Spiral Photonic Crystal Fiber Research Articles

Enhancement of OAM and LP modes based on double guided ring fiber for high capacity optical communication

This article introduced a double guided ring-based spiral photonic crystal fiber (S-PCF) supporting both the orbital angular momentum (OAM) and linear polarization (LP) mode simultaneously with the efficient transmission. The outcomes exhibition that the designed S-PCF have good optical features such as less confinement loss (4.05342 × 10−12 dB/m for the EH9,1 mode), better mode quality and ISO (up to 98.87% and 126 dB, respectively), supported a decent amount of modes which is numerically 64 OAM and 6 LP modes, maintaining the large refractive index differences (>10-4) of all the eigenmodes, and a relatively flat dispersion variation (0.0743 ps/km-nm for the EH1,1 mode). Also, we obtained the crosstalk less than −12 dB and the power fraction is approximately 93%-99% of the S-PCF. All the optimizing properties are obtained using the full-vector finite element method (FEM) and also the perfectly matched layer (PML) as a boundary condition. Thus, the above mentioned optimizing propagation characteristic based S-PCF has effective applications like reliable long-distance communication into the space division multiplexing (SDM) process of the large-capacity fiber communication systems.

Numerical investigation of spiral photonic crystal fiber (S-PCF) with supporting high order OAM modes propagation for space division multiplexing applications

This article proposes a spiral designed photonic crystal fiber (S-PCF) that supports 14 orbital angular momentum (OAM) modes for signal transmission and possess very low nonlinear coefficient and flat dispersion and it could assess for space division multiplexing applications. The core material of the proposed fiber is silicon because it shows excellent transmittance, low thermal response, chemically inert etc. The dispersion variations of 20–110 ps nm−1 km−1 for all OAM-modes are exhibited at 1.00 μm wavelength. In addition, overall dispersion distinction among all modes is under 10 ps nm−1 km−1. Besides, $$TM_{0,1}$$ and $$TE_{0,1}$$ modes are better in dispersion for its flat and low dispersion. Moreover, the nonlinear coefficient is very low that is 2.10 W−1 km−1 for $$EH_{5,1}$$ at 2.50 µm wavelength and the investigated confinement loss is always below than $$10^{ - 5}$$ dB m−1. In addition these basic optical parameters, few other properties such as numerical aperture and the effective-area are also computed. Considering all noble features, this proposed S-PCF is encouraging to be utilized in extra-capacity, large bandwidth and high-volume for optical fiber communication systems.

Design Optimization to Analyze Elliptical Core Spiral Photonic Crystal Fiber with Improved Optical Properties

Design Optimization to Analyze Elliptical Core Spiral Photonic Crystal Fiber with Improved Optical Properties

Extremely Low Loss of Photonic Crystal Fiber for Terahertz Wave Propagation in Optical Communication Applications

AbstractAn enormously low loss symmetrical hybrid decagonal porous core spiral photonic crystal fiber (SH-PCF) has been proposed for terahertz (THz) wave guiding. The modal characteristics of the fiber and its mathematical analysis have been numerically completed using a full-vector finite element method (FEM). Simulation results show an ultra-low material loss of 0.0167 cm−1 and large effective area 1.95×106 µm2 which is 91.6 % of bulk absorption material loss at controlling frequency f=1.0 THz with a core porosity 42 %. Additionally, proposed structure establishes the comparatively higher core power fraction maintaining lower scattering loss about 1.8×10−15 dB/cm at the same operating frequency. It promises the aforementioned advantages for efficient THz wave propagation.

Highly nonlinear silica spiral photonic crystal fiber for supercontinuuam generation extending from 320 nm to 2620 nm

We present a design of a highly nonlinear silica spiral photonic crystal fiber with nonlinear coefficient of 648.48 W−1 km−1 and group velocity dispersion of 20.75 ps2/km at 532 nm pump wavelength for widely extended supercontinuum generation. In the proposed design the first hole in a spiral arm is bigger in size and the subsequent holes are smaller. We use full vector finite element method to evaluate the modal properties of the fiber. The proposed fiber design provides better mode confinement and dispersion control than the conventional triangular and hexagonal core photonic crystal fibers. Our numerical simulations using split step Fourier method show 2300 nm wide blue extended supercontinuum generation ranging from 320 nm to 2620 nm wavelength using a 100 fs, 60 kW pump at 532 nm wavelength using the proposed fiber design. The generated supercontinuum would be useful in optical coherence tomography, fluorescence imaging, and absorption spectroscopy.

