Ultra-broadband shielding of cellulose nanofiber commingled biocarbon functional constructs: A paradigm shift towards sustainable terahertz absorbers

Chemical Engineering Journal, Journal Year: 2023, Volume and Issue: 467, P. 143213 - 143213

Published: April 26, 2023

Language: Английский

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Strong and Broadband Pure Optical Activity in 3D Printed THz Chiral Metamaterials

Advanced Optical Materials, Journal Year: 2023, Volume and Issue: 11(18)

Published: May 15, 2023

Abstract Optical activity (polarization rotation of light) is one the most desired features chiral media, as it important for many polarization‐related applications. However, in THz region, media with strong optical are not available nature. Here, a metamaterial (CMM) structure composed pairs vertical U‐shape resonators “twisted” arms studied, and revealed that demonstrates large pure (i.e., associated negligible transmitted wave ellipticity) low regime. The experimental data show polarization up to 25° an unmatched bandwidth 1 (relative 80%), from 130 µm‐thickness structure, while theoretical optimizations can reach 45°. enhanced response analyzed through equivalent RLC circuit model, which also provides simple optimization rules enhancement its response. proposed design allows easy fabrication via direct laser writing (DLW) electroless metal plating, making structures suitable candidates control

Language: Английский

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Multi‐Band Polarization‐Independent Quasi‐Bound States in the Continuum Based on Tetramer‐Based Metasurfaces and Their Potential Application in Terahertz Microfluidic Biosensing

Advanced Optical Materials, Journal Year: 2023, Volume and Issue: 11(20)

Published: June 25, 2023

Abstract Quasi‐bound state in the continuum (quasi‐BIC) has drawn increasing attention terahertz biosensing and filtering owing to an extremely narrow linewidth ultra‐high quality factor. However, it is usually polarization‐sensitive due broken structure or incidence symmetry mainly holds for polarization‐dependent single dual bands, which sets a limitation on practical applications. Here, this article proposes experimentally demonstrates multi‐band polarization‐independent quasi‐BICs tetramer‐based metasurfaces by using laser etching method. Employing tetramer cluster with C4v as structural unit, consists of four L‐type copper particles flexible optically‐transparent substrate, can support dual‐band tri‐band after performing collective perturbation, specific displacement, both constituent particles. Furthermore, are integrated microfluidic channels explore their potential application biosensing. Experimental results indicate that when concentration bovine serum albumin solutions below 4 mg mL −1 , resonance modes biosensor exhibit sensitivity ≈12 GHz each, detection limits reach 0.17 . This work provides general simple strategy construct supporting quasi‐BICs, have promising applications biosensing, filtering, lasing.

Language: Английский

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High-Q factor terahertz metamaterial sensor based on quasi-BIC

Optical Materials Express, Journal Year: 2024, Volume and Issue: 14(6), P. 1509 - 1509

Published: May 6, 2024

In this paper, we proposed a terahertz (THz) metamaterial sensor, which consists of an array with two mirrored double split ring resonators (DSRRs) in one unit cell deposited on lossless polyimide substrate. The THz spectral response show that when the DSRRs are mirror symmetric and center simultaneously, types symmetry-protected bound states continuum (BICs) can be generated incident polarization unchanged. When gaps short or long arms DSRRs, different modes BIC observed. By breaking symmetry structure deviating from line quasi-BICs achieved, provide high Q-factors for our designed sensor. performance sensor is also evaluated, has characteristics Q-factor, sensitivity, linearity. integration quasi-BIC sensing technology will help solve problems faced design ultra-high Q-factor sensors further expand applications technology.

Language: Английский

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Continuously varifocal metalens for broadband achromatic focusing of terahertz waves

Journal of Science Advanced Materials and Devices, Journal Year: 2023, Volume and Issue: 8(3), P. 100560 - 100560

Published: April 11, 2023

The correction of chromatic aberration is essential for promoting broadband imaging systems, which can be accomplished by recently proposed achromatic metalenses (BAMs) in a more compact and efficient way compared to that traditional optical lenses. However, current BAMs are limited the fixed functionality severely hinders their potential applications. In order address such limitation, continuously varifocal metalens (CVBAM) converging THz waves employing thermally tunable material indium antimonide. At initial temperature, numerical results manifest over 1.8–2.2 well corrected CVBAM transverse sizes corresponding focal spots beyond Abbe diffraction limit. Moreover, aperture (NA) average focusing efficiency up 0.62 73.3%, respectively. addition, length has range from 736.25 μm (NA = 0.62) 861.02 0.56) altering operation temperature. This work may offer an advanced scheme designing BAMs, remarkably facilitate development near-field spectroscopy systems.

