Low Effective Material Loss Research Articles

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.

Wave-Shaped Microstructure Cancer Detection Sensor in Terahertz Band: Design and Analysis

For the quick identification of diverse types of cancer/malignant cells in the human body, a new hollow-core optical waveguide based on Photonic Crystal Fiber (PCF) is proposed and numerically studied. The refractive index (RI) differs between normal and cancerous cells, and it is through this distinction that the other crucial optical parameters are assessed. The proposed cancer cell biosensor’s guiding characteristics are examined in the COMSOL Multiphysics v5.5 environment. The Finite Element Method (FEM) framework is used to quantify the display of the suggested fiber biosensor. Extremely fine mesh elements are additionally added to guarantee the highest simulation accuracy. The simulation results on the suggested sensor model achieve a very high relative sensitivity of 99.9277%, 99.9243%, 99.9302%, 99.9314%, 99.9257% and 99.9169%, a low effective material loss of 8.55×10−5 cm−1, 8.96×10−5 cm−1, 8.24×10−5 cm−1, 8.09×10−5 cm−1, 8.79×10−5 cm−1, and 9.88×10−5 cm−1 for adrenal gland cancer, blood cancer, breast cancer type-1, breast cancer type-2, cervical cancer, and skin cancer, respectively, at a 3.0 THz frequency regime. A very low confinement loss of 6.1×10−10 dB/cm is also indicated by the simulation findings for all of the cancer cases that were mentioned. The straightforward PCF structure of the proposed biosensor offers a high likelihood of implementation when used in conjunction with these conventional performance indexes. So, it appears that this biosensor will create new opportunities for the identification and diagnosis of various cancer cells.

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)

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.

High-Sensitivity Early Detection Biomedical Sensor for Tuberculosis With Low Losses in the Terahertz Regime Based on Photonic Crystal Fiber Technology

Tuberculosis is one of the most contagious and lethal illnesses in the world, according to the World Health Organization. Tuberculosis had the leading mortality rate as a result of a single infection, ranking above HIV/AIDS. Early detection is an essential factor in patient treatment and can improve the survival rate. Detection methods should have high mobility, high accuracy, fast detection, and low losses. This work presents a novel biomedical photonic crystal fiber sensor, which can accurately detect and distinguish between the different types of tuberculosis bacteria. The designed sensor detects these types with high relative sensitivity and negligible losses compared to other photonic crystal fiber-based biomedical sensors. The proposed sensor exhibits a relative sensitivity of 90.6%, an effective area of 4.342×10−8m2, with a negligible confinement loss of 3.13×10−9cm−1, a remarkably low effective material loss of 0.0132cm−1, and a numerical aperture of 0.3462. The proposed sensor is capable of operating in the terahertz regimes over a wide range (1 THz–2.4THz). An abbreviated review of non-optical detection techniques is also presented. An in-depth comparison between this work and recent related photonic crystal fiber-based literature is drawn to validate the efficacy and authenticity of the proposed design.

Terahertz Women Reproductive Hormones Sensor Using Photonic Crystal Fiber With Behavior Prediction Using Machine Learning

In this article, we propose a rectangular hollow core Photonic Crystal Fiber (PCF) sensor for high detection of women’s reproductive hormones (progesterone and estradiol) in the blood sample at THz regime (0.8 THz to 1.7 THz). The numerical sensing performances are evaluated by the full vector finite element method (FVFEM). We have achieved improved relative sensitivity with minimal loss for sensing progesterone concentrations and estradiol concentrations by optimizing structural parameters. The obtained maximum relative sensitivity is 99.87% for 10 n mol/L (progesterone) and 99.88% for 3 n mol/L (Estradiol) at 1.35 THz. Further, we have obtained low effective material loss (EML) and a large effective mode area. The primary takeaway from this research is that it’s critical to monitor estradiol and progesterone levels in order to ensure that a woman’s reproductive system is functioning in a balanced manner and in general health systems. Also, this biosensor can be fabricated by current fabrication technologies. Moreover, the prediction carried out with the help of Locally Weighted Linear Regression, and hyperparameter tuning, we can conclude that for weighting hyperparameter value of 0.02. We have achieved the maximum prediction accuracy with the unity R <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> score and this model can be employed for the prediction of relative sensitivity for various parameters.

