Browsing by Author "Ritesh Kumar Chourasia"

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A novel Bragg fiber waveguide based narrow band inline optical filter
(Elsevier GmbH, 2018) Ritesh Kumar Chourasia; Surendra Prasad; Vivek Singh
Theoretical analysis of Bragg fiber waveguide based inline optical filter having a defect layer is presented. Defect layer is introduced in Bragg fiber waveguide by breaking its cladding layer periodicity. Considering the cylindrical wave equations, the transmittance of proposed waveguide is obtained using transfer matrix method. It is observed that the proposed Bragg waveguide represent photonic band gap and a narrow defect mode (pass band) is present in this band gap region. This defect mode can be obtained in any position between the wavelength ranges 1.241 μm–1.550 μm with the help of incident angle of light. The narrowness of the defect mode depends on the number of unit cell present in the cladding region. This proposed waveguide may be used to design a narrowband transmission filters. © 2018 Elsevier GmbH
Analysis of Bragg fiber waveguides having a defect layer for biosensing application
(Elsevier GmbH, 2020) Ritesh Kumar Chourasia; Chandan Singh Yadav; Abhishek Upadhyay; Nitesh Kumar Chourasia; Vivek Singh
A novel hollow core Bragg fiber waveguides having a defect layer are proposed and analyzed theoretically for sensing application. Matching the electric and magnetic fields at various interfaces, a relation between fields of first layer with final layer has been stabilized; hence, the equations for reflectance and transmittance of proposed structure are derived. Due to periodicity of concentric cylindrical structure, a perfect photonic band gap is observed in considered wavelength range. The presence of defect layer in cylindrical periodic structure shows a peak corresponding to defect mode in perfect photonic band gap region. The full width at half maxima of this peak depends on the periodicity of the cladding layers. Also, the spectral position and shift of peak of defect mode depend on the angle of incidence of light, refractive index of core material and design wavelength of structure. Therefore, it is more appropriate to consider this peak of defect mode as sensing signal instead of considering whole photonic band gap as sensing signal. © 2019 Elsevier GmbH
Comparative analysis of the dispersion characteristic of Bragg fibers having different refractive index contrast
(Optica Publishing Group (formerly OSA), 2016) Ritesh Kumar Chourasia; Vivek Singh
Dispersion characteristics of two Bragg fibers are compared. By matching the Henkel function and its derivative at various boundaries dispersion equations are obtained. In this study the high contrast waveguide guided larger number of modes. © OSA 2016.
Comparative performance study of liquid core cylindrical Bragg fibre waveguide biosensors
(Springer, 2021) Nitesh K Chourasia; Ankita Srivastava; Vinay Kumar; Ritesh Kumar Chourasia
The performance study of various sensing parameters such as sensitivity, detection accuracy and quality parameter of liquid core Bragg fibre waveguide biosensor based on defect mode has been theoretically studied and compared with experimental findings of a similar structure without defect mode. The electromagnetic wave propagation in the present structure has been modelled using the transfer matrix method and Henkel formalism in cylindrical coordinates. The present multilayer structure can provide a band gap between 617 and 929 nm wavelength range at angle of incidence θ= 70 ∘. Due to the presence of a defect layer, a defect mode at 690 nm wavelength is observed in this band-gap region. This defect mode can be treated as a sensing signal in the present study. It is observed that the obtained sensitivity (S≈ 334 nm/RIU) through the defect mode is almost the same as the experimental findings (S≈ 330 nm/RIU) of a similar structure without the defect layer. But the obtained maximum detection accuracy (68.6) and quality parameter (160.4/RIU) of the present structure with defect layer is much larger than the values in a similar structure without defect layer (6.9 and 15/RIU). The present structure having a liquid-filled core, is therefore, favoured and useful in promising biosensing applications. © 2021, Indian Academy of Sciences.
