Core Power Fraction Research Articles

High birefringent slotted core slotted cladding porous core PCF for THz waveguide

A novel design featuring a porous core photonic crystal fiber (PC-PCF) is proposed in this paper for terahertz (THz) waveguide application. This work uses finite element method (FEM) and a boundary condition related to perfectly matched layer (PML) for analyzing the guiding properties. This methodology is supported by a fiber type featuring a slotted core and slotted cladding, utilizing Zeonex as the material. It offers high birefringence valued at 0.0978, small confinement loss of 10−14 dB/cm, a meager amount of effective material loss (EML) valued at 0.011697 dB/cm and a very high core power fraction (CPF) of 67.156%. Additionally, it shows a flattened pattern of dispersion measuring 0.4 ± 0.2 ps/THz/cm at an extensive frequency range of 0.5 THz to 2 THz. Other significant waveguide properties: effective refractive index, numerical aperture (NA), V-parameter, effective area, spot size, and beam divergence of the suggested fiber are numerically analyzed and conferred thoroughly. Regarding its mode of operation, the proposed fiber primarily functions in multimode, but it can also operate in single mode for higher porosity levels and lower core diameters. This unique characteristic renders the proposed PC-PCF structure well-suited for a broad range of applications, offering versatility as to its mode of operation.

Highly sensitive photonic crystal fiber chemical sensor for detecting carbon disulfide and bromoform in the THz regime

In this study, an innovative photonic crystal fiber (PCF) designed specifically for the detection of carbon disulfide and bromoform liquid chemicals within the THz frequency range was introduced. The PCF’s structural design was achieved using the Finite Element Method (FEM) and Perfectly Matched Layer (PML) boundary conditions within COMSOL Multiphysics, ensuring precision through appropriate numerical parameters. Six distinct configurations were developed, incorporating circular, square, rectangular slotted, benzene-shaped circular, and two elliptical core designs, as well as an eight-elliptical core design. The PCF models were constructed utilizing the dielectric material TOPAS for accurate simulation and analysis. Various crucial parameters of the proposed PCF were examined across a wide THz spectrum spanning from 0.2 to 1.2 THz. The PCF model exhibited a peak output at the operating frequency of 0.8 THz for the square-shaped core design, achieving a relative sensitivity of 96.891% for bromoform and 95.603% for carbon disulfide. Remarkably low material losses of 0.0081104 cm−1 for bromoform and 0.006703 cm−1 for carbon disulfide were observed, along with a core power fraction of 93.107% for bromoform and 94.263% for carbon disulfide. The effective area was determined to be 1.77 × 10−07 μm2 for bromoform and 1.70 × 10−07 μm2 for carbon disulfide, while the confinement loss measured 2.25 × 10−17 dB/cm for bromoform and 4.76 × 10−17 dB/cm for carbon disulfide. These superior attributes strongly suggest that this model will be crucial in applications like supercontinuum generation, sensing, and biomedical imaging.

Highly birefringent photonic crystal fibers with near-zero flattened dispersion for polarization-maintaining terahertz transmission

In this work, we present a novel hexagonal lattice porous-core photonic crystal fiber (PCF) exhibiting high birefringence, low loss, and near-zero flattened dispersion in the terahertz regime. The core design incorporates asymmetric rectangular and triangular air holes to achieve enhanced birefringence performance. The background material, TOPAS, is carefully selected to minimize dispersion and transmission losses. Furthermore, by employing the finite element method, the guiding properties of the proposed PCF are comprehensively investigated. Our simulation results reveal a near-zero flattened dispersion value of ±0.2ps⋅THz−1⋅cm−1 within a broad frequency range of 0.8−1.6THz, accompanied by an impressive birefringence value of 0.072. Additionally, the PCF demonstrates outstanding characteristics in terms of confinement loss, effective material loss, effective mode area, core power fraction, and bending loss. Considering its exceptional attributes, the proposed PCF holds significant promise for polarization-maintaining applications and terahertz communication systems.

