scholarly journals Manifestation of propagation traits for polymer square lattice micro-structured optical fiber in THz regime: a simplified model

2021 ◽  
Author(s):  
Hukam Singh ◽  
Dinesh Kumar Sharma ◽  
Saurabh Mani Tripathi
Keyword(s):  
Optical Fiber ◽  
Numerical Aperture ◽  
Relative Sensitivity ◽  
Sensitivity Coefficient ◽  
Spot Size ◽  
Square Lattice ◽  
Confinement Loss ◽  
Design Parameters ◽  
Solid Core ◽  
Material Loss

Abstract To sustain the pace with immense prominence, interest in low-loss terahertz (THz) waveguides increases due to their particular applications in the multidisciplinary arena. This paper narrates a novel solid-core polymer-based square lattice micro-structured optical fiber (SL-MOF) with circular air-holes for efficient propagation of THz waves. The anticipated model’s guiding attributes are described by employing the numerically efficient finite-element method (FEM) in conjunction with an auxiliary Ring Model. Numerical analysis of the model exhibits confinement loss of about ~ 10 -7 dB/cm and low effective material loss of ~ 0.19 cm -1 at the applied frequency of 1.0 THz. It is also demonstrated that the considered geometry furnishes low bending loss over the extended range of THz frequency. The relative sensitivity coefficient is evaluated in context for the targeted design parameters to enable the said model’s practical utility. Other nameworthy propagation characteristics, such as effective mode-index, power fraction, effective mode-area, numerical aperture, spot-size, and the beam divergence are also investigated. The improved outcomes are anticipated that the proposed configuration will be opened a new epoch in the THz waveband.

scholarly journals Terahertz Sensor via Ultralow-Loss Dispersion-Flattened Polymer Optical Fiber: Design and Analysis

Materials ◽  
2021 ◽  
Vol 14 (17) ◽  
pp. 4921
Author(s):  
Wanli Luo ◽  
Peng Jiang ◽  
Qiang Xu ◽  
Lei Cao ◽  
Adam Jones ◽  
...  
Keyword(s):  
Optical Fiber ◽  
Optimum Design ◽  
Numerical Aperture ◽  
Relative Sensitivity ◽  
Confinement Loss ◽  
Polymer Optical Fiber ◽  
Effective Mode Area ◽  
Late Model ◽  
Thz Sensing ◽  
Mode Area

A novel cyclic olefin copolymer (COC)-based polymer optical fiber (POF) with a rectangular porous core is designed for terahertz (THz) sensing by the finite element method. The numerical simulations showed an ultrahigh relative sensitivity of 89.73% of the x-polarization mode at a frequency of 1.2 THz and under optimum design conditions. In addition to this, they showed an ultralow confinement loss of 2.18 × 10−12 cm−1, a high birefringence of 1.91 × 10−3, a numerical aperture of 0.33, and an effective mode area of 1.65 × 105 μm2 was obtained for optimum design conditions. Moreover, the range dispersion variation was within 0.7 ± 0.41 ps/THz/cm, with the frequency range of 1.0–1.4 THz. Compared with the traditional sensor, the late-model sensor will have application value in THz sensing and communication.

Theoretical Assessment of a Porous Core Photonic Crystal Fiber for Terahertz Wave Propagation

2018 ◽  
Vol 0 (0) ◽  
Author(s):  
Izaddeen Kabir Yakasai ◽  
Atta Rahman ◽  
Pg Emeroylariffion Abas ◽  
Feroza Begum
Keyword(s):  
Photonic Crystal ◽  
Photonic Crystal Fiber ◽  
Bulk Material ◽  
Single Mode ◽  
Confinement Loss ◽  
Design Parameters ◽  
Terahertz Waves ◽  
Material Loss ◽  
Crystal Fiber ◽  
Porous Core

AbstractA porous core photonic crystal fiber (PCF) for transmitting terahertz waves is reported and characterized using finite element method. It is shown that by enveloping an octagonal core consisting of only circular air holes in a hexagonal cladding, it is possible to attain low effective material loss that is 73.8% lower than the bulk material absorption loss at 1.0 THz operating frequency. Moreover, a low confinement loss of 7.53×10–5 cm−1 and dispersion profile of 1.0823±0.06 ps/THz/cm within 0.7–1 THz are obtained using carefully selected geometrical design parameters. Other guiding properties such as single-mode operation, bending loss, and effective area are also investigated. The structural design of this porous core PCF is comparatively simple since it contains noncomplex lattices and circular shaped air holes; and therefore, may be implemented using existing fabrication techniques. Due to its auspicious guiding properties, the proposed fiber may be used in single mode terahertz imaging and other short distance terahertz applications.

scholarly journals Study of Optical Fiber Design Parameters in Fiber Optics Communications

2017 ◽  
Vol 2 (3) ◽  
pp. 302-308 ◽  
Author(s):  
Salim Qadir Mohammed ◽  
Asaad M. Asaad M. Al-Hindawi
Keyword(s):  
Optical Fiber ◽  
Fiber Optics ◽  
Numerical Aperture ◽  
Design Parameters ◽  
Light Sources ◽  
Long Distance ◽  
Graded Index ◽  
Large Bandwidth ◽  
Telecommunication Infrastructure ◽  
Distance Communication

Fiber optics is an important part in the telecommunication infrastructure. Large bandwidth and low attenuation are features for the fiber optics to provide gigabit transmission. Nowadays, fiber optics are used widely in long distance communication and networking to provide the required information traffic for multimedia applications. In this paper, the optical fiber structure and the operation mechanism for multimode and single modes are analyzed. The design parameters such as core radius, numerical aperture, attenuation, dispersion and information capacity for step index and graded index fibers are studied, calculated and compared for different light sources.

