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

Sensors ◽  
2018 ◽  
Vol 18 (10) ◽  
pp. 3181 ◽  
Author(s):  
Kunhua Wen ◽  
Li Chen ◽  
Jinyun Zhou ◽  
Liang Lei ◽  
Yihong Fang

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.

2022 ◽  
Author(s):  
Vahid Najjari ◽  
Saeed Mirzanejhad ◽  
Amin Ghadi

Abstract A plasmonic refractive index sensor including a Metal-Insulator-Metal waveguide (MIM) with four teeth is proposed. Transmittance (T), Sensitivity (S) and Figure of Merit (FOM) investigated numerically and analysed via Finite Difference Time Domain method (FDTD). The simulation results show the generation of double Fano resonances in the system that the resonance wavelength and the resonance line-shapes can be adjusted by changing the geometry of the device. By optimizing the structure in the initial configuration, the maximum sensitivity of 1078nm/RIU and FOM of 3.62×105 is achieved. Then change the structure parameters. In this case, the maximum sensitivity and FOM are 1041nm/RIU and 2.94×104 respectively, thus two detection points can be used for the refractive index sensor. Due to proper performance and adjustable Fano resonance points, this structure is significant for fabricating sensitive refractive index sensor and plasmonic bandpass filter.


2022 ◽  
Author(s):  
Haowen Chen ◽  
Yunping Qi ◽  
Jinghui Ding ◽  
Yujiao Yuan ◽  
Zhenting Tian ◽  
...  

Abstract A plasmonic resonator system consisting of a metal-insulator-metal waveguide and a Q-shaped resonant cavity is proposed in this paper. The transmission properties of surface plasmon polaritons in this structure are investigated using the finite difference in time domain (FDTD) method, and the simulation results contain two resonant dips. And the physical mechanism is studied by the multimode interference coupled mode theory (MICMT), the theoretical results are in highly consistent with the simulation results. Furthermore, the parameters of the Q-shaped cavity can be controlled to adjust two dips respectively. The refractive index sensor with a sensitivity of 1578nm/RIU and figure of merit (FOM) of 175, performs better than most of the similar structures. Therefore, the results of the study are instructive for the design and application of high sensitivity nanoscale refractive index sensors.


2020 ◽  
Vol 34 (16) ◽  
pp. 2050173
Author(s):  
Yihong Fang ◽  
Kunhua Wen ◽  
Zhengfeng Li ◽  
Bingye Wu ◽  
Zicong Guo

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.


Author(s):  
Zhaojian Zhang ◽  
Junbo Yang ◽  
Xin He ◽  
Jingjing Zhang ◽  
Jie Huang ◽  
...  

A plasmonic refractive index (RI) sensor based on metal-insulator-metal (MIM) waveguide coupled with concentric double rings resonator (CDRR) is proposed and investigated numerically. Utilizing the novel supermodes of the CDRR, the FWHM of the resonant wavelength can be modulated, and a sensitivity of 1060 nm/RIU with high figure of merit (FOM) 203.8 is realized in the near-infrared region. The unordinary modes as well as the influence of structure parameters on the sensing performance are also discussed. Such plasmonic sensor with simple framework and high optical resolution could be applied to on-chip sensing systems and integrated optical circuits.


2015 ◽  
Vol 29 (33) ◽  
pp. 1550218 ◽  
Author(s):  
Tiesheng Wu ◽  
Yumin Liu ◽  
Zhongyuan Yu ◽  
Han Ye ◽  
Changgan Shu ◽  
...  

A novel surface plasmon polaritons (SPPs) refractive index sensor based on a single defect nanocavity coupled with a metal–insulator–metal (MIM) waveguide is proposed and numerically simulated by using the finite difference time domain (FDTD) method with perfectly matched layer absorbing boundary condition. It is found that the defect structure can realize two Fano resonances and these two Fano resonances originate from two different mechanisms. The results demonstrate the liner correlation between the resonance wavelengths of the device and the refractive index of the material under sensing. Through the optimization of structural parameters, we achieve a theoretical value of the refractive index sensitivity as high as 1800.4 nmRIU[Formula: see text]. It could be utilized to develop ultra-compact nanodevice for high-resolution biological sensing.


