A5049146377- Advanced Fluorescence Microscopy Techniques
- Random lasers and scattering media
- Optical Polarization and Ellipsometry
- Spectroscopy Techniques in Biomedical and Chemical Research
- Photoacoustic and Ultrasonic Imaging
- Spectroscopy and Quantum Chemical Studies
- Laser-induced spectroscopy and plasma
- Advanced SAR Imaging Techniques
- Advanced Fiber Optic Sensors
- Glycosylation and Glycoproteins Research
- Mathematical Analysis and Transform Methods
- Synthetic Aperture Radar (SAR) Applications and Techniques
- Photonic and Optical Devices
- Spectroscopy and Laser Applications
- Cell Image Analysis Techniques
- Analytical chemistry methods development
- Quantum optics and atomic interactions
- Advanced Biosensing Techniques and Applications
- Advanced Chemical Sensor Technologies
- Laser-Matter Interactions and Applications
- Birth, Development, and Health
- Optical and Acousto-Optic Technologies
- Protein Interaction Studies and Fluorescence Analysis
- Optical Imaging and Spectroscopy Techniques
- X-ray Spectroscopy and Fluorescence Analysis
Defence Research and Development Organisation
2021-2022
Mississippi State University
2009-2020
Indian Institute of Technology Bombay
2020
University of Memphis
2016-2018
Breath analysis, a promising new field of medicine and medical instrumentation, potentially offers noninvasive, real-time, point-of-care (POC) disease diagnostics metabolic status monitoring. Numerous breath biomarkers have been detected quantified so far by using the GC-MS technique. Recent advances in laser spectroscopic techniques sources driven analysis to heights, moving from laboratory research commercial reality. Laser detection not only high-sensitivity high-selectivity, as...
The weak absorption spectra of isoprene and acetone have been measured in the wavelength range 261–275 nm using cavity ringdown spectroscopy. cross-sections region 261–266 from 3.65 × 10−21 cm2·molecule−1 at 261 to 1.42 266 nm; these numbers are good agreement with values reported literature. In longer 270–275 nm, however, where attractive applications a single compact diode laser operating 274 is located, has literature no (too be detected). Small this spectroscopy for first time work,...
A fiber loop ringdown (FLRD) concrete crack sensor is described for the first time. bare single mode (SMF), without using other optical components or chemical coatings, etc., was utilized to construct head, which driven by a FLRD system. The performance of evaluated on bars with dimensions 20 cm × 5 cm, made in our laboratory. Cracks were produced manually and responses recorded terms times. demonstrated detection surface width (SCW) 0.5 mm, leads theoretical SCW limit 31 μm. sensor’s...
We have developed a novel technique to quantify submicron scale mass density fluctuations in weakly disordered heterogeneous optical media using confocal fluorescence microscopy. Our method is based on the numerical evaluation of light localization properties an 'optical lattice' constructed from pixel intensity distributions images obtained with Here we demonstrate that reveals differences fluorescently labeled molecules between normal and cancer cells, it has potential degree malignancy...
At epidemic proportions worldwide, one in four persons now has cancer, and this statistic will change to two near future. An important step the fight against cancer is its early accurate detection. This calls for affordable, quick easy diagnostic methods. Standard pathological detection of involves microscopic examination morphological changes using stained biopsy samples, but method prone human error misdiagnosis. A tissue a spatially heterogeneous medium with fractal properties owing...
Light localization is a phenomenon which arises due to the interference effects of light waves inside disordered optical medium. Quantification degree in media widely used for characterizing structural disorder that media. Recently, this approach was extended analyze changes biological cell like heterogeneous media, with potential application cancer diagnostics. Confocal fluorescence microscopy construct “optical lattices,” represents 2‐dimensional refractive index map corresponding spatial...
