D-shaped Photonic Crystal Fiber Research Articles

Single-mode D-shaped photonic crystal fiber surface plasmon resonance sensor with open microchannel

Accessible microchannels that allow microscale fluid control and microparticle-filtering are promising tools for advanced biological and chemical sensing and analysis. To this end, we proposed a d-shaped photonic crystal fiber surface plasmon resonance sensor with open microchannel. The optical characteristics of the sensor were numerically investigated using the Finite Element Method and the fiber structure was then fabricated using a standard stack-and-draw method. The numerical results demonstrate that the d-shaped photonic crystal fiber can be applied as a sensor with wide refractive index detection range between 1.330 and 1.435, a maximum sensitivity of 28400 nm/RIU, finest resolution of 3.52 × 10−6 RIU, and maximum figure-of-merit of 592 RIU−1. The sensor operates in the single-mode regime, has good linearity range, requires simple fabrication, has high coupling efficiency with conventional single-mode fibers, and has low losses, making it a practical candidate for wide range of applications in chemical and biological testing.

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.

Infrared D-type photonic crystal fiber sensor for special drug detection and wide-range refractive index detection

In the field of drug inspection, the refractive indices (RIs) of many halogenated ethers and drugs are in the lower range; for example, the RI of anesthetic sevoflurane is approximately 1.27. Infrared spectral detection technology has significant advantages in the field of drug detection; to realize the RI sensing of such drugs in the infrared region, a D-shaped photonic crystal fiber sensor based surface plasmon resonance was investigated in this study. The side polishing adopted here can significantly shorten the distance between the core and metal layer, making the energy of the core easier to detect, reducing the difficulty of coating the metal layer, and improving the performance of the sensor. The structure is provided with two large-sized air holes on both sides of the fiber core, so that the sensor is suitable for sensing in the low RI range and has high wavelength sensitivity in the low RI range. The sensor works mainly in the infrared band, with a detection range of 1.20–1.34, maximum wavelength sensitivity of 24,000 nm/RIU, and resolution of 4.1667 × 10 − 6 R I U . The sensor has excellent performance and is easy to manufacture due to the simple structure; it has broad application prospects in low RI range detection fields such as biomedicine, drug detection, environmental monitoring, and water quality monitoring.

Surface plasmon resonance sensor based on the dual core D-shape photonic crystal fiber for refractive index detection in liquids

A dual-core D-shape photonic crystal fiber sensor based on surface plasmon resonance is designed and analyzed numerically by the finite element method employing the perfectly matched layer boundary conditions. The resonance peaks shift as the analyte refractive indexes are varied. An average sensitivity of 17,200 nm / RIU is achieved in the RI range between 1.40 and 1.44 and the corresponding resolution is 5.8 × 10 − 6 RIU. The various factors affecting the sensing properties are assessed and in particular, the combined effects of two variables are evaluated.

Surface plasmon resonance sensor based on D-shaped photonic crystal fiber for low refractive index detection

A D-shaped photonic crystal fiber (PCF) low refractive index (RI) sensor based on surface plasmon resonance (SPR) is proposed, and its properties are investigated by the finite element method. Gold is selected as the plasmonic material and coated on the open-ring structure to excite the plasmonic modes. The simulation results indicate that the sensor can detect the RI in the range of 1.00 to 1.29, which is a fairly wide detection range in the detection field of SPR-based PCF low RI sensors. When the analyte of the RI varies from 1.28 to 1.29, the maximum sensitivity of 10,000 nm / RIU and the corresponding resolution of 1 × 10 − 5 RIU are obtained in the wavelength range of 1.6 to 2.4 μm. When the RI of the analyte changes from 1.00 to 1.29, the relationship curve between the RI and the resonance wavelength fits well, and the adjusted R2 value is 0.99609. Furthermore, the sensor achieves the figure of merit of 56.98 RIU − 1 and an amplitude sensitivity of 82.76 RIU − 1, respectively. Therefore, the designed sensor can be effectively applied to low RI detection, having a certain commercial potential in medical detection, organic chemistry detections, and related applications.

