A5009131918- CCD and CMOS Imaging Sensors
- Advanced Fluorescence Microscopy Techniques
- Integrated Circuits and Semiconductor Failure Analysis
- Optical Systems and Laser Technology
- Sparse and Compressive Sensing Techniques
- Ocular and Laser Science Research
- Quantum Information and Cryptography
- Photovoltaic System Optimization Techniques
- Advanced Measurement and Metrology Techniques
- Photonic and Optical Devices
- Conservation, Biodiversity, and Resource Management
- Advanced optical system design
- Adaptive optics and wavefront sensing
- Quantum Mechanics and Applications
- Fault Detection and Control Systems
- Optical measurement and interference techniques
- Quantum Computing Algorithms and Architecture
- Image Processing Techniques and Applications
- Advancements in Photolithography Techniques
- Near-Field Optical Microscopy
- Microwave and Dielectric Measurement Techniques
- Advanced X-ray Imaging Techniques
- Urban, Neighborhood, and Segregation Studies
- Photonic Crystal and Fiber Optics
- Advanced Electrical Measurement Techniques
National Physical Laboratory
2010-2025
Baylor University Medical Center
2020
National Wildlife Federation
2015-2018
North Carolina State University
1993-2011
Applied Photonics (United Kingdom)
2011
The University of Western Australia
1981
Zero-deforestation commitments are a type of voluntary sustainability initiative that companies adopt to signal their intention reduce or eliminate deforestation associated with commodities they produce, trade, and/or sell. Because each company defines its own zero-deforestation commitment goals and implementation mechanisms, content varies widely. This creates challenges for the assessment effectiveness. Here, we develop criteria assess potential effectiveness at reducing within supply...
Quasi-experimental methods increasingly are used to evaluate the impacts of conservation interventions by generating credible estimates counterfactual baselines. These generally require large samples for statistical comparisons, presenting a challenge evaluating innovative policies implemented within few pioneering jurisdictions. Single jurisdictions often studied using comparative methods, which rely on analysts' selection best case comparisons. The synthetic control method (SCM) offers one...
Abstract Quantum key distribution (QKD) provides in principle unconditional security of sharing based on the laws physics only. In last decade, several experimental and commercial QKD networks have been built operated worldwide. Demonstrational applications financial institutions, government networks, critical infrastructures such as power grid initially explored. However, large-scale deployment full-scale commercialization still faces some technological standardisation challenges. this...
Data on land use change and socioeconomic dynamics in developing countries are often collected via paper-and-pencil interviewing (PAPI). This article reviews a computer-aided personal (CAPI) methodology adopted for the fourth wave of panel survey administered remote region Brazilian Amazon 2009. Ruggedized touch-screen laptops were used to address challenges associated with administration this setting as well limitations PAPI method. The authors discuss hardware software considerations,...
In this paper we describe the wavefront aberrations that arise when imaging biological specimens using an optical sectioning microscope and generate simulated wavefronts for a planar refractive index mismatch. We then investigate capability of two deformable mirrors correcting spherical aberration at different focusing depths three objective lenses. Along with measurement analysis mirror influence functions determine optimum pupil size number spatial modes included in expansion present...
LED-based lamps that are currently on the market expensive due to complex packaging required dissipate heat generated. This also limits their performance and lifetime degradation of phosphor or individual LED chips, in case RGB sources. There is a strong commercial imperative develop situ technology measure ultimately compensate for thermal environment luminaire. Utilizing large Stoke's shift InGaN green blue emitting LEDs, emitter pump can induce photocurrent within devices which emit...
Understanding the performance and aging mechanisms in photovoltaic devices requires a spatial assessment of device properties. The current dominant technique, electroluminescence, has disadvantage that it assesses radiative recombination only. A complementary method, laser beam-induced (LBIC), is too slow for high-throughput measurements. This paper presents description, design, proof concept new measurement method to significantly accelerate LBIC allows mapping response map solar cells...
Abstract The detection of single photons plays an essential role in advancing single-photon science and technologies. Yet, within the visible/near-infrared spectral region, accurate fibre-based optical power measurements at few-photon level are not yet well-established. In this study, we report on a setup, enabling traceable region. setup was used to calibrate efficiency (DE) four avalanche diode (SPAD) detectors. relative standard uncertainties mean DE values obtained from repeat...
