204 research outputs found
Various Applications of Methods and Elements of Adaptive Optics
This volume is focused on a wide range of topics, including adaptive optic components and tools, wavefront sensing, different control algorithms, astronomy, and propagation through turbulent and turbid media
Preliminary characterisation measurements of CERN picoTDC
In questa tesi sono presentate misure preliminari per valutare le prestazioni di un nuovo ASIC TDC sviluppato dal CERN (picoTDC) al fine di valutarne l'idoneità per l'implementazione all'interno del rilevatore TOF di ALICE. La parziale sostituzione dell'attuale HPTDC con il picoTDC comporterebbe, oltre al rinnovo dei componenti delle schede di lettura TDC sviluppate circa 20 anni fa, la semplificazione dell'architettura complessiva, consentendo l'integrazione di 64 canali per chip anziché gli 8 attuali dell'HPTDC. Per raggiungere questo obiettivo, sono stati eseguiti test mirati per valutare la risoluzione, la non linearità differenziale e la capacità di risposta ai segnali forniti dalla NINO FEA, la scheda di front-end del rivelatore TOF, del picoTDC.
Dopo una breve introduzione alle varie tipologie di Analog to Digital Converter (ADC) e Time to Digital Converter (TDC), vengono presentate l'architettura del picoTDC e la configurazione sperimentale utilizzata, seguite dall'illustrazione dell'attivitĂ di ricerca condotta in laboratorio. I dati ottenuti hanno evidenziato una buona risoluzione del dispositivo (inferiore a 5 ps) e una notevole compatibilitĂ con la scheda di front-end del rivelatore di ALICE. Tuttavia, i test sulla non linearitĂ differenziale hanno mostrato risultati ancora insoddisfacenti. Pertanto, per il futuro, sarĂ necessario svolgere ulteriori approfondimenti al fine di migliorare la configurazione del chip
A 3-step Low-latency Low-Power Multichannel Time-to-Digital Converter based on Time Residual Amplifier
This paper proposes and evaluates a novel architecture for a low-power
Time-to-Digital Converter with high resolution, optimized for both integration
in multichannel chips and high rate operation (40 Mconversion/s/channel). This
converter is based on a three-step architecture. The first step uses a counter
whereas the following ones are based on two kinds of Delay Line structures. A
programmable time amplifier is used between the second and third steps to reach
the final resolution of 24.4 ps in the standard mode of operation. The system
makes use of common continuously stabilized master blocks that control
trimmable slave blocks, in each channel, against the effects of global PVT
variations. Thanks to this structure, the power consumption of a channel is
considerably reduced when it does not process a hit, and limited to 2.2 mW when
it processes a hit. In the 130 nm CMOS technology used for the prototype, the
area of a TDC channel is only 0.051 mm2. This compactness combined with low
power consumption is a key advantage for integration in multi-channel front-end
chips. The performance of this new structure has been evaluated on prototype
chips. Measurements show excellent timing performance over a wide range of
operating temperatures (-40{\deg}C to 60{\deg}C) in agreement with our
expectations. For example, the measured timing integral nonlinearity is better
than 1 LSB (25 ps) and the overall timing precision is better than 21 ps RMS
Review of Particle Physics
The Review summarizes much of particle physics and cosmology. Using data from previous editions, plus 2,143
new measurements from 709 papers, we list, evaluate, and average measured properties of gauge bosons and the
recently discovered Higgs boson, leptons, quarks, mesons, and baryons. We summarize searches for hypothetical
particles such as supersymmetric particles, heavy bosons, axions, dark photons, etc. Particle properties and search
limits are listed in Summary Tables. We give numerous tables, figures, formulae, and reviews of topics such as Higgs
Boson Physics, Supersymmetry, Grand Unified Theories, Neutrino Mixing, Dark Energy, Dark Matter, Cosmology,
Particle Detectors, Colliders, Probability and Statistics. Among the 120 reviews are many that are new or heavily
revised, including a new review on Machine Learning, and one on Spectroscopy of Light Meson Resonances.
The Review is divided into two volumes. Volume 1 includes the Summary Tables and 97 review articles. Volume
2 consists of the Particle Listings and contains also 23 reviews that address specific aspects of the data presented
in the Listings.
The complete Review (both volumes) is published online on the website of the Particle Data Group (pdg.lbl.gov)
and in a journal. Volume 1 is available in print as the PDG Book. A Particle Physics Booklet with the Summary
Tables and essential tables, figures, and equations from selected review articles is available in print, as a web version
optimized for use on phones, and as an Android app.United States Department of Energy (DOE) DE-AC02-05CH11231government of Japan (Ministry of Education, Culture, Sports, Science and Technology)Istituto Nazionale di Fisica Nucleare (INFN)Physical Society of Japan (JPS)European Laboratory for Particle Physics (CERN)United States Department of Energy (DOE
Fast fluorescence lifetime imaging and sensing via deep learning
Error on title page â year of award is 2023.Fluorescence lifetime imaging microscopy (FLIM) has become a valuable tool in diverse disciplines. This thesis presents deep learning (DL) approaches to addressing two major challenges in FLIM: slow and complex data analysis and the high photon budget for precisely quantifying the fluorescence lifetimes. DL's ability to extract high-dimensional features from data has revolutionized optical and biomedical imaging analysis. This thesis contributes several novel DL FLIM algorithms that significantly expand FLIM's scope.