Micro-Channel Plasmon Sensor Based on a D-Shaped Photonic Crystal Fiber for Malaria Diagnosis With Improved Performance

In this paper, a D-shaped photonic crystal fiber (PCF) sensor based on surface plasmon resonance with a micro-rectangular opening is proposed. The micro-rectangular opening introduces strong coupling between the metal layer and the core-guided mode as it helps in reducing the distance between the sensing channel and the core of the PCF. Gold (Au) is a noble plasmonic material, which is deposited on the micro-rectangular opening in order to generate an ample amount of surface plasmon on the micro-opening area’s surface. This micro opening also allows for the ease of fabrication while maintaining strong bio-detection capabilities. The obtained results as maximum wavelength sensitivity, resolution, and figure of merit are 67,000 nm/RIU, <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${1.5} \times {10}^{-{6}}$ </tex-math></inline-formula> RIU and 279.16 RIU <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$^{-{1}}$ </tex-math></inline-formula> respectively. These results indicate that they are significantly finer than those existing in the related state of the art, and that the proposed fiber sensor is easy to fabricate. Further, the proposed fiber sensor is utilized for the detection of malaria disease. The proposed sensor’s computed sensitivities for ring stage, trophozoite stage, and schizont stage RBCs of malaria disease are 25,715.30 nm/RIU, 33,157.89 nm/RIU, and 44,827.58 nm/RIU, respectively.

D-Shaped Tellurite Photonic Crystal Fiber Hydrogen and Methane Sensor Based on Four-Wave Mixing With SPR Effect

A new D-shaped tellurite photonic crystal fiber sensor based on the four-wave mixing (FWM) effect with the surface plasmon resonance (SPR) effect is designed and optimized. The substrate of the D-shaped photonic crystal fiber (D-PCF) is tellurite glass, and the polished surface is plated with the gold film and hydrogen gas-sensitive film. An air hole of the inner cladding, which is plated with the gold film and methane gas-sensitive film, is selected as the second sensing channel to simultaneously measure the concentration of hydrogen and methane. Based on the four-wave mixing, the wavelength shifts of the Stokes and anti-Stokes spectra resulting from the variation of the gas concentration can be used to accurately detect the concentrations of methane and hydrogen. Meanwhile, it is found that the SPR effect can increase the wavelength shifts, which means the sensitivity of methane and hydrogen augment. After parameter optimization, the maximum sensitivities of methane and hydrogen are 4.03 nm/% and −14.19 nm/%, respectively. Both the linearities are up to 99.9%. The resolution of methane is 1.25×10−2% and hydrogen is 7.14×10−3%. Moreover, the fiber length of this sensor is only 20 mm, which is conducive to the construction of a compact or ultra-compact embedded FWM fiber sensor.

A high sensitivity localized surface plasmon resonance sensor based on D-shaped photonic crystal fiber for low refractive index detection

A high sensitivity localized surface plasmon resonance sensor based on D-shaped photonic crystal fiber for low refractive index detection

D-Shaped Surface Plasmon Photonic Crystal Fiber Temperature Sensor

A D-shaped photonic crystal fiber (PCF) temperature sensor based on surface plasmon resonance (SPR) with high sensitivity and high figure of merit is presented in this paper. To enhance surface plasmon resonance, the gold film is deposited on the polished flat of D-shaped photonic crystal fiber. Ethanol and chloroform are employed as temperature-sensitive materials, which are placed on the outside of the fiber to detect temperature changes. When the phase-matching condition is met, the core mode couples with the surface plasma mode. The finite element method is used to perform all numerical simulations of sensor characteristics in the COMSOL software. The results show that the highest sensitivity of the sensor can reach 6.36 nm/°C and the maximum figure of merit (FOM) is 0.3440/°C in the range of −5 ~ 60 °C. To our knowledge, the achieved sensing characteristics are significantly better than those of the current PCF temperature sensors. Furthermore, excellent linearity with a polynomial fit R2 as high as 0.9981. The proposed sensor has exceptional performance in terms of temperature detection range, sensitivity, FOM, and fabrication, making it suitable for a wide variety of biochemical and medical applications.

