In this paper, we proposed a dual-core D-shaped photonic crystal fiber surface plasmon resonance refractive index sensor based on gold film. The proposed sensor uses two symmetrical fiber cores for enhanced surface plasmon resonance coupling to obtain extremely high amplitude sensitivity. The influence of structural parameters on the sensing performance was investigated. According to the simulation results, the sensor has a superior performance, which achieved the ultra high amplitude sensitivity of 8134.9 RIU− 1, a high average AS of 5,358.25 RIU− 1, the amplitude interrogation resolution of 1.87×10− 6 RIU, the maximum wavelength sensitivity of 39,000 nm/RIU, the wavelength interrogation resolution of 2.56×10− 6 RIU− 1 in a refractive index detection range of 1.37–1.40, and the maximum FOM of 246 RIU− 1. The proposed sensor has a broad prospect of application in biological, environmental, and chemical detection.
Research Article
Sensitivity Enhanced Dual-Core Photonic Crystal Fiber Surface Plasmon Resonance Sensor Based on Gold Film
https://doi.org/10.21203/rs.3.rs-4935722/v1
This work is licensed under a CC BY 4.0 License
Journal Publication
published 24 Sep, 2024
You are reading this latest preprint version
Surface plasmon resonance
Amplitude sensitivity
Dual-core
Photonic crystal fiber
Sensor
In recent years, refractive index (RI) sensing has been increasingly applied in various fields. The rising interest in micro-sensors has led to greater demands for refractive index sensing, including requirements related to sensor size and detection timeliness.[1][2]. SPR sensor has been widely applied in the sensing field in 1980s due to its advantages such as label - free, real-time monitoring and small size [3]. The RI is monitored by detecting the shift of the resonance peak when the analyte RI changes [4]. Traditional optical fibres have a relatively fixed structure, which makes it difficult to modify the phase matching conditions for SPR generation, thereby limiting the performance and usage scenarios[5][6]. Photonic crystal fiber (PCF) shew its emergence in the 1990s and it provided more possibilities for fiber based SPR sensor [7]. In 2020, Fu et al. [8] proposed a PCF-SPR sensor, the sensor has the detection range of 1.39–1.43, and reached the maximum wavelength sensitivity (WS) of 21,200 nm/RIU. In 2022, Guo [9] et al. designed a PCF-SPR sensor which achieved the RI range of 1.423–1.439 and the maximum amplitude sensitivity(AS) of 797RIU− 1.
According to the position of the analyte, the current PCF-SPR sensors can be categorized into external sensing and internal sensing, the external sensing usually has the advantage of the object to be measured is easy to replace as well as the sensor is easy to clean in practical application. In 2020, Xie et al. [10] Designed an internal detect PCF-SPR sensor, reached the maximum WS of 6,116 nm/RIU. In 2022, Falah et al. [11] proposed an external sensing D-shaped PCF-SPR sensor with the RI range of 1.33–1.43 and the WS of 28,400nm/RIU. Zuhayer et al.[12] reported an external sensing dual-core SPR sensor in 2021, the sensor had a RI range of 1.35–1.40, the WS of 8,000 nm/RIU and the maximum AS of 1,443 RIU− 1. Plasma sensors based on PCF are usually with single fiber core for guiding light, compared to the single-core PCF-SPR sensors, dual-core and multi-core PCF are able to contain more energy in the fiber core, which contributes to better loss and coupling conditions[13]. In 2023, a PCF - SPR sensor based on single core was designed by Islam et al. [14], the sensor achieved a detection range of 1.33–1.40, and the maximum WS of 7,000 nm/RIU. In 2020, Tong et al. [15] proposed a D-shaped SPR sensor based on dual-core PCF, the sensor had the RI range of 1.32–1.38, and the WS of 16,000 nm/RIU. Wang et al. [16] reported a dual-core PCF-SPR sensor in 2022, which reached the RI range of 1.36–1.44, the maximum WS of 13,502 nm/RIU and the average WS of 10,315 nm/RIU. In recent years, numerous metals have been used to excite SPR in plasmonic sensors. In 2020, Qu et al. [17] proposed a plasmonic sensor based on Au, Ag and Al, the sensor had the WS of 11,010 nm/RIU, 10940 nm/RIU and 9,760 nm/RIU for Au, Ag and Al plasma medium respectively. In 2021, Wang [18] et al. proposed a Trapezium-shaped groove SPR sensor based on ITO, which had the WS of 9,100 nm/RIU and the AS of 99 RIU− 1. Tondro et al.