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The RDPLF was created in 1986 and collects the main data of peritoneal dialysis of French patients and of various French-speaking countries. The database is structured in several modules: a compulsory core module including a follow-up of comorbidities, assistance, infections, survival, transplantation, and optional modules following more specific aspects: nursing, catheter, anemia, nutrition, heart failure. In addition, since 2012 patients treated at home in hemodialysis are also followed. This article presents a summary of the main characteristics of patients in the RDPLF in 2018. It highlights important differences in practices and patient profiles between francophone countries. Daily low dialysate flow rate hemodialysis is predominant in the new centers and sometimes begins to appear as a transitional mode that allows home maintenance for patients who cannot continue on peritoneal dialysis.

In order to better study conventional and alternative divertor configurations, the TCV Tokamak was recently upgraded. In-vessel graphite baffles were installed in the TCV chamber to delimit a separate divertor chamber from the core that required enhanced diagnostic capabilities. To date, TCV’s Thomson scattering diagnostic provided electron temperature and density profiles of the hot core and the pedestal of the plasma with an array of 96 polychromators. To study the new divertor region, an upgrade added 20 new polychromators specifically to diagnose the plasma in the relatively cold divertor region. New 4-channel polychromators were designed to provide Te measurements down to ~1eV with ne~1.5x1019m-3. Interference filters of only 1.9nm FWHM were required to achieve this goal. Te and ne measurements from the TCV divertor region have been obtained for the first time. Specific diverted plasma discharges where the outer divertor leg is scanned in and out of the TS laser beam’s path are used to demonstrate the diagnostic’s new capabilities and potential with measurements of Te as low as 1.4eV obtained for electron densities of 2 x1018m-3. The system’s 16mm integration length along the laser line is providing, for the first time, Te and ne profiles with sufficient spatial resolution across the divertor legs to resolve the divertor plasma dynamics.

Imaging techniques based on time-correlated single photon counting (TCSPC), such as fluorescence lifetime imaging microscopy (FLIM), rely on fast single-photon detectors as well as timing electronics in the form of time-to-digital or time-to-analog converters. Conventional systems rely on stand-alone or small arrays (up to 32) of detectors and external timing and memory modules. We recently developed a fully integrated image sensor containing 32x32 pixels and fabricated in a 130 nm CMOS technology. The chip produces an overall data rate of 10Gb/s in terms of time-of-arrival measurements in each pixel. As opposed to conventional single detector FLIM systems, the present system can acquire a full image, albeit at low resolution, without the need of an optical scanning system. As a consequence the complexity of the optical setup is reduced and the acquisition speed is dramatically increased. We show the potential of this new technology by presenting high time resolution (119 ps) TCSPC-FLIM images of pollen grains with acquisition times as low as 69 ms. Furthermore, the low noise (similar to 100 Hz) and high photon detection probability (up to 35%) ensure a good photon economy over the visible spectrum. We believe that this technology will open the way to fast TCSPC-FLIM recordings of transient signals in the bio- and life sciences, such as in neuron signaling.

Several methods are tested to extract positional information from light distributions generated in a monolithic block of scintillator read out by an APD array.. The spatial resolution of photons impinging at 0 degrees and 20 degrees angle was studied in various regions of the block. The influence of the block thickness on the spatial resolution was also investigated as well as the effect of a black crystal coating. Finally the performances of detectors based on these continuous scintillator blocks are compared with a detector module based on an array of small scintillation crystals coupled individually to the pixels of the APD array.

In this paper, a measurement procedure to capture properly the electromagnetic fields generated by radiated transient interferences is described. Measuring this type of impulsive noise out of the measurements defined at the EMC standards is essential to acquire the main parameters of the interferences. In order to protect the digital communication systems against radiated transients, the essential measurement requirements, considering the transient characteristics and the communication system parameters, have been established. To accomplish with the requirements, a time-domain measuring procedure combining the sensitivity input stage of an EMI receiver and the capabilities of the oscilloscope for event detection and storage is developed. Moreover, a final postprocessing stage has been also defined to obtain the in-phase and quadrature components of the interference as well as the capability to find the APD diagram, which is a powerful tool to analyse the degradation produced to a communication system. Finally, a measurement of radiated transients considering the impact over a RFID system is performed to illustrate the results that can be achieved employing the developed methodology.

