Light-Science & Applications
·
2025
·Vol. 14
·期 1
·1-9
·
IF 23.4
Yang Jiaxing,Zhang Liyu,Wang Kai,Zhang Chen,Fan Aoyu,He Zijian,Li Zhidi,Han Xiaobo,Ling Furi,Lu Peixiang
The strong coupling between photons and phonons in polar materials gives rise to phonon-polaritons that encapsulate a wealth of physical information, offering crucial tools for the ultrafast terahertz sources and the topological engineering of terahertz light. However, it is still quite challenging to form and manipulate the terahertz phonon-polaritons under the ultrastrong coupling regime till now. In this work, we demonstrate the ultrastrong coupling between the phonon (at 0.95 THz) in a MAPbI 3 film and the metallic bound states in the continuum (BICs) in Au metasurfaces. The Rabi splitting can be continuously tuned from 28% to 48.4% of the phonon frequency by adjusting the parameters (size, shape and period) of Au metasurfaces, reaching the ultrastrong coupling regime. By introducing wavelet transform, the mode evolution information of the terahertz phonon-polariton is successfully extracted. It indicates that the phonon radiation intensity of the MAPbI 3 film is enhanced as the coupling strength is increased. This work not only establishes a new platform for terahertz devices but also opens new avenues for exploring the intricate dynamics of terahertz phonon-polaritons.
研究领域:
光学工程
·
凝聚态物理
·
太赫兹科学与技术
·
纳米光子学
·
材料物理
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Materials Today Physics
·
2022
·
IF 11.021
Inhee Maeng,Shi Chen,Seungjun Lee,Shenghao Wang,Young-Kyun Kwon,Min-Cherl Jung
The realization of terahertz (THz) detectors using organic-inorganic hybrid perovskite (OHP) materials presents a challenge because of the high real conductivities and broad THz absorption spectra required. The control of phonon vibration modes in OHPs depends on the control of defect states such as the defect-incorporated perovskite structure and the δ/α -mixed interfacial structure observed in MAPbI 3 and δ/α -mixed FAPbI 3 , respectively. Difficulties with defect control in particular materials may amplify relative risk factors and invite strong resistance to commercialization. As an alternative to OHPs, the all-inorganic perovskite material CsPbI 3 (lacking the hydrophobic organic cations that generate structural defects) constitutes a good candidate for THz detectors. We investigated the phonon vibration modes of thin films of the all-inorganic perovskite γ -CsPbI 3 containing no atomic or chemical defect states. We observed the three expected major phonon vibration modes at 0.9, 1.5, and 1.8 THz that originate from the transverse I–Pb–I frame, the Cs–I–Cs optical vibration, and the longitudinal I–Pb–I frame, respectively, finding good agreement with theoretical simulations. Significantly, the real conductivity of these all-inorganic perovskite thin films ranged from approximately 10–40 S/cm across a broad frequency range of 0.5–3.0 THz, demonstrating the material's considerable potential for application as a THz-band detector.
研究领域:
材料科学
·
光子学
·
半导体物理
✓ 已验证
产品关联
DOI
高影响因子
Plant Phenomics
·
2022
·
IF 6.961
Yongni Shao,Di Zhu,Yutian Wang,Zhi Zhu,Wenchao Tang,Zhengan Tian,Yan Peng,Yiming Zhu
Moxa wool is a traditional Chinese herbal medicine, which can warm channels to dispel coldness. At present, there is no unified index to evaluate the purity and growing years of moxa wool in the market. Terpineol is one of the effective substances in the volatile oil of moxa wool. Here, we characterize the purity and growing years of moxa wool by studying terpineol. Gas chromatography-mass spectrometry (GC-MS) and high-performance liquid chromatography (HPLC) are the methods for monitoring terpineol at present, all of which have defects of complicated procedures. We established linear fitting to distinguish the different purities of moxa wool through the intensities (areas) of terpineol, the characteristic peaks, and the consequence presented; the coefficient of determination (R2) was higher than 0.90. Furthermore, based on the characteristic peak position of standard terpineol, the correlation model with the purity and growing year of moxa wool was set up, thereby differentiating the quality of moxa wool. We have built the partial least squares (PLS) model of the growing years of moxa wool with high accuracy, and the determination coefficient is greater than 0.98. In addition, we compare the quantitative accuracy of Raman spectroscopy with terahertz technology. Finally, a new method of terahertz spectroscopy to evaluate quality of moxa wool was found. It provides a new idea for the identification of inferior moxa wool in the market and a new method for identifying the quality of moxa wool in traditional Chinese medicine.