[19], reported a D-shaped PCF-SPR sensor, which presented a RI range of1.33-1.38, the WS of 6,900 nm/RIU. Compared with other metals, the chemical stability of gold makes it more desirable as plasma material directly contacted with the analyte[20]. Liu et al. [21] reported a PCF-SPR sensor based on gold in 2020, the sensor had the maximum WS of 42,000 nm/RIU and the AS of 2,204.49 RIU− 1. In 2022, Islam et al. [22] designed a SPR sensor based on gold film which shew the WS of 28,500 nm/RIU. However, sensors with high amplitude sensitivity are very competitive in practical applications, and good amplitude sensitivity means that the designed sensor has good resolution of the medium to be measured with different refractive indices. So, there is still much room for improvement for AS. In 2022, Vijay et al. [23] proposed a PCF-SPR sensor based on TiO2, the sensor reached the maximum AS of 574.3 RIU− 1 and the maximum WS of 12,400 nm/RIU. In 2023, Hasan et al. [24] reported a four-channel PCF-SPR sensor, which achieved the maximum AS of 803.8 RIU− 1 and the maximum WS of 25,000 nm/RIU. Abdullah et al. [25] designed a U-grooved PCF-SPR sensor in 2023, the sensor reached the AS of 1,189 RIU− 1 and the WS of 12,500 nm/RIU.
In this paper, a high AS D-shaped dual-core PCF-SPR sensor is proposed. The sensor employs an external sensing method with a dual polarization mode. We discuss the optimization of different structural parameters of proposed sensor. The results show that the proposed sensor has a maximum AS of 8134.9 RIU− 1, a maximum WS of 39,000 nm/RIU, as well as an amplitude modulation resolution of 1.87 \(\:\times\:\)10− 6, a wavelength modulation resolution of 2.56\(\:\times\:\)10−6, and the maximum figure of merit (FOM) of 246 RIU− 1 in a sensing range of 1.36–1.40. The proposed sensor is applicable to biomedical, environmental monitoring and food safety .
When the incident light at the surface of the medium is totally reflected, part of the energy will be coupled into the surface of the incident medium for transmission, when the evanescent wave caused by the incident light and the plasma wave at the surface of the metal resonate, surface plasmon resonance (SPR) occurs, and at this time, the energy in the incident medium leaks to the surface of the metal, and the loss peak appears. The data analyses and simulations in this paper were carried out using the finite element method (FEM) through COMSOL 6.0 software. The fine meshes and the number of degrees of freedom 137,646 are adopted in order to ensure the accuracy of the simulation. The cross - section and 3D view of the proposed sensor are shown in Fig. 1, and the internal air holes are arranged in hexagonal geometry with the diameter of d, e represents the distance between air holes, the polishing depth of D-shaped surface is denoted by f and the gold film thickness is denoted by t.
A possible manufacturing method of the proposed sensor in this paper is shown in Fig. 2. The air holes of the PCF structure can be constructed by stacking hollow rods and solid core rods of the same size, at which time the intermediate transition structure is obtained, and then the desired D-shaped PCF can be obtained by stretching and grinding, and finally the desired sensor can be obtained by coating the D-shaped surface with CVD method [23].
