Practical sensing approach based on surface plasmon resonance in a photonic crystal fiber

Xue Zhou; Tonglei Cheng; Shuguang Li; Takenobu Suzuki; Yasutake Ohishi

doi:10.1364/OSAC.1.001332

1. Introduction

Surface plasmon resonance (SPR) technology has attracted continuous research interests in chemical and biological sensing region for decades. It was first observed in prims coated with plasmonic materials (Ag, Au, Cu, etc.) and its high sensitivity to RI variation of the dielectric adjacent to the metal shows great potential in sensing application. In 1983, Liedberg et al [1] firstly used SPR on prism to monitor the reaction of antigen and antibody. Because sensors based on SPR in prism is bulky and cannot be used for remote detection [2,3], a new type of sensors has been proposed by utilizing SPR effect in optical fibers [4,5]. Having the advantage of small in size, anti-interference and biocompatibility [6,7], more and more optical fiber SPR sensors have emerged. In 2017 Chao Zhang et al. [8] proposed a real-time refractive index (RI) sensor based on a U-bent fiber coated with the graphene/AgNPs. In 2017, Nunzio Cennamo et al. [9] designed and implemented SPR sensors with thin bilayers of different metals utilized a D-shaped plastic optical fiber with Ag film. However, common optical fibers, such as tapered fibers, side-polished fibers, etched fibers, usually lead to single structure and low sensitivity in the produced sensors, which greatly hinders their application.

In recent years, photonic crystal fiber (PCF) sensors based on SPR have attracted much attention, and its application spread rapidly, ranging from security, medical diagnostics, food safety, biochemistry to environmental monitoring [10–12]. Compared with ordinary optical fibers, PCF’s air hole arrangement, air hole diameter and pitch size can be adjusted, and the metal can be coated to its surface or filled into its air hole to produce SPR. PCF sensor based on SPR can largely be classified into five structures: metal coated on the air hole [13,14], metal filled into the air hole [15–17], microfluidic slotted PCF [18,19], D-shaped PCF [20–22] and metal coated PCF [23,24]. Sensors utilizing the first two structures have to put the analyte into the air hole, and both of the metal preparation and the analyte filling are complex, which causes great difficulty in the manufacture process. Sensors based on the following two structures have to go through fine grinding, which is also a tough process and which will considerately reduce the fiber’s mechanical strength. Consequently, directly coating metal on PCF to realize sensing becomes the best option.

In this paper, a novel PCF sensor based on SPR is proposed. In the PCF, a ring of air holes in hexagonal lattice and two holes in the opposite vertices are replaced by silica rods, which can be easily achieved by the standard stack-and-draw method [25]. An Au film is coated on PCF surface using the CVD method [26] to complete the PCF sensor. The structural parameters of the designed sensor is exploited by adjusting the air hole diameter and the thickness of the Au film. The sensor performance has been analyzed by the wavelength interrogation (WI) and amplitude interrogation (AI) methods. It is easy to make and can be directly put into biological analyte for detection, possessing advantage of being reusable, simple in operation and highly sensitive.

2. Structure design and theoretical model

2.1 Structure design

The standard stack-and-draw method is used to fabricate the PCF. First, the capillary tubes and silica rods with the same outside diameter are arranged in the shape of Fig. 1(A)

Fig. 1 Design structure. (A) Cross-section of the proposed PCF’s stacked preform. (B) Cross-section of the proposed PCF. (C) FEM mesh. (D) Schematic diagram of the proposed sensor set-up.

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. Among them, the two capillaries at the vertices of the hexagon are replaced by silica rods, and there are three reasons for doing this: firstly, the vertex position of the hexagon is closest to the metal film, which helps the evanescent field couple more easily to the metal surface; secondly, the circular symmetry of the structure is broken and birefringence is formed by the two silica rods; lastly, the difference of evanescent field between x and y polarization is conspicuous, so the resonance peak will be different to reduce the interference of detection. A very thin walled glass tube (less than or equal to 1mm) is used to fix these capillaries and silica rods in the drawing process to form a no-cladding, ring-shaped core PCF. After that, an Au film is coated on the designed PCF to generate SPR and contacts with analyte directly, as shown in Fig. 1(B).