A Bimetallic-Coated, Low Propagation Loss, Photonic Crystal Fiber Based Plasmonic Refractive Index Sensor

In this paper, a low-loss, spiral lattice photonic crystal fiber (PCF)-based plasmonic biosensor is proposed for its application in detecting various biomolecules (i.e., sugar, protein, DNA, and mRNA) and biochemicals (i.e., serum and urine). Plasmonic material gold (Au) is employed externally to efficiently generate surface plasmon resonance (SPR) in the outer surface of the PCF. A thin layer of titanium oxide (TiO2) is also introduced, which assists in adhering the Au layer to the silica fiber. The sensing performance is investigated using a mode solver based on the finite element method (FEM). Simulation results show a maximum wavelength sensitivity of 23,000 nm/RIU for a bio-samples refractive index (RI) detection range of 1.32–1.40. This sensor also exhibits a very low confinement loss of 0.22 and 2.87 dB/cm for the analyte at 1.32 and 1.40 RI, respectively. Because of the ultra-low propagation loss, the proposed sensor can be fabricated within several centimeters, which reduces the complexity related to splicing, and so on.

Numerical analysis of a highly nonlinear microstructured optical fiber with air-holes arranged in spirals

• A spiral shape photonic crystal fiber deposition has been designed for nonlinear applications. • Numerical simulation proves that the proposed work gives the extremely high nonlinear coefficient. • It simultaneously offers a desirable optical property of numerical aperture. • The outcome indicates that the proposed PCF is few times more effective than the earlier reported fiber. • A strong candidate in supercontinuum generation and biomedical imaging applications. A spiral shape photonic crystal fiber (S-PCF) deposition with silicon nanocrystal has been designed for nonlinear applications. Full vector finite element method (FV-FEM) based commercially available software COMSOL Multiphysics® version 4.2 has been used here to investigate some essential optical characteristics. Numerical simulation proves that the proposed work gives the extremely high nonlinear coefficient of 2.28 × 10 5 W −1 km −1 and 2.56 × 10 5 W −1 km −1 for the X and Y polarization respectively, at wavelength λ = 1.00 µm. Moreover, it simultaneously offers a desirable optical property of numerical aperture (NA) of 0.54 and 0.56 at the same electromagnetic (EM) wave. The outcome indicates that the proposed PCF is approximately a few times more effective than the earlier reported fiber designs. The proposed PCF designed with circular shape holes and geometrical rhythms which remains enormously convenient in fabrication. This PCF structure provides a way to get the high nonlinearity with NA at the same time, which can find extensive applications in the optical signal processing as well as medical imaging.

Design optimization of a highly sensitive spiral photonic crystal fiber for liquid and chemical sensing applications

• Sensitivity coefficient is analyzed for three liquids water, propane and propylene of different refractive indices. • Confinement loss is investigated for the optimized parameters of PCF. • Relative Sensitivity is analyzed for different pitch values. • Sensitivity is investigated for various air filling fraction in the cladding region. In this paper, a spiral shaped photonic crystal fiber (PCF) is proposed for liquid sensing applications. The guiding properties of the proposed PCF are analysed. Sensitivity coefficient is analysed by varying different structural parameters for a wider wavelength range. In addition, confinement loss is also studied at the same wavelengths. The relative sensitivity achieved for the optimized parameters are 56.8%, 58.3% and 62.7% for water (n = 1.33), propane (n = 1.34) and propylene (n = 1.36) respectively. With its low confinement loss and high sensitivity the proposed PCF can be used for liquid and chemical sensing applications.

Highly Negative Dispersion Nanocore Spiral Photonic Crystal Fiber for Supercontinuum Generation

In this letter, a spiral shape photonic crystal fiber (S-PCF) with nanocore has been suggested for the generation of the supercontinuum. The designing parameters have reformed to optimize the optical properties of the proposed structure. Finite element method is utilized to perform the numerical analysis of the proposed S-PCF. The proposed S-PCF exhibits a highly negative dispersion which ranges from − 82.21 to − 213.90 ps/(nm km) and high nonlinearity in the order of 6.31 × 107 W−1 km−1 at the 1.55 µm wavelength. The birefringence of the proposed structure is zero at the 1.55 µm wavelength. Besides, effective area and field distribution are also described briefly.