It can be seen in the electric field schematic of Fig. 3 that the energy of the fundamental mode of the proposed sensor is well confined in the dual-core at non-resonant wavelength. When the SPR occurs, the energy in the dual-core is able to leak to the surface of the gold film due to the equal effective refractive index (neff) of the fundamental mode and the SPP mode.
The dispersion curves of the odd and even modes for the two dielectric combinations at a RI of 1.40 are shown in Fig. 4. PCF confines energy to the fiber core through special arrangement of air holes. As the incident light wavelength changes to the resonant wavelength, the limitation of the energy in the fibre core is weakened, and the energy leakage of the fibre core reaches the maximum at the resonant wavelength of 1780 nm and 1840 nm for odd mode and even mode respectively.
Sellmier equation can be used to describe the RI of silica according to Eq. 1 [24]:
where the RI of silica is denoted by n, the wavelength of incident light is denoted by λ, and the other parameters are A1 = 0.6961663, A2 = 0.4079426, A3 = 0.8974794, B1 = 0.0684043 µm, B2 = 0.1162414 µm and B3 = 9.896161 µm.
Drude-Lorentz model can be used to describe the dielectric constant of the plasma material gold for the proposed sensor[25] according to Eq. 2.
where the frequency of the dielectric constant is expressed as ε∞, ωD is plasma frequency, Δε denotes the weight factor, the angular frequency of the incident light is ω. ωD and γD represent the plasma frequency and damping frequency, respectively, values of all these parameters have been taken from[25].
The confinement loss can be used to analyse the loss spectrum to obtain various sensing parameters of the sensor and can be expressed as Eq. 3 [26]:
$$\:{\alpha\:}=8.686\times\:{\text{k}}_{0}\times\:\text{I}\text{m}\left({\text{n}}_{\text{e}\text{f}\text{f}}\right)\times\:{10}^{7}(\text{d}\text{B}/\text{c}\text{m})$$
3
where the limiting loss can be expressed in terms of \(\:{\alpha\:}\), the wave vector \(\:{\text{k}}_{0}=2{\pi\:}/{\lambda\:}\) and λ is the wavelength of incident light。The imaginary part of the neff can be expressed as \(\:\text{I}\text{m}\left({\text{n}}_{\text{e}\text{f}\text{f}}\right)\).
The WS of SPR sensors is expressed as the variation of the resonance wavelength with the RI. [27] Generally, the larger resonance wavelength shift indicates a higher WS, and can be calculated according to Eq. 4 [28]:
$$\:{\text{S}}_{{\lambda\:}}=\frac{{{\Delta\:}{\lambda\:}}_{\text{p}\text{e}\text{a}\text{k}}}{{\Delta\:}{\text{n}}_{\text{a}}}(\text{n}\text{m}/\text{R}\text{I}\text{U})$$
4
where the resonance peak shift and the change in RI are expressed as \(\:{\varDelta\:{\lambda\:}}_{\text{p}\text{e}\text{a}\text{k}}\) and Δna, respectively.
AS is used to describe the intensity of the confinement loss variation with wavelength and RI, the larger the AS indicates the more significant resonance peak variation with wavelength and RI, and is calculated from Eq. 5 [29]:
$$\:{\text{S}}_{\text{A}}=-\frac{1}{{\alpha\:}({\lambda\:},{\text{n}}_{\text{a}})}\frac{\partial\:{\alpha\:}({\lambda\:},{\text{n}}_{\text{a}})}{\partial\:{\text{n}}_{\text{a}}}\left({\text{R}\text{I}\text{U}}^{-1}\right)$$
5
where the \(\:{\alpha\:}({\lambda\:},{\text{n}}_{\text{a}})\)is the value of loss that varies with resonance wavelength for a given RI, \(\:\partial\:{\alpha\:}({\lambda\:},{\text{n}}_{\text{a}})\) is the loss difference of two consecutive RI and \(\:\partial\:{\text{n}}_{\text{a}}\) indicates RI variation.