Identification of four detrimental chemicals using square-core photonic crystal fiber in the regime of THz

Numerous techniques and technologies have been proposed for the detection and identification of hazardous chemicals that can harm the lungs and respiratory system as well as the central nervous system and kidneys when inhaled. Most practical techniques can be carried out by extraordinary professionals in well-equipped facilities. A reliable, simple, highly sensitive, and feasible sensing technique is still required. A potential sensor for these harmful chemicals is the photonic crystal fiber (PCF), which achieves several unique properties. A square-core PCF sensor is proposed in this work for the detection of detrimental gases (tetra-chloro silane, tetra-chloro methane, turpentine, and tin terra-chloride) in the THz region. The cladding region is divided into three rings, and each ring has rectangular and square air holes. Within the operating region, we have found a relatively high sensitivity of 96.185% along with 95.407% core power fraction, 0.2211 numerical aperture, and a low effective area of 154 470 μm2 at 1.9 THz frequency. Ignorable confinement loss of 3.071 × 10−14 cm−1 and effective material loss of 0.007 72 cm−1 have been also found. Additionally, the current manufacturing techniques guarantee the viability of the proposed PCF sensor’s manufacture. These obtained results demonstrate that the proposed sensor can be effectively employed for applications involving hazardous chemical compounds, gases, and biosensing.

Topas‐based octa‐circular cladding and rectangular porous core photonic crystal fibre for terahertz waveguide

AbstractThis article presents a novel design for guiding terahertz (THz) waves, which utilises a photonic crystal fibre with a porous core (PC‐PCF). This approach is substantiated by a Topas‐based octagonal‐shaped core with rectangular air slots. By utilising Finite Element Method and Perfectly Matched Layer boundary condition, the guiding properties of a structure consisting of octagonal air holes integrated with circular air slots in the cladding region have been investigated. The proposed structure exhibits a birefringence value of 0.05 and a low effective material loss of 0.013 cm−1. Moreover, it exhibits flattened dispersion measuring at a wide‐ranging frequency of 0.4 to 1.6 THz. In addition to that, the proposed structure offers 60% high core power fraction, 10−18 cm−1 confinement loss at 65% porosity of 290 μm core diameter and 1.6 THz frequency. Other significant waveguide properties: effective refractive index, effective area, spot size, and beam divergence of the proposed fibre are numerically analysed and discussed rigorously along with the fabrication viability of the fibre with existing techniques.

Analytical approach for modeling and simulation of photonic crystal fiber based on low effective material loss

COMSOL Multiphysics simulation software has been used to create a hexagonal photonic crystal fiber (H-PCF) with hexagonal cladding and a rotating hexa elliptical shape core. The hexagonal photonic crystal fiber (H-PCF) fiber is built on five layers of circular air holes, and it is suitable for telecommunication applications especially optical fiber communication in the terahertz (THz) frequency range. The hexagonal photonic crystal fiber (H-PCF) is designed to have an ultra-low effective material loss (EML), a higher core power fraction, a bigger effective area, and reduced confinement loss. The smallest effective material loss from the proposed hexagonal photonic crystal fiber (H-PCF) is 0.00689 cm−1, with a better core power fraction of 82%, less confinement loss of 3.45 × 10–14 cm−1 and a better effective area of 3.65 × 10–4 m2 is achieved at one terahertz (THz) waveguide region. Furthermore, using the features of the V-Parameter, our developed hexagonal photonic crystal fiber (H-PCF) fiber reveals an optical waveguide with one mode throughout a frequency range of terahertz (THz) wave area. So, it has been said that our hexagonal photonic crystal fiber (H-PCF) structure will be highly beneficial for optical fiber communications applications in the THz frequency range.

Performance analysis of slotted rectangular photonic crystal fiber structures in terahertz waveguidance

For an efficient and reliable transmission of data beyond 5G and 6G technologies, proper waveguide structures are needed. We present a rectangular solid-core slotted cladding photonic crystal fiber (PCF) and analyze its signal transmission capability in the terahertz (THz) regime. The proposed PCF performances have been investigated numerically using the finite element method. Various parameters, such as birefringence, core power fraction, effective material loss, effective area, mode-field diameter, beat length, dispersion, confinement loss, etc., have been studied by varying the geometry of the PCFs. The obtained simulation results exhibit dispersion of the order 2 ns / THz / cm, high birefringence of 0.0983, low confinement loss of the order 10 − 19 mm − 1, the effective area of 0.073 mm2, and high core power fraction of 99.8% in 0.2 to 2 THz range. All the parameters have been optimized among six different structures of the proposed PCF. This analysis will be helpful for the researchers to predict the transmission capability of THz waves in a rectangular PCF waveguide, which assures the boost in communication beyond 5G toward 6G evolution.

