Showing papers on "Photonic-crystal fiber published in 2023"

High confidence plasmonic sensor based on photonic crystal fiber with U-shaped detection channel

Abstract: In order to improve the performance of optical fiber sensing and expand its application scenarios, a photonic crystal fiber (PCF) plasmonic sensor with a U-shaped detection channel based on the...

Advances in Photonic Crystal Fiber-Based Sensor for Detection of Physical and Biochemical Parameters—A Review

Abstract: The promising properties of photonic crystal fibers (PCFs) have sparked the interest of a number of research organizations. Due to the PCF’s air holes, liquid or gas samples can be inserted into them. This permits a well-controlled interaction between confined light and sensing samples, enabling the development of novel sensing applications. That was never conceivable with conventional optical fibers. PCF applications in sensing fields can be divided into physical sensors and biochemical sensors based on the parameter being measured. Physical sensors measure pressure, temperature, refractive index (RI), curvature, vibration, torsion, electric field, and displacement, among other physical characteristics. Biochemical sensors can detect chemical and biological (such as antibodies, cells, bacteria, enzymes, viruses, nucleic acids, etc.) substances. The measurement of the chemical RI is a crucial component of biochemical sensors. Due to their close relationship with biosensors, chemical sensors are commonly referred to as biochemical sensors. This article covers the detecting capabilities of surface plasmon resonance (SPR)-based PCF biochemical and physical sensors in addition to a variety of ways to enhance their sensing capacities.

Highly Sensitive Bilirubin Biosensor Based on Photonic Crystal Fiber in Terahertz Region

Abstract: An unstable bilirubin level in the human blood causes many dangerous health problems, such as jaundice, coronary artery disease, ulcerative colitis, and brain lesions. Therefore, the accurate and early detection of bilirubin concentrations in the blood is mandatory. In this work, a highly sensitive biosensor based on photonic crystal fiber (PCF) for monitoring bilirubin levels is proposed and analyzed. The sensor parameters, including relative sensitivity, effective mode area, confinement loss, and effective material loss, are calculated. The geometrical parameters are studied, and a modal analysis of the suggested sensor is carried out using the full-vectorial finite element method (FEM). The fabrication tolerance of the geometrical parameters is also studied to ensure the fabrication feasibility of the reported design. High sensitivities of 95% and 98% are obtained for the x-polarized and y-polarized modes, respectively. Furthermore, a small material loss of 0.00193 cm−1, a small confinement loss of 2.03 × 10−14 dB/cm, and a large effective mode area of 0.046 mm2 are achieved for the y-polarized mode. It is believed that the presented sensor will be helpful in health care and in the early detection of bilirubin levels in the blood.

Plasmonic sensor based on offset-splicing and waist-expanded taper using multicore fiber for detection of Aflatoxins B1 in critical sectors.

Abstract: In this work, authors have developed a portable, sensitive, and quick-response fiber optic sensor that is capable of detection of Aflatoxins B1 (AFB1) quantitatively and qualitatively. Using multi-mode fiber (MMF) and multi-core fiber (MCF), the MMF-MCF-MCF-MMF fiber structure based on symmetric transverse offset splicing and waist-expanded taper is fabricated. The evanescent waves are enhanced to form a strong evanescent field by etching the fiber surface with hydrofluoric acid. To successfully excite the localized surface plasmon resonance phenomenon, gold nanoparticles are deposited on the optical fiber probe's surface. Further, to modify the fiber optic probes, Niobium carbide (Nb2CTx) MXene and AFB1 antibodies are functionalized. Nb2CTx MXene is employed to strengthen the biocompatibility of the sensor and increase the specific surface area of the fiber probe, while AFB1 antibody is used to identify AFB1 micro-biomolecules in a specific manner. The reproducibility, reusability, stability, and selectivity of the proposed fiber probe are tested and validated using various concentration of AFB1 solutions. Finally, the linear range, sensitivity, and limit of detection of the sensing probe are determined as 0 - 1000 nM, 11.7 nm/µM, and 26.41 nM, respectively. The sensor offers an indispensable technique, low-cost solution and portability for AFB1-specific detection in agricultural products and their byproducts with its novel optical fiber structure and superior detecting capability. It is also useful for marine species like fish and consequently affecting health of human body.