Designing of Hollow Core Grapefruit Fiber Using Cyclo Olefin Polymer for the Detection of Fuel Adulteration in Terahertz Region

A grapefruit-shape hollow-core liquid infiltrated photonic crystal fiber (LI-PCF) is proposed and evaluated to identify the percentage of kerosene in adulterated petrol. The proposed hollow-fiber sensor is designed with Cyclo Olefin Polymer (Zeonex) and likely to be filled with different samples of petrol which is adulated by the kerosene up to 100%. Considering the electromagnetic radiation in THz band, the sensing properties are thoroughly investigated by adopting finite element method (FEM) based COMSOL Multiphysics software. However, the proposed sensor offers a very high relative sensitivity (RS) of 97.27% and confinement loss (CL) less than 10-10 dB/m, and total loss under 0.07 dB/cm, at 2 THz operating frequency. Besides that, the sensor also possesses a low effective material loss (EML), high numerical aperture (NA), and large Marcuse spot size (MSS). The sensor structure is fabrication feasible through existing fabrication methodologies consequently making this petrol adulteration sensor a propitious aspirant for real-life applications of petrol adulteration measurements in commercial and industrial sensing.

MODELLING AND NUMERICAL ANALYSIS OF A HIGHLY-EFFICIENT PCF-BASED AMINO ACID SENSOR

Amino acids not only play a vital role as protein-building constituents in living beings but also have a wide range of applications that include commercial industries such as food additives and flavor enhancers as well as medical sectors to resist numerous disease levels and to treat digestive abscesses, liver ailments, etc. Hence a precise and feasible detection of amino acids is a fervent desire for their appropriate applications. This paper presents an amino acid sensor employing a mono-circular hollow-core PCF. This PCF-based sensor has been designed maintaining high fabrication feasibility. Then the performance of this sensor has been numerically studied engaging finite element method while sensing five types of amino acids. Performance metric exhibits that this sensor has a very low effective material and confinement loss of about 0.003795 cm-1 and 3.065×10-15 cm-1 correspondingly at 2.7 THz for Tryptophan. Besides this sensor has offered approximately 97.12% relative sensitivity maintaining a higher numerical aperture for the same type of amino acid. This sensor has maintained admirable values for all the performance indices for all the five types of amino acids analyzed in this paper. Furthermore, the elementary design of this sensor has opened the door of viable fabrication with the aid of existing sol-gel technique or extrusion with 3D printing method.

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.

Nodeless antiresonant hollow core fiber for low loss flatband THz guidance

This paper reveals a THz leading nodeless antiresonant slotted hollow core fiber (NARS-HCF) with low transmission loss and broad band flat near zero dispersion. We have achieved better results in a simpler structure as far as we know: a minimal confinement loss in the order of around 10−4 dBm-1 and a very low effective material loss of 0.0248 dBm-1, resulting in a lowest total transmission loss of 0.0254 dBm-1 at 1.27 THz and offering a 0.88 THz (0.8 THz – 1.68 THz) low loss transmission bandwidth with the loss of less than 0.0811 dBm-1. Additionally, we achieved a 0.0614 ± 0.0468 ps/THz/cm near zero flat dispersion over the widest bandwidth of 1.02 THz (0.80 THz to 1.82 THz). Moreover, our proposed structure can also effectively perform as single mode fiber with excellent bending loss performance, hence, can be useful for efficient THz transmission systems.

Design and analysis of heptagonal cladding with rotated-hexa elliptical core based PCF for the applications of communication sectors in the THz region

Photonic crystal fiber-based heptagonal cladding with the elliptical rotated-Hexa core is reported in the terahertz waveguide for the applications of communication area in this paper. By utilizing the photonic crystal fiber concept, all numerical results have been obtained by the finite element method with perfectly matched layers based on the COMSOL Multiphysics computer software tool. This H-PCF fiber shows a low effective material loss of 0.0076 cm−1, with a larger effective area of 5.95 × 10–8 m2, power flows within the core area of 90%, confinement loss of 3.35 × 10–16 cm−1, and scattering loss of 1.24 × 10–10 cm−1 at 1 THz. Besides, other optical properties like confinement loss, scattering loss, power fraction, V-parameter, and effective area have also been considered briefly. So, it is expected that the mentioned H-PCF structure-based waveguide will significantly improve many kinds of communication fields of the THz technology.

Highly sensitive hollow-core fiber for spectroscopic sensing applications

In this article, a highly sensitive hollow-core photonic crystal fiber (PCF) is proposed and numerically investigated for the application of different chemical identification in the terahertz regime. Commercially available COMSOL Multiphysics software is used to evaluate the sensing and propagation characteristics of the proposed sensor. The numerical analysis informs that extremely high relative sensitivity around 98% can be achieved from the sensor at optimum structural condition. Moreover, at optimum structural dimension and operating frequency significantly low effective material loss (<0.005cm−1) and confinement loss (<10−16cm−1) offered by the proposed fiber buttresses its sensing performance. In addition, other propagation characteristics (numerical aperture, effective area, and dispersion) are also investigated rigorously in this article. The excellent sensing characteristics of the proposed sensor make it a competitive candidate in different industrial sectors like the food and beverage industry.