Comparative study of defect mode intensity and wavelength modulation in Bragg fiber waveguide sensors
(Elsevier GmbH, 2020) Ritesh Kumar Chourasia; Chandan Singh Yadav; Abhishek Upadhyay; Nitesh K. Chourasia; Vivek Singh
Sensing parameters of Bragg fiber waveguides having a defect layer in the cladding region are studied theoretically for bio-sensing and thickness monitoring applications. A comparison between Bragg fiber waveguides consist of a liquid-core surrounded with alternate high refractive index (R.I.) contrast of claddings and low R.I. contrast of claddings is presented. In non-homogeneous multilayer cylindrical system, the transmittance of proposed waveguide-based sensors is formulated using transfer matrix method and Hankel formalism. Both considered structures show photonic bandgap with a narrow passband in the bandgap region. This narrow passband is treated as sensing signal because its position and intensity depends on the diameter and refractive index of core material. The high refractive index contrast cladding waveguide shows larger intensity shift than low refractive index contrast cladding waveguide. The presence of defect layer in both considered waveguides is able to increase the sensing parameters like detection accuracy and overall performance. © 2020 Elsevier GmbH
Cylindrical Bragg waveguide based temperature sensors
(Institute of Electrical and Electronics Engineers Inc., 2017) Ritesh Kumar Chourasia; Vivek Singh
Cylindrical Bragg waveguide based temperature sensor having a defect layer in cladding region is proposed and studied theoretically. The waveguide consists of SiC core surrounded by alternate Si and SiO2 cladding layers with a defect layer. The transmittance of waveguide is obtained using transfer matrix method. It is observed that thermal expansion coefficient and refractive index of SiC varies linearly with temperature. The obtained sensitivity in our proposed sensor is approximately 51.48pm/Celsius, which is much larger than the reported 9pm/Celsius similar fiber Bragg grating based sensors. © 2016 IEEE.
Doubly electrically tuned cylindrical Bragg fiber waveguide inline optical filter for multiwavelength LASER applications
(Elsevier Ltd, 2020) Nitesh K. Chourasia; Ankita Srivastava; Vinay Kumar; Ritesh Kumar Chourasia
In present communication, doubly tuned Bragg fiber waveguide low power inline optical filter with voltage tunable single crystal PMMA defect cavity is theoretically modeled and discussed using Henkel formalism in a cylindrical coordinate system for multiwavelength LASER applications. The structure provides photonic band gap (PBG) with a resonant transmission peak in the obtained PBG region. The defect cavity thickness is controlled by applying an external electric DC voltage. Initially, PBG of the proposed inline optical filter may tune-up to 828nm by modulating the incidence angle upto 80°. Thus, the resonant transmission peak also blue-shifted by 243nm, which can further tuned in presence of DC voltages and so-called doubly electrically tuned. Further, in doubly electrically tuned mode, the application range of such a device is very large up to 129nm for a small change in voltage range about 20V. Thus, the present device can be utilized as multiwavelength laser sources. © 2020 Elsevier Ltd
Estimation of photonic band gap in the hollow core cylindrical multilayer structure
(Academic Press, 2018) Ritesh Kumar Chourasia; Vivek Singh
The propagation characteristic of two hollow core cylindrical multilayer structures having high and low refractive index contrast of cladding regions have been studied and compared at two design wavelengths i.e. 1550 nm and 632.8 nm. With the help of transfer matrix method a relation between the incoming light wave and outgoing light wave has been developed using the boundary matching technique. In high refractive index contrast, small numbers of layers are sufficient to provide perfect band gap in both design wavelengths. The spectral position and width of band gap is highly depending on the optical path of incident light in all considered cases. For sensing application, the sensitivity of waveguide can be obtained either by monitoring the width of photonic band gap or by monitoring the spectral shift of photonic band gap. Change in the width of photonic band gap with the core refractive index is larger in high refractive index contrast of cladding materials. However, in the case of monitoring the spectral shift of band gap, the obtained sensitivity is large for low refractive index contrast of cladding materials and further it increases with increase of design wavelength. © 2018 Elsevier Ltd
