Sensitivity analysis for detecting chemicals by the optical chemical sensor based Photonic Crystal Fiber (PCF) in the Terahertz (THz) regime

This research article demonstrates a good simulation result for identifying and detecting various industrial chemicals in a Terahertz (THz) waveguide with a new heptagonal, five layers of heptagonal photonic fiber elliptic form, heptagonal clading shape (H-PCF). COMSOL 4.2 software based on finite element (FEM) methods and perfectly matched layers check our composition (PML). The different chemicals are also differentiated and identified by each other in different parameters H-PCF fibers show a high relative sensitivity of ethanol of approximately 86.50 percent after numerical analysis, Benzene around 89.35%, and water around 85.15% at a frequency of around 0.7 THz. In our experiment, we obtained very low confinement losses at 1 terahertz (THz) such as 5.95×10−08 dB/m for Ethanol 6.67×10−08 dB/m for Benzene, and 5.80×10−08 dB/m for water. Regarding these results, we can strongly recommend that our proposed heptagonal photonic crystal fiber (H-PCF) will be more congenial in biomedical, bio-medicine, and industrial areas for the identification and detection of various types of chemicals with the help of a THz waveguide.

Efficient Way for Chemicals Identification Using Hexagonal Fiber with the Terahertz (THz) Band

To detect chemicals, we proposed a photonic crystal fiber (PCF) with hexagonal cladding and a hexahedron core (THz). Circular air holes (CAHs) in the vestibule provide the basis of the suggested sensor. To develop and evaluate our suggested hexahedron PCF sensor, we employed the finite element (FEM) technique and perfectly matched layers (PML), which utilized the optical parameters numerically. Here, 92.65%, 95.25%, and 90.70% are relatively sensitive, and confining losses are low. the value 5.40×10− 08, 6.70×10− 08 dB/m, and 5.75×10− 08 dB/m for three chemicals such as Ethanol (n = 1.354), Benzene (n = 1.366) and Water (n = 1.330) and effective material loss (EML) of 0.00694 cm− 1. The suggested Hx-PCF sensor has been successfully tested at 1 THz. We are certain that the suggested sensor's optimal geometric structure can be manufactured and that it can contribute to real-world applications in biomedicine and industry. In terahertz areas, our suggested PCF fiber is also suited for a wide range of medical signals and applications (THz).

A sliced-3D approach to GPR FDTD modelling by optimising perfectly matched layers

Finite-difference time-domain (FDTD) forward modeling is often used to gain a more quantitative understanding of the interactions between electromagnetic fields and targets. To undertake full 3D simulations the computational demands are challenging, so simulations are often undertaken in 2D where assumptions in the propagation of electromagnetic fields and source type can result in errors. We develop the concept of a sliced-3D simulation, wherein a thin slice of a 3D domain with strictly 2D geometry is used to minimize computational demands while obtaining synthetic waveforms that contain full 3D propagation effects. This approach requires optimization of perfectly matched layer (PML) boundary condition parameters so as to minimize the errors associated with the source being located close to the boundary, and as a result of grazing-incident angle wave conversion to evanescent energy. We explore the frequency dependence of PML parameters, and establish a relationship between complex frequency stretching parameters and effective wavelength. The resultant parameter choice is shown to minimize propagation errors in the context of a simple radioglaciological model, where 3D domains may be prohibitively large, and for a near-surface cross-borehole survey configuration, a case where full waveform inversion may typically be used.

Predicting vibration transmission across junctions using diffuse field reciprocity

Predicting the sound insulation of an engineering system is a complex problem since not only the direct path through a separating element but also the flanking transmission paths can largely influence the sound insulation of the system. When conventionally analyzing flanking transmission, a diffuse field is assumed in the walls and floors, which are modelled as plates. The junction connecting the walls and floors is assumed to be of infinite extent and the transmission of vibration across the junction is calculated by integrating over all possible angles of incidence. Due to the limitations of the conventional approach, a new approach based on diffuse field reciprocity is proposed. The diffuse field reciprocity relationship relates the vibration transmission to the direct field of a diffuse subsystem to the direct field dynamic stiffness of the subsystem, i.e., the dynamic stiffness of the equivalent infinite subsystem as observed at the junction. The direct field dynamic stiffness matrices of thin, isotropic, elastic plates can be analytically derived. For more complex walls or floors a possible approach is to calculate the direct field dynamic stiffness using finite elements and perfectly matched layers. The perfectly matched layer surrounding the finite element model absorbs the wave propagating outwards from the bounded domain, thus simulating an infinite subsystem.

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 (CAH) 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 (PML) with the finite element method (FEM). After the simulation process, our proposed O-PCF fiber shows a low effective material loss (EML) of 0.0162 cm −1 , the larger effective area of 5.88×10-8 m2, the core power fraction (PF) 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.