Application of Optical Fiber Made of Various Materials with Composite Properties of Materials in Laser Medical Treatment

2012 ◽  
Vol 600 ◽  
pp. 222-225
Author(s):  
Zhen Zhang ◽  
Fang Liu
Keyword(s):  
Optical Fiber ◽  
Medical Treatment ◽  
Plastic Material ◽  
Numerical Aperture ◽  
Fiber Material ◽  
Spot Size ◽  
Light Transmittance ◽  
Core Diameter ◽  
Transmission Distance ◽  
Fiber Manufacturing

Though introducing the optical fiber in a laser medical treatment made ​​of different materials, contrast expounded integrated characteristic of the different materials in manufacturing an optical fiber material, summed four aspects need to be considered in the choice of the optical fiber manufacturing material. First, the laser parameters, such as maximum laser power, the wavelength, the transmission distance, the laser beam spot size and numerical aperture of the laser light source. Second, according to the optical fiber light transmittance curve, to identify the optimum transmittance of the application wavelength. Third, determining transmission optical slender core diameter, typically a core diameter is greater than the laser spot size of 2/3; decision sets of plastic material finally.

Slitless Optical-Fiber Laser-Raman Spectrometer Employing a Concave Holographic Grating

1977 ◽  
Vol 31 (4) ◽  
pp. 295-298 ◽  
Author(s):  
George E. Walrafen
Keyword(s):  
Optical Fiber ◽  
Fiber Laser ◽  
Numerical Aperture ◽  
Fused Silica ◽  
Holographic Grating ◽  
Photomultiplier Tube ◽  
Solid Core ◽  
Raman Spectrometer ◽  
Focal Line ◽  
Laser Raman

A slitless optical-fiber laser-Raman spectrometer has been developed that employs a single f/3 concave holographic diffraction grating. The exit end of an optical fiber is positioned at the grating focus, and the divergent excitation and Raman radiation are then dispersed and refocussed. Detection is accomplished by translating an exit slit and photomultiplier tube along the focal line. A moveable solid-core optical fiber that transmits light to a fixed photomultiplier tube may also be used. The holographic grating produces a straight focal line, instead of a curve, resulting in accurate focussing from 480 to 650 nm, with linear scanning. The low f-number grating was used to accommodate high numerical aperture optical fibers without loss of light. A comparison between the present spectrometer with a 55 m fused silica fiber and a Jarrell-Ash Czerny-Turner single monochromator using a 1-cm bulk sample indicates a signal/noise improvement by a factor of 137 for the very weak two-phonon band from fused silica near 1600 cm−1.

A comparison of the effect of the ellipticity on the small and large solid-core PCF’s characteristics

Open Physics ◽  
2014 ◽  
Vol 12 (9) ◽  
Author(s):  
Halime Inci ◽  
Sedat Ozsoy
Keyword(s):  
Hexagonal Lattice ◽  
Numerical Aperture ◽  
Simulation Software ◽  
Confinement Loss ◽  
Solid Core ◽  
Large Core ◽  
Small Core ◽  
Crucial Effect ◽  
Circular Holes ◽  
Air Hole

AbstractIn this paper we study small and large solid-core PCFs with elliptical shaped air-holes for the hexagonal lattice, which were constructed by omitting one air-hole (small core) and seven air-holes (large core), respectively, and we compare their characteristics with those with circular holes. We use two types of ellipticity: vertical and horizontal. Birefringence, dispersion, and the numerical apertures of the fundamental modes are analyzed using commercial simulation software. Also, the confinement loss is obtained. The effect of ellipticity on these characteristics is investigated in detail. It is found that the type of ellipticity of the air holes affects the numerical aperture and hence confinement loss significantly, but it has no crucial effect on either the dispersion or the birefringence for the small and large core PCFs.

scholarly journals Theoretical Considerations of Photonic Crystal Fiber with All Uniform-Sized Air Holes for Liquid Sensing

Photonics ◽  
2021 ◽  
Vol 8 (7) ◽  
pp. 249
Author(s):  
Abdul Mu’iz Maidi ◽  
Pg Emeroylarffion Abas ◽  
Pg Iskandar Petra ◽  
Shubi Kaijage ◽  
Nianyu Zou ◽  
...  
Keyword(s):  
Photonic Crystal ◽  
Photonic Crystal Fiber ◽  
Nonlinear Coefficient ◽  
Numerical Aperture ◽  
Relative Sensitivity ◽  
Effective Area ◽  
Confinement Loss ◽  
Crystal Fiber ◽  
Sensing Applications ◽  
Liquid Sensing

