Browsing by Author "Surendra Prasad"

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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
Controlling the band structures and electromagnetic density of modes in one-dimensional photonic crystals with Lamb wave
(Taylor and Francis Ltd., 2022) Ayush Aman; Surendra Prasad; Suraj Prakash; Gaurav Sharma; Vivek Singh
We have modeled and investigated band structures and the electromagnetic density of modes in one-dimensional photonic crystal whose refractive index is modulated by the excitation of the fundamental symmetric mode of Lamb wave using the Wigner phase time approach and transfer matrix method. The Rayleigh–Lamb dispersion curves are plotted to select the proper thickness of each sub-layer of considered photonic crystal structure which is comprised of silica (SiO2) and rutile (TiO2) layers as sub-layers of unit cell. The propagation of Lamb wave into the considered structures produced phononic band gaps in gigahertz frequency for acoustic waves. Also, the propagation of Lamb wave into the considered structures causes compression in SiO2 and dilation in TiO2 or vice versa, which can further increase or decrease the refractive index of both layers. Thus, there can be three combinations of change in refractive indices: case 1 (both layers have an unperturbed refractive index), case 2 (maximum change of the refractive index in SiO2 and minimum change in the refractive layer of TiO2), and case 3 (minimum change of the refractive index in SiO2 and maximum change in the refractive layer of TiO2). The band gap structures of considered structures are plotted for both polarized electromagnetic waves. © 2020 Informa UK Limited, trading as Taylor & Francis Group.
Design of mid-IR sensor based on resonance excitation of bloch surface wave through a Bragg grating
(Springer, 2025) Mahendra Kumar; Surendra Prasad
Theoretical demonstration of excitation of electromagnetic surface waves (EMSWs) via Bragg grating coupler is presented. The present manuscript utilizes the improvised Kretschmann configuration coupling mechanism where the prism is replaced by a dielectric Bragg grating. The sensing performance based on the resonance excitation of EMSWs is studied for transverse magnetic polarized (polarized waves) case. The dispersive properties and the optical properties are also studied. For the designed sensor the refractive index sensitivity is evaluated to be and the angular sensitivity is evaluated to be. Such photonic structure is novel compared to the traditional way of sensing under Kretschmann configuration because it leads to the miniaturization of the sensors which makes it compact and easily portable. © The Author(s), under exclusive licence to The Optical Society of India 2025.
Dispersion and dissipation of shear horizontal wave in magneto-electro-elastic material loaded with complex magnetic viscous fluid
(Institute of Physics, 2025) Ravindra Singh; Ramnarayan; Priyanka Yadav; Surendra Prasad
The present study outlines the theoretical analysis of Shear horizontal (SH) wave propagation on magneto-electro-elastic (MEE) material lying on an elastic half-space and subjected to magnetic fluid loading. Using an exact analytical approach, complex dispersion relations for SH waves are derived under both electric short and electric open boundary conditions. To validate these derived relations, specific cases are considered where the MEE material behaves as piezoelectric and piezomagnetic. The complex dispersion relations are separated into real and imaginary components, revealing nonlinear relationships between phase velocity and attenuation of SH waves in relation to geometric parameters, frequency, and the physical properties of the magnetic fluid. Five different magnetic fluids are examined to illustrate the phase velocity and attenuation characteristics graphically. The effects of geometric and physical parameters of the magnetic fluids, the thickness of the MEE material, and the frequency and density of the elastic half-space on the phase velocity and attenuation of SH waves are discussed. Additionally, the finite element method (FEM) is employed to validate the results, ensuring the accuracy of the analytical findings. The results of this study are fundamental and can be used to design and development of surface acoustic wave (SAW) liquid sensors as well as magnetic field sensors. © 2025 IOP Publishing Ltd. All rights, including for text and data mining, AI training, and similar technologies, are reserved.
