A5101725435- Photonic and Optical Devices
- Photorefractive and Nonlinear Optics
- Advanced Fiber Laser Technologies
- Semiconductor Lasers and Optical Devices
- Optical and Acousto-Optic Technologies
- Photonic Crystals and Applications
- Sports injuries and prevention
- Plasmonic and Surface Plasmon Research
- Optical Coatings and Gratings
- Advanced Fiber Optic Sensors
- Chalcogenide Semiconductor Thin Films
- Surface and Thin Film Phenomena
- 2D Materials and Applications
- Mechanical and Optical Resonators
- Sports Performance and Training
- Solid State Laser Technologies
- Nonlinear Photonic Systems
- Strong Light-Matter Interactions
- Advanced Electron Microscopy Techniques and Applications
- Human-Automation Interaction and Safety
- Tendon Structure and Treatment
- Traffic and Road Safety
- Nonlinear Waves and Solitons
- Quantum optics and atomic interactions
- Sleep and Work-Related Fatigue
George Fox University
2025
Azusa Pacific University
2023-2025
KBR (United States)
2023-2024
United States Air Force Research Laboratory
2023-2024
Wright-Patterson Air Force Base
2024
West Coast University
2023
University of Arizona
2019-2022
Stanford University
2012
HRL Laboratories (United States)
1995-2005
Pacific Institute For Research and Evaluation
2005
Abstract Interlayer excitons (IXs) in MoSe 2 –WSe heterobilayers have generated interest as highly tunable light emitters transition metal dichalcogenide (TMD) heterostructures. Previous reports of spectrally narrow (<1 meV) photoluminescence (PL) emission lines at low temperature been attributed to IXs localized by the moiré potential between TMD layers. We show that IX PL are present even when is suppressed inserting a bilayer hexagonal boron nitride (hBN) spacer compare doping,...
A superior lamellae etching drop-off technique is described for the preparation of W tips without use CCl4. Sharp with an apex 25 nm or less can be produced routinely. In case Pt/Ir wire, chemical inertness material means that it has to reduced in diameter before being etched yield a tip. order accomplish this, capillary reduction also been developed combination technique. The apparatus does not require micromanipulators micromovers. shapes apexes as small investigated by scanning electron...
Indium selenide (InSe) multilayers have attracted much interest recently due to their electronic and optical properties, partially dependent on the existence of an indirect-to-direct bandgap transition that is correlated multilayer thickness. In this work, we investigate stacks van der Waals-bonded InSe, ordered similarly γ phase bulk InSe. We analyze using first-principles methods, identifying structural changes in structures cause modifications result transition. highlight differences...
A plasmonic modulator is a device that controls the amplitude or phase of propagating plasmons. In pure modulator, presence absence pump wave probe through channel. This control has to be mediated by an interaction between disparate waves, typically requiring integration nonlinear material. this work, we demonstrate first 2D semiconductor based on WSe2 monolayer integrated top lithographically defined metallic waveguide. We utilize strong coupling surface plasmon polaritons, SPPs, and...
Achilles tendinopathy (AT) is the most common running-related pathology among masters runners. Previous evidence suggests there are no differences in submaximal running biomechanics between runners with and without AT. Evidence lower extremity power deficits ageing individuals those The single-leg horizontal hop (SLHH) test a valid reliable test. purpose of this study was to investigate SLHH 32 age 50 older AT (60.31 ± 8.37, n = 16) (59.94 4.95 were included. 3D motion capture force plates...
Spectrally narrow optical resonances can be used to generate slow light, i.e., a large reduction in the group velocity. In previous work, we developed hybrid 2D semiconductor plasmonic structures, which consist of propagating frequency surface-plasmon polaritons interacting with excitons monolayer. Here, use coupled exciton-surface plasmon (E-SPPs) monolayer WSe2 demonstrate light 1300 fold decrease SPP Specifically, high resolution two-color laser technique where nonlinear E-SPP response...
We describe an experiment in superconductivity suitable for advanced undergraduate laboratory. Point-contact spectroscopy is performed by measuring the differential conductance between electrochemically etched gold tip and a 100-nm superconducting niobium film with transition temperature Tc ~= 7 K. By fitting results to Blonder-Tinkham-Klapwijk theory using finite lifetime of quasiparticles, we obtain gap energy \delta 1.53 meV, lower bound Fermi velocity vF >= 3.1 x 10^-7 cm/s, BCS...
Among the recent emerging flat display technologies organic LED (OLED) is one of most interesting. Combining OLED with an active matrix substrate, typically made low temperature polysilicon, it possible to greatly reduce power consumption. In substrate ability integrating components can be used mitigate differential degradation.
Objective: To estimate the impact of employee alcohol and drug use on crashes in transit industry from 1995–2000. Design: Secondary analysis federally mandated post crash random testing results. Setting: The US industry. Subjects: Transit employees. Main outcome measures: Relative risk (RR), population attributable (PAR), percentage (PAR%). Results: For testing, estimated PAR% ranged 0.02% (1999) to 0.03% (1995). 0.38% (1998) 0.67% (1997). Based these calculations, number per 1000 was less...
Waveguide gratings with structured period provide controllable ratio between coupling coefficients in different diffraction orders and allow for control of resonant reflection spectra. We report conceptual model, numerical studies, fabrication GaN waveguide designed the mid-IR spectral range.
Resonant cavity structures integrated with phase change material germanium antimony telluride (GST) function as angular insensitive mid-infrared optical filters. The one-dimensional (1D) sub-wavelength grating consisting of GST resonators embedded in metallic (Ag) film act Fabry-Perot observable transmission resonances, that can be tuned by thermal excitation when switches from amorphous to crystalline state, while maintaining insensitivity up 60 degrees. Modeling and experimental results an...
We report on the design and experimental verification of angle polarization insensitive mid-infrared filters based dense arrays dielectric resonators embedded into a metallic film. experimentally show with 60% peak transmission for angles from 0 to 60 degrees perpendicular states. also study surface plasmonic mode excited due periodicity micro-resonators in array. Simulations support results both primary resonance mode. Integrating these IR detectors offers multispectral imaging improved...
Extended abstract of a paper presented at Microscopy and Microanalysis 2008 in Albuquerque, New Mexico, USA, August 3 – 7,
Summary form only given. Laser-based ultrasound is a promising technique for remote ultrasonic inspection. One approach the measurement of small surface displacements uses dynamic holography in photorefractive material to combine distorted signal beam with plane-wave reference and match their wavefronts homodyne detection. Slow variations wavefront are compensated by real-time hologram thus do not produce noise or interfere quality overlap output beams.
Summary form only given. Photorefractive materials have attracted interest in the detection of phase modulated signals as transient hologram material can convert modulation into an amplitude modulation. Due to very nature hologram, principle also works for speckled beams, which enables operation with beams reflected from non-mirror-like surfaces. As adapt changes slower than response time, noise frequencies below time is rejected, leading better signal-to-noise ratios. These features make...
Summary form only given. Laser-based ultrasound is a promising NDE technique for remote sensing, manufacturing diagnostics, and in-service inspection. Nonadaptive homodyne heterodyne reference beam interferometers could not operate effectively with speckle, time-delay (such as the confocal Fabry-Perot) require path-length stabilization to fraction of an optical wavelength. We use dynamic holography in photorefractive quantum well, which acts adaptive splitter compensate wave-front...