Analysis of Tapered Fibre Optic Surface Plasmon Resonance Bio-Sensor Chip With Highly Perturbed Taper Profiles.

A numerical model based on the Transfer matrix method (TMM) is proposed for the first time to study the gold coated tapered fibre optic surface plasmon resonance (SPR) with eight different types of taper profiles namely linear, exponential-linear, Gaussian, quadratic, sinusoidal, error function type and highly perturbed taper profile so-called chirp type of profile. The performance in terms of sensitivity, full width at half maximum (FWHM), detection accuracy (D.A.

High sensitivity detection of different pH ranges with rGO-nanocomposite coated eFBG sensor.

In the proposed work, a highly sensitive reduced graphene oxide (rGO) coated etched fiber Bragg grating (eFBG) pH sensor is developed and characterized. To create the sensing probe, a nanocomposite layer of rGO is coated over the unclad area of the eFBG. The analysis of rGO material has been done using different characterization tools such as UV-VIS-NIR spectroscopy, x-ray diffraction (XRD), and field emission scanning electron microscopy (FESEM).

SPR Based Biosensing Chip for COVID-19 Diagnosis-A Review.

Surface Plasmon Resonance (SPR) techniques are highly accurate in detecting biomolecular like blood group measurement, food adulteration, milk adulteration and recently developing as a rapid detection for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus. In order to validate the clinical diagnosis, Real-time reverse transcriptase-polymerase chain reaction (RT-PCR) of nasopharyngeal swabs has been utilized, which is time consuming and expensive. For fast and accurate detection of the SARS-CoV-2 virus, SPR based biosensing chips are described in this review article.

Numerical analysis of a grating embedded bidirectional integrated optical coupler pressure sensor.

A numerical analysis of a grating embedded bidirectional optical coupled waveguide structure is presented for the first time, to our knowledge. A finite difference method (FDM) based scheme is devised to extract the allowed eigen TE and TM modes of the structure. Sensing characteristics of the grating employed between two high refractive index couplers are then explored.

A Numerical Study of Different Metal and Prism Choices in the Surface Plasmon Resonance Biosensor Chip for Human Blood Group Identification.

Optimized design of Surface plasmon resonance (SPR) based biosensor in terms of different metal choices and prisms are presented to the first time for the high precision detection of human blood group in near infrared wavelength range. The results are well compared with the earlier published gold coated silicon biosensor chip while discussing the pros and cons of various prism/metal choices. In this study buffer layer onto SPR active metal has been deployed to avoid the oxidation problem and contamination issue related with blood samples.

Real-time interrogation of fiber optic biosensor using TiO coated etched long-period grating.

In this work, a TiO coated etched long-period grating (e-LPG) fiber optic biosensor is developed for the detection of Escherichia coli (E. coli) bacteria in food items. Label-free Escherichia coli bacteria monitoring is done over the detection range of 0 cfu/ml-50 cfu/ml using an advanced spectral interrogation mechanism.

Photonic generation of a parabolic-shaped microwave signal and dual-linear-chirp microwave waveform.

Based on an external modulation technique through a dual-polarized dual-parallel Mach-Zehnder modulator, a photonic technique is proposed for the generation of a microwave signal with a parabolic shape. An optically modulated waveform from the modulator is passed through an optical bandpass filter, which results in parabolic signals of 1 GHz and 9 GHz frequencies at the photo detector. A peak power spectral component of -30 power is obtained at 1 GHz and 9 GHz frequencies of the parabolic signal.

Photonic-technique-based highly steerable beamforming system incorporating a prism of super Gaussian apodized tunable chirped fiber Bragg grating for X-band applications.

Conventional phased arrays operate over bandwidths that are inversely proportional to the array size. The use of true-time delays (TTDs) instead of phase shifts would eliminate the bandwidth restrictions due to beam squint. Photonic techniques for dynamically controlling the delay at the input of a phased array antenna opens an area of new powerful methods for remarkably precisely increasing the speed of beamsteering of an antenna in a desired direction.

Class modal analysis of a thin multi-trench-assisted liquid-filled optical waveguide coupler for simultaneous multi-sensing applications.

In this paper, we present an analysis of, to the best of our knowledge, a novel class of the thin multi-trench-assisted optical coupler for multi-sensing of chemical detection. The design structure is an optical waveguide coupler consisting of closely coupled trenches filled with different liquids for chemical sensing. The refractive index profile of the coupler is allowed to vary due to the chemical filled in these trenches.

Design of optical reversible logic gates using electro-optic effect of lithium niobate based Mach-Zehnder interferometers.

In recent years reversible logic has come as a promising solution in the optical computing domain. In reversible gates, there is one-to-one mapping between input and output, causing no loss of information. Reversible gates are useful for application in low power complementary metal-oxide semiconductors, with less dissipation, and in quantum computing.