High Sensitivity Quadrupole Fano Resonances Using Terahertz Metamaterials with Its Application as Biosensor

Abstract We report numerically electromagnetic-induced transparency (EIT) and Fano resonances in simple plasmonic metasurfaces consist of gold nanobars arranged in Pi, H and four shaped fashion. The bright and dark elements in the metasurfaces are responsible for the emergence of EIT and Fano effects in the transmission spectrum. The concept of symmetry breaking is also introduced by incorporating multiple cavities in the metasurface, which relaxes the dipole coupling selection rules resulting in a mixture of dipole and higher order modes that interact and engenders EIT and Fano modes simultaneously in a nanostructure. Furthermore, the EIT and Fano resonances experience a significant red-shift by increasing the refractive index of the background medium due to which high sensitivity of around 574 nmRIU -1 , figure of merit of 32, and contrast ratio of 41% are realized. Moreover, the effective group index of the proposed metasurface is retrieved and is observed to be very high around the steep asymmetric Fano line shape and within the EIT window, signifying its potential use in slow light applications.

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Tunable Fano resonances in a robust quasicylindrical microresonator photonic system

MATEC Web of Conferences ◽

10.1051/matecconf/201818911009 ◽

2018 ◽

Vol 189 ◽

pp. 11009

Author(s):

Xueying Jin ◽

Mengyu Wang ◽

Yongchao Dong ◽

Liming Chen ◽

Fei Li ◽

...

Keyword(s):

Optical Switching ◽

Electromagnetically Induced Transparency ◽

High Sensitivity ◽

Selective Excitation ◽

Fano Resonances ◽

All Optical ◽

Induced Transparency ◽

First Time ◽

And Storage ◽

All Optical Switching

The control of Fano resonances is of critical importance to opto-electronic and all-optical switching devices, light delay and storage, high sensitivity sensors, and quantum information processors. In this paper, we experimentally and theoretically demonstrate that controllable electromagnetically induced transparency (EIT)-like and Fano resonances can be achieved in a single quasi-cylindrical microresonator (QCMR). Robust and selective excitation of localized axial modes in a high quality QCMR is firstly demonstrated. Based on this stable platform, EIT-like lineshapes can be tuned and converted into Fano resonances by vertically moving the resonator. Moreover, by horizontally scanning the resonator, the transmission spectrum exhibits periodically changed Fano-like lineshapes. It is reported for the first time that the above two kinds of Fano resonances originated from different mechanisms can work on the same mode simultaneously. Our approach, demonstrated in this work, provides a robust photonic platform for accessing, controlling, and engineering the Fano resonances.

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Independently Formed Multiple Fano Resonances for Ultra-High Sensitivity Plasmonic Nanosensor

Plasmonics ◽

10.1007/s11468-016-0489-6 ◽

2016 ◽

Vol 13 (1) ◽

pp. 107-113 ◽

Cited By ~ 12

Author(s):

Yilin Wang ◽

Shilei Li ◽

Yunyun Zhang ◽

Li Yu

Keyword(s):

High Sensitivity ◽

Fano Resonances ◽

Plasmonic Nanosensor

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Performance of terahertz metamaterials as high-sensitivity sensor

Modern Physics Letters B ◽

10.1142/s0217984917502402 ◽

2017 ◽

Vol 31 (26) ◽

pp. 1750240 ◽

Cited By ~ 2

Author(s):

Yanan He ◽

Bo Zhang ◽

Jingling Shen

Keyword(s):

Resonant Frequency ◽

Surrounding Medium ◽

High Sensitivity ◽

Substrate Thickness ◽

Transmission Characteristics ◽

Metamaterial Structure ◽

Resonant Transmission ◽

Simulation And Experiment ◽

Sensing Characteristics ◽

Terahertz Metamaterials

A high-sensitivity sensor based on the resonant transmission characteristics of terahertz (THz) metamaterials was investigated, with the proposal and fabrication of rectangular bar arrays of THz metamaterials exhibiting a period of 180 [Formula: see text] on a 25 [Formula: see text] thick flexible polyimide. Varying the size of the metamaterial structure revealed that the length of the rectangular unit modulated the resonant frequency, which was verified by both experiment and simulation. The sensing characteristics upon varying the surrounding media in the sample were tested by simulation and experiment. Changing the surrounding medium from that of air to that of alcohol or oil produced resonant frequency redshifts of 80 GHz or 150 GHz, respectively, which indicates that the sensor possessed a high sensitivity of 667 GHz per unit of refractive index. Finally, the influence of the sample substrate thickness on the sensor sensitivity was investigated by simulation. It may be a reference for future sensor design.

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A Plasmonic Chip-Scale Refractive Index Sensor Design Based on Multiple Fano Resonances

Sensors ◽

10.3390/s18103181 ◽

2018 ◽

Vol 18 (10) ◽

pp. 3181 ◽

Cited By ~ 16

Author(s):

Kunhua Wen ◽

Li Chen ◽

Jinyun Zhou ◽

Liang Lei ◽

Yihong Fang

Keyword(s):

Refractive Index ◽

Fdtd Method ◽

High Sensitivity ◽

Refractive Index Sensor ◽

Fano Resonances ◽

Metal Insulator Metal ◽

High Figure ◽

On Chip ◽

Difference Time ◽

Sub Wavelength

In this paper, multiple Fano resonances preferred in the refractive index sensing area are achieved based on sub-wavelength metal-insulator-metal (MIM) waveguides. Two slot cavities, which are placed between or above the MIM waveguides, can support the bright modes or the dark modes, respectively. Owing to the mode interferences, dual Fano resonances with obvious asymmetrical spectral responses are achieved. High sensitivity and high figure of merit are investigated by using the finite-difference time-domain (FDTD) method. In view of the development of chip-scale integrated photonics, two extra slot cavities are successively added to the structure, and consequently, three and four ultra-sharp Fano peaks with considerable performances are obtained, respectively. It is believed that this proposed structure can find important applications in the on-chip optical sensing and optical communication areas.

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Plasmonic refractive index sensor with multi-channel Fano resonances based on MIM waveguides

Modern Physics Letters B ◽

10.1142/s0217984920501730 ◽

2020 ◽

Vol 34 (16) ◽

pp. 2050173

Author(s):

Yihong Fang ◽

Kunhua Wen ◽

Zhengfeng Li ◽

Bingye Wu ◽

Zicong Guo

Keyword(s):

Refractive Index ◽

Optical Filter ◽

High Sensitivity ◽

Refractive Index Sensor ◽

Fano Resonances ◽

Coupled Mode ◽

Dual Channel ◽

Metal Insulator Metal ◽

Group Delays ◽

Coupled Cavity

A multi-channel Fano resonant structure is proposed and analyzed based on subwavelength metal–insulator–metal (MIM) waveguides. First, two MIM output ports associated with specific side-coupled cavities are designed to locate at the center and quarter positions of an end-coupled cavity, respectively. Since the interference between the dark and bright modes, dual-channel Fano resonances with asymmetrical lines shapes are obtained at both ports, respectively. High sensitivity and figure of merits are investigated. Besides, phase shifts are also investigated leading to positive and negative group delays available at the Fano peaks and dips, respectively. Likewise, two extra output ports with identical resonant cavities are placed on the other side of the end-coupled cavity. In this case, four-channel Fano resonances with considerable performances are obtained. The proposed structure is analyzed by the coupled mode theory and the finite difference time domain method. It is believed this device can be used as a chip-scale refractive index sensor and optical filter.

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