Plasmonic photonic crystal fiber sensor for optical partial discharge detection

Detection of partial discharge (PD) is vital to reassure the operation reliability of high voltage (HV) electrical power systems. Optical detection methods have been developed in recent years due to their high sensitivity and immunity to electromagnetic interference. In this work, D-shaped photonic crystal fiber sensor based on surface plasmon resonance is reported for optical PD detection in HV equipment. A photochromic spirooxazine dye-doped silica sol–gel is utilized for sensing the UV radiation emitted from the PD. The sol–gel refractive index depends on the radiation intensity which affects the resonance wavelength where coupling occurs between the core and surface plasmon modes. The sensing performance is demonstrated with the help of full vectorial finite element method (FVFEM). The geometrical parameters are studied to maximize the sensor sensitivity where high sensitivity of 2.4 nm/mW.cm−2 is achieved. To the best of our knowledge, it is the first time to use a simple design of plasmonic PCF for optical PD detection.

A Reconfigurable Surface-Plasmon-Based Filter/Sensor Using D-Shaped Photonic Crystal Fiber.

A reconfigurable surface-plasmon-based filter/sensor using D-shaped photonic crystal fiber is proposed. Initially a D-shaped PCF is designed and optimized to realize the highly birefringence and by ensuring the single polarization filter. A tiny layer of silver is placed on the flat surface of the D-shaped fiber with a small half-circular opening to activate the plasmon modes. By the surface plasmon effect a maximum confinement loss of about 713 dB/cm is realized at the operating wavelength of 1.98 µm in X-polarized mode. At this wavelength the proposed fiber only allows Y-polarization and filters the X-polarization using surface plasmon resonance. It is also exhibiting maximum confinement loss of about 426 dB/cm at wavelength 1.92 µm wavelength for Y-polarization. At this 1.92 µm wavelength the proposed structure attenuated the Y-polarization completely and allowed X-polarization alone. The proposed PCF polarization filter can be extended as a sensor by adding an analyte outside this filter structure. The proposed sensor can detect even a small refractive index (RI) variation of analytes ranging from 1.34–1.37. This sensor provides the maximum sensitivity of about 5000 nm/RIU; it enables this sensor to be ideally suited for various biosensing and industrial applications.

Highly sensitive fiber optic biosensors with graphene-MoS2 heterostructure for hemoglobin detection

Two-dimensional materials, which can be used to modify sensor surfaces to increase sensor sensitivity, have important research in the field of sensors. In this paper, we design a highly sensitive D-shaped photonic crystal fiber sensor with graphene-MoS2 heterostructure for hemoglobin detection. The research utilized the finite element method and involved addition of different layers of graphene and MoS2 to the optical fiber sensing area, and it was determined that the hybrid nano-heterostructures made of monolayer graphene and bilayer MoS2 provided the greatest improvement in sensor performance. The sensor shows excellent detection performance in 1.33∼1.38 refractive index units. Using incident light in the wavelength ranges of 650 nm and 850 nm, the proposed sensor has a maximum wavelength sensitivity of 4700 nm/RIU, a maximum amplitude sensitivity of 327.5 RIU-1, and a resolution of 2.17×10−5 RIU. The range of hemoglobin concentrations detected with this sensor was 0 g/L∼241 g/L, with an average sensitivity of 0.7 nm/(g/L). A fiber biosensor was enhanced with graphene-MoS2 hybrid nanostructures, which exhibit excellent photoelectric properties and detection performance, enabling highly sensitive, highly accurate, and real-time hemoglobin detection. The result shows the significant research value and application prospects in the field of biomedical detection.

Wide refractive index detection range surface plasmon resonance sensor based on D-shaped photonic crystal fiber

We propose and simulate a surface plasmon resonance (SPR) refractive index (RI) sensor based on a novel D-shaped photonic crystal fiber. We used an open air hole coated with gold film to improve SPR effect. The sensor uses photonic crystal fiber with the same air holes diameter. The effects of structural parameters on resonance spectrum were analyzed by finite element method (FEM). Three SPR peaks were obtained in the wavelength range of 800–1300 nm. The maximum sensitivity is 5626.86 nm/RIU and the maximum resolution is 1.78 × 10−5 RIU at the refractive index of 1.38. The simulation results show that the refractive index detection range of the sensor is 1.26–1.38. Compared with other D-shaped structures, our sensor can measure larger RI ranges of the analyte.