Flexible and Wearable Photonic-Crystal Fiber Interferometer for Physiological Monitoring and Healthcare

Abstract: Utilization of flexible optical systems for real-time comprehensive physiological monitoring has been restricted by their low mechanical robustness and reconfigurability. Here we report a mechanically robust, reconfigurable, flexible, and wearable photonic interferometer system for real-time precision tracking of limb activities, facial motions, respiration, and pulse rate with significant temporal stability and repeatability. Vital health diagnostic parameters have been measured by virtue of a highly sensitive response of the system. The proposed system features curvature sensitivity of 3.1 nm/m–1 over the range of 0–1.71 m–1, temperature sensitivity of 284 pm/°C between 30 and 60 °C, and physical strain sensitivity of 540 pm/1% tensile strain. Such a robust, reconfigurable, and sensitive system would have a wide practical and sustainable utility for real-time dynamic activity monitoring in health, industrial, and various other sectors.

Spiral Shaped Photonic Crystal Fiber-Based Surface Plasmon Resonance Biosensor for Cancer Cell Detection

Abstract: This work presents the design and simulation of an all-optical sensor for detection of cancer cells. The proposed device is based on the surface plasmon resonance effect on a spiral shaped photonic crystal fiber structure. The finite element method (FEM) based simulations are carried out for the different cancer cells, such as HELA, Basal, Jurkat, and MDA-MB-231, MCF7, and PC12 detection. The sensor has shown the maximum sensitivity of −289 RIU−1 for the refractive index of the detection of breast cancer cell with the resolution of 2.33 × 10−4. The sensor is effective for the refractive index range of 1.36 to 1.401.The structure is based on spiral shaped photonic crystal fiber, and has shown promising linear sensing response to support the practical feasibility of the device. The proposed sensor design is effective in detecting cervical cancer, skin cancer, blood cancer, breast cancer type 1, breast cancer type 2, and adrenal gland cancer.

Novel Bottom-Side Polished PCF-Based Plasmonic Biosensor for Early Detection of Hazardous Cancerous Cells

Abstract: This work presents a single-core bowl-shaped bottom-side polished (BSP) photonic crystal fiber (PCF) sensor based on surface plasmon resonance (SPR) concept for the early detection of hazardous cancer cells in human blood, skin, cervical, breast, and adrenal glands. We have studied liquid samples of cancer-affected and healthy samples with their concentrations/refractive indices in the sensing medium. To induce a plasmonic effect in the PCF sensor, the bottom flat section of a silica PCF fiber is coated with a 40nm plasmonic material, such as gold. To strengthen this effect, a thin TiO ₂ layer of 5 nm is sandwiched between fiber and gold as it strongly holds gold nanoparticles with smooth fiber surface. When the cancer-affected sample is introduced to the sensor’s sensing medium, it produces a different absorption peak in the form of a resonance wavelength than the healthy sample. This reallocation of the absorption peak is used to determine sensitivity. Hence, the obtained sensitivities for blood cancer, cervical cancer, adrenal gland cancer, skin cancer, and breast cancer (type-1and type-2) cells are 22,857nm/RIU, 20000nm/RIU, 20714nm/RIU, 20000nm/RIU, 21428nm/RIU, and 25000, respectively, with highest detection limit 0.024. These strong findings indicate that our proposed cancer sensor PCF is a viable choice for early cancer cell detection.

Highly sensitive V-shaped SPR PCF biosensor for cancer detection

Abstract: Abstract In this paper, a novel design of photonic crystal fiber (PCF) biosensor based on surface plasmon resonance (SPR) is introduced and analyzed for cancer cell detection. The full vectorial finite element method (FVFEM) is used throughout the numerical analysis of the suggested biosensor. The reported PCF has a V-shaped surface that is coated with ZrN as a plasmonic material. A coupling occurs between the core guided mode and surface plasmon mode SPM which depends on the studied analyte. Such a coupling is improved by using the suggested V-shape geometry which increases the sensor sensitivity.The geometrical parameters are optimized to achieve high sensor sensitivity. The proposed biosensor has high optical sensitivity of 6214.28, 3800, and 5008.33 nm/RIU, for quasi-transverse magnetic (TM), and 6000 nm/RIU, 4400 nm/RIU, and 5333.3 nm/RIU, for quasi-transverse magnetic (TE), for breast, basal, and cervical cancer cells, respectively. The reported optical sensor can pave the way for efficient and simple technique for cancer detection with low cost and high sensitivity instead of surgical and chemical techniques.