Figure-of-merit (FOM) of the SPR sensor, which affects the accuracy of detection and the FOM can be calculated according to Eq. 6[29]:
$$\:\text{F}\text{O}\text{M}=\frac{{\text{S}}_{{\lambda\:}}}{\text{F}\text{W}\text{H}\text{M}}\left({\text{R}\text{I}\text{U}}^{-1}\right)$$
6
The resolution of the sensor can be calculated in both wavelength and amplitude measuring methods defined by Eq. 7 and Eq. 8 [30]:
$$\:{\text{R}}_{\text{w}}=\frac{{\Delta\:}{\lambda\:}}{{\text{S}}_{{\lambda\:}}}\left(\text{R}\text{I}\text{U}\right)$$
7
$$\:{\text{R}}_{\text{A}}=\frac{{{\Delta\:}\text{n}}_{\text{a}}}{{\text{S}}_{\text{A}}}\left(\text{R}\text{I}\text{U}\right)$$
8
where the resolution of the spectrometer is represented by \(\:{\Delta\:}{\lambda\:}\) and assumed to be 0.1 nm in this paper, and the \(\:{{\Delta\:}\text{n}}_{\text{a}}\) is the minimum change in RI which is 0.01 in this paper.
We mainly derive the structural parameters by parameter optimization, to avoid confusion, only the odd mode is analysed in following sections. During optimization process, we carried out the sensing performance by comparing the loss curves for the RI of 1.37 and 1.38. The initial structural parameters are set as d = 1.1 µm, e = 2.0 µm, f = 4.2 µm, and t = 20 nm. For the air hole diameter d, we can see in Fig. 5(a) that the resonance wavelength is blue-shifted with the increase of the air hole diameter, which is caused by the increase of the real part neff of fundamental mode with the increase of d. From Fig. 5(b) we can see that the WS decreases with the increase of d and reaches 42,000 nm/RIU at d = 1.1 µm, the peak loss decreases with the increase of d. The increase of d restricts the leakage of the energy from the fundamental mode and FOM reaches the maximum at d = 1.2 µm, so d = 1.2 µm is chosen as the optimal parameter.
As shown in Fig. 6, the resonance wavelength is red-shifted with the increase of the air hole spacing e, which is caused by the decrease of the real part of the neff of the fundamental mode due to the increase of e. The increase of e decreases the neff difference between the cladding and the core of the fibre, leading to more core energy leaking out, which enhances the coupling between the fundamental mode and SPP mode. At the same time, the increase of e will also decrease the loss of the fundamental mode. The WS reaches the 54,000 nm/RIU at e = 2.0 µm and FOM increases when e is larger, so e = 2.0 µm is chosen as the optimal parameter.
From the Fig. 7, it can be seen that the resonance wavelength red-shifts with the increasing polishing depth f, which is caused by the increase in f decreasing the real part of the neff of the fundamental mode. The peak loss increases with the increase of f, but this leads to the increase of the width of the loss curve with the increase of f, which will affect the detection range and the sensing performance. The WS is larger at f = 4.2 µm and f = 4.4 µm, but FOM is better at f = 4.2 µm, so we choose f = 4.2 µm as the optimal parameter.
A comparison plot of the gold film thickness t shows that the resonance wavelength is red-shifted with the increase of t, which is because the increase of t causes the increase of neff. The WS and loss peak are larger at t = 20 nm, reaching 42,000 nm/RIU. The increase in t results in larger collective oscillations of free electrons inside the metal and enhanced coupling of the fundamental and SPP modes, which increases the peak loss, when t is too large, the excessively thick gold films diminish the depth of transmission of the surface plasmon wave (SPW), which reduces the peak loss. However, the FOM increases with t and WS is larger at t = 20 nm, so t = 20 nm was chosen as the optimal parameter.
