Plasmonic Photonic Crystal Fiber Research Articles

A Plasmonic Photonic Crystal Fiber Sensor with Simplified Features for Identifying Unidentified Analytes

A Plasmonic Photonic Crystal Fiber Sensor with Simplified Features for Identifying Unidentified Analytes

Design and simulation of a compact plasmonic photonic crystal fiber filter with wide band and high extinction ratio

In order to realize the performance optimization and function expansion of modern all-optical systems, this work presents a compact plasmonic photonic crystal fiber (PCF) filter, using finite element tool. The deposited gold and graphene layers within the elliptical pores interact with the transmitted light, creating surface plasmon resonance (SPR) effect that amplifies the energy difference between x- and y-polarized light greatly. The simulation results indicate that the structural parameters are configured with the cladding holes' diameter of 0.6 μm, the large-holes’ diameter of 1.2 μm, the inner small-holes’ diameter of 0.2 μm, the lattice constant of 2.0 μm, the elliptical holes' minor axis length of 0.45 μm, the elliptical holes' major axis length of 1.30 μm, the gold layer thickness of 50 nm, and the graphene layer thickness of 20 nm, the central wavelength of the proposed PCF filter is 1.56 μm. When the length of this PCF filter is 1 mm, a maximum extinction ratio (ER) of 133 dB, an operating bandwidth exceeding 800 nm, covering two common communication windows of 1.31 μm and 1.55 μm, as well as a low insertion loss (IL) of 0.59 dB can be achieved. What's more, the feasibility of fabricating the device is also examined. This filter with compactness, broadband and high-extinction demonstrates promising applications in optical communication, optical sensing, optical computing, and various other fields.

A Simple Structure of High Sensitivity of Plasmonic Photonic Crystal Fiber Sensors with Minimal Air Hole Density in Fiber Cladding

A Simple Structure of High Sensitivity of Plasmonic Photonic Crystal Fiber Sensors with Minimal Air Hole Density in Fiber Cladding

Cancer cell detection by plasmonic dual V-shaped PCF biosensor

In this paper, a highly sensitive plasmonic photonic crystal fiber (PCF) biosensor is reported for cancer cell detection. The modal analysis of the reported biosensor is performed using the full vectorial finite element method. The suggested PCF sensor has dual V-shaped groves to enhance the sensor sensitivity where two gold nano-rods are mounted on the etched surfaces. The main idea of the optical sensors is to track the electromagnetic coupling between the leaky core mode and the surface plasmon mode (SPM) at the metal/dielectric interface. When the SPM and one of the fundamental core modes are phase-matched, strong coupling occurs. Therefore, maximum confinement loss is achieved for the core-guided mode at the resonance wavelength, which depends on the analyte refractive index (RI). The V-shaped groove enhances the core/SPM coupling where high RI sensitivity of 24,000 nm/RIU is achieved along the RI range from 1.38 to 1.39, with a resolution of 2.703×10−6RIU. The potential of using the suggested RI sensor for cancer cell detection is then demonstrated. In this context, high sensitivities of 23,700 nm/RIU, 8,208 nm/RIU, and 14,428.6 are obtained for basal, cervical, and breast cancer cells with resolutions of 4.22×10−6RIU, 12.18×10−6RIU, and 6.93×10−6RIU, respectively. The achieved sensitivity and resolution are higher than those of the recently reported cancer biosensors. Moreover, the developed label-free biosensor is safer than other chemical and surgical techniques.

Design of Plasmonic Photonic Crystal Fiber for Highly Sensitive Magnetic Field and Temperature Simultaneous Measurement.

