Faculty Publications
Permanent URI for this communityhttps://idr.nitk.ac.in/handle/123456789/18736
Publications by NITK Faculty
Browse
6 results
Search Results
Item Porous-Silicon Assisted Hybrid Plasmonic Slot Waveguide Based On-Chip Ethanol Sensor(Institute of Electrical and Electronics Engineers Inc., 2022) Reddy, S.K.; Singh, M.Refractive index (RI) sensors have an overarching compass jutting into the biological and chemical fields and hence are efficacious. The evinced work appertains with an infra-red (IR)-band ethanol sensor, perceived with a Metal-Insulator-Semiconductor-Insulator-Metal (MISIM) waveguide structure consisting of porous-silicon as the absorbing/sensing medium. It is validated through modeling, and numerical simulations that the enhanced electric field confined into a low index slot undergoes a red-shift in wavelength in the presence of harmful ethanol. The red-shift in wavelength can be controlled by changing the silicon porosity and the physical dimensions of the hybrid waveguide. With finite-element-method based COMSOL Multiphysics simulations, we have obtained the optimized metrics of the sensor namely sensitivity (S TM) = 400.43-612.43 nm/RIU, figure of merit (FoM) = 12.42-19.46/RIU, and quality factor (Q-factor) = 46.8-52.9, for 10% to 25% p-Si porosity. The fabrication stages of the on-chip sensor are also articulated in brief. The detailed assessment shows that this sensor is a feasible choice for ethanol detection in hazardous environments. © 2001-2012 IEEE.Item Sensitivity improvement of photonic crystal refractive index sensor using porous silicon nano rods(Elsevier Ltd, 2023) Mehta, S.; Vankalkunti, S.; Kachhap, P.K.; Gautam, P.R.; Singh, M.This work proposes a photonic crystal refractive-index sensor for detecting volatile organic compounds (VOC). Two sensor designs are analyzed with Y-splitter photonic crystal waveguide using the finite-difference time-domain (FDTD) method. Also, simultaneous monitoring of two different analytes is possible across the arms of the Y-splitter. The porous silicon (p-Si) rods with a porosity of 25% are used to create a variable refractive index sensing region, which induces a relative shift in the resonant wavelength of the traveling mode. The response at the output ports is monitored in terms of transmittance power versus wavelength plot. The numerical simulations confirm ∼195.83 nm/RIU sensitivity and ∼24.482 RIU−1 figure-of-merit in the presence of hazardous alcohols. © 2023 Elsevier LtdItem Plasmonic Biosensor for DNA Hybridization Using Integrated Graphene-Porous Silicon Waveguide(Institute of Electrical and Electronics Engineers Inc., 2023) Vankalkunti, S.; Singh, M.This work uses the full-vectorial finite element method to study a novel 3-D integrated graphene-porous silicon (p-Si) plasmonic waveguide-based nanostructure for deoxyribonucleic acid (DNA) hybridization. In this study, a p-Si waveguide is designed using the Maxwell Garnett model and is sandwiched between two low-indexed silicon dioxide (slot) layers. Next, a single graphene layer is deposited in both slot regions to enhance the sensor's absorption, tuneability, and sensitivity. The extraordinary optical transmission (EOT) through subwavelength nanoaperture reduces the ohmic losses and improves the optical transmission near the infrared region. Moreover, to optimize the sensor's design, a parametric analysis involving variations in the geometric dimensions of the sensor is performed using COMSOL multiphysics software. With 10% porosity of p-Si, the highest sensitivity value of 318.5 nm/RIU, 3.395/RIU figure of merit, 17.36 quality factor, and 0.01/nm detection accuracy with the presence of rectangular nanoaperture is achieved. Due to nanoscale size, the proposed label-free multilayer or hybrid plasmonic slot waveguide (HPSWG) biosensor offers the potential for future lab-on-a-chip (LOC) biological applications. © 2001-2012 IEEE.Item Hybrid Plasmonic Circular Aperture Waveguide for Blood Glucose Sensing(Institute of Electrical and Electronics Engineers Inc., 2024) Vankalkunti, S.; Singh, N.; Singh, M.A novel approach for blood glucose (or blood sugar) sensing utilizing a hybrid plasmonic circular aperture waveguide (HPCAW)-based nanostructure is proposed. The reported sensor combines the unique optical properties of plasmonic waveguides and circular aperture to achieve higher sensitivity and specificity in glucose detection. The HPCAW structure is designed to efficiently confine and propagate surface plasmon polaritons (SPPs) along the circular aperture, enabling enhanced light-matter interaction within the sensing region. Through rigorous numerical simulations and validation, we demonstrate the superior performance of the HPCAW sensor in terms of sensitivity (391.72 nm/RIU), figure of merit (FOM) (7.08 RIU-1), and detection accuracy (DA) (0.018 nm-1) compared to conventional glucose sensing techniques. Moreover, the proposed sensor offers inherent advantages, such as label-free detection, compact footprint, and compatibility with microfluidic systems. HPCAW provides a promising platform for the next-generation blood glucose monitoring applications with potential clinical translation. 1558-1748 © 2024 IEEE.Item Engineering Porous Silicon-Based Plasmonic Microdisk Resonator for Highly Sensitive Methanol Sensing(Institute of Electrical and Electronics Engineers Inc., 2024) Mehta, S.; Nakul Nayak, V.B.; Singh, M.This study introduces a novel application of a plasmonic microdisk resonator as a highly sensitive sensor for detecting methanol vapor. Leveraging the inherent advantages of plasmonic nanostructures, the microdisk resonator demonstrates a remarkable capability to detect minute concentrations of methanol. In this work, we modeled a novel 3-D porous-silicon (p-Si)-based hybrid plasmonic aperture-coupled microdisk resonator (HPACMR) with specific dimensions and porosity to optimize the sensitivity toward methanol vapor detection. The resonator's design incorporates a thin layer of copper on a dielectric microdisk, creating a plasmonic cavity that supports localized surface plasmon resonances. Finite element method-based simulations predict strong interactions between the resonator's plasmonic field and methanol molecules, leading to detectable shifts in the resonant frequency. By tuning the layout dimensions and p-Si properties, we achieved an altitudinous sensitivity of 569.52 nm/RIU and a Q-factor of nearly 370. The sensors' miniature footprint and potential for integration into portable devices make it an attractive candidate for field-deployable applications. © 2001-2012 IEEE.Item High-Q Plasmonic Resonator for Volatile Organic Compound Detection(Institute of Electrical and Electronics Engineers Inc., 2025) Mehta, S.; Shivaputra, S.; Ramesh, S.; Mandi, M.V.; Singh, M.A hybrid plasmonic waveguide (HPWG)-based resonator designs are studied for on-chip detection of volatile organic compounds (VOCs). The HPWG, which combines dielectric and metallic layers, significantly enhances the confinement of electromagnetic field, leading to increased interaction between the guided light and the surrounding analytes. The system achieves high spectral sensitivity and narrow linewidth by integrating multiple microring resonators in a cascaded configuration. This is critical for distinguishing small changes in the refractive index (RI) associated with different VOCs. Finite element method (FEM) simulations demonstrate the superior sensing performance of a proposed device, showing a spectral sensitivity of 469.5 nm/RIU and a quality factor (QF) of 518.75. The compact design and high sensitivity make this sensor an excellent candidate for on-chip VOC monitoring in industrial safety, as well as portable breath sensors to detect VOC biomarkers for early disease diagnosis. © IEEE. 1973-2012 IEEE.