A5081493778- Adaptive optics and wavefront sensing
- Spectroscopy and Laser Applications
- Optical Wireless Communication Technologies
- Astronomy and Astrophysical Research
- Atmospheric aerosols and clouds
- Advanced Optical Sensing Technologies
- Photonic Crystal and Fiber Optics
- Stellar, planetary, and galactic studies
- Analytical Chemistry and Sensors
- Atmospheric and Environmental Gas Dynamics
- Superconducting and THz Device Technology
- Radio Astronomy Observations and Technology
- Advanced Fiber Laser Technologies
- Advanced Fiber Optic Sensors
- Air Traffic Management and Optimization
- Augmented Reality Applications
- Semiconductor Lasers and Optical Devices
- Infrared Target Detection Methodologies
- Optical Network Technologies
- Optical Imaging and Spectroscopy Techniques
- Soil Moisture and Remote Sensing
- Glass properties and applications
- Galaxies: Formation, Evolution, Phenomena
- Water Quality Monitoring and Analysis
- Atmospheric Ozone and Climate
Johns Hopkins University Applied Physics Laboratory
2013-2024
SLAC National Accelerator Laboratory
2018-2023
National Trust
2023
Johns Hopkins University
2010-2022
K Lab (United States)
2021
Advisory Board Company (United States)
2020
Australian Astronomical Observatory
2014-2018
Macquarie University
2018
Rolls-Royce (United Kingdom)
1959-2016
Pennsylvania State University
1990-2014
We describe the newest generation of SLAC Microresonator RF (SMuRF) electronics, a warm digital control and readout system for microwave-frequency resonator-based cryogenic detector multiplexer systems, such as microwave superconducting quantum interference device multiplexers (μmux) or kinetic inductance detectors. Ultra-sensitive measurements in particle physics astronomy increasingly rely on large arrays sensors, which turn necessitate highly multiplexed accompanying room-temperature...
The next generation of cryogenic CMB and submillimeter cameras under development require densely instrumented sensor arrays to meet their science goals. readout large numbers (~10,000-100,000 per camera) sub-Kelvin sensors, for instance as proposed the CMB-S4 experiment, will substantial improvements in cold warm techniques. To reduce cost integration complexity, efforts are presently focused on achieving higher multiplexing density while maintaining noise subdominant intrinsic detector...
A supercontinuum source has been proposed as a new tool for measurement of minor species concentrations on long paths through the atmosphere. The present work describes results from recent experiments that demonstrate potential Differential Absorption Spectroscopy (DAS) and Spectral Pattern Recognition Lidar (SPR-DIAL) measurements utilizing source. As an initial example this approach, include quantification water vapor concentration indoor outdoor path absorption using collimated...
We propose a design for free space optical communications (FSOC) receiver terminal that offers an improved field of view (FOV) in comparison to conventional FSOC receivers. The utilizes microlens couple the incident signal into individual fiber bundle routed remote detectors. Each collects power from solid angle space; utilizing multiple fibers enhances total FOV over typical single-fiber designs. microlens-to-fiber-bundle is scalable and modular can be replicated array increase aperture...
TAIPAN is a spectroscopic instrument designed for the UK Schmidt Telescope at Australian Astronomical Observatory. In addition to undertaking survey, it will serve as prototype MANIFEST fibre positioner system future Giant Magellan Telescope. The design incorporates up 300 optical fibres situated within independently-controlled robotic positioners known Starbugs, allowing precise parallel positioning of every fibre, thus significantly reducing configuration time and increasing observing...
Hector<sup>[1,2,3]</sup> will be the new massively-multiplexed integral field spectroscopy (IFS) instrument for Anglo-Australian Telescope (AAT) in Australia and next main dark-time observatory. Based on success of SAMI instrument, which is undertaking a 3400-galaxy survey, unit (IFU) imaging fibre bundle (hexabundle) technology under-pinning being improved to innovative design Hector. The distribution hexabundle angular sizes matched galaxy survey properties order image 90% galaxies out 2...
We study the transverse mode instability (TMI) in limit where a single higher-order (HOM) is present. demonstrate that when beat length between fundamental and HOM small compared to scales on which pump amplitude optical amplitudes vary, TMI three-wave mixing process two modes with phase-matched component of index refraction induced by thermal grating. This usual applications, this identified as stimulated Rayleigh scattering (STRS) process. model based equations can have large computational...
The concentration of atmospheric oxygen is measured over a 540-m path using supercontinuum absorption spectroscopy. data compared favorably with MODTRAN™ 5 simulations the spectra after adjusting for differences index refraction air and matching instrument spectral resolution, as described by effective slit width. Good agreement expected obtained previously developed multiwavelength maximum likelihood estimation inversion algorithm. This study demonstrates use SAS technique measuring...
Historical data on co-occurring taxa are extremely rare. As such, the extent to which distinct experience similar long-term patterns in species richness and compositional change (e.g., when exposed a changing environment) is not clear. Using from diverse ecological community surveyed 1930s resurveyed 2010s, we investigated whether local plant insect assemblages displayed cross-taxon congruence-that is, spatiotemporal correlation change-across six taxa: vascular plants, non-vascular...
An airborne DIfferential Absorption Lidar (DIAL) system was used to detect methane, propane, and light crude gas vapors during real-world collections. A series of overflights were conducted at two separate test locations (Kingsville/Corpus Christi, TX Spencerport, NY). DIAL, digital orthophotography, video data collected, processed analyzed both sites. new Hydrocarbon Detection Algorithm (HHDA) developed gasses other than methane. The HHDA shows promise for detecting multiple species in a...