A high-sensitivity plasmonic photonic crystal fiber (PCF) sensor is designed and a metal thin film is embedded for achieving surface plasmon resonance (SPR), which can detect the magnetic field and temperature simultaneously. Within the plasmonic PCF sensor, the SPR sensing is accomplished by coating both the upper sensing channel (Ch1) and the lower sensing channel (Ch2) with gold film. In addition, the temperature-sensitive medium polydimethylsiloxane (PDMS) is chosen to fill in Ch1, allowing the sensor to respond to the temperature. The magnetic field-sensitive medium magnetic fluid (MF) is chosen to fill in Ch2, allowing this sensor to respond to the magnetic field. During these processes, this proposed SPR-PCF sensor can achieve dual-parameter sensing. The paper also investigates the electrical field characteristics, structural parameters and sensing performance using COMSOL. Finally, under the magnetic field range of 50-130 Oe, this sensor has magnetic field sensing sensitivities of 0 pm/Oe (Ch1) and 235 pm/Oe (Ch2). In addition, this paper also investigates the response of temperature. Under the temperature range of 20-40 °C, Ch1 and Ch2 have temperature sensitivities of -2000 pm/°C and 0 pm/°C, respectively. It is noteworthy that the two sensing channels respond to only a single physical parameter; this sensing performance is not common in dual-parameter sensing. Due to this sensing performance, it can be found that the magnetic field and temperature can be detected by this designed SPR-PCF sensor simultaneously without founding and calculating a sensing matrix. This sensing performance can solve the cross-sensitivity problem of magnetic field and temperature, thus reducing the measurement error. Since it can sense without a matrix, it further can solve the ill-conditioned matrix and nonlinear change in sensitivity problems in dual-parameter sensing. These excellent sensing capabilities are very important for carrying out multiparameter sensing in complicated environments.

Experimental and numerical characterization of a D-shaped PCF refractive index sensor

Highly sensitive D-shaped plasmonic photonic crystal fiber (PCF) sensor is proposed, analyzed and fabricated for refractive index (RI) sensing. The reported sensor relies on the coupling between the core guided mode and the surface plasmon mode at the metallic/dielectric interface. The resonance frequency is a function of the analyte RI within a range of 1.33–1.354. Therefore, the reported D-shaped PCF holds great potential as a highly sensitive RI sensor to detect an unknown analyte refractive index within the tested RI range. The geometrical parameters are studied to maximize the sensor sensitivity by using full vectorial finite element method. Then, the optimum design is fabricated by using stack and draw technique. The fabricated PCF sensor achieves high sensitivity of 294.11 nm/RIU with a resolution of 3.4 times 10^{ - 4} ;{text{RIU}}. The reported RI sensor can be used for glucose concentration detection where the analyte refractive index changes with the glucose concentration within the studied RI range. Hence, this design will play a significant role in the biomedical sensor industry.

Refractive index sensor based on plasmonic D-shaped photonic crystal fiber with pyramid grating

In this work, highly sensitive D-shaped photonic crystal fiber (PCF) sensor with plasmonic pyramid grating is introduced and analyzed. The sensing mechanism depends on the coupling between the fundamental core mode and the surface plasmon mode around the plasmonic pyramid grating. The resonance frequency depends on the analyte refractive index (RI) which can be employed to detect the analyte RI changes. The geometrical parameters of the proposed PCF and gold pyramid grating are studied to enhance the RI sensor sensitivity. The simulation results are obtained using full vectorial finite element method. The suggested sensor has higher sensitivity of 5200 nm/RIU than 3340 nm/RIU of the conventional grating design through the studied RI range from 1.355 to 1.385. Therefore, the reported RI sensor can be used for basal cancer cell detection with normal and cancerous cells’ refractive indices of 1.36 and 1.38, respectively. Additionally, linear performance is achieved using the reported design.

Efficient Partial Discharge Detection by Plasmonic Photonic Crystal Fiber Sensor With Bimetallic Grating

In this article, a new approach for optical partial discharge (PD) detection in gas-insulted systems is introduced for the first time to the best of our knowledge. The suggested sensor is based on plasmonic D-shaped photonic crystal fiber (PCF). Further, bimetallic grating structure of Ag/Au is utilized to enhance the sensor sensitivity. For light detection, methyl-red-doped poly (methyl methacrylate) polymer (MR-PMMA) is used as a sensing material for its photochromic characteristics and its fast response to visible light radiation. At resonance, good coupling occurs between the surface plasmon mode and the core guided mode. The radiated light intensity reflects the charge magnitude of the occurred PD process which can be detected by calculating the shift in the resonance wavelength of the loss spectra. The structural geometrical parameters are studied to improve the sensing performance using full vectorial finite-element method. The proposed sensor achieves high sensitivity of 667 pm/mW<inline-formula> <tex-math notation="LaTeX">$\cdot $ </tex-math></inline-formula>cm^&#x2212;2 with a linear performance with the light intensity. Moreover, the proposed sensor has advantages of simple and compact design, fabrication feasibility, electromagnetic interference immunity, fast response, and high sensitivity relative to conventional PD detection techniques using electrical methods. The designed sensor can be also utilized for laboratory testing and it could be evolved to accomplish real-time detection of PD phenomenon in gas-insulted systems.