High Birefringence D-Shaped Germanium-Doped Photonic Crystal Fiber Sensor.

In this work, a surface plasmon resonance (SPR) sensor based on a D-shaped germanium-doped photonic crystal fiber (PCF) is proposed. The finite element method (FEM) is introduced to analyze the structure parameters, such as germanium-doped concentration, lattice pitch, and air hole size. In addition, the coupling properties and birefringence properties of PCF are also studied. The computer simulation results indicate that two different surface plasmon polariton (SPP) coupling modes are produced on the polished surface, covered with metal film, when the analyte refractive index (RI) is . Then, with the increase of the RI, the incompleteness of one of the coupling modes will be transformed into the complete coupling. The effect of germanium concentration on the birefringence is also analyzed. It has an optimal wavelength sensitivity of 5600 nm/RIU when the RI is 1.37. This sensor exhibits a maximum birefringence of 1.06 × 10−2 and a resolution of 1.78 × 10−5 RIU with high linearity.

Surface plasmon resonance biosensor based on a D-shaped photonic crystal fiber using Ti3C2Tx MXene material

In this article, an Au/Ti3C2Tx MXene hybrid layered D-shaped Photonic Crystal Fiber (DPCF) based Surface Plasmonic Resonance (SPR) biosensor is proposed. The D-shape of PCF is used to make the sensor practically more feasible. The MXene-Au hybrid thin films are placed over the DPCF to induce the surface plasmon polariton (SPP). The resonance wavelength shift occurs when analytes refractive index (RI) is changed. The numerical analysis has been performed by finite element analysis. The results have shown the wavelength sensitivity of 7000 nm/RIU and 13,000 nm/RIU for MXene layer thickness of 14 nm and 27 nm respectively. On comparing, it has been observed that the MXene/Au layered sensor has achieved 3.5 to 6.5 times higher wavelength-sensitivity compared to without MXene thin film. In addition, sensing parameters like resolution, amplitude sensitivity and figure of merit has also been investigated. The proposed sensor is used for sensing the analytes having RI range of 1.33–1.39. The range of RI covers most of the blood cells compositions, cancerous cells, protein and viruses. Therefore, this study can facilitate the use of MXene material with D-shaped PCF to detect the biochemical and chemical liquids. Index termsPhotonic crystal fiber, MXene material, Gold, Surface plasmon resonance, Biomolecules.

Graphene-assisted tunable D-shaped photonic crystal fiber sensor in the visible and IR regions

A simple design of a D-shaped photonic crystal fiber sensor with 10 layers of graphene on the surface plasmon of gold is proposed for tuning refractive index (RI) sensitivity in the visible and IR regions. The proposed structure has been simulated by optimizing the mesh size and the method of finite-difference eigenmode. By tuning the chemical potential of graphene ( μ c ), we realize tunable and enhanced RI sensing for a wide RI range from 1.35 to 1.42. The maximum wavelength sensitivities of the proposed sensor are 5200 nm/RIU, 6000 nm/RIU, and 7500 nm/RIU for μ c = 0.8 e v , 1.0 ev, and 1.2 ev, respectively. Further, sensor characteristic parameters such as amplitude sensitivity, resolution, and figure of merit have been investigated for different chemical potentials. All dramatic changes in sensor parameters show an advancement plan to control and tune RI-based optical sensors assisted by graphene.