研究领域:
中药学
·
光谱分析
·
生物医学工程
✓ 已验证
DOI
高影响因子
ANNALEN DER PHYSIK
·
2021
·Vol. 533
·期 2
·2000464
·
IF 2.987
Xinxi Zeng,Han Zhang,Xiaoqing Xi,Bo Li,Ji Zhou
The terahertz (THz) spectral range offers a platform for experimentally collecting electromagnetic pulses to analyze the intrinsic resonances of matter and has become an important field for applying intrinsic responses to future information devices. However, a lack of numerical methods for signal denoising exists in the knowledge of the THz spectral range. In this paper, numerical methods that employ the Bézier curve and its generalization ( B -spline) to denoise thermally tunable and thickness-dependent terahertz signals are proposed. Different thicknesses of ErFeO 3 are chosen and prepared. Both Bézier curves and B -splines have the ability to denoise the signals and the effect of the Bézier curves on the noise is close to but slightly less than that of the B -splines. Additionally, the B -splines show a better noise reduction effect and have better signal strength stability and robustness than do the Bézier curves. Thus, B -splines are applied to process the raw data, and quantitative insight into the trend of the resonant frequencies, peak heights, and transmittances of antiferromagnetic resonance and ferromagnetic resonance with temperature is obtained.
研究领域:
物理学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
Polymers
·
2021
·Vol. 13
·期 23
·4250
·
IF 4.329
Hongchuan Dong,Yunfan Liu,Yanming Cao,Juzhen Wu,Sida Zhang,Xinlong Zhang,Li Cheng
Moisture is detrimental to the performance of epoxy resin material for electrical equipment in long-term operation and insulation. Therefore, moisture absorption is one of the critical indicators for insulation of the material. However, some relevant test methods, e.g., the direct weighing method, are time-consuming, and it usually takes months to complete a test. For this, it is necessary to have some modification to save the test time. Firstly, the study analyzes the present prediction method (according to ISO 62:2008). Under the same accuracy, the time required is reduced from 104 days to 71 days. Subsequently, the Langmuir curve-fitting method for water absorption of epoxy resin is analyzed, and the initial values of diffusion coefficient, bonding coefficient, and de-bonding coefficient are determined based on the results of molecular simulation, relevant experiment, and literature review. With the optimized prediction model, it takes only 1.5 days (reduced by 98% as compared with the standard prediction method) to determine the moisture absorbability. Then, the factors influencing the prediction accuracy are discussed. The results have shown that the fluctuation of balance at the initial stage will affect the test precision significantly. Accordingly, this study proposes a quantitative characterization method for initial trace moisture based on the terahertz method, by which the trace moisture in epoxy resin is represented precisely through the established terahertz time-domain spectroscopy system. When this method is used to predict the moisture absorbability, the experimental time may be further shortened by 33% to 1 day. For the whole water absorption cycle curve, the error is less than 5%.Keywords:epoxy resins;Langmuir;terahertz;molecular simulation;prediction
研究领域:
材料科学
·
电气工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Optical Materials Express
·
2020
·Vol. 11
·期 1
·171-179
·
IF 3.064
Shi-Tong Xu,Shi-Tong Xu,Fei Fan,Shu Chen,Yanzhao Xing,Yuebo Gao,Huixin Li,Guangcheng Niu,Sheng-Jiang Chang,Sheng-Jiang Chang,Sheng-Jiang Chang
In this work, a new strategy was proposed for active control of mm-thick liquid crystals (LC) cell to realize the polarization manipulation in terahertz (THz) regime, which through the electric field control and static magnetic field pre-anchoring. The LC cell was fabricated by a nematic 5CB LC and two silica substrates that were coated with the graphite layer as the transparent electrode. Under the pre-anchoring of the static magnetic field, the optical axis of LC can be precisely controlled by the variable electric field. By using a THz-TDS with a wire grid polarizer, the output THz polarization from the LC cell can be deduced from the amplitude and phase shift of ±45° components. Here, we systematically analyzed three different outfield configurations. Only if the ±45° components that output from the polarizer have phase shifts, can the polarization state conversion be realized. The results show that the linear to circular or the cross-polarization conversion were realized under the specific electric field. This work provides a new approach for the thick-LC layer anchoring and orientation control, and also the tunable polarization manipulation of THz LC devices.
