Photonic Crystal Fiber Structure Research Articles

Harnessing THz Technology: Biosensor for Highly Accurate Cervical Cancer Cell Detection via Refractive Index.

In order to rapidly identify various species of cancer cells in the tissues of person, a unique diamond shaped hollow-core photonic crystal fiber (PCF)-formed by optical waveform is developed and computationally studied. In this investigation, we found the most prevalent cancers, such as HeLa-derived cervical carcinoma. Since normal and cancer cells differ in their refractive indices (RIs), other significant optical properties can be assessed using this information. With the use of the finite element method, a computational tool for solving simultaneous equations, the defining characteristics the suggested cancer cell sensor are examined using COMSOL-Multiphysics software. Additionally, strict mesh parts are used to preserve the utmost level of modeling realism. At 2.4 THz, the PCF detector attains a Relative Sensitivity of around 97.51% and 96.29%, Confinement Loss of 6.1 × 10 -09db/m and 4.39 × 10-07db/m with respect to cervical carcinoma cell and cervical normal cell. The straightforward PCF structure provides a wide chance of application using the continuing fabrication technique, based on these conventional values of performance indices. This biosensor utilizes the distinctive refractive characteristics of cancer cells, providing a highly accurate and dependable approach for the early identification of cervical cancer. This has the potential to significantly transform the process of cervical cancer screening. The novel method boosts the ability to detect and identify certain conditions, leading to increased diagnostic capabilities for early treatment and better results for patients.

Research on sensing characteristics of microfluidic sensor based on photonic crystal fiber

To address the challenges associated with sample injection into the air hole of photonic crystal fiber (PCF) and collimation, in this paper, we assemble a single-mode photonic crystal single-mode fiber structure sensor chip based on the Mach–Zehnder interference principle using microfluidic chip processing technology. The sensing principle is analyzed mathematically and the sensing characteristics are verified theoretically and experimentally. The temperature sensitivity of the sensor is −1.3325 nm °C−1, and the refractive index sensitivity is 1666.2 nm RIU−1. This structure solves the difficulty of filling and coupling PCFs. Furthermore, it introduces a novel research methodology for the design and assembly of high-performance biosensors based on PCFs.

Precise detection of trace level protein using MIP-MoS2 nanocomposite functionalized PCF based interferometer.

Fiber optic interferometry combined with recognizing elements has attracted intensive attention for the development of different biosensors due to its superior characteristic features. However, the immobilization of sensing elements alone is not capable of low-concentration detection due to weak interaction with the evanescent field of the sensing transducer. The utilization of different 2D materials with high absorption potential and specific surface area can enhance the intensity of the evanescent field and hence the sensitivity of the sensor. Here, a biosensor has been fabricated using an inline hetero fiber structure of photonic crystal fiber (PCF) and single-mode fiber (SMF) functionalized with a nanocomposite of molybodenum di-sulfide (MoS2) and molecular imprinting polymer (MIP) to detect trace levels of bovine serum albumin (BSA). The sensor showed a wide dynamic detection range with a high sensitivity of 2.34 × 107 pm/µg L-1. It shows working potential over a wide pH range with a subfemtomolar detection limit. The compact size, easy fabrication, stable structure, long detection range, and high sensitivity of this sensor would open a new path for the development of different biosensors for online and remote sensing applications.

Structural dependence of transmission characteristics for photonic crystal fiber with circularly distributed air-holes

Abstract In this study, design and transmission characteristics of a special type of photonic crystal fiber (PCF) geometry namely, circular-lattice photonic crystal fiber (C-PCF) structure are presented. The cladding of the structure consists by a cylindrically symmetrical distribution of air-holes in the silica background and the core is created by omitting one air-hole at the center. The structure provides high degree of flexibility in the fiber design and hence tailorable modal properties. Structural dependence of transmission characteristics of the geometry is numerically investigated by using finite difference mode convergence algorithm. The wavelength responses of fiber parameters, such as effective refractive index, chromatic dispersion, mode-effective area, and nonlinear coefficient of the structure are systematically investigated. Besides, effective V-parameter and single-mode operation of the fiber are also evaluated and discussed. The simulation results show the possibility of large negative dispersion and dispersion flattened nature of the geometry.