Maximizing spectral sensitivity of plasmonic photonic crystal fiber sensor

We propose a novel design for a plasmonic photonic crystal fiber (PCF) sensor. Our design includes a metal film incorporated within the PCF structure. Compared to previously discussed sensing configurations, the metal surface does not come in direct contact with the sample being tested in our design. The metal film serves to provide absorption due to the excitation of surface plasmon-polaritons (SPP). This absorption is enhanced when a PCF-guided mode resonantly couples to the SPP, or in other words when phase matching between the mode and the SPP is satisfied. We consider a configuration where a hollow PCF core is filled with a liquid sample, while the metal surfaces are kept tens of microns away within the PCF cladding. Our sensor detects small changes in the sample's refractive index, over a broad wavelength range, by taking advantage of the refractive index sensitivity of the resonance/phase-matching condition. We model the sensor and characterize its performance by using the COMSOL environment based on the finite element method. We evaluate and compare three elements: gold, silver, and copper, in order to increase the absorption at particular wavelengths. We also vary the thickness of the metal layer and optimize it to enhance the sensitivity. The results show a performance that exceeds a minimal sensor resolution over an ultra-broad spectral range while maintaining a reasonable amplitude sensitivity.

DNA Hybridization Detection based on Plasmonic Photonic Crystal Fiber

A novel design of surface plasmon (SP) photonic crystal fiber (PCF) for DNA hybridization detection is proposed and analyzed. The suggested biosensor relies on plasmonic D-shaped PCF configuration. Accordingly, the core guided mode in the silica core is coupled with the SP mode near the plasmonic layer. The resonance wavelength is sensitive to the DNA hybridization process. Therefore, the suggested bio-sensor is studied to maximize the DNA hybridization detection sensitivity by adjusting the structural geometrical parameters. The numerical results are obtained using full vectorial finite element method with perfectly matched layer boundary condition and non-uniform meshing capabilities. The reported D-shaped PCF offers high wavelength sensitivity of 405.4 nm/RIU with a corresponding amplitude sensitivity of 5.65 RIU−1. Consequently, the applications based on DNA classification can be potentially implemented by the reported biosensor.

Highly Sensitive Twin Resonance Coupling Refractive Index Sensor Based on Gold- and MgF2-Coated Nano Metal Films.

A plasmonic material-coated circular-shaped photonic crystal fiber (C-PCF) sensor based on surface plasmon resonance (SPR) is proposed to explore the optical guiding performance of the refractive index (RI) sensing at 1.7–3.7 m. A twin resonance coupling profile is observed by selectively infiltrating liquid using finite element method (FEM). A nano-ring gold layer with a magnesium fluoride (MgF) coating and fused silica are used as plasmonic and base material, respectively, that help to achieve maximum sensing performance. RI analytes are highly sensitive to SPR and are injected into the outmost air holes of the cladding. The highest sensitivity of 27,958.49 nm/RIU, birefringence of 3.9 × , resolution of 3.70094 × RIU, and transmittance dip of −34 dB are achieved. The proposed work is a purely numerical simulation with proper optimization. The value of optimization has been referred to with an experimental tolerance value, but at the same time it has been ensured that it is not fabricated and tested. In summary, the explored C-PCF can widely be eligible for RI-based sensing applications for its excellent performance, which makes it a solid candidate for next generation biosensing applications.