Reduction of effective material loss (EML) using decagonal photonic crystal fiber (D-PCF) for communication applications in the terahertz wave pulse

We present an excellent design of five layers of decagonal shape in the cladding area and two elliptical shapes of core area based photonic crystal fiber (PCF) for many types of communiqué arenas in the THz wave pulse in this study. The Finite Element Method with perfectly matched layers used the optical parameters of our proposed D-PCF structure numerically to design and analyze. Therefore, D-PCF shows a low effective material loss of 0.0079 cm−1, an increase in effective area of 3.49 × 10–8 m2, a core power fraction of 85%, a low confinement and scattering loss, of 3.35 × 10–16 and 1.27 × 10–10 dB/km respectively at 1 THz of frequency. After analyses all the graphical results, our proposed D-PCF will be highly suitable for communiqué parts in the THz regions.

FEA_LiNbO3: Finite element analysis of novel LiNbO3 material based fiber for optical communication properties of nonlinear applications

This study introduces a distinctive LiNbO3-based five-ring heptagonal-shaped photonic crystal fiber (PCF) geometry that demonstrates exceptionally high birefringence (Br) and nonlinear coefficient (NLC). Fundamental simulation studies are conducted through the COMSOL software utilizing the finite element method (FEM) with a perfectly matched layer (PML) boundary condition in order to comprehensively explore a variety of relevant optical characteristics, including birefringence, effective area, nonlinearity, core power fraction, dispersion, numerical aperture, confinement loss and so on. The simulation outcomes reveal an ultra-high Br and NLC of 0.081 and 5843.32 W-1Km-1 sequentially, at the operative wavelength of 1.55μm. The designed PCF with ultra-high Br and NLC features can be fabricated suitably, which is an advantageous aspect for potential prospective utilization in polarization-maintaining, nonlinear optics, supercontinuum generation, etc.

A comprehensive study of large negative dispersion and highly nonlinear perforated core PCF: theoretical insight

A photonic crystal fiber (PCF) containing circularly organized square-shaped air holes in the cladding region is investigated. The fiber core is perforated with four circular air-filled holes to instate high nonlinearity and large negative dispersion. The numerical analysis is done with a finite element method based COMSOL Multiphysics tool to investigate different optical properties of the propounded PCF. The simulation outcome verifies a high nonlinear coefficient value of 85 W−1 Km−1 at telecommunication window 1.55 μm which is, the highest ever achieved value on comparing with the other existing literature without using any nonlinear materials or liquids to the best of the authors’ knowledge. In parallel, the large negative value of dispersion −597 ps nm−1 km−1 is achieved for S/Λ equals 0.70 at the same communication window. However, the highest achieved nonlinearity and negative dispersion are 300 W−1 Km−1 and −1689 ps/nm/km. Moreover, birefringence, numerical aperture, and propagation loss are also measured as 2.40 × 10−3, 0.59, and 4.12 × 10−11 dB m−1 respectively along with an extremely high core power fraction of 99.98%. Hence, the propounded PCF is suitable for residual dispersion compensation, supercontinuum generation, and high bitrate transmission.

Design and simulation of heptagonal porous core photonic crystal fiber for terahertz wave transmission

A heptagonal core and hexagonal cladding Porous Core Photonic Crystal Fiber (PC-PCF) is proposed for terahertz wave guidance. Important transmission properties including confinement loss, effective material loss (EML), and core power fraction are investigated by using the Finite Element Method (FEM) in COMSOL Multiphysics simulation software. At an operating frequency of 1 THz and a carefully selected optimum parameter set, the proposed fiber shows confinement loss in the order of 10−4 dB/m, relative material absorption loss of 0.04 cm−1, and core power fraction of 45%. Guidance properties such as effective area, bending loss, and dispersion are also investigated in detail. Due to the simple design of circular air holes in both core and cladding, the PC-PCF is envisaged to be fabricated using the available stack and draw method. The proposed fiber is envisaged serve as an efficient waveguide for transmitting terahertz wave, particularly in communication applications due to its small loss and dispersion.

GaP-filled PCF with ultra-high birefringence and nonlinearity for distinctive optical applications

A gallium phosphide (GaP) based photonic crystal fiber (PCF) with hexagonal air hole arrangements is introduced in this study that reveals high birefringence (Br) and nonlinear coefficient (NLC). Numerous optical properties, such as birefringence, nonlinearity, dispersion, confinement loss, effective area, core power fraction, etc. are studied by finetuning the geometrical variables, applying the finite element method (FEM). The numerical analyses demonstrate that an ultra-high Br of 59.1 × 10−2 and NLC of 2.37 × 105 𝑊−1𝐾𝑚−1 with a large negative dispersion of ―3875.21 ps. nm―1 . km−1 can be accomplished at the wavelength of 1.55 𝜇𝑚. Consequently, the developed PCF can be applied in a plethora of intriguing applications, including supercontinuum generation, telecommunications, etc.