MANIFEST is a fibre feed system for the Giant Magellan Telescope that, coupled to seeing-limited instruments GMACS and G-CLEF, offers qualitative quantitative gains over each instrument's native capabilities in terms of multiplex, field view, resolution. The instrument concept based on semi-autonomous probes called "Starbugs" that hold position hundreds optical IFUs under glass plate placed at GMT Cassegrain focal plane. Starbug feature co-axial piezoceramic tubes via application appropriate...
A series of head-tracking, see-through, head-mounted display prototypes were developed and evaluated by five controllers at Moffett Field air traffic control tower. The controller cadre identified several deficiencies in the initial prototype, such as low optical transmissivity display, unacceptable compensation for tower lighting conditions, inadequate symbology data block information discomfort caused wearing head-worn displays. Though found prototype too immature operational use, they...
A laser differential image-motion monitor (DIMM) system was designed and constructed as part of a turbulence characterization suite during the DARPA free-space optical experimental network experiment (FOENEX) program. The developed link measurement measures atmospheric coherence length (r0), scintillation, power in bucket for 1550 nm band. DIMM measurements are made with two separate apertures coupled to single InGaAs camera. angle arrival (AoA) wavefront at each aperture can be calculated...
Vertically aligned carbon nanotube (VACNT) arrays have been reported to be the ``blackest'' material fabricated date. They also a thermal conductivity parallel VACNT axis that is much larger than their perpendicular axis. Even so, because of large length-to-radius ratio, they can assumed same temperature in any cross section tube Consequently, pulsed-laser irradiated array candidate produce fast emissions from face grown on high substrate. This represented as one-dimensional problem, where...
MANIFEST is a facility multi-object fibre system for the Giant Magellan Telescope, which uses 'Starbug' positioning robots. MANIFEST, when coupled to telescope's planned seeing-limited instruments, GMACS, and G-CLEF, offers access to: larger fields of view; higher multiplex gains; versatile reformatting focal plane via IFUs; image-slicers; in some cases spatial spectral resolution. The Prototyping Design Study phase nearing completion, has focused on developing working prototype Starbugs...
We present a scalar, time-dependent, plane-wave model for stimulated Brillouin scattering (SBS) within fiber amplifier having seed linewidth comparable to, or greater than, the frequency shift. The broadband introduces existence of backward anti-Stokes wave, in addition to Stokes wave narrowband model. also incorporates Fresnel reflection at exit face. In absence reflections, SBS threshold increases linearly with linewidth, up linewidths least three times presence reflections that...
A series of experiments were conducted to validate the performance free-space optical communications (FSOC) subsystem under DARPA's FOENEX program. Over six days, bidirectional links at ranges 10 and 17 km characterized during different periods day evaluate link performance. This paper will present test configuration, FSOC against a variety characterization approaches, discuss impact results, particularly with regards terminals. Finally, this summarize turbulence conditions on methods for...
Starbugs are miniature piezoelectric 'walking' robots that can be operated in parallel to position many payloads (e.g.optical fibres) across a telescope's focal plane.They consist of two concentric piezo-ceramic tubes walk with micron step size.In addition individual optical fibres, have moved payload 0.75kg at several millimetres per second.The Australian Astronomical Observatory previously developed prototype devices and tested them the laboratory.Now we optimising Starbug design for...
TAIPAN will conduct a stellar and galaxy survey of the Southern sky. The positioner is being developed as prototype for MANIFEST instrument on GMT. design incorporates 150 optical fibres (with an upgrade path to 300) situated within independently controlled robotic positioners known Starbugs. Starbugs allow precise parallel positioning individual fibres, thus significantly reducing configuration time increasing amount observing time. Presented engineering overview UKST completely new...
Augmented reality technology adapted for air traffic control tower applications was used to track an OH-58C helicopter in proximity airport. A camera and 'see-through' display system measure the registration error of static airport features dynamic test aircraft. The observed errors aircraft were largely attributable two terms error: 1) surveillance transport latency, 2) (from all sources) environment. Compensating objects modeling movement reduces (aircraft) ≤2° aircraft-surveillance...
This paper presents the first, to our knowledge, direct measurement of aerosol produced by an aluminized solid rocket propellant (SRP) fire on ground. Such fires produce aluminum oxide particles small enough loft high into atmosphere and disperse over a wide area. These results can be applied spacecraft launchpad accidents that expose such fires; during these fires, there is concern some plutonium from power system will carried with aerosols. Accident-related lofting this material would net...
A multi-wavelength, multi-static lidar has been designed and is being tested for the characterization of atmospheric aerosols. This design builds upon lidar, multiple scattering analyses, supercontinuum DIAL experiments that have previously developed at Penn State University. Scattering measurements two polarizations are recorded over a range angles using CCD imagers. Measurements made three discrete visible wavelength lasers as sources, or source with spanning near-IR wavelengths. The...
A gimbal-free wide field-of-regard (FOR) optical receiver has been built in a laboratory setting for proof-of-concept testing. Multiple datasets are presented that examine the overall FOR of system and receiver's ability to track collect signal from moving source. The design is not intended compete with traditional free space communication systems, but rather offer an alternative minimizes number complexity mechanical components required at surface small mobile platform. composed micro-lens...