In order to testify the performance of the designed PCF sensor, the finite element method (FEM) is used to calculate its transmission characteristics by the commercial software COMSOL. Figure 1(C) shows the FEM mesh, where a cylindrical perfect matching layer (PML) is added around the analyte and the perfect scattering boundary is set to reduce the reflection and increase the calculation accuracy. The schematic diagram of sensing system is shown in Fig. 1(D). The PCF sensor is fixed in a microgroove to set up a testing platform and light is launched into it from a wide band light source. PCF is in direct contact with the liquid analyte, the inflow and outflow of which is controlled by a pump. Finally, the transmitted light is coupled into an optical spectrum analyzer to observe any change in analyte.

2.2 Mode analysis

As shown in Fig. 1(B), three layers of air holes form a ring-shaped core and the Gaussian beam can transmit steadily based on the total internal reflection. The evanescent field can be coupled to the metal film to excite the surface plasmon polarization (SPP) mode. When the core mode and SPP mode meet the phase matching conditions, SPR will be generated. If the thickness of Au film is smaller than the penetration depth of evanescent wave, the evanescent wave will connect with the analyte on the outside of Au film. The wave vector of core mode is [27],

K_{z} = \frac{ω}{c} \sqrt{ε_{0}} \sin θ

where ω is the angular frequency of the incident light, c is the speed of light, ε₀ is the dielectric constant of the cladding, and θ is the angle of incidence.

The diameter of the air hole is d₁, the distance between the air hole center (pitch size) is Λ, and the thickness of Au film is d₂. The RI of the background material (fused silica) is calculated by the Sellmeier equation [5],

n (λ) = \sqrt{1 + \sum_{i = 1}^{m} \frac{B_{i} λ^{2}}{λ^{2} - λ_{i}}}

where n is the RI, λ is wavelength in μm, m = 3, B₁ = 0.6961663, B₂ = 0.4079426, B₃ = 0.8974794, λ₁ = 4.67914826 × 10⁻³μm², λ₂ = 1.35120631 × 10⁻²μm², λ₃ = 97.9340025μm². According to the RI of PCF material and structure size of PCF, the effective RI of PCF cladding can be calculated.

The light excites the free electrons in Au film to vibrate and travel across the interface between Au film and the analyte, which is called the surface plasmon wave. The wave vector of SPP mode is [27],

K_{s p w} = Re [\frac{ω}{c} \sqrt{\frac{ε_{1} ε_{2}}{ε_{1} + ε_{2}}}]

where ε₁ is the dielectric constant of the Au film, ε₂ is the dielectric constant of analyte. The dielectric constant of Au is defined by the Drude-Lorentz model [24],

ε_{1} = ε_{\infty} - \frac{ω_{D}^{2}}{ω (ω + j γ_{D})} - \frac{Δ ε Ω_{L}^{2}}{(ω^{2} - Ω_{L}^{2}) + j Γ_{L} ω}

where ε_m is the permittivity of gold, ε_∞ is the permittivity in high frequency and is 5.9673 approximately. ω_D and γ_D are the plasma frequency and damping frequency, respectively.

The weighting factor Δε is 1.09. $ω = 2 π c / λ$ is the angular frequency, where c is the velocity of light, whereas $ω_{D} / 2 π = 2113.6 THz$ and $γ_{D} / 2 π = 15.92 THz$ . The frequency and spectral width of the Lorentz oscillator are Ω_L and Γ_L, respectively, $Ω_{L} / 2 π = 650.07 THz$ and $Γ_{L} / 2 π = 104.86 THz$ .