Surface bio-sensor based on terahertz Bragg fiber

Hollow-core photonic Bragg fibers have a wide range of sensing applications. In this paper, a hollow-core photonic Bragg fiber with a defect layer for surface bio-sensing is proposed and analyzed for bacterium detection in the terahertz (THz) frequency range. The hollow core is surrounded by a periodic sequence of high/low refractive index multilayers including the photosensitive resin and air. The analytes are deposited on the inner surface of the hollow-core THz Bragg fiber. The performance of the proposed sensor is numerically investigated. The result shows that the proposed surface bio-sensor provides a high core power fraction. The confinement loss of the sensor takes on two peaks in the frequency range of 0.3–0.4 and 0.45–0.55 THz, respectively. The distinguishable characteristic frequencies of the sensor are obtained with different bacterium deposited on the inner surface of the THz Bragg fiber. Furthermore, the thickness-independent surface sensing can be realized in the high frequency range. The proposed surface bio-sensor based on THz Bragg fiber can be used to recognize the kind of the bacterium and has a great potential in microorganism detections.

Tunable Temperature Characteristic of Terahertz Bragg Fiber Filled with Liquid Water

Hollow-core terahertz (THz) fibers have attracted a lot of research interest due to the low loss and easy inner modification with functional materials. Liquid water has unique properties in the THz region and has been widely investigated in THz emission, sensing, and devices. In this paper, a hollow-core THz Bragg fiber with a water defect layer is proposed. The finite element method is used to verify and analyze the tunable temperature characteristic of the water-filled THz fiber. The numerical analysis results show that the confinement loss and the low-frequency side of the dip near 0.5 THz can be controlled by the temperature of the liquid water. The temperature sensitivity of the THz fiber is obtained at 0.09614 dB·m−1/K at 0.45 THz with a high core power fraction up to 98%. The proposed THz fiber has potential applications in THz interaction with liquid and THz tunable devices.

Identification of detrimental chemicals of plastic products using PCF in the THz regime

A square cored PCF (SC-PCF) sensor is proposed in this paper for the purpose of detecting detrimental chemical analytes (DEHP, BPA, and BPS) that are generally found in different plastic products. This SC-PCF sensor is capable of operating in the 1–2 THz regimes. Within this operable range, we found a relatively higher sensitivity of 96.5% along with 95.73% core power fraction, 0.225 numerical aperture, and a lower Aeff of 1.48 × 105 μm2 at 1.9 THz frequency. A tiny confinement loss of 2.68 × 10−13 cm−1 and effective material loss of 0.008 cm−1 are also evaluated. Besides the present fabrication techniques ensures the feasibility of fabrication for this proposed SC-PCF sensor. These estimated results evinced that our proposed sensor can efficiently be used in terms of the noxious chemical compounds, gas, and bio-sensing applications.

Design and analysis of the effect of Zeonex based octagonal photonic crystal fiber for different types of communication applications

In this present work, a novel structure of octagonal cladding with two elliptical air holes based on photonic crystal fiber (O-PCF) has been presented for the application of different types of communication areas within the terahertz (THz) wave propagation. There are five layers of octagonal design shape of circular air holes in cladding region with elliptical design shape of two air holes in core area has been reported in this research work. This O-PCF fiber has been investigated by the perfectly matched layers with the finite element method. After the simulation process, our proposed O-PCF fiber shows a low effective material loss of 0.0162 cm−1, the larger effective area of 5.88 × 10–8 m2, the core power fraction of 80%, the scattering loss of 1.22 × 10–10 dB/km, and the confinement loss of 3.33 × 10–14 dB/m at the controlling region of 1 terahertz (THz). Due to its excellent characteristics, this proposed O-PCF fiber gives proficient transmission of broadband terahertz waves of signals. Moreover, for different kinds of optical communication applications and biomedical signals, our suggested O-PCF fiber will be highly perfect in the terahertz (THz) regions.