Design and Theoretical Analysis of a Dual-Polarized Quasi D-Shaped Plasmonic PCF Microsensor for Back-to-Back Measurement of Refractive Index and Temperature

We present a new quasi D-shaped plasmonic photonic crystal fiber (PCF) microsensor with dual polarization for back-to-back measurement of refractive index (RI) and temperature. The PCF structure of the microsensor is form birefringent and supports two orthogonal polarizations for independent probing of both RI and temperature variations. Thin layers of tantalum pentoxide (Ta2O5) and gold (Au) are applied to the side-polished plane to form the RI sensing section. Furthermore, four micro air holes in the lower part of its outer cladding ring are gold-coated and selectively infiltrated with a temperature-sensitive liquid. A detailed investigation and numerical analyses of the coupling characteristics and sensing responses are presented using the finite element method (FEM) with a circular perfectly matched layer (PML). The RI metrics show a maximum wavelength sensitivity of 5000 nm/RIU and a maximum amplitude sensitivity of 266.54 RIU−1 from 1.35 to 1.46 RI range in the specified operating wavelength range of 1.25- $1.65~\mu \text{m}$ . The corresponding RI resolution is $2.0\times 10^{-5}$ RIU. For the temperature sensing metrics, a maximum amplitude sensitivity of $4.8\times 10^{-2}\,\,^\circ \text{C}^{-1}$ , a maximum wavelength sensitivity of 3.0 nm/°C, and a maximum resolution of $3.33\times 10^{-2}\,\,^{\circ }\text{C}$ from −50°C to 50°C is achieved. With appropriate instrumentation incorporating a polarization selector, the microsensor can double as a real-time simultaneous multiparameter sensor. Applications for the proposed microsensor can be found in molecular science, medical measurement and analysis, terrestrial environmental engineering and data assessment, aquatic ecosystem investigations, pharmaceutical and alimentary process control and validation, cryogenic studies, and several others.

A Review of Plasmonic Photonic Crystal Fiber

"Nanophotonics technology is the study of the confinement of electromagnetic fields on a subwavelength scale and surface plasmons plays a major role in advancing this arising field. They can take various forms, ranging from freely propagating electron density waves along metal surfaces to localized electron oscillations on metal nanoparticles. The interaction between the free electrons' oscillations and electromagnetic waves of light gives the surface plasmons their appealing characteristics. Their ability of light confinement and propagation through subwavelength structures grants the construction of photonic devices with minimum size, hence the characterize and design of plasmonic devices can be resolved using numerical simulation. This review starts with general introduction about Plasmonic photonic crystal fiber. This is followed by a historical background and literature review of Plasmonic PCF. Some types of designs are illustrated. Finally, the applications of Plasmonic PCF are mentioned dependent on the types of design including the circular plasmonic photonic crystal fiber technique.

New Plasmonic Photonic Crystal Fiber Sensor based on Core Size

New Plasmonic Photonic Crystal Fiber Sensor based on Core Size

A miniaturized and high-bandwidth polarization filter based on a plasmonic and liquid crystal offset core photonic crystal fiber

Miniaturized and broadband polarization-dependent filters with high crosstalk values are extremely desirable for practical applications in the fields of optical communications and sensing. A miniaturized photonic crystal fiber (PCF) with highly broadband polarization filtering properties is proposed in this paper. Two relatively large air holes coated with a gold film on opposite sides of the liquid crystal-filled offset core are introduced in this PCF structure to produce highly broadband polarization-dependent filtering transmissions. The impacts of the filtering properties with variable structural parameters have been studied based on the finite element method. By altering the gold film thickness (t) to be 18.7 nm and 13.8 nm, the proposed broadband polarization filter offers high resonance peaks of 2041.79 dB/cm and 2342.88 dB/cm for y-polarized mode at the wavelengths of 1.31 μm and 1.55 μm, while the corresponding loss for x-polarized one is 0.10 dB/cm and 0.83 dB/cm, respectively. Moreover, the crosstalk of the 100-μm-long PCF polarization filter with t = 18.7 nm and t = 13.8 nm is up to 177.34 dB and 203.43 dB at 1.31 μm and 1.55 μm, respectively. As the fiber length is 100 μm, the bandwidth with the crosstalk less than − 20 dB can be up to 1200 nm, from 1.2 to 2.4 μm. In addition, the proposed broadband and miniaturized PCF filter is not sensitive to the temperature variation and exhibits stable filtering characteristics with the ± 1% fabrication tolerances.