Optimizing temperature-dependent molar volume fraction of biodiesel fuel in a pseudo-binary mixture through Bragg fiber waveguide sensor having defect layer
(Elsevier Ltd, 2021) Nitesh K. Chourasia; Ankita Srivastava; Vinay Kumar; Ritesh Kumar Chourasia
In the present communication, the temperature-dependent molar volume fraction of various kinds of renewable biodiesel fuel resources in a pseudo-binary mixture is theoretically optimized through the Bragg fiber waveguide (BFW) sensor with a geometrical defect in periodic cylindrical Bragg reflectors. BFW structure is modelled using a transfer matrix method (TMM) and Henkel formalism in a cylindrical coordinate system. The temperature dependence molar volume fraction is linked to the change in the refractive index of the pseudo-binary mixture, which is further predicted using the capacity of various models; Lorentz-Lorenz, Dale-Gladstone, Eykman, Newton, and Kay. In the presence of a geometric defect layer, a sharp transmission peak of 0.1nmfull width at half maxima (FWHM) is obtained in the considered photonic band gap (PBG), which is sensitive to the change in core refractive index. The temperature-dependent (due to different weather conditions) maximum sensitivity of the proposed sensor is found to be 1280 nm/RIU, which is further compared with the phoxonic crystal-based static temperature sensor having sensitivity 142 nm/RIU only. Along with improved sensitivity in the proposed sensor, other sensing performance parameters detection accuracy and quality parameter (which are inversely proportional to the FWHM) are also improved due to least FWHM of resonant transmission peak about 0.1 nm comparatively. © 2021 Elsevier Ltd
Photonic nanostructured bragg fuel adulteration sensor
(Bentham Science Publishers, 2023) Ritesh Kumar Chourasia; Nitesh K. Chourasia; Ankita Srivastava; Narendra Bihari
The adulteration of liquid fuels has several far-reaching repercussions, including pollution and a rising energy crisis. Around the world, fossil fuels are widely utilized for transportation and energy generation. Fuel adulteration currently threatens a big number of customers. Adulteration of fossil fuels with other recognised hydrocarbons is a common occurrence. Adulterants are added to these base fuels in the form of additional low-cost hydrocarbons with similar compositions, leading the base to be altered and degraded. Adulteration is an unauthorised or illegal introduction of a lower-quality external substance into a higher-quality commodity, causing the latter to lose its original composition and qualities. The Opto-Microfluidics approach is a new field that uses a small sample to identify adulteration in food and fuel, resulting in high-resolution findings. Consumers will benefit from very sensitive detection of dangerous adulteration in any commodity thanks to opto-microfluidic lab-on-chip technologies. Using the metal-polymer nanocomposites' multilayer cylindrical nanostructure with a microfluidic channel, we develop a real-time and temperature-dependent prototype of the Bragg Opto-microfluidic sensor for effective tracking of contaminated fossil fuels. The purpose of this chapter is to examine the biological motivations for the development of multilayer photonic nanostructures and various types of fuel adulteration detection optical sensors using various sensor-based techniques, as well as to compare the Bragg Metal-Polymer nanocomposites optical sensor with other optical sensors. This chapter is devoted entirely to the use of the theoretical model's Kay, Eykman, Dale-Gladstone, Newton, and Lorentz-Lorenz, as well as Hankel formalism and the transfer matrix method for cylindrical symmetry. © 2023 Bentham Science Publishers. All rights reserved.