Chronic stress affects nano to microscale structures of the brain cells/tissues due suppression neural growths and reconnections, hence neuronal activities. This results in depression, memory loss even death cells. Our recently developed novel optical technique, partial wave spectroscopic microscopy has nanoscale sensitivity, hence, can detect changes tissues stress. In this study, we applied technique quantify related structural corticosterone-treated mouse model show that brains from mice...
As cancer progresses, macromolecules, such as DNA, RNA or lipids, inside cells undergo spatial structural rearrangements and alterations. Mesoscopic light transport-based optical partial wave spectroscopy (PWS) was recently introduced to quantify changes in the nanoscale disorder biological cells. The PWS measurement is performed using a parameter termed "disorder strength" (L d ), which represents degree of It shown that cancerous have higher strength than normal In this work, we first used...
Chronic alcoholism is known to alter the morphology of hippocampus, an important region cognitive function in brain. Therefore, understand effect chronic on hippocampal neural cells, we employed a mouse model and quantified intranuclear nanoscale structural alterations these cells. Transmission electron microscopy (TEM) images neurons were obtained, degree alteration terms mass density fluctuation was determined using light-localization properties optical media generated from TEM imaging....
A portable optical emission spectroscopy-cavity ringdown spectroscopy (OES-CRDS) dual-mode plasma spectrometer is described. compact, low-power, atmospheric argon microwave torch (MPT) utilized as the source when operating in OES mode. The same MPT serves atomization for measurements CRDS Initial demonstration of instrument carried out by observing multiple elements including mercury (Hg) mode and measuring absolute concentrations Hg metastable state 6s6p 3P0 mode, which a palm-size diode...
Time domain matched filtering is a classic method used in radar and sonar applications to maximize signal noise ratio (SNR) gain, estimate time delay, improve range resolution. Fractional Fourier transform, fractional are extensively overcome the drawbacks of shown have improved performance for linear chirp. This paper presents generalized (GFMF) estimating higher order chirp parameters with known delay. It provide SNR gain equivalent filtering. As an application GFMF, novel minimize...
We report a new method of measuring elemental mercury (Hg) at the 405 nm transition line, which corresponds to optical from metastable state 5d106s6p 3P0 upper 5d106s7s 3S1. Observation absorption spectra and measurements absolute number density Hg in are achieved by stepwise electron impact excitation-cavity ringdown technique, population atoms is realized through excitation energetic electrons (< 10 eV) generated an atmospheric argon microwave plasma torch detection via cavity spectroscopy...
Fiber loop ringdown (FLRD) has demonstrated to be capable of sensing various quantities, such as chemical species, pressure, refractive index, strain, temperature, etc.; and it high potential for the development a sensor network. In present work, we describe design three different types FLRD sensors water, cracks, temperature in concrete structures. All aforementioned were indigenously developed very recently our laboratory their capabilities detecting respective quantities demonstrated....
Optical scattering strength of fractal optical disordered media with varying dimension is reported. The diffusion limited aggregation (DLA) technique used to generate samples in 2D and 3D, dimensions are calculated using the box-counting method. degree structural disorder these their light localization strength, via inverse participation ratio (IPR) analyses eigenfunctions. Results show non-monotonous behavior disorder-induced dimension, attributed competition between increasing due decrease...
The squinted strip-map synthetic aperture radar (SAR) mode for fighter airborne provides more operational advantage than the side-looking mode. high platform dynamics of plane and severe range-azimuth coupling squint scenario imposes challenges compared to SAR image formation algorithm. Most algorithms fail provide reasonable focusing performance with computational complexity in high-squint, high-resolution This paper presents real-time hardware implementable version <tex...
Nanoscale structural alteration in the nuclei of cells with progression carcinogenesis is due to rearrangements basic building blocks cell such as DNA, RNA, lipids, etc. Although epigenetic modifications underlie development cancer, exposure carcinogenic chemicals alcohol also enhances cancer. We report effects chronic alcoholism on early-carcinogenesis based changes degree nanoscale alterations (L d) nuclei. For this, transmission electron microscopy (TEM) imaging colonic performed for...