Computational modeling of tellurite based photonic crystal fiber for infrared supercontinuum generation

In this paper, we have numerically designed a golden spiral photonic crystal fiber using tellurite glass for supercontinuum generation. Dispersion engineering technique has been used for the optimization of geometrical parameters of the fiber. At a pump wavelength of 1.35 μm, the proposed fiber offers the high value of nonlinear coefficient as 884 W−1. km−1 and low effective mode area as 3.79 μm2. An ultra-broadband supercontinuum spectrum ranging 1000 – 5500 nm has been generated with a bandwidth of 4500 nm using designed fiber of length 5.5-centimeters long pumped with few femtosecond laser sources in the infrared wavelength region.

Spiral photonic crystal fiber structure for supporting orbital angular momentum modes

We propose a spiral photonic crystal fiber structure for supporting orbital angular momentum modes. The structure has 12 arms, arranged in a spiral shape in the cladding region, and a big air hole at the center of the structure. It can support 14 well-separated OAM modes with a mode index difference of 10−4. Our numerical results show a nonlinear coefficient of 2.78 W−1 Km−1 for the HE21 mode at 1550-nm wavelength. The fiber shows a dispersion difference over a 600 nm bandwidth for HE21 mode is 12.1 ps/km-nm, and the structure shows a low confinement loss. We have also calculated the effect of ellipticity on the mode’s effective index. Numerical results suggest that, this structure can be utilized in high-capacity communication systems for multiplexing fiber-based OAM.

Spiral Photonic Crystal Fiber-Based Dual-Polarized Surface Plasmon Resonance Biosensor

We numerically demonstrate a surface plasmon resonance biosensor-based on dual-polarized spiral photonic crystal fiber (PCF). Chemically stable gold material is used as the active plasmonic material, which is placed on the outer layer of the PCF to facilitate practical fabrication. Finite-element method-based numerical investigations show that the proposed biosensor shows maximum wavelength sensitivity of 4600 and 4300 nm/RIU in ${x}$ - and ${y}$ -polarized modes at an analyte refractive index of 1.37. Moreover, for analyte refractive index ranging from 1.33 to 1.38, maximum amplitude sensitivities of 371.5 RIU−1 and 420.4 RIU−1 are obtained in ${x}$ - and ${y}$ -polarized modes, respectively. In addition, the effects of changing pitch, different air hole diameter of the PCF and thickness of the gold layer on the sensing performance are also investigated. Owing to high sensitivity, improved sensing resolution and appropriate linearity characteristics, the proposed dual-polarized spiral PCF can be implemented for the detection of biological analytes, organic chemicals, biomolecules, and other unknown analytes.

Ultrashort polarization rotator based on spiral photonic crystal fiber aided by liquid crystal.

A novel polarization rotator (PR) is proposed based on a spiral photonic crystal fiber aided by liquid crystal. The proposed PR has an ultrashort length of only ∼4.17 μm and a low cross talk of ∼-20.93 dB, and the proposed PR offers a nearly 100% polarization conversion efficiency for the whole C-band. In addition, a large temperature tolerance of ∼±5°C and a large rotation angle tolerance of ∼±4° can be accepted based on the full-vector finite-element method simulation. The proposed PR is a potentially effective polarization conversion device for applications in modern communication systems.

Single-mode spiral shape fiber based liquid sensor with ultra-high sensitivity and ultra-low loss: Design and analysis

This paper represents a spiral photonic crystal fiber (S-PCF) based optical sensor which exhibits high relative sensitive as well as low confinement loss simultaneously. The proposed PCF contains ten arms as well as each arm consists of nine circular air holes that forms spiral shape and core is formatted with circular holes filled with ethanol. Various geometrical parameters including diameters and pitches of the suggested S-PCF are tuned with the most efficient structure applying the full vectorial finite element method (FEM). Overall outcomes satisfy O + E + S + C + L + U (range of 1.26–1.675 μm) electromagnetic (EM) bands. The relative sensitivities of about 72.95%, 74.55% and 75.14% with ultra-low confinement loss of 1.85 × 10−10 dB/m, 4.62 × 10−11 dB/m and 6.35 × 10−11 dB/m are gained at the 1.33 μm wavelength for water (n = 1.33), ethanol (n = 1.354) and benzene (n = 1.366) analytes respectively. In addition, effective area, non-linear coefficient and V-parameter are also examined. Finally, the inquiry procedure depicts that the proposed S-PCF is highly capable in not only sensing applications but also high data traffic transmission applications.

