Characteristics Of Photonic Crystal Fiber Research Articles

Three-parameter sensing characteristics of PCF based on surface plasmon resonance

In this study, a refractive index-temperature sensor based on surface plasmon resonance (SPR) in photonic crystal fiber (PCF) is proposed. Unlike conventional dual-parameter sensing research, this sensor features three sensing channels, offering the advantages of high-sensitivity measurements without cross-interference, utilizing three different plasmonic materials (Au, AZO, Ag), and enabling accurate measurement of temperature and refractive indices of two different analytes simultaneously. The finite element method is employed to investigate the influence of sensor structural parameters on sensing performance and optimize these parameters. In channel 1, analytes within the range of 1.37–1.43 can be detected, with maximum wavelength sensitivity (WS) of 31,500 nm/RIU and maximum amplitude sensitivity (AS) of 5690RIU−1. The range of the SPR sensor in CH-2 is 1.25–1.40, with a max WS value of 5500 nm/RIU and peak AS of 10,845RIU−1. Furthermore, the sensor obtains a higher figure of merit of 2357RIU−1 and a maximum wavelength resolution of 9.2208×10−7. Regarding temperature sensing, the proffered sensor has shown its ability to detect environmental temperature, with a wide detection range from 5°C to 95°C degrees and a maximum WS of 6.3 nm/°C. In summary, the proposed PCF-SPR sensor is capable of precise measurement of solution concentration and environmental temperature over a wide range, exhibiting high sensitivity and possessing potential applications in biosensing, environmental temperature detection, and more.

Mixed integer programming with kriging surrogate model technique for dispersion control of photonic crystal fibers

In this paper, mixed integer nonlinear programming (MINLP) optimization algorithm integrated with kriging surrogate-model is newly formulated to optimize the dispersion characteristics of photonic crystal fibers (PCFs). The MINLP is linked with full vectorial finite difference method (FVFDM) to optimize the modal properties of the PCFs. Through the optimization process, the design parameters can take real and/or integer values. The integer values can be used to selectively fill the PCF air holes to control its dispersion characteristics. However, the other optimization techniques deal with real design parameters where the PCF can be optimized using none or predefined infiltrated air holes. The MINLP algorithm is used to obtain an ultra-flat zero dispersion over a broadband of wavelength range from 1.25 to 1.6 μm using silica PCF selectively infiltrated with Ethanol material. To show the superiority of the proposed algorithm, nematic liquid crystal selectively infiltrated PCFs are also designed with high negative flat dispersion over wide range of wavelengths from 1.25 to 1.6 μm for the quasi transverse magnetic (TM) and the quasi transverse electric (TE) modes. Such designs have negative flat dispersions of − 163 ± 0.9 and − 170 ± 1.2 ps/Km nm, respectively over the studied wavelength range. Therefore, the MINLP algorithms could be used efficiently for the design and optimization of selectively filled photonic devices.

Design and simulation of Zeonex Based Suspended Microstructure Photonic Crystal Fiber for Chemical Sensing Application

Over the last few years for sensing applications in terahertz regime photonic crystal fiber (PCF) has gained attention quite extensively. The optical characteristics of photonic crystal fiber can be controlled by fine-tuning of the structural parameters like core radius and effecctive area. In this context, a terahertz sensor based on a hollow-core photonic crystal fiber has been developed for chemical identification in the terahertz frequency range with very low loss. The proposed structure contains hexagonal manner sectored suspension type cladding and hexagonal manner sectored core region, all the sector are formed by zeonex based struts. To investigate the optical characteristics of developed design, finite element method (FEM) based COMSOL multiphysics v.5.4a software has been used. The simulation result shows the sensitivity of 83.37% and 83.63% at the optimum condition in x-polarization mode for ethanol and benzene respectively with low effective material loss of 0.0291 cm−1 and low confinement loss of 1.87×10-13 cm-1. Moreover, the developed design implementation is possible in the existing fabrication method. Physical features and comparative performance analysis are also showed in this research. DUJASE Vol. 7 (2) 56-61, 2022 (July)

Study on Optical Features of Circular Photonic Crystal Fibers with Various Air-hole Size