Role of ultrathin Ti3C2Tx MXene layer for developing solution-processed high-performance low voltage metal oxide transistors
(American Institute of Physics, 2024) Ankita Rawat; Utkarsh Pandey; Ritesh Kumar Chourasia; Gaurav Rajput; Bhola Nath Pal; Nitesh K. Chourasia; Pawan Kumar Kulriya
Metal oxide transistors have garnered substantial attention for their potential in low-power electronics, yet challenges remain in achieving both high performance and low operating voltages through solution-based fabrication methods. Optimizing interfacial engineering at the dielectric/semiconductor interface is of utmost importance in the fabrication of high-performance thin film transistors (TFTs). In the present article, a bilayer Ti3C2Tx-MXene/SnO2-semiconductor (Tx stands for surface termination) configuration is used to fabricate a high-performance n-type thin film transistor by using an ion-conducting Li-Al2O3 gate dielectric on a p+-Si substrate, where electrical charges are formed and modulated at the Li-Al2O3/SnO2 interface, and Ti3C2Tx-MXene nanosheets serve as the primary electrical charge channel due to their long lateral size and high mobility. A comparative characterization of two distinct TFTs is conducted, one featuring Ti3C2Tx MXene and SnO2 semiconductor layer and the other with SnO2 only. Notably, the TFT with the Ti3C2Tx MXene layer has shown a significant boost in the carrier mobility (10.6 cm2/V s), leading to remarkable improvements in the on/off ratio (1.3 × 105) and subthreshold swing (194 mV/decade), whereas the SnO2 TFT without the Ti3C2Tx MXene layer shows a mobility of 1.17 cm2/V s with 8.1 × 102 on/off ratio and 387 mV/decade subthreshold swing. This investigation provides a possible way toward the development of high-performance, low-voltage TFT fabrication with the MXene/semiconductor combination. © 2024 Author(s).
Thermal Kinetics Through Differential Scanning Calorimetry in Chalcogenide Glassy Semiconductors
(Springer Science and Business Media Deutschland GmbH, 2024) Ankita Srivastava; Chandrabhan Dohare; Ritesh Kumar Chourasia; Neeraj Mehta; Namrata Chandel; Dinesh Pathak; Amodini Mishra; Dhirendra Sahoo
Differential Scanning Calorimetry (DSC) is one of the best ways to examine the thermal kinetics of non-equilibrium nature of synthesized non-crystalline materials. The exact thermal kinetics of glassy materials during the glass transition, involves crystallization and polymorphic transition. DSC, a characteristic technique of thermal phase transitions, evolves in the micro-structural properties. The endothermic (glass transition, Tg) and exothermic (crystallization temperature, Tc) nature of chalcogenide glasses obtained during the DSC thermal scanning have been investigated. The phenomenon of crystallization and glass transition kinetics of glassy semiconductors has been deliberated at various different heating rates using differential DSC. The present work deals with model fitting and model free non-isothermal (Kissinger–Akahira–Sunose, Ozawa-Flynn-Wall, Starink and Tang) approaches that are used to determine the various kinetic parameters i.e., activation energy (crystallization, Ec and glass transition, Eg), fraction of crystallization, pre-exponent factor etc. of the growing generations of Chalcogenide glassy binary, ternary, quaternary and multi-component alloys. © The Author(s), under exclusive license to Springer Nature Switzerland AG 2024.
Voltage-tunable pass band in cylindrical multilayered structure containing PMMA and 0.67PMN–0.33PT single crystal as a defect layer
(Springer New York LLC, 2016) Ritesh Kumar Chourasia; Surendra Prasad; Vivek Singh
In present paper, an inline optical demultiplexer through cylindrical multilayered structure having a cavity of Poly-methyl methacrylate surrounded with single crystal 0.67PMN–0.33PT is presented. The required transmission of the proposed structure is obtained by transfer matrix method using cylindrical coordinate system. It is observed that the multilayer cylindrical structure is able to provide the photonic band gap, where groups of wavelengths are stopped from propagation through the waveguide. The insertion of cavity in considered structure also provides a pass band in the photonic band gap region. The 0.67PMN–0.33PT crystal in the present structure is used to control the thickness of cavity by applying an external DC voltage. Hence, the obtained shift of pass band is approximately 6 nm/V in the proposed structure. © 2016, Springer Science+Business Media New York.