52 research outputs found
Stone Soup: No Longer Just an Appetiser
This paper announces version 1.0 of Stone Soup: the open-source tracking and state estimation framework. We highlight key elements of the framework and outline example applications and community activities.Stone Soup is engineered with modularity and encapsulation at its heart. This means that its many components can be put together in any number of ways to build, compare, and assure almost any type of multi-target tracking and fusion algorithm. Since its inception in 2017, it has aimed to provide the target tracking and state estimation community with an open, easy-to-deploy framework to develop and assess the performance of different types of trackers. Now, through repeated application in many use cases, implementation of a wide variety of algorithms, multiple beta releases, and contributions from the community, the framework has reached a stable point.In announcing this release, we hope to encourage additional adoption and further contributions to the toolkit. We also acknowledge and express appreciation for the many contributions of time and expertise donated by the tracking and fusion community
A Diamond Nanowire Single Photon Antenna
The development of a robust light source that emits one photon at a time is
an outstanding challenge in quantum science and technology. Here, at the
transition from many to single photon optical communication systems, fully
quantum mechanical effects may be utilized to achieve new capabilities, most
notably perfectly secure communication via quantum cryptography. Practical
implementations place stringent requirements on the device properties,
including stable photon generation, room temperature operation, and efficient
extraction of many photons. Single photon light emitting devices based on
fluorescent dye molecules, quantum dots, and carbon nanotube material systems
have all been explored, but none have simultaneously demonstrated all criteria.
Here, we describe the design, fabrication, and characterization of a bright
source of single photons consisting of an individual Nitrogen-vacancy color
center (NV center) in a diamond nanowire operating in ambient conditions. The
nanowire plays a positive role in increasing the number of single photons
collected from the NV center by an order of magnitude over devices based on
bulk diamond crystals, and allows operation at an order of magnitude lower
power levels. This result enables a new class of nanostructured diamond devices
for room temperature photonic and quantum information processing applications,
and will also impact fields as diverse as biological and chemical sensing,
opto-mechanics, and scanning-probe microscopy.Comment: 16 pages, 4 figures, v2: Includes improved reference list; modified
figure 1 to show a large array of NW and FDTD simulation of field profile;
direct experimental comparsion of several bulk/NW devices in figure
Diamond-based structures to collect and guide light
We examine some promising photonic structures for collecting and guiding light in bulk diamond. The aim of this work is to optimize single photon sources and single spin read-out from diamond color centers, specifically NV− centers. We review the modeling and fabrication (by focused ion beam and reactive ion etching) of solid immersion lenses, waveguides and photonic crystal cavities in monolithic diamond
Superconducting single photon detectors integrated with diamond nanophotonic circuits
Photonic quantum technologies promise to repeat the success of integrated
nanophotonic circuits in non-classical applications. Using linear optical
elements, quantum optical computations can be performed with integrated optical
circuits and thus allow for overcoming existing limitations in terms of
scalability. Besides passive optical devices for realizing photonic quantum
gates, active elements such as single photon sources and single photon
detectors are essential ingredients for future optical quantum circuits.
Material systems which allow for the monolithic integration of all components
are particularly attractive, including III-V semiconductors, silicon and also
diamond. Here we demonstrate nanophotonic integrated circuits made from high
quality polycrystalline diamond thin films in combination with on-chip single
photon detectors. Using superconducting nanowires coupled evanescently to
travelling waves we achieve high detection efficiencies up to 66 % combined
with low dark count rates and timing resolution of 190 ps. Our devices are
fully scalable and hold promise for functional diamond photonic quantum
devices.Comment: 28 pages, 5 figure
Diamond waveguides fabricated by reactive ion etching
We demonstrate for the first time the feasibility of all-diamond integrated optic devices over large areas using a combination of photolithography, reactive ion etching (RIE) and focused ion beam (FIB) techniques. We confirm the viability of this scalable process by demonstrating guidance in a two-moded ridge waveguide in type lb single crystal diamond. This opens the door to the fabrication of a diamond-based optical chip integrating functional elements such as X-crossings, Y-junctions, evanescent couplers, Bragg reflectors/couplers and various interferometers
Evaluation, Modification and Damage Tolerance of an In-service Aircraft Critical Area - ABSTRACT ONLY
Peer reviewed: YesNRC publication: Ye
Dynamics of bone mineralization in primiparous sows as a function of dietary phosphorus and calcium during lactation
To maximize the efficiency of dietary P utilization in swine production, understanding the mechanisms of P utilization in lactating sows is relevant due to their high P requirement and the resulting high inorganic P intake. Gaining a better knowledge of the Ca and P quantities that can be mobilized from bones during lactation, and subsequently replenished during the following gestation, would enable the development of more accurate P requirements incorporating this process of bone dynamics. The objective was to measure the amount of body mineral reserves mobilized during lactation, depending on dietary digestible P and phytase addition and to measure the amount recovered during the following gestation. Body composition of 24 primiparous sows was measured by dual-energy x-ray absorptiometry 2, 14, 26, 70 and 110 days after farrowing. Four lactation diets were formulated to cover nutritional requirements, with the exception of Ca and digestible P: 100% (Lact100; 9.9 g Ca and 3.0 g digestible P/kg), 75% (Lact75), 50% without added phytase (Lact50) and 50% with added phytase (Lact50 + FTU). The gestation diet was formulated to cover the nutritional requirements of Ca and digestible P (8.2 g Ca and 2.6 g digestible P/kg). During the 26 days of lactation, each sow mobilized body mineral reserves. The mean amount of mobilized bone mineral content (BMC) was 664 g, representing 240 g Ca and 113 g P. At weaning, the BMC (g/kg of BW) of Lact50 sows tended to be lower than Lact100 sows (−12.8%, linear Ca and P effect × quadratic time effect) while the BMC of Lact50 + FTU sows remained similar to that of Lact100 sows. During the following gestation, BMC returned to similar values among treatments. Therefore, the sows fed Lact50 could recover from the higher bone mineral mobilization that occurred during lactation. The P excretion was reduced by 40 and 43% in sows fed Lact50 and Lact50 + FTU, respectively, relative to sows fed Lact100. In conclusion, the quantified changes in body composition during the lactation and following gestation of primiparous sows show that bone mineral reserves were mobilized and recovered and that its degree was dependent on the dietary P content and from phytase supplementation during lactation. In the future, considering this potential of the sows’ bone mineralization dynamics within the factorial assessment of P requirement and considering the digestible P equivalency of microbial phytase could greatly limit the dietary use of inorganic phosphates and, thus, reduce P excretion
Progress towards achieving diamond waveguides
We report on the progress made towards achieving light guidance in long diamond waveguides (i.e. > mm) fabricated using a combination of photolithography, reactive ion etching (RIE), ion implantation and FIB techniques
CALCULATION OF ACTUATOR LOADS FOR FULL-SCALE AIRCRAFT FATIGUE TESTING - ABSTRACT ONLY
Peer reviewed: YesNRC publication: Ye
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