Broadband dual parametric fiber sensor for concentration and temperature sensing with high sensitivity and linearity

A dual parametric sensor is proposed based on photonic crystal fiber (PCF) structure and surface plasmon resonance (SPR) effect in this paper. The proposed SPR-PCF sensor has a broadband spectral response from 1200 to 2400 nm. Detections of the alcohol with different concentrations and temperatures are carried out to demonstrate its dual parametric performance. When the concentration of the alcohol solution changes from 10 % to 87 %, the resonance-wavelength sensitivity is −1588.3 pm/% and the resonance-loss sensitivity is −0.34837 dB/%. While the external temperature is verified in a range of 20 °C and 80 °C, the resonance-wavelength and resonance-loss sensitivities are 2031.8 pm/°C and 0.473 dB/°C, respectively. Its R2 can always be larger than 0.99. Dual-parameter sensing can be realized via using the sensitivities as the coefficients to construct a transfer matrix. The proposed SPR-PCF sensor is expected to have potential applications in chemistry, biology, and environment monitoring.

Characteristics Analysis of Different Photonic Crystal Fiber Lattice Structures

This study presents a comprehensive analysis of various photonic crystal fiber (PCF) lattice structures using the Finite Element Method (FEM). PCFs have gained significant importance in various optical and communication applications due to their unique optical properties. Understanding the characteristics and optimal designs of different PCF lattice structures is crucial for their effective utilization. In this research, we explore eight distinct lattice designs, including circle, square, pentagon, hexagon, heptagon, octagon, decagon, and dodecagon. We investigate how variations in the air filling fraction, a critical structural parameter, affect the performance of these PCF structures. The utilization of FEM allows for a detailed analysis of these lattice structures, offering insights into their behavior under different conditions. By varying the air filling fraction, we gain valuable insights into the optimal design choices for specific applications. This research aims to provide a deeper understanding of the applicability of each PCF lattice structure. By scrutinizing their performance and characteristics, it becomes possible to distinguish which lattice structure is best suited for various optical and communication applications. The findings from this study offer significant contributions to the field of photonics, guiding researchers and engineers in selecting the most suitable PCF lattice structure for their specific applications. Understanding the structural parameters that influence PCF behavior is a key step toward optimizing the performance of optical and communication systems.

New proposal for a two-channel optical multiplexer based on photonic crystal fibers

An innovative idea for a photonic crystal fiber-based 2 × 1 power beam combiner is presented. This research introduces an optical multiplexer (MUX) that supports wavelength multiplexing at 1.46 and 1.48 µm using a photonic crystal fiber topology. The multiplexer is a component that combines the specific wavelengths into the group of wavelengths in a network. This paper aims to create a new design structure for an optical Multiplexer based on photonic crystal fibers while optimizing the geometrical parameters and the multiplexer device and illustrating how a PCF structure could combine several optical signals into a group of signals in a single fiber. High-performance waveguides known as photonic crystal fibers (PCF) are constructed from a microstructured combination of substances with varying refractive indices. The PCF Mux design relies on appropriate PCF structure improvements and the replacement of specific air-hole sections with pure silica to manage the light coupling between the cores over the PCF axis; in comparison to traditional fiber, they have a shorter coupling length between close core and more design flexibility.

Polarization-maintaining photonic crystal fiber with high Brillouin gain coefficient for Brillouin lasers.

Stimulated Brillouin scattering (SBS) is effective for realizing a laser with an ultra-narrow linewidth. Although photonic crystal fiber (PCF) is considered an excellent medium to achieve SBS, it does not meet the requirements of low loss, large birefringence, and ease of fabrication. We propose a polarization-maintaining PCF (PM-PCF) structure and theoretically analyze the effects of the geometric structural parameters of the PM-PCF on various optical properties. Our theoretical analysis and experimental results contribute to the advancement of the field of ultra-narrow linewidth fiber lasers, distributed fiber sensing, and fiber-optic gyroscopes related to SBS.

Residual dispersion compensation photonic crystal fiber based on simulated annealing algorithm and Livelink data interaction

An octagonal photonic crystal fiber (O-PCF) structure with equal air hole diameter of the cladding is proposed for residual dispersion compensation, and a high refractive index material SF57 is introduced in the core region to make it have the advantages of high negative dispersion, low attenuation loss, low fabrication difficulty. Due to the symmetric structure, no additional polarization control is required in the dispersion compensation process, which further reduces the production cost. Using Livelink data interaction not only accelerates the modeling of O-PCF, but also enables the effective refractive index of HE11 to be unattended continuously searched. Furthermore, simulated annealing algorithm is used to reverse design the structural parameters of cladding air hole diameter and central solid hole diameter. The results show that, based on the simulated annealing algorithm interacting with Livelink data, the optimize efficiency, design accuracy and dispersion characteristics are improved. The ultra-flat high negative dispersion O-PCF can be reverse designed in the S + C + L and S + C + L + U bands which shows the average dispersion of −847.34 ps/(nm·km) and −752.90 ps/(nm·km) with the absolute dispersion of only ±7.25 ps/(nm·km) and ±10.28 ps/(nm·km), respectively. The designed RDCF is tolerant to ±1% and ±2% variation of the central solid hole diameter and the cladding air hole diameter during fabrication, respectively. The combination of simulated annealing algorithm and Livelink data interaction provides an efficient method for reverse design of PCF.