Thermal Sensitivity of Birefringence in Polarization-Maintaining Hollow-Core Photonic Bandgap Fibers

Abstract: Polarization-maintaining (PM) fiber is the core sensitive component of a fiber optic gyroscope (FOG); its birefringence temperature stability is crucial for maintaining accuracy. Here, we systematically investigated the structural thermal deformation and the resulting birefringence variation in typical PM hollow-core photonic bandgap fibers (HC-PBGFs) for FOG according to varying fiber structure parameters. To verify the application potential of PM HC-PBGFs in FOG, we compared the thermal sensitivity of birefringence (TSB) with that of the commonly used Panda PM fiber, which was tested to 5.07 × 10−5/100 °C. For rhombic-core fibers, the TSB was determined by the structure of the cladding and could be tuned as low as low as 10−7/100 °C, two orders of magnitude smaller than that of the panda PM fibers. For hexagonal-core fibers, the birefringence variation depended mainly on the drift of the surface modes (SMs) caused by the deformation of the core. A slight drift in SMs could cause a dramatic birefringence variation in hexagonal-core fiber, and the TSB could be as high as 10−4/100 °C, much higher than that of panda PM fiber. This study lays the foundation for the development of high birefringence temperature-stable HC-PBGFs and their applications in FOG.

High-Sensitivity Early Detection Biomedical Sensor for Tuberculosis With Low Losses in the Terahertz Regime Based on Photonic Crystal Fiber Technology

Abstract: Abstract Tuberculosis is one of the most contagious and lethal illnesses in the world, according to the World Health Organization. Tuberculosis had the leading mortality rate as a result of a single infection, ranking above HIV/AIDS. Early detection is an essential factor in patient treatment and can improve the survival rate. Detection methods should have high mobility, high accuracy, fast detection, and low losses. This work presents a novel biomedical photonic crystal fiber sensor, which can accurately detect and distinguish between the different types of tuberculosis bacteria. The designed sensor detects these types with high relative sensitivity and negligible losses compared to other photonic crystal fiber-based biomedical sensors. The proposed sensor exhibits a relative sensitivity of 90.6%, an effective area of 4.342×10 −8 m 2 , with a negligible confinement loss of 3.13×10 −9 cm −1 , a remarkably low effective material loss of 0.0132cm −1 , and a numerical aperture of 0.3462. The proposed sensor is capable of operating in the terahertz regimes over a wide range (1 THz–2.4THz). An abbreviated review of non-optical detection techniques is also presented. An in-depth comparison between this work and recent related photonic crystal fiber-based literature is drawn to validate the efficacy and authenticity of the proposed design.

A Deep Learning Regression Model for Photonic Crystal Fiber Sensor With XAI Feature Selection and Analysis

Abstract: A Deep Learning Multi-output regression model is employed to correctly model the relationships between optical design parameters of an asymmetric Twin Elliptical Core Photonic Crystal Fiber (TEC-PCF) and its sensing performances. TEC-PCF acts as a biosensor to detect the blood glucose level taking hemoglobin components into account. Since asymmetric TEC-PCF uses a dual elliptical core, four super modes have to be evaluated to analyze the sensing performance in terms of effective index difference, transmission spectrum, coupling length, and sensor sensitivity. The dataset used in this work is of the optical design parameters of the sensor and Finite Element Method (FEM) results with effective indices of four super modes obtained from the COMSOL Multiphysics by varying hemoglobin concentration to 120 g/L, 140 g/L, and 160 g/L. Gretel.ai's free open-source synthetic data library is used to augment the dataset to make the training more efficient. Explainable AI (XAI) feature analysis using Shapley Additive Explanations (SHAP) framework is used for two purposes: feature selection and to know the feature's effect on prediction. The former led to the development of an optimal model with much fewer computational demands and the latter made the model interpretable. The proposed model can predict the accurate super modes when given input specifications with wavelength ranging from 1.27- [Formula: see text] and for various glucose concentrations under the influence of hemoglobin much faster compared to the other numerical simulations which are computationally expensive. Computation time taken by the proposed Artificial Neural Network (ANN) model, the proposed model with XAI and FEM is also being compared.