The optimized performance parameters of the proposed sensor are d = 1.2, e = 2.0, f = 4.2, t = 20. We also give the specific parameters of the sensor over the entire detection range as shown in Table I:
Table Ⅰ Properties of the proposed sensor
| Analyte RI | Res. Wavelength (nm) | Loss peak (dB/cm) | WS (nm/RIU) | AS (RIU− 1) |
|---|---|---|---|---|
| 1.4 | 1,780 | 6.10 | 26,000 | 1,341.4 |
| 1.39 | 2,040 | 33.22 | 39,000 | 4,652.0 |
| 1.38 | 2,430 | 135.60 | 37,000 | 7,304.7 |
| 1.37 | 2,800 | 302.91 | 32,000 | 8,134.9 |
Figure 9 shows the loss profile of the proposed sensor, in which the resonance wavelength is blue-shifted with the increase of RI, which is caused by the decrease of SPP mode neff with the increase of the analyte RI, the peak of the loss curve decreases with the increase of RI and reaches the maximum of 255.8 dB/cm at a RI of 1.37. The maximum WS of the proposed sensor is 39,000 nm/RIU, and the average WS is 33,500 nm/RIU. The AS curve of the proposed sensor is shown in Fig. 10, the proposed sensor achieves excellent amplitude sensitivity due to its significant loss difference in different refractive indices and small half-height width, which can significantly improve the accuracy of sensor detection. The maximum AS of the proposed sensor is 8,134.9 RIU− 1 at RI = 1.37 and the average AS is 5,358.25 RIU− 1.
Figure 11 shows the fitting results of RI versus the resonance wavelength for proposed sensor. Here, we use the third-order fitting. The fitting equation of the fitting result is \(\:\text{y}=1.43066\times\:{10}^{8}\text{x}-1.036\times\:{10}^{8}{\text{x}}^{2}+2.5\times\:{10}^{7}{\text{x}}^{3}\). To highlight the superior performance of the proposed sensor, we show the performance comparison of the proposed sensor with the recent PCF-SPR sensor in Table II
Table Ⅱ Performance comparison of the proposed sensor with recently reported sensors.
| Refs. | Plasmonic material | RI Range | WS (nm/RIU) | Wavelength resolution (RIU) | AS (RIU-1) | Amplitude resolution (RIU) |
|---|---|---|---|---|---|---|
| [14] | Au | 1.33–1.40 | 7,000 | 1.43×10− 5 | 94.97 | 1.05×10− 4 |
| [31] | Au | 1.33–1.39 | 8,100 | 1.23 × 10− 5 | - | - |
| [32] | Ag | 1.33–1.37 | 11,400 | 8.77 × 10− 6 | - | - |
| [33] | Au-TiO2 | 1.31–1.38 | 21,000 | 8.77×10− 6 | 914 | 1.09×10− 5 |
| [34] | Au-TiO2 | 1.29–1.36 | 9,425 | 1.08 × 10− 5 | 1,312 | 7.62×10− 6 |
| This work | Au | 1.37–1.40 | 39,000 | 2.56×10− 6 | 8,134.9 | 1.87×10− 6 |
In this paper, an ultra high AS dual-core PCF-SPR sensor is proposed. The structural parameters of the sensor were optimized and the performance analysis was carried out. The sensor has a simple fabrication method while achieving an extreme high AS of 8,134.9 RIU− 1 and a high average AS of 5,358.25 RIU− 1, an amplitude modulation resolution of 1.87×10− 6 RIU, a maximum WS of 39,000 nm/RIU, a wavelength modulation resolution of 2.56×10− 6 RIU, and the RI detection range of 1.37–1.40. The sensor is expected to be used in medical, food, and other applications.
Authors' contributions
Honggang Pan: Review, Supervision, Resources, Project administration. Zihong Zhao: Writing, Supervision, Resources. Qingcheng You: Conceptualization, Methodology, Software, Formal analysis, Investigation, Writing - original draft. Yukun Zhu: Software, Validation. Rupeng Li: Software, Validation. Chunqi Chen: Software, Validation.