SPR Sensor Based on a Concave Photonic Crystal Fiber Structure with MoS2/Au Layers.

We propose a surface plasmon resonance (SPR) sensor based on the concave photonic crystal fiber (PCF) coated with molybdenum disulfide (MoS2) and Au layers, which can detect the refractive index (RI) of the analyte. The finite element method (FEM) was used to verify our design, and the loss spectra of the fundamental mode are calculated. Compared with the SPR sensor with only a Au layer, the wavelength sensitivity can be improved by from 3700 to 4400 nm/RIU. Our proposed sensor works in near-infrared band and has a wide RI range from 1.19 to 1.40. The influences of the geometrical parameters of PCF and the thicknesses of Au and MoS2 layers on the loss spectra are discussed in detail, and the maximum wavelength sensitivity of 5100 nm/RIU can be achieved. Meanwhile, a high resolution of 1.96 × 10-5 RIU and the largest FOM of 29.143 can be obtained. It is believed that our findings show the sensor's excellent potential in medical testing, unknown biological detection, environmental monitoring and organic chemical detection.

Design of New Photonic Crystal Fiber for Orbital Angular Momentum Modes Transmission

In order to achieve the flexibility and miniaturization of orbital angular momentum (OAM) fiber coupler, it is necessary to continuously design and optimize the base fiber to cooperate with the efficient transmission of multiplexed beam. It is more advantageous to use the photonic crystal fiber (PCF) instead of ring fiber in the coupler design. We have proposed a new fiber based on circular PCF structure to support high performance OAM modes transmission. The optimal parameters are selected to realize the stable transmission of 4 OAM mode groups with high mode quality. In the wavelength range of 1.2 μm∼2.0 μm, the confinement loss of low order mode is less than 10−8 dB/m, and the mode purity is more than 81.7%. Because of its flexible structure and low loss characteristics, the proposed OAM fiber can be widely used in the design of optical fiber devices in modular division multiplexing (MDM) communication systems.

Design of a new 2-channel demultiplexer based on Photonic Crystal Fiber

As miniaturization becomes a critical need in many integrated applications, various researchers have primarily focused on creating optical systems and components based on photonic crystal fiber during the past few decades. This article describes a brand-new 1x2 power demultiplexer idea using photonic crystal fiber as a basis. The luminous connection between the center core and coherent laser sources is made possible by inserting defects in the structure of the photonic crystal fiber (PCF) to change the silica and air index. Simulation results will show that two optical signals, 1.46 µm and 1.48 µm, at the input of a PCF structure can be separated into two parts at the output. The novel design controls the direction of light propagation between layers by swapping various air-hole locations using pure silica layers along the length of the fiber. In optical systemic communications, wavelength demultiplexers are crucial components. They act as data distributors and generate several outputs with a single input. This article aims to propose a novel structure with the best performance by introducing flaws in the structure to guide light according to the desired path and demultiplex our signals. By employing a DWDM system, this device may help increase the data bitrate.

Performance analysis of photonic crystal fiber structure based on different highly nonlinear materials

Generally, fiber with a large mode area is desired for fiber laser and beam delivery applications. But the use of these fiber types is restricted to linear optical applications due to the lower value of the nonlinear coefficient. This paper investigates a single material-based photonic crystal fiber (PCF) with improved optical characteristics, applicable for linear and nonlinear optics. The light propagation in the structure is explored by applying finite element solver-based COMSOL multiphysics software. Five nonlinear optical materials are utilized as background material to get the optimized material with high performance PCF. Using this PCF, the improved optical properties of PCF such as moderate effective mode area of 115.85 [Formula: see text], chromatic dispersion, confinement loss of 10[Formula: see text] dB/m, the nonlinear coefficient of 543W[Formula: see text]Km[Formula: see text], splicing loss of 2.013 dB, and numerical aperture are numerically analyzed. This single-mode PCF also shows the low bending loss for the bending radius of 7[Formula: see text]mm. The amended PCF structure is found to be suitable for high-power fiber laser, supercontinuum generation, wavelength conversion, and slow-light generation.