A novel liquid-infiltrated photonic crystal fiber model applicable in liquid sensing for different test liquids—water, ethanol and benzene—has been proposed. One core hole and three air hole rings have been designed and a full vector finite element method has been used for numerical investigation to give the best results in terms of relative sensitivity, confinement loss, power fraction, dispersion, effective area, nonlinear coefficient, numerical aperture and V-Parameter. Specially, the assessed relative sensitivities of the proposed fiber with water, ethanol and benzene are 94.26%, 95.82% and 99.58%, respectively, and low confinement losses of 1.52 × 10−11 dB/m with water, 1.21 × 10−12 dB/m with ethanol and 6.01 × 10−16 dB/m with benzene, at 1.0 μm operating wavelength. This novel PCF design is considered simple and can be easily fabricated for practical use, and the assessed waveguide properties has determined the potential applicability in real liquid sensing applications.

scholarly journals Neural network approach for faster optical properties predictions for different PCF designs

2021 ◽  
Vol 2070 (1) ◽  
pp. 012001
Author(s):  
Hardik Kumar ◽  
Tanya Jain ◽  
Mritunjay Sharma ◽  
Kamal Kishor
Keyword(s):  
Neural Network ◽  
Optical Properties ◽  
Imaging Spectroscopy ◽  
Confinement Loss ◽  
Design Parameters ◽  
Solid Core ◽  
Network Approach ◽  
Neural Network Approach ◽  
The Neural Network ◽  
Mode Area

Abstract Photonic Crystal Fibres (PCFs) are emerging as an alternative to standard fibres for applications in many disciplines like fibre lasers & amplifiers, imaging, spectroscopy and telecommunications. They have superior light guiding properties compared to ordinary Optical Fibres (OFs). This paper illustrates the potential of neural networks to efficiently and accurately compute the optical properties of PCFs including solid-core, hollow-core and multi-core designs. The proposed method takes a range of design parameters and wavelengths as input to predict PCF optical properties like effective index, effective mode area, confinement loss and dispersion desired for optimal specifications. The neural network approach is significantly better in terms of the low computational runtimes (~5 milli-sec) required for predicting the properties against the longer runtimes (~18 sec) required for similar calculations by traditional numerical methods.

scholarly journals PCF Design With Extremely High Nonlinearity And Extremely Negative Dispersion

2021 ◽  
Author(s):  
Sanat Kumar Pandey ◽  
J.B. Maurya ◽  
Yogendra Kumar Prajapati
Keyword(s):  
Numerical Aperture ◽  
Effective Area ◽  
Confinement Loss ◽  
Performance Parameters ◽  
Material Loss ◽  
Crystal Fiber ◽  
Negative Dispersion ◽  
High Nonlinearity ◽  
Very High ◽  
Air Hole

Abstract In this manuscript we designed a circular photonic crystal fiber (PCF) having three rectangular holes filled with GaP in the core region, three air hole rings and one annular air ring in cladding region. We found highest negative dispersion for the 1.8µm pitch alongwith very low confinement loss at wavelength 1.55µm. This designed PCF offers high nonlinearity (39612 W-1km-1) and high negative dispersion (-6586 ps nm-1 km-1) alongwith zero confinement loss at 1.55µm wavelength. We also compared the proposed PCF with the previously published PCF structure and found that the nonlinearity and negative dispersion of the designed PCF are very high in comparison to circular air hole based PCF. Another performance parameters viz. birefringence, numerical aperture, effective area and effective material loss are also analyzed.

A Refractive Index Based Micro-Structured Sensor for Blood Components Detection in Terahertz Regime

2020 ◽  
Vol 18 (1) ◽  
pp. 74-82 ◽  
Author(s):  
Md. Ahasan Habib
Keyword(s):  
Optical Sensor ◽  
Numerical Aperture ◽  
Relative Sensitivity ◽  
Confinement Loss ◽  
Geometric Condition ◽  
Blood Components ◽  
Absorption Loss ◽  
Efficient Manner ◽  
Crystal Fiber ◽  
Sensing Applications

In this article, a hexagonal packing photonic crystal fiber based optical sensor is presented and analyzed for different blood components identification using terahertz (THz) signal. The numerical analysis of the proposed sensor is performed by using finite element method based software Comsol V5.0. The proposed fiber is investigated in terahertz frequency spectrum from 1.3 THz to 2.5 THz for higher relative sensitivity and numerical aperture as well as lower absorption loss and confinement loss for better sensing applications. The reported hollow core fiber provide better interaction of light and the analytes, so that high relative sensitivity of 83.45%, 81.20%, 80.78%, 79.60% and 78.80% are obtained for RBCs, Hemoglobin, WBCs, Plasma and Water respectively at a particular geometric condition. Moreover, very low confinement loss and absorption loss with high numerical aperture is offered by the proposed sensor in terahertz spectrum. This optical sensor may be an alternative option to detect blood components present in the blood in a very efficient manner.

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