Firstly, a hardware-friendly pixel-wise DL algorithm is proposed for fast FLIM data analysis. The algorithm has a simple architecture yet can effectively resolve multi-exponential decay models. The calculation speed and accuracy outperform conventional methods significantly.
Secondly, a DL algorithm is proposed to improve FLIM image spatial resolution, obtaining high-resolution (HR) fluorescence lifetime images from low-resolution (LR) images. A computational framework is developed to generate large-scale semi-synthetic FLIM datasets to address the challenge of the lack of sufficient high-quality FLIM datasets. This algorithm offers a practical approach to obtaining HR FLIM images quickly for FLIM systems.
Thirdly, a DL algorithm is developed to analyze FLIM images with only a few photons per pixel, named Few-Photon Fluorescence Lifetime Imaging (FPFLI) algorithm. FPFLI uses spatial correlation and intensity information to robustly estimate the fluorescence lifetime images, pushing this photon budget to a record-low level of only a few photons per pixel.
Finally, a time-resolved flow cytometry (TRFC) system is developed by integrating an advanced CMOS single-photon avalanche diode (SPAD) array and a DL processor. The SPAD array, using a parallel light detection scheme, shows an excellent photon-counting throughput. A quantized convolutional neural network (QCNN) algorithm is designed and implemented on a field-programmable gate array as an embedded processor. The processor resolves fluorescence lifetimes against disturbing noise, showing unparalleled high accuracy, fast analysis speed, and low power consumption.Fluorescence lifetime imaging microscopy (FLIM) has become a valuable tool in diverse disciplines. This thesis presents deep learning (DL) approaches to addressing two major challenges in FLIM: slow and complex data analysis and the high photon budget for precisely quantifying the fluorescence lifetimes. DL's ability to extract high-dimensional features from data has revolutionized optical and biomedical imaging analysis. This thesis contributes several novel DL FLIM algorithms that significantly expand FLIM's scope.
Firstly, a hardware-friendly pixel-wise DL algorithm is proposed for fast FLIM data analysis. The algorithm has a simple architecture yet can effectively resolve multi-exponential decay models. The calculation speed and accuracy outperform conventional methods significantly.
Secondly, a DL algorithm is proposed to improve FLIM image spatial resolution, obtaining high-resolution (HR) fluorescence lifetime images from low-resolution (LR) images. A computational framework is developed to generate large-scale semi-synthetic FLIM datasets to address the challenge of the lack of sufficient high-quality FLIM datasets. This algorithm offers a practical approach to obtaining HR FLIM images quickly for FLIM systems.
Thirdly, a DL algorithm is developed to analyze FLIM images with only a few photons per pixel, named Few-Photon Fluorescence Lifetime Imaging (FPFLI) algorithm. FPFLI uses spatial correlation and intensity information to robustly estimate the fluorescence lifetime images, pushing this photon budget to a record-low level of only a few photons per pixel.
Finally, a time-resolved flow cytometry (TRFC) system is developed by integrating an advanced CMOS single-photon avalanche diode (SPAD) array and a DL processor. The SPAD array, using a parallel light detection scheme, shows an excellent photon-counting throughput. A quantized convolutional neural network (QCNN) algorithm is designed and implemented on a field-programmable gate array as an embedded processor. The processor resolves fluorescence lifetimes against disturbing noise, showing unparalleled high accuracy, fast analysis speed, and low power consumption
Development of high-performance quantum dot mode-locked optical frequency comb
This PhD thesis focus on the development of high-performance optical frequency combs (OFCs) generated by two-section passively mode-locked lasers (MLLs) based on novel optimised InAs quantum dot (QD) structures grown on GaAs substrates. Throughout the thesis, several important aspects are covered: the epitaxial structures, the device designs, the fabrication process, the characterisation of the fabricated laser devices and the evaluation of their performance.
To gain a deep level comprehension of the mode-locking mechanisms in two-section QD MLLs, a detailed study is presented on a series of QD MLLs with different saturable absorber (SA) to gain section length ratios (from 1: 3 to 1: 7) in either ridged-waveguide structure or tapered waveguide structure. The effect of temperature on different device configurations is experimentally examined. And the data transmission capability of the QD MLLs is systematically investigated in different scenarios.