研究领域:
光学
·
材料科学
✓ 已验证
DOI
高影响因子
SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
·
2024
·
IF 4.3
Yuyue Yan,Liyuan Liu,Guanhua Ren,Xueqian Zhang,Chunmei Ouyang,Hongwei Zhao,Jiaguang Han
The co-solvent system of tert -butanol and water is commonly employed in the field of freeze-drying pharmaceuticals. Investigating the phase composition and behavior of this system at low temperatures contributes to furthering its applications. In this study, THz-TDS was used to investigate the melting process of the frozen tert -butanol-water binary system for the first time. Utilizing the THz fingerprint peaks, we discovered that following the initial freezing, the system only formed metastable dihydrate tert -butanol, but near the melting point, it transformed into stable heptahydrate tert -butanol. This transition did not occur at high tert -butanol contents. Combining DFT calculations, all observed absorption peaks were attributed to the low-frequency vibration modes of each crystal. A phase diagram of the tert -butanol-water binary system was constructed based on the difference in absorbance intensity between the solid and liquid phases. The results demonstrate the potential of THz spectroscopy for applications in pharmaceutical freeze-drying.
研究领域:
药学
·
物理化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
OPTICS EXPRESS
·
2025
·Vol. 33
·期 6
·13895-13906
·
IF 3.3
Xiaoxiao Chen,Xueguang Lu,Lu Tang,Kefan Chen,Wanxia Huang
Despite striking advances in terahertz (THz) sources and detectors, the exploitation of active materials that can alter their properties in response to external excitations for the manipulation of THz waves is another major issue. Here, freestanding and easily scalable composite film based on vanadium dioxide/carboxymethyl cellulose (VO2/CMC) is proposed to realize thermally and optically tunable THz waves. This VO2/CMC composite film exhibits broadband modulation with a modulation depth of up to 76%, a response time of about 1.2 s and high stability both in mechanical deformation and in air. Based on the above VO2/CMC composite film, a THz metamaterial with absorption-reflection switchability is demonstrated. By controlling the temperature-dependent phase transition of VO2 particles, the reflection dip of the metamaterial at 0.423 THz with an amplitude of -25 dB first shifts to lower frequencies accompanied by an increase in amplitude, and finally disappears with the THz metamaterial reflecting THz waves almost completely. The experimental results agree well with numerical simulations and the modulation mechanism of the metamaterial is also investigated. This work provides a simple and low-cost method for developing VO2-based THz multifunctional smart devices with promising applications in areas such as but not limited to THz modulators and sensors.
研究领域:
材料科学
·
光学工程
·
太赫兹技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
OPTICS LETTERS
·
2019
·Vol. 44
·期 10
·2450-2453
·
IF 3.866
Shi-Tong Xu,Fei Fan,Yun-Yun Ji,Jie-Rong Cheng,Sheng-Jiang Chang
We experimentally demonstrate an active terahertz (THz) resonance switch induced by the polarization conversion in a compound metasurface, which is a LC layer sandwiched by a metallic wire grating and resonance metamaterial (LCGM). Here, the liquid crystal (LC) plays the role of polarization conversion, which can induce the TE resonance. Moreover, there exists a localized resonance between metallic grating and metamaterial layers, and then the excited resonance will be greatly enhanced. The results show that the high extinction ratio of the resonance switch exceeds 30 dB at 0.82 THz. This work will bring new ideas for the research in developing THz phase, polarization, and switch devices with LC and metasurface.