Design and performance analysis of background material of zeonex based high core power fraction and extremely low effective material loss of photonic crystal fiber in the terahertz (THz) wave pulse for many types of communication areas

In this reported work, an excellent design model of quasi-shape of cladding areas with rotated-Hexa based elliptical shape of core areas in photonic crystal fiber (Q-PCF) has been reported for terahertz (THz) waves of communication signals. Here, we have presented a six-layer circular air hole in the quasi-shape of cladding regions with two layers rotated-Hexa-based ellipse shape of air holes in the core regions of photonic crystal fiber (Q-PCF) for analysis of communication networks in the terahertz (THz) regime. On the other hand, perfectly matched layers (PML) and finite element method (FEM) based on COMSOL software tool are used to design this photonic crystal fiber (Q-PCF). For short and wide-band of communication sectors, our proposed quasi shape-based photonic crystal fiber (Q-PCF) is highly useful because of reducing different types of losses such as ultra-low effective material loss (EML), confinement loss, and scattering loss in the terahertz (THz) regime. After analysis of numerical results, our suggested quasi shape-based photonic crystal fiber (Q-PCF) shows an ultra-low effective material loss (EML) of 0.0163 cm−1, power fraction in the core area and large effective area of 74%, 5.52 × 10−8 m2, confinement loss of 3.25 × 10−12 cm−1 and the scattering loss of 1.23 × 10−10, respectively at 1 terahertz (THz) frequency range. Moreover, our proposed quasi photonic crystal fiber (Q-PCF) discloses a single-mode propagation by the graphical results of V-parameter over 0.80–3 THz frequency range. As a result, we can say clearly that the reported Q-PCF fiber will be highly appropriate for terahertz (THz) wave propagation for many communication networks such as bio-medical signals and various data transfer communications system.

An ultra-high birefringent and nonlinear decahedron photonic crystal fiber employing molybdenum disulphide (MoS2): A numerical analysis

A novel Decahedron photonic crystal fiber (DHn-PCF) is proposed. To sustain high birefringence and nonlinearity, the central elliptical core is filled with a highly nonlinear 2D material molybdenum disulphide (MoS2). The significant performance parameters of the proposed DHn-PCF like birefringence, nonlinearity, confinement loss, and core power fraction has been investigated with change in its structural parameters. Simulation results confirmed an exceptionally high birefringence and nonlinearity of 0.632 and 9.68 × 105 W−1 Km−1 with the outstanding core power fraction of 98.6% for the well-known communication window at 1.55μm. Besides, the effective material loss (EML) and confinement loss (CL) are also found very low as 0.0302cm-1 and 8.7×10-10dB/mfor the same communication window. Therefore, with all these excellent outcomes, the proposed DHn-PCF proves itself a potential candidate for polarization maintenance, residual polarization compensation, dispersion compensator, bio-medical imaging, supercontinuum and solitons generation, high bit data rate telecommunication and sensing application.

Design and numerical analysis of Zeonex-based photonic crystal fiber for application in different types of communication networks

A photonic crystal fiber (O-PCF) with a novel structure consisting of five octagonal-shaped layers of circular air holes in the cladding region and two elliptical air holes in the core region is presented for application in different communication fields for terahertz (THz) wave propagation. The O-PCF fiber is investigated using perfectly matched layers by applying the finite element method. Based on the results of the simulations, the proposed O-PCF fiber shows a low effective material loss of 0.0162 cm−1, a higher effective area of 5.88 × 10–8 m2, a core power fraction of 80%, a scattering loss of 1.22 × 10–10 dB/km, and a confinement loss of 3.33 × 10–14 dB/m in the target region of 1 terahertz (THz). Due to its excellent characteristics, the proposed O-PCF fiber offers excellent transmission characteristic across a broad band of the terahertz region. Moreover, the suggested O-PCF fiber will be ideal for use in the terahertz (THz) region for different kinds of optical communication and biomedical applications.

Numerical Investigation of the Optical Properties for Multiple PCF Structures in the THz Regime

This paper presents three different PCF structures including circular, hexagonal, and square holes forming four rings. To investigate various optical properties, simulation has been performed in between 1 THz to 2 THz regimes. Using these PCF structures, the core power fraction (CPF), dispersion, confinement loss (CL), effective material loss (EML), effective area (Aeff), and propagation constant are analyzed. TOPAS is selected as the fiber material for these designed PCF structures. From the analysis, a larger CPF of 97.4% is attained for the square PCF, a small Aeff of 1.65 × 105 μm2, a negligible CL of 5.82 × 10−12 cm−1, and a lower EML of 0.014 cm−1 are obtained for the hexagonal PCF. Besides, a negative dispersion is found for all three PCF structures. However, these PCFs can be fabricated using the prevailing fabrication technologies. Our designed PCFs can be efficiently used in optical signal transmission, also different kinds of analyte sensing can be performed by applying a suitable core structure into these PCFs.