Supercontinuum generation in a square-lattice photonic crystal fiber using carbon disulfide infiltration

This study proposed new liquid-filled photonic crystal fiber structures as a new supercontinuum source with low pumping energy. The designed fiber has square lattices on its cross-section and its core being infiltrated by carbon disulfide. We studied numerically optical properties of the square lattice fiber with the modification of its structural parameters including lattice constant (Λ) and hole diameter (d). From the simulated results, two PCF structures supporting the best broadband supercontinuum generations were selected. The first optimized fiber #F1 having lattice pitch Λ = 1.0 µm and filling factor d1/Λ = 0.7 provides an all-normal dispersion. This fiber offers the supercontinuum spectrum broadening from 860 nm to 1738 nm (resulting in a bandwidth of 878 nm) by pumping at a wavelength of 1300 nm, 80 fs pulse duration and input energy of 1.5 nJ, corresponding to the input power of 18.75 kW. The second fiber #F2 (lattice pitch Λ = 1.5 µm, filling factor d1/Λ = 0.3) exhibits mostly anomalous dispersion region. In this fiber, the octave-spanning of the supercontinuum spectrum was formed with a bandwidth of 1935 nm from 594 nm to 2529 nm for an input pulse are 1670 nm pump wavelength, 80 fs duration and energy of 0.5 nJ, corresponding to the input power of 6.25 kW. The proposed fibers are good candidates for low-cost all-fiber sources for potential application in the fields of telecommunications and mid-infrared detection.

Numerical Analysis of Highly Sensitive Twin-Core, Gold-Coated, D-Shaped Photonic Crystal Fiber Based on Surface Plasmon Resonance Sensor.

This research article proposes and numerically investigates a photonic crystal fiber (PCF) based on a surface plasmon resonance (SPR) sensor for the detecting refractive index (RI) of unknown analytes. The plasmonic material (gold) layer is placed outside of the PCF by removing two air holes from the main structure, and a D-shaped PCF-SPR sensor is formed. The purpose of using a plasmonic material (gold) layer in a PCF structure is to introduce an SPR phenomenon. The structure of the PCF is likely enclosed by the analyte to be detected, and an external sensing system is used to measure changes in the SPR signal. Moreover, a perfectly matched layer (PML) is also placed outside of the PCF to absorb unwanted light signals towards the surface. The numerical investigation of all guiding properties of the PCF-SPR sensor is completed using a fully vectorial-based finite element method (FEM) to achieve the finest sensing performance. The design of the PCF-SPR sensor is completed using COMSOL Multiphysics software, version 1.4.50. According to the simulation results, the proposed PCF-SPR sensor has a maximum wavelength sensitivity of 9000 nm/RIU, an amplitude sensitivity of 3746 RIU-1, a sensor resolution of 1 × 10-5 RIU, and a figure of merit (FOM) of 900 RIU-1 in the x-polarized direction light signal. The miniaturized structure and high sensitivity of the proposed PCF-SPR sensor make it a promising candidate for detecting RI of analytes ranging from 1.28 to 1.42.

Wave-Shaped Microstructure Cancer Detection Sensor in Terahertz Band: Design and Analysis

For the quick identification of diverse types of cancer/malignant cells in the human body, a new hollow-core optical waveguide based on Photonic Crystal Fiber (PCF) is proposed and numerically studied. The refractive index (RI) differs between normal and cancerous cells, and it is through this distinction that the other crucial optical parameters are assessed. The proposed cancer cell biosensor’s guiding characteristics are examined in the COMSOL Multiphysics v5.5 environment. The Finite Element Method (FEM) framework is used to quantify the display of the suggested fiber biosensor. Extremely fine mesh elements are additionally added to guarantee the highest simulation accuracy. The simulation results on the suggested sensor model achieve a very high relative sensitivity of 99.9277%, 99.9243%, 99.9302%, 99.9314%, 99.9257% and 99.9169%, a low effective material loss of 8.55×10−5 cm−1, 8.96×10−5 cm−1, 8.24×10−5 cm−1, 8.09×10−5 cm−1, 8.79×10−5 cm−1, and 9.88×10−5 cm−1 for adrenal gland cancer, blood cancer, breast cancer type-1, breast cancer type-2, cervical cancer, and skin cancer, respectively, at a 3.0 THz frequency regime. A very low confinement loss of 6.1×10−10 dB/cm is also indicated by the simulation findings for all of the cancer cases that were mentioned. The straightforward PCF structure of the proposed biosensor offers a high likelihood of implementation when used in conjunction with these conventional performance indexes. So, it appears that this biosensor will create new opportunities for the identification and diagnosis of various cancer cells.