Chiral Dual-Core Photonic Crystal Fiber for an Efficient Circular Polarization Beam Splitter

Abstract: As a function of a circular polarization beam splitter (CPBS), combining a linear polarization beam splitter with a quarter-wave plate results in a polarization error in a circular polarization fiber-optic circuit. To relieve the error, chiral dual-core photonic crystal fiber (DC-PCF) is investigated as a kind of an efficient circular polarization beam splitter by using the chiral plane-wave expansion (PWE) method. On the basis of the competitive effect in polarization and coupling length between the circular asymmetry of the structure and the chirality of the medium, the effects of the structure and the chirality are analyzed. The numerical results demonstrate that a CPBS needs the weak circular asymmetry in its structure and a relatively stronger chirality of the medium. Then, a kind of CPBS based on chiral DC-PCF is designed with weaker chirality, with a central wavelength of 1.55 μm. The simulation shows the superior performance of having a shorter coupling length and a higher extinction ratio. Furthermore, the dual-wavelength of 1.55 μm and 1.30 μm with left-circular polarization can further be separated by the corresponding chiral DC-PCF. The results show promising applications for the circular polarized multiplexer/demultiplexer in fiber laser communication systems.

Highly Nonlinear Composite-Photonic Crystal Fibers with Simplified Manufacturing Process and Efficient Mid-IR Applications

Abstract: This paper reveals special design features of the proposed highly nonlinear circular-lattice-silicon-core and silica-doped-with-fluorine (1%) cladding-composite photonic crystal fiber (PCF) in the Mid-infrared region of the spectrum. A region of small negative group velocity dispersion (GVD), managed higher order dispersions (HODs), and unique nonlinearity of silicon have been used to demonstrate a supercontinuum broadening from 1500 nm to 4700 nm with consumption of low input power of 400 W over short fiber distances. It will be also shown that the fiber’s high-level engineered structure finally results in a simple manufacturing process compared with other designed nano-sized silicon PCFs. The designed fiber could have massive potential in gas sensing, soliton effect pulse compression, spectroscopy, material processing, etc.

Plasmonic metafiber for all-fiber Q-switched cylindrical vector lasers

Abstract: Abstract Metafibers, by integrating metasurface at the optical fiber tip, are emerging as the significant optical coupling platforms for nanophotonics and fiber-optic communities. Here, we propose a plasmonic metafiber for converting the fundamental mode to first-order mode in fiber, and as proof of device performance, demonstrate an all-fiber Q-switched cylindrical vector laser using the metafiber. Based on polarization-dependent plasmonic resonance, a polarization-independent mode conversion metasurface is designed theoretically and numerically, fabricated directly on fiber facet, and packaged as an all-fiber component with efficiency up to 21% at 1550-nm band. Using the metafiber in an all-fiber laser, Q-switched azimuthally polarized beam (APB) and radially polarized beam (RPB) are delivered at wavelength of 1548.5 nm with pulse durations from ∼7 to ∼2 μs when pump power increases from 30 to 120 mW. The mode purities of the APB and RPB are 86.5% and 90.7%, respectively. This work outlines a new strategy to integrate metasurfaces into “all-in-fiber” systems and offers a reliable route to construct next-generation laser sources, such as all-fiber ultrafast structured lasers.

Photonic crystal fiber (PhCF) for petrochemical sensing

Abstract: A square-core photonic crystal fiber (PhCF) has been presented for liquid (petrochemical) sensing application. The sensor performance has been studied numerically in the frequency range from 1.2 to 3.8 THz. The core hole is filled with pure petrol, kerosene, and diesel. Strut size is varied to explore the sensor’s performance and the analysis is performed in terahertz (THz) frequencies. The photonic crystal fiber sensor shows a relative sensitivity of around 97.0% and a confinement loss in the order of 10−14 at 3.7 THz. This photonic crystal fiber sensor can be fabricated using extrusion and 3D-printing technologies.

A Review on Various Sensing Prospects of SPR Based Photonic Crystal Fibers

Abstract: This review article deals with various prospects of the Photonic Crystal Fiber (PCF) and its applications in biosensing, refractive index (RI) sensing, biomedical imaging, dispersion compensation, supercontinuum and solitons generation. The gradual progress in PCF technology not only explored its application in optical communication but also extended to its effective utilization in PCF-based sensors. PCF is extensively used as a research object in order to curb the positive dispersion by changing either its cladding or core structure. Some existing works also focused on obtaining high nonlinearity in the PCF structures since high nonlinear PCF is used to direct the light in the fiber core only so that light can travel a larger distance without any alteration. But, nowadays, the modern era of optical fiber technology has been more inclined towards PCF-based surface plasmon resonance (SPR) biosensors or RI sensors. The functional mechanism of a biosensor relies on SPR which involves fiber integrated with plasmonic metals (i.e. gold, silver, copper, etc.) as these metals are responsible for the sensitivity of a biosensor. But, the major drawback of plasmonic metals is that they exhibit poor biomolecule adsorption. Therefore, this review mainly explores the possible way such as the incorporation of 2D/TMD materials (i.e. graphene, MoS2, etc.) to increase biomolecule adsorption. These materials play an important role to increase the sensitivity of a biosensor. Hence, metal/2D/TMD based combined heterostructure opens a suitable study window in the field of SPR biosensing that finds its application in cholesterol detection, cancer cell detection, DNA detection, protein and glucose sensing.