When $K_{z} = K_{s p w}$ , the SPR will occur and the wavelength of the incident light is called the resonant wavelength of SPR at this moment. The relationship between wave vector and effective RI is as follows,

K = \frac{ω}{c} n_{e f f}

In other words, SPR will occurs when the effective RI of core mode is equal to that of SPP mode at a particular wavelength. The confinement loss can be obtained by the following equation,

α (d B / c m) = 8.686 \times \frac{2 π}{λ} Im (n_{e f f}) \times 10^{4}

where λ is the wavelength in μm and Im(n_eff) is the imaginary part of the effective RI.

The SPR causes the light to be absorbed quickly at the resonant wavelength and to appear as an absorption peak on the transmission spectrum. From the above formula derivation, it can be seen that the change of analyte RI will affect the resonant wavelength and the transmission spectrum. As a result, via the shift of resonant wavelength or the change of absorption peak intensity the RI of the unknown analyte could be detected.

The power distributions of the three lowest order modes are shown in Fig. 2

Fig. 2 Power distributions of core modes in the designed PCF. Red arrows represent the direction of electric field in d₁ = 0.4Λ, Λ = 2μm, d₂ = 40nm, n_a = 1.35, and λ = 1.55μm. (A) $H E_{11}^{x}$ mode. (B) $H E_{11}^{y}$ mode. (C) TE₀₁ mode. (D) TM₀₁ mode

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, in which the wavelength is 1.55μm and the analyte RI is 1.35. The red arrow indicates the electric field direction of each mode. Because of the lack of two air holes, the power distributions of

H E_{11}^{x}

and

H E_{11}^{y}

are different, and their electric fields are perpendicular to each other, as shown in Fig. 2 (A) and (B). Due to the asymmetry of structure,

H E_{11}^{y}

mode has a weak coupling and is insensitive to the analyte RI. On the other hand, core mode TE₀₁ mode (Fig. 2 (C)) and TM₀₁ mode (Fig. 2 (D)) are also stimulated, but the former cannot excite SPP. Therefore, only the sensing properties of

H E_{11}^{x}

mode and TM₀₁ mode are analyzed in this study. It’s worth mentioning that the resonance wavelengths of these modes are different, so the peaks don’t interfere with each other.

The loss spectrums of $H E_{11}^{x}$ mode and TE₀₁ mode are calculated and shown in Fig. 3(A) and (B)

Fig. 3 Loss spectrum (red solid line) and effective RI (black dotted line) of core mode and SPP mode (black solid line). (A) $H E_{11}^{x}$ mode. (B) TE₀₁ mode. Inserts are the electric field distributions of resonance point

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, respectively. The red solid lines are the loss curves of

H E_{11}^{x}

and TE₀₁, the black solid lines are the effective RI of SPP mode, and the dotted lines are the effective RI of the core mode. It can be found that there is an intersection point between the core mode and SPP mode, so when their effective refractive indices are the same, the resonance matching condition will be satisfied and SPR will be excited, leading to a rapid absorption of light at resonance wavelength. The insets of Fig. 3 are the electric field distributions of the resonance points. It is clear that some light is coupled to the Au film, resulting in a sharp peak in the loss curve. Because the change of the external analyte RI will affect the resonance point and the transmission loss. As the result, detecting the change of the transmission spectrum can help us locate the analyte RI.

Furthermore, it is to be noted that in Fig. 3, the two resonance peaks are located around 1.3μm and 1.5μm, both of which belong to the near-infrared region. When the analyte RI changes, they will change more simultaneously and by detecting the change in their location, self-calibration can be realized. Therefore, this designed sensor has potential for near-infrared biosensing, especially for detecting the concentration of bio logical molecules and biological reactions.

3. Results and performance analysis

3.1 Structural parameter optimization

In order to achieve the optimum performance, the structural parameters of the proposed sensor are exploited. Firstly, the thickness of Au film is adjusted. The thickness of metal film in reported research is mostly dozens of nanometers, so in this paper, the loss of $H E_{11}^{x}$ mode and TE₀₁ mode with Au film thickness of 30 nm, 40 nm and 50 nm are calculated (the analyte RI set to be 1.35 or 1.36), as shown in Fig. 4 (A) and (B)

Fig. 4 Loss curves of the designed PCF with 30nm, 40nm, and 50nm Au film, when the analyte RI is 1.35 or 1.36, respectively. (A) $H E_{11}^{x}$ mode. (B) TE₀₁ mode.