A hybrid structured PCF for fuel adulteration detection in terahertz regime

An elliptical core based hybrid structured photonic crystal fiber (PCF) is proposed and analyzed in order to identify the fuel adulteration level using the terahertz spectrum. The performance of the proposed sensor is assessed by COMSOL software which uses the finite element method as a solver. At 2.8 THz, the proposed sensor shows an extremely high relative sensitivity of 102% with a very small confinement loss of 3.46× 10−11 cm−1 and a high numerical aperture of 0.45. Moreover, the proposed sensor also shows a large effective area of 1.715× 10−8 m2 with a low effective material loss of 0.0105 cm−1 at optimum structural conditions. Except for one elliptical air hole in cladding, the optical sensor contains circular air holes which ensure less complexity during fabrication. The sensor's excellent sensing and guiding properties will make it a competitive candidate in chemical 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.

PCF Based Formalin Detection by Exploring the Optical Properties in THz Regime

Introduction: Ongoing amelioration of semiconductor nano-crystal in chemical sensing applications has led the Photonic Crystal Fiber (PCF) as the most appropriate candidate for chemical sensing. A PCF based sensor model has been proposed in this paper. Objective: The aim of this model is to detect formalin at a high level of sensitivity. Method: This sensor model has been designed and simulated in COMSOL MULTIPHYSICS to analyze the sensing performance based on the optical parameters such as relative sensitivity, confinement loss, and effective material loss. Formalin solution is placed into the core and then the simulation is performed in THz regime ranging from 1 to 2 THz to carry out the optical properties. Simulation data collected from COMSOL are used in Matlab to carry out the graphical representation of the optical parameters. Results: Simulation results demonstrate that the sensor model inherits high relative sensitivity of approximately 77.71 % at 1.8 THz. In addition to that, the proposed sensor exhibits zero confinement loss above 1.3 THz and very low effective material loss in the THz regime for the optimum model. Conclusion: All the optical parameters maintain standard and desirable values in the THz regime. Besides, the flexible fabrication of the proposed model is feasible using existing fabrication methods. Simulation results validate the high performance of this proposed model in formalin detection.

Design and analysis of low loss porous-core photonic crystal fiber for terahertz wave transmission

We present a low loss hexagonal-core porous Photonic Crystal Fiber (PCF) for wave propagation in terahertz (THz) range. The cladding contains circular air holes whereas the core consists of elliptical air holes. As background material, Cyclo-Olefin Copolymer (COC) (also known as TOPAS) was used because in the terahertz range (0.1–2 THz), it shows a constant refractive index. The design has been analysed by using FEM-based COMSOL software for a particular frequency range and by varying radius along the x-axis. We observed that at radius of 8 µm and an operating frequency of 0.9 THz, the proposed fiber exhibits low effective material loss of 0.0697 cm−1 and low confinement loss in the order of 10−3 cm−1. Moreover, we did a complete analysis of the transition of core air holes from elliptical to circular.

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.

Hollow Core Photonic Crystal Fiber (PCF)–Based Optical Sensor for Blood Component Detection in Terahertz Spectrum

Hollow core photonic crystal fiber is suggested and analyzed in this article for the identification of different blood components present in human blood. In order to visualize the fiber and investigate the performance of that sensor based on COMSOL simulation software, the suggested fiber is numerically analyze in terahertz frequency spectrum from 1.5 to 3 THz to obtain higher relative sensitivity (RS) and NA as well as lower absorption loss and confinement loss (CL) for better sensing applications. The reported hollow core fiber provides better interaction of light and the analytes, so that extremely high RS is achieved at a particular geometric condition. Furthermore, extremely low CL and effective material loss (EML) with high numerical aperture (NA) can be achieved from the suggested sensor which paves the way to apply the fiber in numerous biomedical applications.

Highly Birefringent, Low Flattened Dispersion Photonic Crystal Fiber in the Terahertz Region

High-performance photonic crystal fiber (PCF) has an important impact on the development of the full potential of complex terahertz systems. A new kind of PCF with D-shaped air holes in core region was proposed for terahertz (THz) region. The numerical simulation results showed that the proposed PCF has a flat dispersion of 0.09 ± 0.28 ps/THz/cm at 0.8-1.2 THz. At 1 THz, an ultra-high birefringence of 0.0595, a low effective material loss (EML) of 0.0557 cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-1</sup> , and dispersion that can be considered zero were obtained. In addition, other characteristics of the proposed PCF were strictly analyzed, such as confinement loss, bending loss, and effective mode area. The PCF is expected to be used for short distance propagation of terahertz, polarization maintaining and sensing applications of terahertz waves.