Funding Declaration
There is no funding supported for this paper.
Competing Interests
The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
Data Availability
The datasets generated during and/or analysed during the current study are not publicly available but are available from the corresponding author on reasonable request.
- Jorgenson RC, Yee SS. A fiber-optic chemical sensor based on surface plasmon resonance, Sens. Actuat. B Chem 1993;12(3):213-220.
- J. Homola, Surface Plasmon Resonance Sensors for Detection of Chemical and Biological Species, Chemical Reviews 108 (2) (2008) 462-493.
- J. Homola, S.S. Yee, G. Gauglitz. Surface plasmon resonance sensors: review, Sensors and Actuators B: Chemical 54 (1) (1999) 3-15.
- A.G. Brolo. Plasmonics for future biosensors, Nat, Photon. 6 (11) (2012) 709-713.
- S. Patskovsky, A.V. Kabashin, M. Meunier, J.H. Luong, Properties and sensing characteristics of surface plasmon resonance in infrared light, J. Opt. Soc. Am. A 20 (8) (2003) 1644-1650.
- P.S.J. Russell. Photonic-Crystal Fibers, Journal of Lightwave Technology 24 (12) (2006) 4729-4749.
- Zhu, M., Yang, L., Lv, J. et al., Highly Sensitive Dual-core Photonic Crystal Fiber Based on a Surface Plasmon Resonance Sensor with Gold Film. Plasmonics 17, (2022) 543-550.
- Yongbo Fu, Min Liu,et al., An ultrahighly sensitive photonic crystal fiber based surface plasmon resonance sensor, Optik, 212, (2020) 164649.
- Xiaowan Guo, Jian Shen, Chaoyang Li, An ultra-sensitive quasi-periodic dipole resonance photonic crystal fiber sensor, Optik, 265, (2022) 169521.
- Dehuai Xie, Haiwei Zhang, et al., Sensitivity and linearity enhanced wide-detection range surface-plasmon-resonance photonic-crystal-fiber sensor, Results in Physics, 29, (2021) 104707.
- Ahmed A. Saleh Falah, Wei Ru Wong, et al., Single-mode D-shaped photonic crystal fiber surface plasmon resonance sensor with open microchannel, Optical Fiber Technology, 74, (2022) 14212.
- Asif Zuhayer, Araf Shafkat, Design and analysis of a gold-coated dual-core photonic crystal fiber bio-sensor using surface plasmon resonance, Sensing and Bio-Sensing Research, 33, (2021) 100432.
- Pan, H., Pan, F., Zhanga, A. et al., Wide refractive index detection range surface plasmon resonance sensor based on D-shaped photonic crystal fiber. Opt Quant Electron 54, (2022) 393.
- Nazrul Islam, Md. Faizul Huq Arif, Mohammad Abu Yousuf, et al. Highly sensitive open channel based PCF-SPR sensor for analyte refractive index sensing, Results in Physics 46, (2023) 106266.
- Kai Tong, Zhiyuan Cai, et al., D-type photonic crystal fiber sensor based on metal nanowire array, Optik, 218, (2020), 165010.
- Wang, Y., Yan, X., Cheng, T. et al. High sensitivity with wide detection range refractive index sensor based on dual-core photonic crystal fiber. J Opt 51, (2022) 397-407.
- Yuwei Qu, Jinhui Yuan, Shi Qiu,et al., A novel photonic crystal fiber refractive index sensor with ultra wide detection range based on surface plasmon resonance effect, Optik, 262, (2022) 169287.
- Yanan Wang, Guangyu Jiang, et al., Trapezium-shaped groove photonic crystal fiber plasmon sensor for low refractive index detection, Sensing and Bio-Sensing Research, 34, (2021) 100452.
- Sayyad Tondro, A., Sadeghi, M., Kamaly, A. et al., Modeling and analysis of D–shaped plasmonic refractive index and temperature sensor using photonic crystal fiber. Opt Quant Electron 54, (2022) 603.
