A5067955883- Orbital Angular Momentum in Optics
- Optical Wireless Communication Technologies
- Advanced Fiber Laser Technologies
- Laser-Matter Interactions and Applications
- Underwater Vehicles and Communication Systems
- Optical Polarization and Ellipsometry
- Near-Field Optical Microscopy
- Advanced Fiber Optic Sensors
- Integrated Circuits and Semiconductor Failure Analysis
- Microfluidic and Bio-sensing Technologies
- Copyright and Intellectual Property
- Cold Atom Physics and Bose-Einstein Condensates
- Optical Coherence Tomography Applications
- Sperm and Testicular Function
- Optical and Acousto-Optic Technologies
- Electrohydrodynamics and Fluid Dynamics
- Solid State Laser Technologies
- Glass properties and applications
- Photonic Crystal and Fiber Optics
- Library Science and Administration
- Semiconductor materials and devices
- Plasmonic and Surface Plasmon Research
- Optical Network Technologies
- Ion-surface interactions and analysis
- Force Microscopy Techniques and Applications
Clemson University
2015-2024
Naval Air Warfare Center Weapons Division
2008-2012
Vanderbilt University
2000-2007
Rutgers, The State University of New Jersey
1992
Jefferson Institute
1992
Thomas Jefferson University
1992
University of Pittsburgh
1988
University of Illinois Urbana-Champaign
1980
Philadelphia University
1977
Beams with fast and continuously-tunable orbital angular momentum (OAM) have potential applications in classical quantum optical communications, sensing, the study of beam propagation through turbulence. An acousto-optical deflector (AOD) is a sophisticated, well-studied device that continuously rapidly tunes deflection angle an output beam. The log-polar HOBBIT setup can generate beams OAM by wrapping elliptically shaped Gaussian linear phase tilt to ring. By combining tilted from AOD...
Concentric optical vortex beams of 3-petal, 5-petal, and 6-petal spatial profiles are generated at 450 nm using a single diffractive element. The temporal propagation characteristics these then studied in scattering underwater environment. Experimental results demonstrate less than 5% reduction the pattern for turbidities excess 10 attenuation lengths. properties concentric by temporally encoding an on-off keyed, non-return-to-zero (OOK-NRZ) data stream 1.5 GHz.
Propagation of a continuous spectrum orbital angular momentum (OAM) states through realistic and controlled 3-dimensional turbulent condition has not been studied to date the authors' knowledge. Using Higher Order Bessel-gauss Beams Integrated in Time (HOBBIT) system 60 meter optical path Variable Turbulence Generator (VTG), we demonstrate that by changing OAM scan, OAMs provide an opportunity take advantage additional propagation channels within aperture transmitter receiver. Experimental...
Wireless communication through underwater environments has become an area of increased interest in recent years. The use Laguerre-Gaussian beams for turbid been well explored. We propose and demonstrate a high data rate method using Ince-Gaussian (IG) beams. Using the second harmonic generation process, IG beam can be generated modulated at gigahertz speeds. By controlling phase matching condition SHG coefficients modes controlled. Modulating provides constant envelope modulation. One...
A model was developed to account for the recent observations indicating that type I collagen fibrils assembled in vivo grow from symmetrical pointed tips. The essential features of are (i) a distinctive structural nucleus forms at each end growing fibril and growth then proceeds by propagation two nuclei, (ii) nuclei have similar spiral or helical conformations, (iii) assembly requires kinds specific binding steps defined as 3.4 D-period 0.4 overlaps, but only step.
We report first studies of long-lived oscillations in optical pump-probe measurements on GaSb-GaAs heterostructures. The arise from a photogenerated coherent longitudinal acoustic phonon wave, which travels the top surface GaSb across interface into GaAs substrate, providing information properties material as function time/depth. Wavelength-dependent near bandgap indicate strong correlations to GaAs.
Propagation of laser light is distorted in the presence atmospheric turbulence. This poses an issue for sensing, free-space optical communications, and transmission power. The presented system offers a novel solution to mitigate effects By rapidly probing turbulent volume by varying beam's spatial phase characteristics, best mode can be determined updated real time. Unlike traditional tip-tilt system, this scheme fully electronic, has scalable architecture leverage multiple paths...
In this work, a 1550 nm fiber-to-free-space optical communication link is successfully demonstrated employing the superposition of two coherently coupled orbital angular momentum (CCOAM) states. Information encoded onto both amplitude and phase CCOAM beams mapped to three-dimensional (3D) constellation space using quadrature modulation (QAM) equivalent architecture. The 3D QAM based on higher-order Poincare sphere for OAM states, multiple spherical constellations are 64- 128-QAM, providing...
