Abstract-Dual-band ultrasensitive terahertz sensor based on tunable graphene metamaterial absorber

 

Tao Chen, Weijie Jiang, Xianhua Yin, 

https://www.sciencedirect.com/science/article/abs/pii/S0749603621000963

In this paper, we propose a dual-band tunable absorber with a graphene-dielectric-metal structure as a sensor in the terahertz (THz) region. The finite element method (FEM) based on the CST microwave studio software is used in modeling and numerical analysis. Strong interaction between graphene surface plasmon resonance (SPR) and the absorber gives rise to two ultra-narrow perfect absorption peaks, and the position of the resonance frequencies can be adjusted by tuning the chemical potential of graphene in a wide range. In addition, the high symmetry of the absorber brings polarization and angle insensitivity, in which an absorption rate of over 90% can be obtained when the oblique incident angle is close to 80° in the transverse magnetic (TM) mode. For refractive index sensing, the simulation results show that the proposed structure achieves the maximum sensitivity, Q factor, and figure-of-merit (FOM) of 2.475 THz per refractive index unit (THz/RIU), 216.29, and 76.89 RIU−1, respectively. Therefore, we believe that the proposed sensor with such high performance has a promising application for biomedical diagnosis and environmental monitoring.

Abstract-Graphene Based Double Ring Label-Free Terahertz Sensor with High Sensitivity

Fatemeh Ghaedi Vanani, Alireza Fardoost, and Reza Safian

https://www.osapublishing.org/abstract.cfm?uri=ES-2019-ETu3A.3

In our proposed structure, deformation of the normal double waveguide mode into photonic-plasmonic confined super mode by curving the waveguide into a small ring is exploited to increase the sensitivity of the terahertz label-free sensor.

© 2019 The Author(s)

Abstract-Ultrasensitive specific terahertz sensor based on tunable plasmon induced transparency of a graphene micro-ribbon array structure

Pei-ren Tang, Jiang Li, Liang-hui Du, Qiao Liu, Qi-xian Peng, Jian-heng Zhao, Bing Zhu, Ze-ren Li, Li-guo Zhu,

Fig. 1 Conceptual view of the PIT-sensor based on graphene micro-ribbon (GMR). The electromagnetic field is mainly concentrated at the edges of GMR, when excited by a THz wave, leading to the enhanced interaction between THz wave and the analyte. The tunability of the PIT sensor is achieved by changing the bias voltages (V1 and V2) applied on the two sets of GMR arrays.

https://www.osapublishing.org/oe/abstract.cfm?uri=oe-26-23-30655

We proposed an ultrasensitive specific terahertz sensor consisting of two sets of graphene micro-ribbon with different widths. The interference between the plasmon resonances of the wide and narrow graphene micro-ribbons gives rise to the plasmon induced transparency (PIT) effect and enables ultrasensitive sensing in terahertz region. The performances of the PIT sensor have been analyzed in detail considering the thickness and refractive index sensing applications using full wave electromagnetic simulations. Taking advantage of the electrical tunability of graphene’s Fermi level, we demonstrated the specific sensing of benzoic acid with detection limit smaller than 6.35 µg/cm2. The combination of specific identification and enhanced sensitivity of the PIT sensor opens exciting prospects for bio/chemical molecules sensing in the terahertz region.

© 2018 Optical Society of America under the terms of the OSA Open Access Publishing Agreement

Abstract-Ultrasensitive dual-band terahertz sensing with metamaterial perfect absorber

Weihao Zhang,   Feng Lan,  Jinyang Xuan,   Pinanki Mazumder,  Mahdi Aghadjani,  Ziqiang Yang,  Lin Men

https://ieeexplore.ieee.org/document/8247404/

Due to the weak energy storage characteristics of the monolayer metamaterial, how to increase the sub-wavelength scale interaction between biological or chemical samples and terahertz wave on sufficient sensitivity premise becomes the key scientific problems in the study of terahertz sensing technology. In this paper, an ultrasensitive dual-band spectral terahertz sensor with polarization insensitive metamaterial perfect absorber (MPA) is demonstrated. A double-ring shaped metal microstructure integrated with microfluidic channel is applied in the polarization sensitive terahertz sensor. The numerical results show that the normalized sensitivity of refractive index unit 0.638/RIU with mode A and 0.582/RIU with mode B are obtained at 1.04THz and 0.506THz, respectively. The absorptive sensing mechanism is elucidated by the electric field and surface current distributions. Compared to other metamaterials (MMs) based terahertz sensors, the proposed MPA sensor with significantly confined field, enhanced sensitivity and polarization insensitivity is much more suitable for label-free terahertz probing of fluidic matter detection.

Abstract-Experimental demonstration of magnetoplasmon polariton at InSb(InAs)/dielectric interface for terahertz sensor application

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• Jan Chochol, 
• Kamil Postava, 
• Michael Čada & 
• Jaromír Pištora

https://www.nature.com/articles/s41598-017-13394-0

We experimentally demonstrate surface plasmon resonance (SPR) in the terahertz range in InSb and InAs. The surface plasmon is excited on the interface between a thin polymer film and the semiconductor using a silicon prism in Otto configuration. The low effective mass of InSb and InAs permits tuning of the SPR by an external magnetic field in the transversal configuration. The data show a good agreement with a model. Strong excitation of the surface plasmon is present in both materials, with a shifting of resonance position by more than 100 GHz for the field of 0.25 T, to both higher and lower energies with opposite orientation of the magnetic field. Applicability of the terahertz SPR sensor is discussed, along with modeled design for the Kretschmann configuration.

Abstract-Terahertz Sensor Using Photonic Crystal Cavity and Resonant Tunneling Diodes

Kazuma Okamoto, Kazuisao Tsuruda, Sebastian Diebold, Shintaro Hisatake, Masayuki Fujita Tadao,  Nagatsuma

https://link.springer.com/article/10.1007%2Fs10762-017-0391-0

In this paper, we report on a terahertz (THz) sensing system. Compared to previously reported systems, it has increased system sensitivity and reduced size. Both are achieved by using a photonic crystal (PC) cavity as a resonator and compact resonant tunneling diodes (RTDs) as signal source and as detector. The measured quality factor of the PC cavity is higher than 10,000, and its resonant frequency is 318 GHz. To demonstrate the operation of the refractive index sensing system, dielectric tapes of various thicknesses are attached to the PC cavity and the change in the resonator’s refractive index is measured. The figure of merit of refractive index sensing using the developed system is one order higher than that of previous studies, which used metallic metamaterial resonators. The frequency of the RTD-based source can be swept from 316 to 321 GHz by varying the RTD direct current voltage. This effect is used to realize a compact frequency tunable signal source. Measurements using a commercial signal source and detector are carried out to verify the accuracy of the data obtained using RTDs as a signal source and as a detector.