Effects of holes radius on plasmonic photonic crystal fiber sensor with internal gold layer

In this study, a plasmonic photonic crystal fiber (PCF) sensor was designed with an internal gold layer between the liquid holes and the air holes. The study shown that the thickness of the gold layer, the radius of the air holes and the radius of the liquid holes all have a significant effect on the sensitivity of the sensor, where a wavelength sensitivity of (10,500 nm/RIU) was achieved at certain simulation conditions. Under these chosen conditions, the relationship of resonance wavelength with the refractive index of the liquid was linear and this gives flexibility to extend the range of the refractive index of the analyte without changing the sensor design. Approaching or moving away of the holes from center in the proposed design has a fundamental role in determining the sensor characteristics.

Ultra-short polarization splitter based on a plasmonic dual-core photonic crystal fiber with an ultra-broad bandwidth.

A compact polarization beam splitter based on a gold-filled photonic crystal fiber with a square lattice is proposed. The full vector finite element method is used to design and characterize the proposed ultra-compact and ultra-broadband polarization splitter. The plasmonic plays an important role in order to achieve an ultra-short length of 56.33 µm with a high extinction ratio of 132.92 dB at the wavelength of 1.55 µm. It can ensure an ultra-broad bandwidth of 530 nm, from 1225 to 1755 nm, covering all the communication bands with an extinction ratio better than 20 dB. The proposed polarization splitter may be a promising candidate in communication due to its ultra-short length and ultra-broad bandwidth.

Plasmonic Nodeless Hollow-Core Photonic Crystal Fibers for In-Fiber Polarizers

A novel plasmonic nodeless hollow-core photonic crystal fiber (NHC-PCF) is proposed based on selective metal incorporation in the cladding tubes. The polarization filtering characteristics of the plasmonic NHC-PCF are investigated in detail. The effects of the fiber structural parameters such as cladding tube thickness, tube diameter, tube gap, and core diameter on the polarization characteristics are fully discussed. The coupling mechanism between core modes and specific surface plasmon polariton (SPP) modes at resonant wavelengths is analyzed, which clarifies the different confinement losses of core modes in two perpendicular directions for both gold-filled and gold-coated NHC-PCFs. In addition, enhanced polarization filtering function can be implemented by double gold incorporation structures, especially, the particular SPP supermode coupling is noticed. The in-fiber NHC-PCF polarizers with the wavelength range of 1310–1550 nm are then designed. Our detailed results will benefit understanding of SPPs in the hollow-core PCFs and accelerate realization of the compact NHC-PCF polarization devices and their wide applications.

Modified D-shaped SPR PCF polarization filter at telecommunication wavelengths

A compact surface plasmon photonic crystal fiber (PCF) polarization filter is proposed and analyzed at the two communication windows of 1.3 and 1.52 µm. The y-polarized mode can be filtered out at wavelength of 1.3 µm while the x-polarized mode can be excluded at λ = 1.52 µm using the same design. The effects of the geometrical parameters of the PCF on the polarization filter performance are studied by full vectorial finite element method. The numerical simulations reveal that the suggested polarization filter with a compact device length of 23 µm can achieve good crosstalk (CT) of − 46.4 and − 41.2 dB at the communication wavelengths of 1.3 and 1.52 µm, respectively. Further, bandwidths of 45 nm and 110 nm can be obtained around λ = 1.3 µm and 1.52 µm, respectively where the CT is better than − 20 dB. Therefore, the reported design has advantages in terms of low crosstalk, large bandwidth, short device length and multi-functionality.

Multifunctional surface plasmon resonance photonic-crystal fiber polarization filter at telecommunication wavelengths

A compact surface plasmon photonic-crystal fiber (PCF) polarization filter is proposed and analyzed at the two communication windows of 1310 and 1490 nm, respectively. The x-polarized mode can be filtered out at the wavelength of 1310 nm, while the y-polarized mode can be excluded at λ = 1490 nm. Therefore, the reported PCF design can be used as x-polarized or y-polarized filters using the same design. The effects of the geometrical parameters of the PCF on the performances of the polarization filter are studied by the full vectorial finite-element method. The numerical simulations reveal that the suggested polarization filter with a compact length of 150 μm can achieve good cross talk (CT) of −78 and −80.7 dB at the communication wavelengths of 1310 and 1490 nm, respectively. Further, bandwidths (BW) of 97 nm and 580 nm can be obtained around wavelengths of 1310 and 1490 nm, respectively, where the CT is better than −20 dB. Therefore, the reported design has advantages in terms of low cross talk, large BW, short device length, and multifunctionality.