- Jingao Zhang, Jinhui Yuan, Yuwei Qu, et al., A novel surface plasmon resonance-based photonic crystal fiber refractive index sensor with an ultra-wide detection range, Optik 259, (2022) 168977.
- Yundong Liu, Hailiang Chen, Ying Guo, et al., Ultra-high sensitivity plasmonic sensor based on D-shaped photonic crystal fiber with offset-core, Optik 221, (2020) 165309.
- Mohammad Rakibul Islam, Md. Moinul Islam Khan, Rahbar Al Rafid, et al., Trigonal cluster-based ultra-sensitive surface plasmon resonance sensor for multipurpose sensing, Sensing and Bio-Sensing Research 35, (2022) 100477.
- V. S. Chaudhary, D. Kumar, et al. Plasmonic Biosensor With Gold and Titanium Dioxide Immobilized on Photonic Crystal Fiber for Blood Composition Detection. IEEE Sensors Journal 22, 9 (2022), 8474-8481.
- M. S. Hasan, M. A. E. Kalam and M. Faisal, PCF Based Four-Channel SPR Biosensor With Wide Sensing Range. IEEE Transactions on NanoBioscience 23, 2 (2024), 233-241.
- A. M. T. Hoque, K. F. Al-Tabatabaie, et al., U-Grooved Selectively Coated and Highly Sensitive PCF-SPR Sensor for Broad Range Analyte RI Detection. IEEE Access 11, (2023), 74486-74499.
- S. Mittal, A. Saharia, et al., Design and Performance Analysis of a Novel Hoop-Cut SPR - PCF Sensor for High Sensitivity and Broad Range Sensing Applications, in IEEE Sensors Journal 24 (3), (2024) 2697-2704.
- Zhao, Z., Zhang, A., Pan, H. et al., Wide Detection Range and Sensitivity Enhanced Dual Eccentric-Core D-Shaped Photonic Crystal Fiber Surface Plasmon Resonance Sensor. Plasmonics 19, (2024) 1659-1666.
- S. Mittal, A. Saharia, et al., Design and Performance Analysis of a Novel Hoop-Cut SPR - PCF Sensor for High Sensitivity and Broad Range Sensing Applications, in IEEE Sensors Journal 24 (3), (2024) 2697-2704.
- X. Zhang, J. Ding, X. S. Zhu et al., Numerical Simulation of Optical Fiber Tamm Plasmon Polariton Sensor Based on D-Shaped Hollow-Core Photonic Crystal Fiber Coated With a Gold Film, IEEE Sensors Journal 24 (5), (2024) 6207-6212.
- R. Mu, H. Wan, W. Shi, et al., Design and Theoretical Analysis of High-Sensitive Surface Plasmon Resonance Sensor Based on Au/Ti 3C2Tx-MXene Hybrid Layered D-Shaped Photonic Crystal Fiber, IEEE Sensors Journal 23 (16), (2023) 18160-18167.
- Chaoyi Liu, Yingyue Zhang, Xingyuan Li, et al., A gold film coated dual-core photonic crystal fiber for refractive index and temperature sensing with high isolation, Optical Fiber Technology 72, (2022) 102975.
- Jiao, S., Li, X., Ren, X. et al., Research on three-core photonic crystal fiber plasmonic sensor based on surface plasmon resonance with three V-groove microfluidic channel. Opt Rev 29, (2022) 80-90.
- M. Hussayeen Khan Anik, S.M. Riazul Islam, Hriteshwar Talukder, et al., A highly sensitive quadruple D-shaped open channel photonic crystal fiber plasmonic sensor: A comparative study on materials effect, Results in Physics 23, (2021) 104050.
- De, M., Singh, V.K. Wide range refractive index sensor using a birefringent optical fiber. Opt Quant Electron 53, (2021) 198.
No competing interests reported.