A new photovoltaic (PV) device current mapping method has been developed, combining the recently introduced compressed sensing (CS) sampling theory with light beam induced (LBIC) measurements. Instead of a raster scan, compressive is applied using digital micromirror device. The aim to significantly reduce time required produce map, compared conventional LBIC This achieved by acquiring fewer measurements than full scan and utilizing fast response modulate measurement conditions. implemented...
A previously unrecognized sinistral shear event recently has been identified in Silurian–Devonian rocks of the Millimagassett Lake region, north-central Maine, USA. This predates ‘classic’ Early-Mid-Devonian Acadian orogeny yet affects as young Early Devonian. The zone places significant time constraints on an early phase tectonics that may well extend throughout northern and Newfoundland Appalachians.
The Compressed Sensing (CS) sampling theory has been combined with the Light Beam Induced Current (LBIC) method, to produce an alternative current mapping technique for photovoltaic (PV) devices. Compressive of photocurrent is experimentally implemented using a Digital Micro-mirror Device (DMD). main advantage this new method that measurement time can be significantly reduced compared conventional LBIC systems. This achieved mainly by acquiring fewer measurements than raster scan would need...
We describe the characterization of a ferroelectric-liquid-crystal-on-silicon (FLCOS) spatial light modulator (SLM) in production holograms for use interferometric metrology. It has already been shown that such device can be used producing small-amplitude arbitrary reference surfaces with small but appreciable errors due to contaminating effect higher-order structures being propagated through filter. Here we further quantify size these residuals increasingly large aberrations up nine waves...
We have developed a multi-band ground viewing radiometer based on light-emitting diodes (LEDs) to create self-calibrating sensing system for land-based measurements. The is intended in-situ data collection needed vicarious calibration, using the reflectance-based method, earth observing satellites. An autonomous prototype radiometer, which part of sensor web 5 radiometers could be geographically distributed over hundreds meters, has been realized. Temporally continuous measurement land...
Light Beam Induced Current (LBIC) measurements are a useful tool in photovoltaic (PV) device characterisation for accessing the local electrical properties of PV devices. The main disadvantage typical LBIC system is measurement time, as raster scan silicon solar cell can last several hours. focus this paper reduction time by means compressed sensing (CS). CS-LBIC described theoretically reduce to less than 25% that required standard scan. Measurement simulations presented well practical...
Compressive sensing has been widely used in image compression and signal recovery techniques recent years; however, it received limited attention the field of optical measurement. This paper describes use compressive for measurements photovoltaic (PV) solar cells, using fully random matrices, rather than mapping an orthogonal basis set directly. Existing systems optically surface object under test, this contrasts with method described, where illumination patterns defined by precalculated...
Abstract Quantum grade interconnects, which includes quantum optical fibre links and Photonic Integrated Circuits (QPICs), are rapidly developing components central to the successful development of Internet Key Distribution (QKD). These interconnects will present new metrological challenges that need be addressed ensure key support future scientific industrial development. Potential solutions evolving alongside associated standardisation success reliability this advanced technology provide...
This paper reports an investigation into measurement techniques and infrastructure suitable for underpinning traceable calibration of devices beam propagation parameter measurement. The accurate knowledge the M2 is required a diverse range applications including semiconductor manufacture, process control, laser machining, thin-film transistors (TFT), fundamental research frequency doubling, production characterisation optical components. Characterisation size position waist essential correct...
Measurement of the laser beam propagation factor M<sup>2</sup> is essential in many applications including materials processing, therapy, and lithography. In this paper we describe characterisation a prototype device using cross-distorted diffraction grating known as an Image Multiplex (IMP<sup>(R)</sup>) grating, to measure value beams. The advantage IMP<sup>(R)</sup> instrument lies its ability simultaneously image nine positions along path. This enables parameters be calculated both for...
This paper describes the development of a versatile software platform for optical radiation safety based analysis today's generation spectrally broad light sources such as High Brightness emitting diode (HB-LED), intense pulsed lamp (IPL) and Supercontinuum laser. The is capable implementing broadband source hazard using two main international standards safety, namely IEC 60825 ('laser'and 62471 ('lamp) series standards, allows results both regimes to be compared with each other. Aside from...
The paper describes the characterization of “quantum-grade” interconnects using Mode Field Diameter as a figure merit. We discuss metrology needs for Quantum Network interconnects, supporting development commercially relevant traceable standards.