High-sensitivity photonic crystal fiber methane sensor with a ring core based on surface plasmon resonance and orbital angular momentum theory

ObjectiveWith the advent of optical fiber sensing technology, photonic crystal fiber (PCF) sensors based on surface plasmon resonance (SPR) have become a research hotspot. Herein, a PCF-SPR methane sensor with a ring-core structure is designed based on the orbital angular momentum (OAM) theory. To our best knowledge, this type of sensor has not been reported yet. MethodsThrough the finite element method, the PCF structure is designed and the appropriate filling material is selected. ResultsThe sensor consists of a three-layer clad air hole and an extra-large central gas channel, forming a ring core for beam transmission. By adding high refractive index material Amethyst and methane sensitive material to the central gas channel, the mode field is improved and the methane concentration is detected efficiently. Numerical results show that the sensor can stably transmit OAM modes and excite SPR with the OAM2,1 mode, namely the HE3,1 eigenmode. With the help of methane sensitive film, changes in methane concentration can greatly affect the refractive index distribution in PCF and alter the excitation characteristics of SPR. In the methane concentration range of 0–3.5 %, the resonance wavelength shifts from 4.52 µm to 4.58 µm. The average wavelength sensitivity reaches 17.07 nm/%, and the corresponding detection limit is 117 ppm. The results reveal that the designed PCF-SPR methane concentration sensor has excellent performance, which can stably transmit OAM mode while achieving SPR effect. It has great innovation and commercial potential in the petroleum, biomedical, chemical, and other industry.

Analysis of a photonic crystal fiber with ellipse air-holes for supporting 82 orbital angular momentum modes

We proposed a photonic crystal fiber (PCF) with ellipse air holes and high refractive index ring-core, which can stably support 82 orbital angular momentum states from the wavelength of 1.25–1.65 μm. The modes’ average confinement loss keeps as low as 10−9 dB m−1. In addition, the effective refractive index separation (Δn eff) between HE m +1,1 and EH m −1,1 (m = 2–21) is up to 10−3, which makes the mode degeneracy to LP mode can be almost neglected. The dispersion curves of low order eigenmodes are low and flat, especially at the wavelength of 1.4 μm the minimum absolute value of chromatic dispersion for HE1,1 mode is as low as 0.246 ps (nm·km)−1. Furthermore, we also analyze the effect of ellipticity change on the cladding air holes, which instructively show the favorable fault tolerance of confinement loss and dispersion. The proposed PCF structure will be a potential candidate for high-capacity optical fiber communications.

D-shaped photonic crystal fiber sensor based on the surface plasmon resonance effect for refractive index detection.

In this paper, a photonic crystal fiber (PCF) sensor based on the surface plasmon resonance (SPR) effect for refractive index (RI) detection is proposed. We design a D-shaped polished PCF structure consisting of air holes arranged in a hexagonal lattice. The silver film is coated on the middle channel of the polished surface of the PCF. The finite element method is used to analyze the propagation characteristics of the proposed D-shaped SPR-PCF sensor. Simulation results show that the proposed D-shaped SPR-PCF sensor has a maximum wavelength sensitivity of 30,000nm/RIU, an average wavelength sensitivity of 6785.71nm/RIU, and a maximum resolution of 3.33×10-6 R I U in the RI range of 1.22-1.36. Owing to the high wavelength sensitivity in the considered RI range, the proposed D-shaped SPR-PCF sensor is suitable for applications in water contamination detection, liquid concentration measurement, food safety monitoring, etc.

High Performance Dual-Core D-Shaped PCF Refractive Index Sensor Coated with Gold Grating

In this study, a dual−core D-shaped photonic crystal fiber (PCF) surface plasmon resonance sensor coated with gold grating is designed and analyzed using the finite-element method (FEM). The surface plasmon resonance (SPR) effect between the fiber core modes and surface plasmon polariton (Spp) modes is used to measure the analyte refractive index. The effects of the PCF structure parameters (polishing depths, large holes, and small holes) and grating parameters (grating heights, grating periods, and grating duty) are discussed, and a two-feature interrogation method that combines wavelength and intensity interrogations is introduced to enhance the resolution. The results show that the grating and dual-core play important roles in enhancing the sensor properties. The proposed sensor achieves an average wavelength sensitivity of 994.5 nm/RIU when the analyte refractive index increases from 1.33 to 1.37. Furthermore, a maximum amplitude sensitivity of 181.049 RIU−1 is obtained. The two-feature interrogation is determined to have a resolution of 2.03 × 10−6 RIU, which is better than the wavelength and amplitude interrogations. The proposed sensor has a good sensing performance and is highly suitable for practical applications.