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. It can be found that the resonance wavelengths shift red with the increase of the Au film thickness, and the moving range increases when decreasing the film thickness. Moreover, the half tall wide of the output spectrum increases when the thickness of Au film decreases. It comes to the conclusion that the thinner the Au film thickness, the more sensitive the sensor. But if the Au film is too thin, the peak of transmission spectrum will become too different to detect. Taking this into consideration, the thickness 40nm is selected.

The duty ratio of air holes is also an important parameter, which refers to the ratio of air hole area to the silica area and which can be converted to the ratio of air hole diameter to pitch size, d/Λ. In order to explore the effect of duty ratio on the proposed sensor, the transmission loss of PCF with different d/Λ are calculated with the analyte RI set to be 1.35 or 1.36, as shown in Fig. 5(A) and (B)

Fig. 5 Loss curves of the designed PCF with 0.3, 0.4, and 0.5 d/Λ, when the analyte RI is 1.35 or 1.36, respectively. (A) $H E_{11}^{x}$ mode. (B) TE₀₁ mode.

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. Figure 5 (A) shows the loss curves of

H E_{11}^{x}

mode. The resonance wavelengths of different duty ratio (d/Λ = 0.3, 0.4 and 0.5) have roughly the same movement even if the analyte RI has increased 0.01. The resonance peak first shifts blue and then red with the increase of d/Λ. From Fig. 5(B), it can be found that the loss of TE01 mode increases rapidly and leads to TE₀₁ mode cutoff at 1.5 μm with d/Λ = 0.3, and the resonance peak has disappeared. Furthermore, with the increase of d/Λ the loss decreases while the half tall wide of the output spectrum increases. In order to guarantee the existence of resonance peaks in both modes and make sure their easy detection, d/Λ = 0.4 is considered the best.

In the designed sensor, evanescent field is utilized to interact with the analyte. And the longer interaction time, the more obvious the effect of analyte change on the transmission spectrum. Clearly, longer PCF can increase the interaction time, but the transmission loss of the PCF may run too high. In order to control the transmission loss, the PCF length has to be shortened according to the actual situation.

3.2 Sensing performance analysis

In order to analyze the RI sensitivity of the designed sensor, the loss of $H E_{11}^{x}$ mode and TE₀₁ mode with the analyte RI ranging from 1.33 to 1.41 are calculated respectively, as shown in Fig. 6

Fig. 6 Loss spectrums by varying the analyte RI from 1.33 to 1.41 (d₁ = 0.8μm, d₂ = 40nm, Λ = 2μm). (A) $H E_{11}^{x}$ mode. (B) TE₀₁ mode

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. Figure 6(A) is the loss curves of

H E_{11}^{x}

mode and Fig. 6(B) is the loss curves of

T E_{01}

mode.

In Fig. 6, the resonance peaks shift red with the increase of analyte RI, thus WI method can be utilized to analyze the performance of the sensor. The wavelength sensitivity of the sensor can be defined as the movement of resonant wavelength with per analyte RI and calculated by the following equation,

S_{λ} = \frac{d λ_{p e a k} (n_{a})}{d n_{a}}

where n_a is the analyte RI, λpeak is the resonant wavelength.

Figure 7

Fig. 7 Fitting curves of resonance wavelength with analyte RI. And the Red line is $H E_{11}^{x}$ mode, the black line is TE₀₁ mode.

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shows the fitting curves of resonance wavelength with analyte RI (black line for

H E_{11}^{x}

mode, red line for TE₀₁ mode), and according to Eq. (7), the slope of the curve represents the wavelength sensitivity of the sensor. From the figure we can see both curves increase gradually with the change of analyte RI, while the red one exhibits a sharper slope, which means TE₀₁ mode has a higher wavelength sensitivity.