Highly birefringent single mode spiral shape photonic crystal fiber based sensor for gas sensing applications

This article represents a gas sensor based on spiral photonic crystal fiber (S-PCF) for detecting harmful or colorless gasses and monitoring air pollution by metering gas condensate elements in production facilities. The proposed micro-structured S-PCF contains two layers porous core encircled by a spiral shape cladding. The geometrical parameters are tuned to fix the optimized S-PCF structure. The numerical analysis of the proposed S-PCF is performed by utilizing finite element method (FEM) with circular perfectly match layer (C-PML). The relative sensitivity and birefringence of the recommended structure are 57.61% and 7.53×10−3 respectively at 1.33μm wavelength on the absorption line of toxic gasses (methane and hydrogen fluoride). The exhibited beam divergence is about 4.1° at the same wavelength. Besides, beat length, nonlinear coefficient, effective area and V parameters are also described briefly for optimized S-PCF structure over broader wavelength range from 1μm to 1.8μm.

Design of single mode spiral photonic crystal fiber for gas sensing applications

In this paper, a spiral shape photonic crystal fiber (S-PCF) has been suggested as a gas sensor for detecting toxic or colorless gases as well as monitoring the air pollution by metering gas condensate elements in production facilities. Our reported S-PCF is micro-structured where two layers porous core is encircled by a spiral shape cladding. The geometrical parameters have altered to optimize the parameters of the proposed structure. The numerical analysis of the proposed S-PCF is performed by utilizing finite element method (FEM). The relative sensitivity and birefringence of the proposed S-PCF are 55.10% and 7.23×10−3 respectively at the 1.33μm wavelength that lies in the absorption line of toxic gases (methane and hydrogen fluoride). Besides, effective area, nonlinear coefficient and V parameters are also described briefly.

Design and analysis of an ultrahigh birefringent nonlinear spiral photonic crystal fiber with large negative flattened dispersion

We proposed a simple design of spiral photonic crystal fiber (PCF) using an elliptical soft-glass rod in the core region for the purpose of controlling the property of dispersion and enhancing the performance of birefringence and nonlinearity simultaneously. The simulation results show that the proposed spiral PCF has ultra-flattened negative dispersion of 0.32ps/(nmkm) for y-polarized mode over a 150nm wavelength range, large negative dispersion values of −491.16ps/(nmkm) and −399.98ps/(nmkm) for x/y-polarized modes at 1.55μm, large nonlinearity up to the order of 102W−1km−1 for x/y-polarized modes, and ultrahigh birefringence up to the order of 10−2 within the wavelength range from 1.35 to 1.65μm. The main advantage of this new design is that large negative flattened dispersion, large nonlinearity and ultrahigh birefringence can be realized simultaneous simply by introducing an elliptical soft-glass rod in the fiber core region to a spiral PCF.

Analysis of Dispersion and Nonlinear Property in Doping Defected Core Spiral Photonic Crystal Fiber

Analysis of Dispersion and Nonlinear Property in Doping Defected Core Spiral Photonic Crystal Fiber

Polarization-maintaining low-loss porous-core spiral photonic crystal fiber for terahertz wave guidance.

A polarization-maintaining porous-core spiral photonic crystal fiber is proposed for efficient transmission of polarization-maintaining terahertz (THz) waves. The finite element method with perfectly matched layer boundary conditions is used to characterize the guiding properties. We demonstrate that by creating artificial asymmetry in the porous core, an ultrahigh birefringence of 0.0483 can be obtained at the operating frequency of 1.0THz. Moreover, a low effective material loss of 0.085 cm-1 and very small confinement loss of 1.91×10-3 dB/cm are achieved for the y-polarization mode with optimal design parameters. This article also focuses on some crucial design parameters such as power fraction, bending loss, and dispersion for usability in the THz regime.

Equiangular spiral photonic crystal fiber for code synchronization in all-optical analog-to-digital conversion based on lumped time delay compensation scheme

In this paper, we propose a lumped time delay compensation scheme for the all-optical analog-to-digital conversion (ADC) based on soliton self-frequency shift (SSFS) and optical interconnection techniques. By inserting a length of equiangular spiral photonic crystal fiber (PCF) between quantization and coding modules, the time delay of quantized pulses can be compensated. Simulation results show that the pulses can be synchronized utilizing a span of equiangular spiral PCF with flat negative dispersion of −258.92 ps/nm km in the wavelength range 1350nm to 1675nm. In addition, the amount of time delay and time error are analyzed, a maximum supportable sampling rate of 40GSa/s is obtained.