Dispersion behavior of electromagnetic wave near the resonance in 1D magnetized ferrite photonic crystals
(Springer New York LLC, 2018) Yogesh Sharma; Surendra Prasad; Vivek Singh
In the present article, we have analyzed the dispersion of electromagnetic wave in the one dimensional magnetized ferrite photonic crystals near the resonance in the permeability of the constituent materials for transverse magnetization in the transverse electric mode. The dispersion relation is obtained by transfer matrix method. It is observed that in the vicinity of resonant frequency, large numbers of oscillations occur in the normalized Bloch wave number. These oscillations in the Bloch wave number are strongly dependent on external magnetic fields, filling factor, and damping constant. The frequency regime of these oscillations is found to be shifted in higher frequency range with increase in the magnitude of the magnetic fields. With increase in the filling factor keeping length of periods fixed, number of oscillations is found to be increased. Near the resonance, effect of incident angle is negligible. It is demonstrated that these nearly equidistant oscillations occurring in the vicinity of resonance may be used for making filter in micro wave frequency range. © 2018, Springer Science+Business Media, LLC, part of Springer Nature.
Dispersion Characteristics and Phase Index of One-Dimensional Magnetized Ferrite Photonic Crystals in Transverse Magnetization Configuration for TE Modes
(Springer New York LLC, 2019) Yogesh Sharma; Surendra Prasad
The dispersion characteristics and phase index of magnetized one-dimensional ferrite photonic crystals in transverse magnetization for transverse electric modes are investigated. The dispersion relation and expression for phase index are derived by using transfer matrix method. The effects of structural parameters such as external magnetic fields, filling factor, and β on dispersion properties and phase index are investigated. The dielectric nature of the considered magnetized ferrite photonic crystal structure is demonstrated. Also, the band structure for ω < 1.5 × 1010 rad s− 1 is strongly affected by external magnetic fields. It is observed that phase index occurs in the form of lobes and is found to be controlled by external magnetic field, β, and filling factor. © 2018, Springer Science+Business Media, LLC, part of Springer Nature.
Dispersion properties of one-dimensional magnetized ferrite photonic crystals in transverse magnetization configuration for transverse magnetic modes
(Springer Science and Business Media, LLC, 2018) Yogesh Sharma; Surendra Prasad
Abstract: The dispersion characteristics of electromagnetic wave in one-dimensional magnetized ferrite photonic crystals containing yttrium iron garnets and nickel ferrite in a unit cell is investigated for transverse magnetic mode when external magnetic field is perpendicular to the plane of wave propagation. The dispersion relation is derived using transfer matrix method based on the continuity conditions of tangential electric and magnetic field components. It is observed that dispersion properties and phase index are strongly dependent on the normalized parallel wave vector and the filling factor. At the Brewster angle, width of photonic band gap shrinks to zero. Also, the considered structure indicates its dielectric behavior for electromagnetic wave propagation. Graphical abstract: [Figure not available: see fulltext.]. © 2018, EDP Sciences, SIF, Springer-Verlag GmbH Germany, part of Springer Nature.
Dispersion property of electromagnetic wave in 1D magnetized ferrites photonic crystals for TE mode in longitudinal magnetization configuration
(Elsevier B.V., 2019) Yogesh Sharma; Surendra Prasad
In this article, properties of dispersion characteristics and phase index of magnetized one dimensional ferrite photonic crystals are investigated for transverse electric mode when external magnetic field is along the propagation direction. The dispersion relation and phase index equation for electromagnetic wave propagating in the considered structure is obtained by using transfer matrix method. It is found that in this configuration, two Eigen modes viz. LCP and RCP waves are obtained. The effect of external magnetic field, filling factor and normalized parallel wave vector β on dispersion and phase index are investigated. It is found that filling factor, external magnetic field and β have strong influence on the dispersion and phase index for LCP wave. For RCP wave, dispersion and phase index do not show external field dependence. With increase in external magnetic fields, the first order PBGs is shifted towards high frequency domain for LCP wave whereas for RCP wave there is no effect of external magnetic field on dispersion. With increase of β at constant external magnetic field and filling factor, thickness of PBGs increases for both LCP & RCP waves. PBGs occur in the form of lobes and the number of lobes decreases with increase in β values in the same frequency domain. For same f-value, the magnitude of ɸ is lower for LCP wave as compared to RCP wave. © 2019 Elsevier B.V.