Surface plasmon resonance (SPR)-based D-shaped photonic crystal fiber polarization filter and refractive index sensor with a hexagonal pore structure

A D-shaped photonic crystal fiber (PCF) polarization filter and sensor with a standard hexagonal arrangement of pores is designed. The effects of geometric parameters, metal film thickness, liquid refractive index, and optical material refractive index on polarization filtering and sensing characteristics are analyzed by the finite element method (FEM). The proposed PCF shows single-polarization filtering in communication window and has ultra-high corresponding bandwidth. At the 1.55 µm communication window band, the confinement loss of the y-polarized core mode is 819.27 dB/cm, while the x-polarized core mode is only 3.45 dB/cm. The crosstalk (CT) reached a maximum of 708.6 dB in the communication bands, and the corresponding bandwidth reaches 1000 µm when the fiber length is 1 mm. Meanwhile, the D-type PCF is widely used in sensing because it avoids filling the gold film and analyte in the internal pores. The change in the thickness of the mental coating from 39 nm to 22 nm provides the proposed PCF with sensing properties. By reducing the refractive index of fiber material, the maximum sensitivity is 10,741 nm/RIU. When the refractive index measurement range of the analyte is specified from 1.33 to 1.36, the average sensitivity reaches 7313 nm/RIU. Good performance enables the proposed compatible filtering and sensing PCF may be used in a wide range of scenarios.

Refractive index (RI) sensing by a D-shaped photonic crystal fiber with a deposited graphene–polymethyl methacrylate (PMMA) platform

A D-shaped photonic crystal fiber (PCF) with graphene-polymethyl methacrylate (PMMA) stack was employed to determine the refractive index from 1.33 to 1.41 and improve the extinction ratio. The proposed sensor was numerically analyzed using the finite element method. The polishing depth, period of the graphene-PMMA stack, and number of graphene layers on the sensing performance of the proposed structure were evaluated. The results indicate that the spectrum and sensitivity may be modulated. The proposed sensor exhibits a wavelength sensitivity of 2200 nm/RIU, a wavelength resolution of 4.54 × 10−5 RIU, and linearity of 0.9918 with a high extinction ratio. Thus, this device has potential applications in PCF sensors.

Microchannel-Embedded D-Shaped Photonic Crystal Fiber-Based Highly Sensitive Plasmonic Biosensor

An improved design of a D-shaped photonic crystal fiber (PCF)-based refractive index (RI) sensor is proposed that uses the surface plasmon resonance phenomenon. The sensor consists of a large semicircular open channel that is inserted at the upside of the D-shaped PCF. A thin plasmonic sensing layer is deposited on the interior surface of the channel to excite the surface plasmon wave that eliminates the requirement of additional effort to fabricate a well-polished sensing layer of the D-shaped sensor. The sensor’s optical properties are numerically explored by the finite element method. The sensor is optimized to detect the RI of biological and biochemical analytes in the range of 1.33 to 1.44, shows spectral sensitivity as high as 63,000 nm/RIU with a spectral resolution of 1.59 × 10−06 RIU, and maximum amplitude sensitivity of 1439 RIU−1 with a resolution of 6.94 × 10−06 RIU. It is also found that the sensor’s linearity parameter is very high with a large figure of merit of about 839. Additionally, the sensor’s fabrication tolerance is studied by varying its structural parameters. Therefore, high sensing parameters with a wide detection range make this microchannel-based D-shaped PCF sensor an appropriate device for the application of biological and biochemical analyte detection.

Bragg grating sensor for refractive index based on a D-shaped circular photonic crystal fiber.

In this paper, a silica-based D-shaped circular photonic crystal fiber Bragg grating sensor for refractive index sensing is proposed theoretically. D-shaped fiber construction can effectively enhance the coupling effect between the guiding mode and external liquid analyte, which then causes a distinct shift in the typical reflection spectrum as the refractive index of the analyte varies. This design exhibits highly improved sensitivity of 487 nm/RIU in a large refractive index range from 1.30 to 1.40 compared with the previous fiber grating sensors. Study of the dependence of sensing performance on the structure parameters suggests that the resonance peak shifts towards longer wavelengths with the increased air-hole diameter of fiber, while it is almost immobile as the hole spacing and the number of air-hole layers change in a certain range. For the influence of the Bragg grating structure, results show that the resonance peak is not sensitive to the grating length, but linearly increases as the grating period expands. The effects of polishing depth and fiber preparation error on the sensor are also discussed in detail. This high-sensitivity sensor based on a D-shaped photonic crystal fiber and Bragg grating has great potential in biochemical detection, environmental monitoring, and medical sensing.