Theoretically, the maximum sensitivity of the sensor can reach 6900 nm/RIU. According to the resolution of the existing spectrometer in our lab (20 pm), the resolution of the proposed sensor is 2.899 × 10⁻⁶ RIU (20pm/6900(nm/RIU)).

Because the absorption intensity in Fig. 6 varies with the analyte RI, the AI method can also be used to analyze the performance of the proposed sensor, which obtains the analyte RI by detecting the change of output loss at a certain wavelength. The amplitude sensitivity can be calculated by the following equation,

S_{A} (λ) [R I U^{- 1}] = - \frac{1}{α (λ, n_{a})} \frac{\partial α (λ, n_{a})}{\partial n_{a}}

where α(λ, n_a) is the transmission loss when the analyte RI is n_a.

Figure 8. (A) and (B)

Fig. 8 Amplitude sensitivities of different mode by varying the analyte RI from 1.33 to 1.41. (A) $H E_{11}^{x}$ mode. (B) TE₀₁ mode.

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show respectively the amplitude sensitivities of

H E_{11}^{x}

mode and

T E_{01}

mode as the analyte RI changes from 1.33 to 1.41. For

H E_{11}^{x}

mode, the amplitude sensitivity decreases at the analyte RI range of 1.4~1.33 and reaches its maximum 132 RIU⁻¹ at 1.40. The amplitude sensitivity of TE₀₁ mode shows the same trend, but only reaches 58.97 RIU⁻¹ at 1.40. According to the AI method, the theoretical maximum resolution of the proposed sensor is 7.59 × 10⁻⁵ RIU, assuming that all practical noise influence is ignored and a minimum change 1% of the transmission intensity is detected.

According to the above discussion, it is clear that the proposed PCF sensor has good performance. Table 1

Table 1. Comparison with former research

View Table

is a comparison of our work with other similar sensors in existence, which highlights our advantages.

4. Conclusion

A novel PCF sensor based on SPR is proposed in this paper. The PCF’s transmission characteristics are analyzed by the FEM method and its structural parameters are optimized. The performance of the proposed sensor is investigated and its maximum wavelength sensitivity amounts to 6900 nm/RIU, and the maximum amplitude sensitivity reaches 132 RIU⁻¹. There are two resonance peaks in its transmission spectrum, which can realize self-calibration in analyte RI measurement. This sensor has the advantages of high sensitivity, simple production, easy operation and real-time detection. It can be used for real-time detection of the concentration and variety of biological molecules.

Funding

The authors thank the national “Young 1000 Talent Plan” program of China. This work is supported by National Natural Science Foundation of China (61475134, 61775032 and 11604042), Fundamental Research Funds for the Central Universities (N170405007 and N160404009), JSPS KAKENHI Grant(15H02250, 17K18891 and 18H01504), JSPS and CERN under the JSPS-CERN joint research program, and 111 Project (B16009).

References

1. S. Avino, V. D’Avino, A. Giorgini, R. Pacelli, R. Liuzzi, L. Cella, P. De Natale, and G. Gagliardi, “Ionizing radiation detectors based on Ge-doped optical fibers inserted in resonant cavities,” Sensors (Basel) 15(2), 4242–4252 (2015). [CrossRef] [PubMed]

2. G. Robinson, “The commercial development of planar optical biosensors,” Sens. Actuators B Chem. 29(1-3), 31–36 (1995). [CrossRef]

3. J. N. Dash and R. Jha, “Highly Sensitive Side-Polished Birefringent PCF-Based SPR Sensor in near IR,” Plasmonics 11(6), 1505–1509 (2016). [CrossRef]

4. Y. Zhao, M. Lei, S. X. Liu, and Q. Zhao, “Smart Hydrogel-based Optical Fiber SPR Sensor for pH Measurements,” Sens. Actuators B Chem. 261, 226–232 (2018). [CrossRef]

5. D. F. Santos, A. Guerreiro, and J. M. Baptista, “SPR Microstructured D-Type Optical Fiber Sensor Configuration for Refractive Index Measurement,” IEEE Sens. J. 15(10), 5472–5477 (2015). [CrossRef]

6. M. Janik, A. Mysliwiec, M. Koba, A. Celebanska, W. Bock, and M. Smietana, “Sensitivity pattern of femtosecond laser micromachined and plasma-processed in-fiber Mach-Zehnder interferometers, as applied to small-scale refractive index sensing,” IEEE Sensors Journal (2017), in press.