Dynamically Tuning the Density of Mode in a Photonic Crystal with Double Defects
(Institute of Electrical and Electronics Engineers Inc., 2018) Ayush Aman; Surendra Prasad
The density of mode in acoustically modulated one-dimensional photonic crystal with two defects embedded has been calculated using the Wigner time phase approach. The acoustic wave redistributes the periodicity and the refractive index of each layer in the unit cell of photonic crystal. It is observed that there are two peaks in the density of mode plots whose intensity as well as frequency domain are dynamically tuned as these peaks are affected by the fractional change in the time period of acoustic waves. In case of synchronous modulation of density of mode, coupled and uncoupled defect modes are observed, which might be useful in realizing future optoelectronic devices. © 1989-2012 IEEE.
Estimation of photonic band gap in silicon crystal waveguide through acousto-optic interaction
(Springer Science and Business Media, LLC, 2015) Gaurav Sharma; Sushil Kumar; Surendra Prasad; Vivek Singh
The photonic band gap through acousto-optic interaction in a face-centred cubic silicon crystal is theoretically studied. The dispersion relation for acoustic wave is obtained using method of potentials with boundary conditions involving the bulk and surface stress of considered materials. The dispersion relation for optical wave is derived by transfer matrix method and boundary conditions based on electromagnetic theory. Observation shows that the central frequency of photonic band gap in silicon crystal can be chosen in any desired infrared optical frequency range by adjusting the frequency of acoustic wave. Also, the size of these band gaps in chosen optical frequency range can be further tuned through incident angle of light wave. This study may provide an efficient method to obtain tuneable photonic crystal. © Springer Science+Business Media New York 2015.
Fabrication of a metal clad planar polymer waveguide based sensor for detection of low-refractive-index-contrast of liquid
(Elsevier GmbH, 2017) Gulab Chand Yadav; Gaurav Sharma; Sushil Kumar; Deepak; Rajesh Kumar; Surendra Prasad; Vivek Singh
A four layer polymer film based planar waveguide having a metallic clad is fabricated and analysed. The fabricated waveguide is validated for detection of small variation in the refractive index of aqueous media solution. It is observed that with increase of refractive index of aqueous media solution, the mode coupling angle of incident light increases. As the thickness of polymer film is increased from 810 nm to 1650 nm, this mode coupling angle is shifted toward higher angle of incidence. The angular interrogation of our fabricated waveguide shows that the maximum obtained sensitivity is 30 deg/RIU for 810 nm polymer film waveguide. Also, our analysis shows that the obtained experimental results are in good agreement with theoretical results. © 2017 Elsevier GmbH
Foreword
(Bentham Science Publishers, 2023) Surendra Prasad
[No abstract available]
High performance mid infrared temperature sensor based on resonance excitation of hybrid Tamm surface states
(Elsevier B.V., 2022) Mahendra Kumar; Surendra Prasad
Theoretical design of mid infrared temperature sensor based on the resonance excitation of hybrid Tamm surface state (HTSS) is presented. An excellent sensing performance is attained by the coupling of graphene plasmon polaritons and hexagonal boron nitride (hBN) phonon polaritons that forms hybrid polariton modes at the interface. In one dimensional ternary photonic crystal (1D TPC), terminated by hBN layer sandwiched between graphene monolayers, the coupling between Bloch surface waves and hybrid polariton modes leads to the formation of HTSS or Tamm plasmon-phonon modes. Employing Kretschmann configuration coupling mechanism, the excitation of the HTSSs at the truncated interface is manifested for transverse magnetic (TM) polarized wave. The structure supports excited HTSS between 7.14μm to 10.34μm that allows astounding control over the sensing ability by varying the number of unit cells and the resonant angles. The sensor has a high detection accuracy of 1010 at room temperature (300K). It is proved that for 50 unit cells and at 49° angle, a high quality factor of 372176, detection limit of 5K and sensitivity of 0.20pm/K is attained with operating range between 280K to 380K. The operating range is widened from 300K to 900K by changing the resonant angle from 49° to 53°. Further, for 30 unit cells and at 53° angle, the temperature sensing ability of the sensor extends from 100K to 900K with a sensitivity of 0.80pm/K and detection limit of 54.16K. © 2022 Elsevier B.V.
