Faculty Publications
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Publications by NITK Faculty
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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.