研究领域:
光学
·
材料科学
✓ 已验证
DOI
PubMed
高影响因子
OPTICS EXPRESS
·
2021
·Vol. 29
·期 10
·14894-14904
·
IF 3.894
Guanhua Ren,Guanhua Ren,Guanhua Ren,Guanhua Ren,Lu Zhou,Lu Zhou,Ligang Chen,Ligang Chen,Ligang Chen,Liyuan Liu,Liyuan Liu,Jianbing Zhang,Jianbing Zhang,Hongwei Zhao,Hongwei Zhao,Hongwei Zhao,Jiaguang Han,Jiaguang Han
Terahertz spectroscopy provides a powerful and informative link between infrared spectroscopy and microwave spectroscopy, and is now beginning to make its transition from initial development to broader use by chemists, materials scientists and biologists. In this study, utilizing terahertz spectroscopy we monitored the crystallization and isomerization of azobenzene. In flash-frozen trans-azobenzene solutions, the processes of crystallization and phase transition were observed. A new phase has been experimentally confirmed to exist stably at low temperatures. The results on gradual-frozen experiment indicate that the formation of the observed new phase is determined by the cooling rate. Besides, based on the distinctive spectral features of the isomers, the thermal- and photo-induced isomerization processes of azobenzene were investigated. This work presents that the terahertz spectroscopy has a great potential to study the phase transitions and crystallization of liquid samples under different freezing conditions.
研究领域:
化学
·
材料科学
·
光谱学
✓ 已验证
DOI
高影响因子
JOURNAL OF CHEMICAL PHYSICS
·
2024
·Vol. 160
·期 19
·
IF 3.1
Yan Yuyue,Chen Ligang,Zhang Jiaqi,Ren Guanhua,Zhou Lu,Liu Liyuan,Zhang Xueqian,Ouyang Chunmei,Wang Huabin,Han Jiaguang
Ion hydration plays a crucial role in numerous fundamental processes. Various spectroscopic methods are employed to investigate the slowing down of hydration bond dynamics in the proximity of both anions and cations. To date, most of these studies have primarily focused on the properties of binary systems. However, in comparison to ion–water binary systems, ternary systems that involve ions, water, and organic matter are more prevalent in nature and provide more realistic insights into biological processes. This study focuses on ion hydration in water and alcohol mixture using terahertz spectroscopy and x-ray diffraction (XRD). The results reveal a distinct behavior depending on the type of alcohol used. Specifically, the presence of both methanol and ethanol results in the disappearance of absorption peaks associated with NaCl hydrate at low temperatures. In contrast, tert-butanol does not exhibit such an effect, and isopropanol demonstrates a more complex response. By combining these terahertz spectroscopic findings with low-temperature XRD data, we gain insights into the formation, or lack thereof, of NaCl · 2H 2 O hydrate crystals. Crucially, our observations suggest a dominant correlation between the polarity of the alcohol molecules and its impact on the Na + hydration. Strongly polar alcohols preferentially solvating the Na + ion lead to the failure of hydrate formation, while weakly polar alcohols do not have this effect.
研究领域:
化学
·
物理学
·
生物物理学
✓ 已验证
DOI
PubMed
高影响因子
INTERNATIONAL JOURNAL OF PHARMACEUTICS
·
2022
·
IF 6.51
Pengfei Wang,Juntong Zhao,Yuman Zhang,Zhongjie Zhu,Liyuan Liu,Hongwei Zhao,Xianchao Yang,Xiaonan Yang,Xiaohong Sun,Mingxia He
Cocrystal is constructed to improve physicochemical properties of active pharmaceutical ingredient and prevent polymorphism via intermolecular interactions. However, recent examples on cocrystal polymorphs display significantly different properties. Even though some analytical techniques have been used to characterize the cocrystal polymorphic system, it remains unclear how intermolecular interactions drive and stabilize the structure. In this work, we study the cocrystal polymorphs of nifedipine (NFD) and isonicotinamide (INA) using terahertz (THz) spectroscopy. Form I and form II of NFD-INA cocrystals show spectral fingerprints in THz region. Temperature-dependent THz spectra display distinguished frequency shifts of each fingerprint. Combined with solid-state density functional theory (DFT) calculations, the experimental fingerprints and their distinct responses to temperature are elucidated by specific collective vibrational modes. The vibrations of hydrogen bonding between dihydropyridine ring of NFD and INA are generally distributed below 1.5 THz, which play important roles in stabilizing cocrystal and preventing the oxidation of NFD. The rotations of methyl group in NFD are widely distributed in the range of 1.5–4.0 THz, which helps the steric recognition. The results demonstrate that THz spectroscopy is a sensitive tool to discriminate cocrystal polymorphs. It has the potential to be used as a non-invasive technique for pharmaceutical screening.
研究领域:
药物化学
·
物理化学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）