High-Resolution Temperature Sensor Based on Resonance Excitation of Tamm Plasmon Polaritons: Graphene Plasmon Polariton Hybrid Mode
(Springer, 2023) Mahendra Kumar; Surendra Prasad
A theoretical demonstration of a high-quality-factor photonic crystal (PC) temperature sensor in the near-infrared frequency domain is presented. The sensor is based on coupling of Tamm plasmon polaritons (TPPs) existing at the graphene-PC interface and graphene plasmon polaritons (GPPs) existing at the graphene surface. This leads to the appearance of a TPP-GPP hybrid mode in one-dimensional ternary photonic crystals (1D TPC) truncated by a dielectric layer between graphene monolayers. For a transverse magnetic (TM) polarized wave, the excited TPP-GPP hybrid modes are localized within the range 180–270 THz or 1.11–1.67 µm. Excellent control over the resonance frequency is established via Kretschmann configuration excitation that covers the temperature range spanning from 1 K to 1500 K with high coupling efficiency and high quality factor (QF) of the order of 10 5 . It has been proved that the QF is strongly governed by temperature. The design parameters of the sensor are optimized so that temperature sensitivity of 5.75fm/K is achieved, with an excellent figure of merit of the order of 10-4K-1 and high detection accuracy of the order of 10 11 . The proposed sensor exhibits a high temperature detection limit or temperature resolution of 3.915 × 10 - 4K . A comparative analysis of the sensor parameters in the near infrared wavelength is provided, and the wavelengths are resolved at the femtometer length scale with very high QF. Graphical Abstract: [Figure not available: see fulltext.] © 2023, The Minerals, Metals & Materials Society.
Influence of abiotic factors on incidence of Tetranychus macfarlanei (Acarina: Tetranychidae) on pumpkin (Cucurbita moschata) and its control
(2003) Surendra Prasad; R.N. Singh
An experiment was conducted during 1998-2000 to study the influence of abiotic factors on incidence of Tetranychus macfarlanei Baker & Pritchard (Acarina : Tetranychidae) on pumpkin (Cucurbita moschata Duochense ex Pior.). The mite population started building up on the crop from the second fortnight of March and continued till the first fortnight of July; however, its maximum populations of 98.30 and 87.80/ leaf were recorded on the first fortnight of June 1998 and May 1999 respectively. There was a significant positive correlation between population and temperature, while relative humidity and rainfall showed negative correlation. Among acaricides, Dicofoal 0.05% up to day 7 and among botanicals NSKE 5% up to day 3 proved most effective against the mite.
Investigation of magneto-optical effects on properties of surface modes in one dimensional magnetized plasma photonic crystals
(American Institute of Physics Inc., 2016) Shikha Shukla; Surendra Prasad; Vivek Singh
We have studied the properties of surface modes on one dimensional magnetized plasma photonic crystals in two configurations: Faraday and Voigt configurations. The results have been demonstrated by using the transfer matrix method and employing boundary conditions for TE and TM modes, respectively. For the Voigt effect, only the TM mode is considered because the TE modes under the influence of external magnetic field have the same properties as un-magnetized plasma. The influence of external magnetic field has been studied for three cases, i.e., TE left circular polarization, TE right circular polarization, and TM surface modes. It is shown that the properties of surface modes can be tuned correspondingly by changing the cap layer thickness, wave vector, and external magnetic field in the desired photonic band gap. The results show that collision frequency has a negligible effect on surface modes. A new type of wave called Fano mode has been reported for the Voigt effect for the TM mode in the first band gap. Proof of its existence has been demonstrated in the present paper. © 2016 Author(s).