: In this workwe proposed a newly designed photonic crystal fiber (PCF) with a circular lattice, the difference between the air-hole diameters of the first ring and the other rings makes it possible to improve the nonlinear properties of fibers. We investigated the effect of varying the filling factor (d1/Ʌ) and lattice constant (Ʌ) on the nonlinear characteristics of photonic crystal fibers in the 0.5 - 2 µm wavelength range. The advantages of these photonic crystal fibers are the flat and near-zero dispersion, low attenuation, and high nonlinear coefficient. From simulation results, we have selected three optimal structures (Ʌ = 1.0 μm; d1/Ʌ = 0.4, Ʌ = 0.8 μm; d1/Ʌ = 0.6, and Ʌ = 0.8 μm; d1/Ʌ = 0.65) to analyze the nonlinear characteristics at the pump wavelengths. The proposed fibers are valuable for supercontinuum generation.
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Applications of photonic crystal fibers in optical communication

Abstract Photonic crystal fiber is a category of optical fibers, getting great attention by its promise to offer a range of optical characteristics that are not achievable in conventional optical fibers. Engineered dispersion and nonlinear characteristics of photonic crystal fiber (PCF) make it an attractive candidate for nonlinear optics and advanced optical networking in the all-optical domain. An optical network consists of different optical components such as laser sources, amplifiers, regenerators, and convertors for proper signal transmission over long distances. In recent years, the performance of the components has been improving by employing the appealing properties of PCF. The PCF’s application on such components is discussed, and the simulated results on gain amplification, regeneration, conversion, fiber laser are reviewed. These developments reveal that the enhanced performance provided by PCF makes it suitable for different optics applications.

The Rise of Graphene Photonic Crystal Fibers

Abstract2D graphene with tremendous novel properties is an ideal material for optical and optoelectronic applications. Meanwhile, photonic crystal fibers (PCFs) have been recognized as next‐generation optical fibers that possess a designable porous structure, rich functions, and different working mechanisms. Recently, the integration of graphene with a PCF has formed a new hybrid fiber, a graphene photonic crystal fiber (Gr‐PCF), which exhibits an extremely strong and tunable light–matter interaction across a broadband spectrum range and opens up a new interdisciplinary research direction. In this review, recent studies on, and achievements in graphene‐traditional fibers and Gr‐PCFs have been summarized from the aspects of the development process, preparation method, and device application. First, the graphene properties and the development and characteristics of PCFs are introduced. The discussion is continued with the existing fabrication technologies for hybrid graphene‐traditional fibers. Next, the chemical vapor deposition method for Gr‐PCFs is elaborated. Then, fiber devices based on graphene‐traditional fibers, Gr‐PCFs, and other 2D material fibers are presented. To conclude, challenges and perspectives are presented to encourage advanced Gr‐PCF study.

Research on the Dispersion Characteristics of Photonic Crystal Fiber with Different Inner Structures Used to Transmit Oam Modes

Research on the Dispersion Characteristics of Photonic Crystal Fiber with Different Inner Structures Used to Transmit Oam Modes

Propagation characteristics of photonic crystal fibers selectively filled with ionic liquid

We present a numerical and experimental study of the propagation characteristics of photonic crystal fibers (PCFs) selectively filled with ionic liquid (IL; 1-butyl-3-methylimidazolium iodine). Three types of IL-filled PCF are investigated: one with all air holes filled, one with an IL-filled air hole in the second ring, and one with an IL-filled air hole in the third ring. The results show that the third type of IL-filled PCF is the most sensitive to temperature; the sensitivity of resonant dips between the LP01 and LP21 modes is ∼−2.9 nm/°C. Moreover, the intensity of the resonant dips changes with the polarization angle of the light source; the sensitivity is ∼−0.79 dB per unit polarization angle. Based on this property, IL-filled PCFs with different utilities can be realized by changing the filling position flexibly. Consequently, IL-filled PCFs can be used under flexible conditions and controllable temperatures to create a compact polarization-angle sensor.

Characteristics of photonic crystal fibers with different lattices: Realization of constant air percentage by fixing air-filling fraction

The mode properties of solid-core photonic crystal fibers (PCFs) having square, pentagonal, hexagonal, octagonal, nonagonal, decagonal, and dodecagonal lattice formats with uniform air-filling fractions (AFFs) have been evaluated by a full-vector finite-element method using the software COMSOL Multiphysics 4.3. Irrespective of the hole-to-hole spacing for a particular type of lattice, the ratio of air-hole radii of two PCFs having different AFFs is a constant. The ratio of air-hole radii of a pair of PCFs consisting of different lattice types is also found to be constant if the AFF is the same. With dependence on value of AFF used the effect of the order of lattice on the mode area of PCFs exhibit a reversal characteristic while approaching higher order. The effective nonlinear coefficient has been found to be maximized for octagonal PCFs. A reduction in confinement loss to the order of 10−6 has been observed for higher order PCFs with increased AFF. The variation of the effective area with AFF indicates that it almost reaches saturation for higher ordered structures, but its magnitude is found to decrease with increasing AFF. A flattened dispersion is observed for square PCFs over a wide wavelength range.