Nanomaterials ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 2097
Author(s):  
Yuan-Fong Chou Chau ◽  
Chung-Ting Chou Chao ◽  
Siti Zubaidah Binti Haji Jumat ◽  
Muhammad Raziq Rahimi Kooh ◽  
Roshan Thotagamuge ◽  
...  

This work proposed a multiple mode Fano resonance-based refractive index sensor with high sensitivity that is a rarely investigated structure. The designed device consists of a metal–insulator–metal (MIM) waveguide with two rectangular stubs side-coupled with an elliptical resonator embedded with an air path in the resonator and several metal defects set in the bus waveguide. We systematically studied three types of sensor structures employing the finite element method. Results show that the surface plasmon mode’s splitting is affected by the geometry of the sensor. We found that the transmittance dips and peaks can dramatically change by adding the dual air stubs, and the light–matter interaction can effectively enhance by embedding an air path in the resonator and the metal defects in the bus waveguide. The double air stubs and an air path contribute to the cavity plasmon resonance, and the metal defects facilitate the gap plasmon resonance in the proposed plasmonic sensor, resulting in remarkable characteristics compared with those of plasmonic sensors. The high sensitivity of 2600 nm/RIU and 1200 nm/RIU can simultaneously achieve in mode 1 and mode 2 of the proposed type 3 structure, which considerably raises the sensitivity by 216.67% for mode 1 and 133.33% for mode 2 compared to its regular counterpart, i.e., type 2 structure. The designed sensing structure can detect the material’s refractive index in a wide range of gas, liquids, and biomaterials (e.g., hemoglobin concentration).


Nanomaterials ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 3399
Author(s):  
Haoyuan Cai ◽  
Shihan Shan ◽  
Xiaoping Wang

Surface plasmon resonance (SPR) biosensors consisting of alternate layers of silver (Ag) and TiO2 thin film have been proposed as a high sensitivity biosensor. The structure not only prevents the Ag film from oxidation, but also enhances the field inside the structure, thereby improving the performance of the sensor. Genetic algorithm (GA) was used to optimize the proposed structure and its maximum angular sensitivity was 384°/RIU (refractive index unit) at the refractive index environment of 1.3425, which is about 3.12 times that of the conventional Ag-based biosensor. A detailed discussion, based on the finite difference time domain (FDTD) method, revealed that an enhanced evanescent field at the top layer–analyte region results in the ultra-sensitivity characteristic. We expect that the proposed structure can be a suitable biosensor for chemical detection, clinical diagnostics, and biological examination.


Sensors ◽  
2017 ◽  
Vol 17 (4) ◽  
pp. 784 ◽  
Author(s):  
Yue Tang ◽  
Zhidong Zhang ◽  
Ruibing Wang ◽  
Zhenyin Hai ◽  
Chenyang Xue ◽  
...  

Author(s):  
Zhaojian Zhang ◽  
Junbo Yang ◽  
Xin He ◽  
Jingjing Zhang ◽  
Jie Huang ◽  
...  

A plasmonic refractive index (RI) sensor based on metal-insulator-metal (MIM) waveguide coupled with concentric double rings resonator (CDRR) is proposed and investigated numerically. Utilizing the novel supermodes of the CDRR, the FWHM of the resonant wavelength can be modulated, and a sensitivity of 1060 nm/RIU with high figure of merit (FOM) 203.8 is realized in the near-infrared region. The unordinary modes as well as the influence of structure parameters on the sensing performance are also discussed. Such plasmonic sensor with simple framework and high optical resolution could be applied to on-chip sensing systems and integrated optical circuits. Besides, the special cases of bio- sensing and triple rings are also discussed.


The Analyst ◽  
2015 ◽  
Vol 140 (21) ◽  
pp. 7263-7270 ◽  
Author(s):  
Yujia Wang ◽  
Jianjun Chen ◽  
Chengwei Sun ◽  
Kexiu Rong ◽  
Hongyun Li ◽  
...  

By using a novel optical illumination scheme, high-contrast and broadband plasmonic sensors with ultra-high figure of merits are experimentally demonstrated.


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