transition VO2 Thin Film

Lü

Gao

et al. 2021

Nanomaterials

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The reversible and multi-stimuli responsive insulator-metal transition of VO2, which enables dynamic modulation over the terahertz (THz) regime, has attracted plenty of attention for its potential applications in versatile active THz devices. Moreover, the investigation into the growth mechanism of VO2 films has led to improved film processing, more capable modulation and enhanced device compatibility into diverse THz applications. THz devices with VO2 as the key components exhibit remarkable response to external stimuli, which is not only applicable in THz modulators but also in rewritable optical memories by virtue of the intrinsic hysteresis behaviour of VO2. Depending on the predesigned device structure, the insulator-metal transition (IMT) of VO2 component can be controlled through thermal, electrical or optical methods. Recent research has paid special attention to the ultrafast modulation phenomenon observed in the photoinduced IMT, enabled by an intense femtosecond laser (fs laser) which supports “quasi-simultaneous” IMT within 1 ps. This progress report reviews the current state of the field, focusing on the material nature that gives rise to the modulation-allowed IMT for THz applications. An overview is presented of numerous IMT stimuli approaches with special emphasis on the underlying physical mechanisms. Subsequently, active manipulation of THz waves through pure VO2 film and VO2 hybrid metamaterials is surveyed, highlighting that VO2 can provide active modulation for a wide variety of applications. Finally, the common characteristics and future development directions of VO2-based tuneable THz devices are discussed.

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Near-perfect terahertz wave amplitude modulation enabled by impedance matching in VO2 thin films

Cited by 57 publications

References 41 publications

Large‐Area Plasmonic Switches Based on Crystalline Au Nanoparticles Between VO₂ Layers for Enhanced Switching in Visible–Near‐Infrared Regime

Large‐Area Plasmonic Switches Based on Crystalline Au Nanoparticles Between VO₂ Layers for Enhanced Switching in Visible–Near‐Infrared Regime

Flexible and Giant Terahertz Modulation Based on Ultra-Strain-Sensitive Conductive Polymer Composites

Dynamic Manipulation of THz Waves Enabled by Phase-Transition VO2 Thin Film

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Near-perfect terahertz wave amplitude modulation enabled by impedance matching in VO2 thin films

Cited by 57 publications

References 41 publications

Large‐Area Plasmonic Switches Based on Crystalline Au Nanoparticles Between VO2 Layers for Enhanced Switching in Visible–Near‐Infrared Regime

Large‐Area Plasmonic Switches Based on Crystalline Au Nanoparticles Between VO2 Layers for Enhanced Switching in Visible–Near‐Infrared Regime

Flexible and Giant Terahertz Modulation Based on Ultra-Strain-Sensitive Conductive Polymer Composites

Dynamic Manipulation of THz Waves Enabled by Phase-Transition VO2 Thin Film

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Large‐Area Plasmonic Switches Based on Crystalline Au Nanoparticles Between VO₂ Layers for Enhanced Switching in Visible–Near‐Infrared Regime

Large‐Area Plasmonic Switches Based on Crystalline Au Nanoparticles Between VO₂ Layers for Enhanced Switching in Visible–Near‐Infrared Regime