7. G. Wang, C. Wang, S. Liu, J. Zhao, C. Liao, X. Xu, H. Liang, G. Yin, and Y. Wang, “Side-Opened Suspended Core Fiber-Based Surface Plasmon Resonance Sensor,” IEEE Sens. J. 15(7), 4086–4092 (2015). [CrossRef]

8. C. Zhang, Z. Li, S. Z. Jiang, C. H. Li, S. C. Xu, J. Yu, Z. Li, M. H. Wang, A. H. Liu, and B. Y. Man, “U-bent fiber optic SPR sensor based on graphene/AgNPs,” Sens. Actuators B Chem. 251, 127–133 (2017). [CrossRef]

9. N. Cennamo, L. D. Maria, C. Chemelli, P. Zuppella, M. G. Pelizzo, A. J. Corso, M. Pesavento, F. Mattiello, and L. Zeni, “SPR sensors based on bilayer metals in a D-shaped plastic optical fiber: Analysis and experimental results with different metals,” 18th Italian National Conference on Photonic Technologies (Fotonica 2016), Rome, 2016, pp. 1-4..

10. A. Ricciardi, M. Consales, G. Quero, A. Crescitelli, E. Esposito, and A. Cusano, “Versatile Optical Fiber Nanoprobes: From Plasmonic Biosensors to Polarization-Sensitive Devices,” ACS Photonics 1(1), 69–78 (2014). [CrossRef]

11. X. Fan and I. M. White, “Optofluidic Microsystems for Chemical and Biological Analysis,” Nat. Photonics 5(10), 591–597 (2011). [CrossRef] [PubMed]

12. A. A. Rifat, R. Ahmed, A. K. Yetisen, H. Butt, A. Sabouri, G. A. Mahdiraji, S. H. Yun, and F. R. M. Adikan, “Photonic crystal fiber based plasmonic sensors,” Sens. Actuators B Chem. 243, 311–325 (2017). [CrossRef]

13. D. Gao, C. Guan, Y. Wen, X. Zhong, and L. Yuan, “Multi-hole fiber based surface plasmon resonance sensor operated at near-infrared wavelengths,” Opt. Commun. 313, 94–98 (2014). [CrossRef]

14. A. A. Rifat, G. A. Mahdiraji, D. M. Chow, Y. G. Shee, R. Ahmed, and F. R. Adikan, “Photonic Crystal Fiber-Based Surface Plasmon Resonance Sensor with Selective Analyte Channels And Graphene-Silver Deposited Core,” Sensors (Basel) 15(5), 11499–11510 (2015). [CrossRef] [PubMed]

15. T. Biswas, R. Chattopadhyay, and S. K. Bhadra, “Plasmonic hollow-core photonic band gap fiber for efficient sensing of biofluids,” J. Opt. 16(4), 045001 (2014). [CrossRef]

16. X. Yang, Y. Lu, M. Wang, and J. Yao, “An Exposed-Core Grapefruit Fibers Based Surface Plasmon Resonance Sensor,” Sensors (Basel) 15(7), 17106–17114 (2015). [CrossRef] [PubMed]

17. Y. Lu, J. Yao, X. Yang, and M. Wang, “Surface plasmon resonance sensor based on hollow-core PCFs filled with silver nanowires,” Electron. Lett. 51(21), 1675–1677 (2015). [CrossRef]

18. R. Otupiri, E. K. Akowuah, and S. Haxha, “Multi-channel SPR biosensor based on PCF for multi-analyte sensing applications,” Opt. Express 23(12), 15716–15727 (2015). [CrossRef] [PubMed]