Highly Sensitive Open Channel Based PCF-SPR Sensor for Analyte Refractive Index Sensing

Abstract: The control of light in photonic crystal fiber (PCF) is a special characteristic that is obtained due to the relations between material and light. In this paper, a surface plasmon resonance (SPR) based PCF sensor is introduced with two open-channel which cover an extensive field of bio-detection applications. Gold (Au) is considered as an effective plasmonic ingredient. The transformation of light through the fiber core is coupled with the gold and stimulates SPR. The proposed PCF-SPR sensor reports the highest wavelength sensitivity (WS) of 7000 nm/RIU (refractive index unit) as well as an amplitude sensitivity (AS) of 593.61 RIU−1. It also acquires an increased sensor resolution of 1.43 × 10−5 RIU and a decent figure of merit (FOM) is 94.97 RIU−1. Additionally, the operating constraints of the sensor such as corresponding air-holes diameter, the pitch, gold layer (Au) thickness and open-channel radius are revised to improve detection performance. The overall measurement is carried out over a broad range of variations in refractive index (RI) from 1.33 to 1.40. The sensor's appreciable performance makes it suitable for bio-sensing applications.

Thermally robust and highly stable method for splicing silica glass fiber to crystalline sapphire fiber

Abstract: This research reports an advancement in splicing silica glass fiber to sapphire single-crystal optical fiber (SCF) using a specialized glass processing device, including data that demonstrate the thermal stability of the splice to 1000°C. A filament heating process was used to produce a robust splice between the dissimilar fibers. A femtosecond laser is used to inscribe a fiber Bragg gratings sensor into the SCF to measure the high-temperature capabilities and signal attenuation characteristics of the splice joint. The experimental results demonstrate that the proposed splicing method produces a splice joint that is robust, stable, repeatable, and withstands temperatures up to 1000°C with a low attenuation of 0.5 dB. The proposed method allows placement of SCF-based sensors in the extreme environments encountered in various engineering fields, such as nuclear, chemical, aviation, and metals manufacturing, to enable improvements in process monitoring, product quality, and production efficiency.

Photonic Crystal Fiber Pollution Sensor based on Surface Plasmon Resonance

Abstract: In this work, a pollution-sensitive Photonic Crystal Fiber (PCF) based on Surface Plasmon Resonance (SPR) technology is designed and implemented for sensing refractive indices and concentrations of polluted water . The overall construction of the sensor is achieved by splicing short lengths of PCF (ESM-12) solid core on one side with traditional multimode fiber (MMF) and depositing a gold nanofilm of 50nm thickness on the end of the PCF sensor. The PCF- SPR experiment was carried out with various samples of polluted water including(distilled water, draining water, dirty pond water, chemical water, salty water and oiled water). The location of the resonant wavelength peaks is seen to move to longer wavelengths (red shift) as the refractive index increases due to the transfer of maximum energy from the reflected power of the light guided through the fiber to the surface plasmons. The experimental results show that the highest sensitivity reached 4202.6nm/RIU for oiled water, the signal to noise ratio was 0.625, the resolution was 2.4*10-5 RIU, and the figure of merit was 22.8. The prepared sensor exhibited excellent performance features, making it an excellent element for detecting water pollutants.

Tapered PCF Mach–Zehnder interferometer based on surface plasmon resonance (SPR) for estimating concentration toxic metal ions (lead)

Abstract: In this study, a surface plasmon resonance based on Mach–Zehnder interferometer is produced by combining two normal Single mode fibers with a Photonic Crystal Fiber SMF-PCF-SMF for measuring the refractive index (RI) for ion toxic metal lead. In the center of the sensor, a small portion (4 cm) of PCF is created, and after the process of tapering is complete, gold is deposited with a thickness of about (40 nm). A photonic crystal fiber's gold-coated core receives a deposit of toxic lead ions. The computed signal to noise ratio (SNR), sensitivity (S), resolution (R), and figures of merit (FOM): SNR is 0.18, Sensitivity is 11.11 m/RIU, Resolution is 1.7 × $${10}^{-4}$$ , and FOM is 22.87.