In this thesis we propose the use of photodiodes fabricated in planar technologies to address the detection problem in these applications. A number of solutions exist, optimized for these wavelengths, based on Germanium (Ge) and other III-V materials. In this thesis we focused on Ge thanks to its versatility and ease to use in the clean room. The main advantage of this material is in fact a good compatibility with Silicon and standard CMOS processes. Note that the proposed technology is not based on Silicon/Germanium (SiGe), whereby Ge is used to strain Si to achieve higher bandwidth in Si, not higher sensitivity. In our pure Ge approach, Ge is grafted onto Si (Ge-on-Si), achieving high responsivity at wavelengths of 900nm and higher. The proposed devices can operate in avalanche mode (avalanche photodiodes - APDs), and in Geiger mode (Geiger mode APDs (GAPDs) or single-photon avalanche diodes (SPADs)). To combine the advantages of Ge with single-photon sensitivity and excellent timing resolution of Si-based SPADs, this thesis proposes a new generation of SPADs, achieved in collaboration with Prof. Nanver at TUDelft, aimed at near-infrared range. The fabrication process of the Ge-on-Si SPAD approach, which we are investigating together with the TUDelft group, consists of a standard CMOS process combined with post-processing steps to grow Ge on top of a Si/SiO2 layer. In our study we have investigated the potential for a new generation of massively parallel, Ge-on-Si sensors fabricated in fully CMOS compatible technology. The objective was to address the next challenges of super-parallel pixel arrays, while exploiting the advantages of Ge substrate. The key technology developed in the thesis is a selective chemical-vapor deposition (CVD) epitaxial growth. A novel processing procedure was developed for the p+ Ge surface doping by a sequence of pure-Ga and pure-B depositions (PureGaB). The resulting p+n diodes have exceptionally good I-V characteristics with ideality factor of ~1.1 and low saturation currents. They can be operated both in proportional and in Geiger mode, and exhibit relatively low dark counts. We also looked at techniques to improve red and infrared sensitivity in conventional deep-submicron CMOS processes, by careful selection of standard layers at high depths in the Si substrate. Using the proposed approach, 12 µm-diameter SPADs were fabricated in 0.18µm CMOS technology showing low dark count rates (363 cps) at room temperature and considerably lower rates at cryogenic temperatures (77 K), while the FWHM timing jitter is as low as 76 ps. That of cryogenic SPADs is a novel research direction and in this thesis it was advocated as a significant trend for the future of optical sensing, especially in mid-infrared wavelengths. Low temperature characterizations reported in this thesis exposed how the relevant properties of fabrication materials, such as strength, thermal conductivity, ductility, and electrical resistance are changing. One of the most important properties is superconductivity in materials cooled to extreme temperatures: this is an important trend that will be pursued in the future activities of our group.

Among advanced electronic designs, vision systems are perhaps those that have undergone the most dramatic technological revolutions of the last decades. Recently, a new family of vision systems has emerged aimed at three-dimensional (3D) imaging. Many applications exist or will soon come to existence that can use 3D image sensors and the image sensor community is responding with conventional and unconventional solutions. This thesis presents a new concept for imaging and, in particular, for 3D imaging, based on single-photon detection. In our approach, single-photon detection is performed by a device known as single-photon avalanche diode (SPAD). Large arrays of SPADs were demonstrated for the first time in this thesis and time resolutions consistently in the picosecond range were achieved. It has thus become feasible to design solid-state 3D imagers with millimeter depth perception based on the time-of-flight principle. Initially, large arrays of SPAD devices and associated circuitry have been investigated in a 0.8µm CMOS technology. Extremely low-noise detectors were implemented in this technology. In arrays of 64x48 pixels, the median dark count rate was 0.5Hz per square micrometer of active area. For these devices, the maximum photon detection probability was 26% at 550nm optical wavelength. Subsequently, a technology migration of SPADs towards deep-submicron CMOS has been successfully achieved. For the first time, SPADs in 0.35µm and 0.13µm CMOS technologies were designed and characterized. Outstanding photon detection probabilities up to 35.4% and 34.5% have been measured in devices manufactured in 0.35µm and 0.13µm CMOS, respectively. Median dark count rate has increased with technology scaling. The median dark count rate over an array of 128x128 pixels was 18 Hz/µm2 in 0.35µm CMOS, whereas it was 385Hz/µm2 in 0.13µm CMOS for a single device. With the aim of enabling high-performance system-on-a-chip implementations using single-photon detectors, appropriate front-end and ancillary circuits utilized in the detection, measurement, and storage of time-of-flight evaluations have been introduced. For the first time, passive quenching circuits using a single MOS transistor were investigated. Based on the proposed biasing regime, the single MOS quenching circuit provides well defined dead time and leads to high pixel fill factor. Active recharge is achieved in this thesis by means of a new dual-threshold quenching and recharge circuit. This circuit allows the implementation of a hold-off time using low in-pixel transistor count, thus improving afterpulsing probability with little or no penalty in fill factor. 3D image sensors based on a pulsed detection technique known as time-correlated single-photon counting (TCSPC) have been investigated. Moreover, a technique has also been investigated for range imaging using SPADs that operate with continuously modulated optical signals. This technique, known as single-photon synchronous detection (SPSD), was invented in the course of this thesis and it is introduced here for the first time. In order to demonstrate the potential of TCSPC in solid-state 3D imaging, a complete theoretical and experimental investigation was conducted. An analytical model for the evaluation of ranging performance based on TCSPC was introduced. A fully-integrated TCSPC system for single-photon time-of-flight evaluation was implemented in CMOS, for the first time. Depth maps of 3D scenes were achieved at millimeter precisions using only 1mW of laser power and an integration time of 50ms. Thanks to SPAD technology, accurate distance measurements are now possible even with extremely low photon count rates of a few thousand per second. The maximum non-linearity in distance measurement was 9 millimeters over the full measurement range. Time-varying uncertainty (1σ) at the farthest distance was 5.2 millimeters. The SPSD approach has been theoretically and experimentally investigated. The design of the first fully-parallel implementation of a single-photon image sensor in CMOS has been introduced. The sensor has enabled the acquisition of real-time 3D images, based on CMOS SPADs, for the first time. A 3D camera prototype was designed and built based on the SPSD image sensor with a field-of-view of 50°. Experimental results showed that the SPSD rangefinder is effective. Distance measurement performance was characterized with a maximum non-linearity error of 11cm within a range of a few meters. In the same range, the maximum repeatability error was 3.8cm.

令和2年度