In this thesis, an ultra-stable 25.5 GHz QD mode-locked OFC source emitted solely from the QD ground state from 20 °C to a world record 120 °C with only 0.07 GHz tone spacing variation has been demonstrated. Meanwhile, a passively QD MLL with 100 GHz fundamental repetition rate is developed for the first time, enabling 128 Gbit sâ1 λâ1 PAM4 optical transmission and 64 Gbit sâ1 λâ1 NRZ optical transmission through 5-km SSMF and 2-m free-space, respectively. All of the studies aim to prove that our two-section passively InAs QD MLLs can be used as simple, compact, easy-to-operate, and power-efficient multi-wavelength OFC sources for future high-speed and large-capacity optical communications
European Strategy for Particle Physics -- Accelerator R&D Roadmap
The 2020 update of the European Strategy for Particle Physics emphasised the
importance of an intensified and well-coordinated programme of accelerator R&D,
supporting the design and delivery of future particle accelerators in a timely,
affordable and sustainable way. This report sets out a roadmap for European
accelerator R&D for the next five to ten years, covering five topical areas
identified in the Strategy update. The R&D objectives include: improvement of
the performance and cost-performance of magnet and radio-frequency acceleration
systems; investigations of the potential of laser / plasma acceleration and
energy-recovery linac techniques; and development of new concepts for muon
beams and muon colliders. The goal of the roadmap is to document the collective
view of the field on the next steps for the R&D programme, and to provide the
evidence base to support subsequent decisions on prioritisation, resourcing and
implementation.Comment: 270 pages, 58 figures. Editor: N. Mounet. LDG chair: D. Newbold.
Panel chairs: P. V\'edrine (HFM), S. Bousson (RF), R. Assmann (plasma), D.
Schulte (muon), M. Klein (ERL). Panel editors: B. Baudouy (HFM), L. Bottura
(HFM), S. Bousson (RF), G. Burt (RF), R. Assmann (plasma), E. Gschwendtner
(plasma), R. Ischebeck (plasma), C. Rogers (muon), D. Schulte (muon), M.
Klein (ERL
Manufacturing Metrology
Metrology is the science of measurement, which can be divided into three overlapping activities: (1) the definition of units of measurement, (2) the realization of units of measurement, and (3) the traceability of measurement units. Manufacturing metrology originally implicates the measurement of components and inputs for a manufacturing process to assure they are within specification requirements. It can also be extended to indicate the performance measurement of manufacturing equipment. This Special Issue covers papers revealing novel measurement methodologies and instrumentations for manufacturing metrology from the conventional industry to the frontier of the advanced hi-tech industry. Twenty-five papers are included in this Special Issue. These published papers can be categorized into four main groups, as follows: Length measurement: covering new designs, from micro/nanogap measurement with laser triangulation sensors and laser interferometers to very-long-distance, newly developed mode-locked femtosecond lasers. Surface profile and form measurements: covering technologies with new confocal sensors and imagine sensors: in situ and on-machine measurements. Angle measurements: these include a new 2D precision level design, a review of angle measurement with mode-locked femtosecond lasers, and multi-axis machine tool squareness measurement. Other laboratory systems: these include a water cooling temperature control system and a computer-aided inspection framework for CMM performance evaluation
Recent advances on time-stretch dispersive Fourier transform and its applications
The need to measure high repetition rate ultrafast processes cuts across multiple areas of science. The last decade has seen tremendous advances in the development and application of new techniques in this field, as well as many breakthrough achievements analyzing non-repetitive optical phenomena. Several approaches now provide convenient access to single-shot optical waveform characterization, including the dispersive Fourier transform (DFT) and time-lens techniques, which yield real-time ultrafast characterization in the spectral and temporal domains, respectively. These complementary approaches have already proven to be highly successful to gain insight into numerous optical phenomena including the emergence of extreme events and characterizing the complexity of laser evolution dynamics. However, beyond the study of these fundamental processes, real-time measurements have also been driven by particular applications ranging from spectroscopy to velocimetry, while shedding new light in areas spanning ultrafast imaging, metrology or even quantum science. Here, we review a number of landmark results obtained using DFT-based technologies, including several recent advances and key selected applications. © 2022 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group
Fast-Gated 16 x 16 SPAD Array With 16 on-Chip 6 ps Time-to-Digital Converters for Non-Line-of-Sight Imaging
We present the design and characterization of a fully-integrated array of 16 x 16 Single-Photon Avalanche Diodes (SPADs) with fast-gating capabilities and 16 on-chip 6 ps time-to-digital converters, which has been embedded in a compact imaging module. Such sensor has been developed for Non-Line-Of-Sight imaging applications, which require: i) a narrow instrument response function, for a centimeter-accurate single-shot precision; ii) fast-gated SPADs, for time-filtering of directly reflected photons; iii) high photon detection probability, for acquiring faint signals undergoing multiple scattering events. Thanks to a novel multiple differential SPAD-SPAD sensing approach, SPAD detectors can be swiftly activated in less than 500 ps and the full-width at half maximum of the instrument response function is always less than 75 ps (60 ps on average). Temporal responses are consistently uniform throughout the gate window, showing just few picoseconds of time dispersion when 30 ns gate pulses are applied, while the differential non-linearity is as low as 250 fs. With a photon detection probability peak of 70% at 490 nm, a fill-factor of 9.6% and up to 1.6 . 10(8) photon time-tagging measurements per second, such sensor fulfills the demand for fully-integrated imaging solutions optimized for non-line-of-sight imaging applications, enabling to cut exposure times while also optimizing size, weight, power and cost, thus paving the way for further scaled architectures
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