This Letter demonstrates the nonlinear conversion of asymmetric perfect vortex (APV) beams with fractional orbital angular momentum (OAM). By controlling amplitude and phase fundamental light field, we create APVs whose global OAM a one-to-one correspondence charge numbers for values. The results show that second-harmonic generation fields follow conservation law. interactions multiple are also investigated as they relate to frequency shown exhibit unique frequencies result Doppler tagged
This paper presents a novel method for optical probing by generating fields with characteristics of wavelets. The wavelets form basis rotated asymmetric beams scaled orbital angular momentum (OAM) and beam sizes. was used experimentally to measure the continuous wavelet transform turbulent propagation path, giving insight into properties about fixed radius. three-dimensional turbulence distribution measured; measurements are much faster than changes, allowing characterization an...
Orbital angular momentum (OAM) is a potential tool for remote sensing applications since amplitude/phase distributions can be decomposed into an OAM basis analysis. We demonstrate the generation of spatially asymmetric perfect vortex (APV) based on pulsed 2D HOBBIT (Higher Order Bessel Beams Integrated in Time) system using two acousto-optic deflectors and optical coordinate transformation optics. Results are demonstrated numerous radii charges as high 20, with switching speeds greater than...
We present an investigation of the optical property orbital angular momentum (OAM) for use in detection objects obscured by a turbid underwater channel. In our experiment, target is illuminated Gaussian beam. An vortex formed passing object-reflected and backscattered light through diffractive spiral phase plate at receiver, which allows spatial separation coherent non-coherent light. This provides method discriminating from environment. Initial laboratory results show that ballistic return...
Elderly patients hospitalized for management of major depression frequently have an extensive medical evaluation to determine if physical illness is masquerading as, or serving as the precipitating event for, depression. The purpose this study was incidence newly discovered problems and yield various diagnostic modalities in such elderly depressed patients. Of 100 geropsychiatric inpatients, most frequent new diagnoses included: electrolyte abnormalities (6 patients), bacteriuria (13),...
Nonlinear processes of laser beams carrying orbital angular momentum (OAM) offer a means to generate new wavelengths and manipulate OAM charge numbers. We demonstrate the second-harmonic generation (SHG) asymmetric Bessel-Gaussian (BG) both integer fractional Experimental results show good one-to-one correspondence numbers compliance with conservation law. The SHG conversion process efficiency different combined are also discussed.
We demonstrate a new method for the generation of beams with rapidly tunable orbital angular momentum (OAM). This is based on using single-axis scanning galvanometer mirror to add phase tilt an elliptical Gaussian beam that then wrapped ring optics perform log-polar transformation. system can switch between modes in kHz range and use relatively high power efficiency. HOBBIT was applied light/matter interaction application photoacoustic effect, 10 dB enhancement generated acoustics at...
Underwater turbulence presents a myriad of challenges for underwater optical systems through wavefront distortion and beam deflection. In this work, an emulator is developed thoroughly characterized to experimentally test the proposed mitigation technique. This technique applies modified HOBBIT system introduced in atmospheric relatively unknown domain. By varying beam's spatial position relative phase gradient, volume rapidly probed determine state optimal propagation. probe control method...
VO2 thin films synthesized via direct oxidation on piezoelectric GaN/AlGaN/GaN/Si and SiO2/Si substrates have been used to demonstrate free space modulation of near mid-IR light using a pulsed electric field. Interdigitated metal finger patterns deposited high-quality 140 nm suspended III-nitride or membranes were apply the field modulate laser beams wavelengths varying from 1064 2600 passing through it as switched between semiconducting phases. Strong wavelength dependence intensity is...
Information can be encoded onto transverse spatial light modes, providing a platform that improve the spectral efficiency of communications link. Switching speed between these modes and detection methods limit information capacity such links. This work demonstrates high capabilities Transverse are created switched at rates by coherently coupling twisted using passive optical elements in line with electro-optical modulators. Here we demonstrate encoding two coupled 0.5 Gbaud quadrature...
We demonstrate a new method for systematic, dynamic, high-speed, spatio-temporal control of femtosecond light filamentation in BK7 as particular example nonlinear medium. This is based on using coherent conjugate asymmetric Bessel-Gaussian beams to the far-field intensity distribution and turn location. Such allows every pulse have unique that results generation structured patterns demand. The switching speed this technique dependent rise time acousto-optic deflector, which can operate MHz...
Abstract We report comprehensive studies of long‐lived oscillations in femtosecond optical pump‐probe measurements on GaAs based systems. The arise from a photo‐generated coherent longitudinal acoustic phonon wave at the sample surface, which subsequently travels surface into substrate, thus providing information properties material as function time/depth. Wavelength‐dependent near bandgap indicate strong correlations to GaAs. also use waves probe thin buried Ga 0.1 In 0.9 As layers...
The current effort reports on the spectroscopic properties (absorption, emission and fluorescence lifetime) as a function of varying Erbium concentration in Y<sub>2</sub>O<sub>3</sub>. Results show non-linear behavior lifetimes radiative-emission intensities for <sup>4</sup>I<sub>11/2 </sub>and <sup>4</sup>I<sub>13/2</sub> energy levels.