19. S. I. Azzam, M. F. O. Hameed, R. E. A. Shehata, A. M. Heikal, and S. S. A. Obayya, “Multichannel photonic crystal fiber surface plasmon resonance based sensor,” Opt. Quantum Electron. 48(2), 142 (2016). [CrossRef]

20. N. Luan, R. Wang, W. Lv, and J. Yao, “Surface plasmon resonance sensor based on D-shaped microstructured optical fiber with hollow core,” Opt. Express 23(7), 8576–8582 (2015). [CrossRef] [PubMed]

21. Z. Tan, X. Li, Y. Chen, and P. Fan, “Improving the Sensitivity of Fiber Surface Plasmon Resonance Sensor by Filling Liquid in a Hollow Core Photonic Crystal Fiber,” Plasmonics 9(1), 167–173 (2014). [CrossRef]

22. J. N. Dash and R. Jha, “On the Performance of Graphene-Based D-Shaped Photonic Crystal Fibre Biosensor Using Surface Plasmon Resonance,” Plasmonics 10(5), 1123–1131 (2015). [CrossRef]

23. A. A. Rifat, G. A. Mahdiraji, R. Ahmed, D. M. Chow, Y. M. Sua, Y. G. Shee, and F. R. Mahamd Adikan, “Copper-Graphene-Based Photonic Crystal Fiber Plasmonic Biosensor,” IEEE Photonics J. 8(1), 1–8 (2016). [CrossRef]

24. A. A. Rifat, G. A. Mahdiraji, Y. M. Sua, Y. G. Shee, R. Ahmed, D. M. Chow, and F. R. M. Adikan, “Surface Plasmon Resonance Photonic Crystal Fiber Biosensor: A Practical Sensing Approach,” IEEE Photonics Technol. Lett. 27(15), 1628–1631 (2015). [CrossRef]

25. G. Amouzad Mahdiraji, D. M. Chow, S. R. Sandoghchi, F. Amirkhan, E. Dermosesian, K. S. Yeo, Z. Kakaei, M. Ghomeishi, S. Y. Poh, S. Yu Gang, and F. R. Mahamd Adikan, “Challenges and Solutions in Fabrication of Silica-Based Photonic Crystal Fibers: An Experimental Study,” Fiber Integr. Opt. 33(1-2), 85–104 (2014). [CrossRef]

26. P. Malinský, P. Slepička, V. Hnatowicz, and V. Svorčík, “Early stages of growth of gold layers sputter deposited on glass and silicon substrates,” Nanoscale Res. Lett. 7(1), 241 (2012). [CrossRef] [PubMed]

27. J. Chen, D. Brabant, W. J. Bock, P. Mikulic, and T. Eftimov, “Photonic crystal fiber refractive index sensor based on surface plasmon resonance,” Proceedings of SPIE - The International Society for Optical Engineering 7750, 77502K (2010).

Type of sensor	Ref.	Wavelength sensitivity	Amplitude sensitivity
Multi-hole fiber with analyte and metal film in the hole	[14]	2000nm/RIU	370 RIU⁻¹
Exposed-core grapefruit fiber with analyte around PCF	[13]	13500nm/RIU	NA
Hollow core photonic band gap fiber with analyte filled hollow core	[17]	2151nm/RIU	NA
D-shape PCF with analyte covered metal film	[19]	3700nm/RIU	216RIU⁻¹
Hollow core PCF with analyte in the hole	[22]	6430nm/RIU	NA
Two core PCF with analyte around PCF	[20]	4000 nm/RIU	320 RIU⁻¹
Our work	NA	6900nm/RIU	132RIU⁻¹

Practical sensing approach based on surface plasmon resonance in a photonic crystal fiber

Abstract

1. Introduction

2. Structure design and theoretical model

2.1 Structure design

2.2 Mode analysis

3. Results and performance analysis

3.1 Structural parameter optimization

3.2 Sensing performance analysis

4. Conclusion

Funding

References

Cited By

Figures (8)

Tables (1)

Equations (8)

OSA Continuum