Liquid Level and Refractive Index Double-Parameter Sensor Based on Tapered Photonic Crystal Fiber

In this article, a liquid level and refractive index double-parameter sensor with single-mode fiber-tapered photonic crystal fiber (TPCF)-single-mode fiber structure is designed. We utilized the temperature-insensitive characteristics of photonic crystal fiber (PCF) to solve the crosstalk caused by temperature. Tapering techniques are adopted to increase the evanescent wave and the sensing region length of the PCF surface and improve the sensitivity and measurement range of the sensor. The liquid level and refractive index can be simultaneously detected through the mode analysis of the sensor's interference spectrum, along with the double-parameter matrix equation. Experimental results show that the maximum sensitivity of the sensor is 0.58466 nm/mm within a liquid level range of 0-10 mm (for an aqueous solution). The maximum sensitivity of the sensor is 195.969 nm/RIU within the refractive index range of 1.336-1.382. The sensor has simple structure and excellent sensing performance, as well as several application prospects in the fields of fuel storage and chemical liquid level measurement.

Structural and Behavioural Analysis of As<sub>2</sub>Se<sub>3</sub>, TeO<sub>2</sub>, SiC, SiO<sub>2</sub> and Si<sub>3</sub>N<sub>4</sub> for Photonic Application

The materials significantly influence the structural, optical and photoelectrical characteristic. Materials such as Arsenic selenide, Tellurite Glass, Silicon carbide, Silicon dioxide and Silicon nitride are investigated through finite element method. The models are established to analyse the structural behaviour of polarization preserving fibre of proposed materials. Photoelectric characteristic determines guided properties of photon particles. Refractive index of the materials influences the properties of photonic crystal fibre. A Polarization Splitter based hexagonal structure is proposed, where inner ring of cladding is in elliptical shape air holes and outer rings are in circular air holes. It provides highly negative dispersion, low confinement loss and high nonlinear coefficient between 1µm to 2µm wide wavelength ranges. The dispersion result shows -2000 db/km-nm at 1.55µm wavelength. Polarization beam splitters photonic crystal fiber characteristics of proposed materials are analysed with same structural parameters.

Design of methane sensor based on slow light effect in hollow core photonic crystal fiber

A tunable methane gas sensor is proposed and optimized by introducing a gas-sensitive film into the cladding air holes of hollow core photonic crystal fiber (HC-PCF). The characteristics of dispersion curve and group index of band-gap photonic crystal fiber are analyzed by the Plane Wave Expansion Method (PWM) and Finite Element Method (FEM). The results show that the micro-fluid infiltration technology can effectively improve the slow light characteristics of photonic crystal fiber (PCF), and make the central wavelength of slow-light region at the target gas absorption to discriminate the gas species. The coating technique allows the spectrum of absorption enhancement factor linearly shift with the increase of methane concentration, and the sensitivity can reach up to 0.794 nm/%. The sensor is simple and reliable with good linearity, which provides a new way for mixed gas measurements.

Empirical relations for far-field characterization of photonic crystal fibers

To characterize far-field of a solid-core photonic crystal fiber (PCF), we present simple empirical relations for angle of beam divergence of PCF only depending on the opto-geometrical parameters like wavelength of the light used and the two structural parameters – the air hole diameter and the hole pitch. We validate the accuracy of the proposed expressions by comparing the empirical relations with the results of exact values. We can easily evaluate the far-field properties of PCFs through the empirical relations without the need for numerical computations of V parameter or spot size or the effective cladding index.

Near infrared polarization filtering characteristics of photonic crystal fibers filled with silver nanowire

Abstract We proposed a novel near infrared polarization filtering of photonic crystal fiber (PCF) with a silver nanowire. The finite element method (FEM) is used to study the optical properties of PCF filled with a silver nanowire. The effect of air fill ratio on the polarization characteristics of the fiber is discussed. A photonic crystal fiber capable of achieving good polarization filtering at 1.21 μm and 1.17 μm was designed. The results show that when the air hole diameter d0 is 0.7 μm, the fiber has the strongest filter response in the x-polarization direction at the wavelength of 1.2 μm, and its intensity can reach 7210.35 dB/m. However, the filtering response of the y-polarization direction at the wavelength of 1.168 μm is not very strong, and that of the x-polarization direction is 1394.86 dB/m. Thus a good polarization filter is achieved in the designed PCF. The research is of great significance for the photonic crystal fiber in polarizing devices.