Mid-infrared Biosensor Based on Bloch Surface Mode Excitation in Truncated One-Dimensional Ternary Photonic Crystal Under Kretschmann Configuration
(Springer, 2021) Mahendra Kumar; Surendra Prasad
We have theoretically investigated the performance of mid-infrared (mid-IR) sensitive biosensor constructed by truncated one-dimensional (1D) ternary photonic crystal (TPC) on the prism base under Kretschmann configuration coupling technique. The control over resonance wavelength (RW) of the excited Bloch surface modes (EBSMs) for the case of incident transverse magnetic polarized electromagnetic waves (EMWs) has been shown. The band structures and the reflection spectra of the considered model are computed using transfer matrix method (TMM). The variation in different design parameters of the theoretically constructed biosensor, such as thickness of the truncation layer, refractive index of the sensing medium, and number of unit cells in photonic crystal (PC), allows us to have good control over the resonance wavelengths in fixed frequency regime of the PBGs. The excitation of BSMs is characterized by a dip in the reflectance spectra. The measured sensitivity of the sensor is 10 - 3 orders of magnitude sensitive to the change in dc and dt values. © 2021, Springer Science+Business Media, LLC, part of Springer Nature.
Mid-infrared sensor based on resonance excitation of graphene plasmon polariton-coupled Bloch surface modes at the interface of anisotropically truncated one-dimensional ternary photonic crystal
(Taylor and Francis Ltd., 2024) Mahendra Kumar; Surendra Prasad
In this article, we have theoretically demonstrated the sensor performance in mid-IR frequency domain by resonance excitation of Bloch surface modes through energy coupling with graphene surface plasmon polaritons in truncated one-dimensional (1D) ternary photonic crystal (TPC) under Kretschmann configuration coupling technique. The involvement of optical anisotropy via graphene monolayer enhances light-matter interaction thus enabling excellent control over the resonance wavelength (RW) of the excited Bloch surface modes (EBSMs). For incident transverse magnetic-polarized electromagnetic waves, the band structure, reflection spectra and field profile are computed using 2 (Formula presented.) 2 transfer matrix method. The control over the RW has been established by examining the effect of variation of different model parameters like thickness of truncation layer, refractive index of external medium, temperature, chemical potential and the periodicity of TPC. The variations in periodicity result in the expansion of the range of confinement of EBSMs in photonic band gaps from (Formula presented.) to (Formula presented.). We proved that the variation in temperature between (Formula presented.) and (Formula presented.) confines the EBSMs with high coupling efficiency (CE). Also, at room temperature the best achievable quality factor (QF) is 1421 and a high Q.F. of 8170 is attained at (Formula presented.). © 2021 Informa UK Limited, trading as Taylor & Francis Group.
Modeling of shear horizontal waves propagation in magneto-electro-elastic substrate loaded with complex conductive fluid
(Taylor and Francis Ltd., 2024) Ravindra Singh; Surendra Prasad
In this study, the dissipation and dispersion of shear horizontal (SH) wave in magneto-electro-elastic (MEE) materials overlying an elastic half-space loaded with a complex conductive fluid have been investigated. The complex dispersive relation of SH waves for magnetic short and magnetic open cases has been derived using an exact analytical approach. The derived dispersive relations have been theoretically and graphically validated against previous work. The study explores the impact of geometrical parameters, frequency, conductivity, and permittivity of the complex conductive fluid on the phase velocity and attenuation of SH waves. © 2024 Taylor & Francis Group, LLC.
Modelling and optimization of TiO2based two- dimensional photonic crystal for salinity detection in water
(Elsevier GmbH, 2025) Priyanka Yadav; Ravindra Singh; Ram Narayan; Surendra Prasad
In this article, we have presented a computational analysis of two-dimensional photonic crystals (2D- PCs) having circular and elliptical waveguide structures inside aTiO2 host material for the salinity detection in the water. The band structure of the proposed 2D- PCs has been optimized for better salinity detection based on the number of circular and elliptical waveguiding pores taken in the PCs structure and changes in the radius of circular pores and for different major-minor axis of elliptical pores. The electric field profiles corresponding to these structures have also been plotted. The salinity detection sensitivity is calculated by computing the change in transmittance (∆Tn1.333−n1.35) corresponding to changes in refractive indices due to salinity in water. It is observed that maximum sensitivity is obtained corresponding to refractive indices, n1.333,n1.35 which is equal to 0.9198 in the circular pore in the 2D-PCs structure. For the elliptical pore, the sensitivity is 0.8679. © 2024 Elsevier GmbH