Language: Английский

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Near-Field Spectroscopy of Individual Asymmetric Split-Ring Terahertz Resonators

ACS Photonics, Journal Year: 2023, Volume and Issue: 10(8), P. 2832 - 2838

Published: Aug. 3, 2023

Metamaterial resonators have become an efficient and versatile platform in the terahertz frequency range, finding applications integrated optical devices, such as active modulators detectors, fundamental research, e.g., ultrastrong light-matter investigations. Despite their growing use, characterization of modes supported by these subwavelength elements has proven to be challenging it still relies on indirect observation collective far-field transmission/reflection properties resonator arrays. Here, we present a broadband time-domain spectroscopic investigation individual metamaterial via THz aperture scanning near-field microscope (a-SNOM). The a-SNOM allows mapping quantitative analysis strongly confined resonators. In particular, cross-polarized configuration presented here weakly radiative modes. These results hold great potential advance future metamaterial-based optoelectronic platforms for research photonics.

Language: Английский

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Tunable transparent terahertz absorber for sensing and radiation warming

Carbon, Journal Year: 2023, Volume and Issue: 214, P. 118376 - 118376

Published: Aug. 18, 2023

Language: Английский

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High-performance terahertz modulators induced by substrate field in Te-based all-2D heterojunctions

Light Science & Applications, Journal Year: 2024, Volume and Issue: 13(1)

Published: March 5, 2024

Abstract High-performance active terahertz modulators as the indispensable core components are of great importance for next generation communication technology. However, they currently suffer from tradeoff between modulation depth and speed. Here, we introduce two-dimensional (2D) tellurium (Te) nanofilms with unique structure a new class optically controlled demonstrate their integrated heterojunctions can successfully improve device performances to optimal applicable levels among existing all-2D broadband modulators. Further photoresponse measurements confirm significant impact stacking order. We first clarify direction substrate-induced electric field through first-principles calculations uncover unusual interaction mechanism in photoexcited carrier dynamics associated charge transfer interlayer exciton recombination. This advances fundamental applicative research Te nanomaterials high-performance optoelectronics.

Language: Английский

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Super perfect polarization-insensitive graphene disk terahertz absorber for breast cancer detection using deep learning

Optics & Laser Technology, Journal Year: 2024, Volume and Issue: 183, P. 112246 - 112246

Published: Dec. 8, 2024

Language: Английский

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Terahertz Metamaterial Optoelectronic Modulators With GHz Reconfiguration Speed

IEEE Transactions on Terahertz Science and Technology, Journal Year: 2022, Volume and Issue: 12(5), P. 520 - 526

Published: May 30, 2022

All-electronicultrafast control of terahertz radiation is demonstrated in integrated metamaterial/graphene devices. By electrostatic gating the graphene conductivity, overall optical response incident $E$ -field modified. Depending on configuration, amplitude, phase, and polarization could be modulated with GHz range reconfiguration speed. An extinction ratio notation="LaTeX">$>$ 7.6 dB amplitude achieved at resonant frequency 0.75 THz. Additionally, a relative phase shift notation="LaTeX">$>\!\!17.4^\circ$ observed around 0.68 When operating as modulator, device has reported an ellipticity change notation="LaTeX">$\sim 40\%$ THz dynamic rotation plane by notation="LaTeX">$>\!\!9^\circ$ resonance. The switching capability modulators been investigated all electronically reporting speed exceeding 3 GHz, only limited available instrumentation. Consequently, GHz-speed modulation can for frequencies These results represent breakthrough applications where fast, versatile, efficient required, such next-generation wireless communication, quantum electronics, ultrafast imaging.

Language: Английский

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