Ultra-wide bandwidth polarization filter based on gold-coated photonic crystal fiber around the wavelength of 1.55 µm

A novel ultra-wide bandwidth photonic crystal fiber (PCF) polarization filter based on surface plasmon resonance (SPR) is proposed. The PCF has two large cladding air holes in the direction of y-axis that are selectively coated with gold films to create resonance. There are two small holes in the direction of x-axis, which provides high birefringence. The polarization characteristics of PCF are studied by finite element method (FEM). The numerical simulation results indicate that the loss of y-polarized core mode is 718.87 dB/cm, while the loss of x-polarized core mode is only 0.95 dB/cm at the resonant wavelength of 1.55 µm. The extinction ratio is better than 20 dB at the wavelength ranging from 1.43 to 1.79 µm, the corresponding bandwidth is 360 nm.

Research on Dual-Wavelength Single Polarizing Filter Based on Photonic Crystal Fiber

Dual-wavelength single polarizing filter has many important applications in the field of optical communication. Based on the principle of surface plasma resonance, a kind of dual-wavelength single polarizing filter with the broadband of low crosstalk was proposed in the paper by adopting good polarization characteristics of photonic crystal fiber. It could have single polarizing filtering in the dual-wavelength of 1310 and 1550 nm and the polarization direction of optical output is independent of the wavelength of incident light. The polarization direction of emergent light through filter can always keep the core mode in x-polarized direction (x-PCM) in a wide range of wavelength, which increases the difference of confinement loss of core mode in y-polarized direction (y-PCM) and x-PCM, and reduces mutual crosstalk. Meanwhile, the theoretical result also showed that the wavelength location and intensity of loss peak of polarizing mandrel are only affected by the air holes adjacent to fiber core and metal film and have little correlation with the structural parameters of other air holes, which ease the difficulty level of preparing filter based on photonic crystal fiber. Under certain structural parameters, the confinement loss of y-PCM could reach 265.04 dB/cm in 1310 nm and 230.5 dB/cm in 1550 nm. The half-width of confinement loss in the wavelength of 1310 nm is only 12 nm, while the loss of x-PCM is much smaller than that in y-PCM.

Versatile dispersion characteristics of water solution of glycerine in selective filling of holes in photonic crystal fibers.

Using a glycerine-water solution with various concentrations, we investigate the dispersion characteristics of photonic crystal fibers by selective filling of holes. Our analysis is based on a simple but accurate semi-vectorial solution of Helmholtz's equation by the finite difference method devised with a mode-field convergence technique and crosschecked by results with those from a deeply involved multipole method. Significantly, a better ultra-flatness but near-zero group velocity dispersion is revealed with a 20% glycerine-water solution that is superior to pure water of a very recent case when the holes of the first ring of the fiber are filled. This versatile effect in management of holes of identical diameter with liquid is expected to play a guiding role in studies of supercontinuum generation.

Influence of temperature on dispersion properties of photonic crystal fibers infiltrated with water

Temperature change of the water infiltrated PCF is an interesting and practical method for a dynamical fine tuning of dispersion in active dispersion shift compensating systems. In this paper we present a numerical study on the influence of the temperature of infiltrated water on the dispersion and modal characteristics of photonic crystal fiber. We study regular hexagonal lattice photonic crystal fibers with various geometrical parameters using finite element method.

Design of a polarization filtering photonic crystal fiber with a big gold-coated air hole

The polarization characteristics of photonic crystal fiber (PCF) with nanoscale gold film is evaluated by using the finite element method. The cross-section structure of the PCF is composed of a hexagonal lattice of air holes in which an air hole is gold coated. The resonance strength and the impact of structural parameters of the PCF on the polarization filter characteristics are studied. By our structure, the loss of y-polarized mode is further larger than the loss of x-polarized mode at the wavelength 1.31 and 1.55 μm. The corresponding loss in y-polarized can reach a value of 136,253 and 167607 dB/m at the resonance wavelengths of 1.31 and 1.55 μm respectively. It can be used for carrying data/voice at the communication windows of 1.31 and 1.55 μm. Meanwhile, we can realize the filtering effect with a very short fiber.

基于磁流体填充的光子晶体光纤传感特性研究

基于磁流体填充的光子晶体光纤传感特性研究