- 标题
- 摘要
- 关键词
- 实验方案
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Modeling and Readout of Quantum Dots Photodetector
摘要： In this article, an equivalent modeling approach of quantum dots (QDs) photodetector is proposed and simple model has been constructed. Experimental results show that the simulation curves and parameters agree very well with the test results. This equivalent circuit model can be simulated using the Specter tool of Cadence platform as a signal source for readout circuit design. In order to explore its higher sensitive application, readout circuits are designed to detect the weak photocurrent and turn to voltage response. In addition, a high sensitivity mico-spectrometer based on the QDs photodetector array has been designed. Based on the QDs micro-spectrometer and Olympus microscope, the skin transmittance spectra of rat have been studied.
关键词： Equivalent circuit model,micro-spectrometer,readout circuit
更新于2025-09-12 10:27:22
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Photothermal Microfluidic Sensing Platform Using Near-Infrared Laser-Driven Multiplexed Dual-Mode Visual Quantitative Readout
摘要： The application of different sensing principles in microfluidic devices opens up further possibilities for the development of point-of-care testing (POCT). Herein, the photothermal sensing principle is introduced in microfluidic paper-based analytical devices (μPADs) to develop a photothermal microfluidic sensing platform using near-infrared (NIR) laser-driven multiplexed dual-mode visual quantitative readout. Prussian blue (PB) as the analyte-associated photothermal agent was in-situ synthesized in thermoresponsive poly(N-isopropylacrylamide) hydrogels to serve as the on-chip photothermal sensing element. NIR laser-driven photothermal effect of PB triggered not only on-chip dose-dependent heat generation but also phase transition-induced dye release from the hydrogels, simultaneously enabling both thermal image- and distance-based dual-mode visual quantitative readout of the analyte concentration in a multiplexed manner. Both the on-chip temperature elevation value of the hydrogels and the traveling distance of released dye solutions were proportional to the concentration of PB. Using the detection of silver ions in environmental water as a proof-of-concept study, the photothermal μPAD can detect silver ions at a concentration as low as 0.25 μM with high selectivity and satisfactory accuracy. The photothermal microfluidic sensing platform holds great potential for POCT with promising integratability and broad applicability, owing to the combination of synergistic advantages of the photothermal sensing principle, μPADs and photothermally responsive hydrogels.
关键词： Microfluidic device,Photothermal effect,Visual readout,Point-of-care testing,Thermoresponsive hydrogel
更新于2025-09-11 14:15:04
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readout chip
摘要： In order to solve the leakage current saturation of Topmetal-???? ? and to maintain its low noise, Topmetal-?????? has been designed. The new chip has the same Rolling-Shutter module as Topmetal-???? ?. It contains a charge-collection electrode and a metal layer surrounding it, called guard ring. This new design contains three different sections. Section A has the same structure as Topmetal-???? ?, in that the electrode is exposed and guard ring is covered by insulating layer. Section B has both electrode and guard ring exposed. Section C has guard ring exposed but electrode covered by insulating layer. Preliminary experiments show that if coupled with CdZnTe detector, Section C of the Topmetal-?????? chip is capable of solving the leakage current saturation. Meanwhile, the electrode receives induced signal. Moreover, the charge induction efficiency is influenced by several parameters, such as thickness of adhesive epoxy resin, collecting electrode size, etc. Thus, the optimization of parameters for induction efficiency is studied by simulations. According to the simulation results, it can be concluded that thinner epoxy resin thickness and bigger anode size contribute to higher induction efficiency.
关键词： Leakage current,CdZnTe,Induced signal simulation,Topmetal,Low noise readout chip,Pixel
更新于2025-09-10 09:29:36
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An Advanced 100-Channel Readout System for Nuclear Imaging
摘要： Reading out from large-scale silicon photomultiplier (SiPM) arrays is a fundamental technical obstacle blocking the application of revolutionary SiPM technologies in nuclear imaging systems. Typically, it requires using dedicated application-specific integrated circuits (ASICs) that need a long iterative process, special expertise, and tools to develop. The pico-positron emission tomography (Pico-PET) electronics system is an advanced 100-channel readout system based on 1-bit sigma–delta modulation and a field-programmable gate array (FPGA). It is compact (6 × 6 × 0.8 cm3 in size), consumes little power (less than 3W), and is constructed with off-the-shelf low-cost components. In experimental studies, the Pico-PET system demonstrates excellent and consistent performance. In addition, it has some unique features that are essential for nuclear imaging systems, such as its ability to measure V–I curves, breakdown voltages, and the dark currents of 100 SiPMs accurately, simultaneously, and in real time. The flexibility afforded by FPGAs allows multiple-channel clustering and intelligent triggering for different detector designs. These highly sought-after features are not offered by any other ASICs and electronics systems developed for nuclear imaging. We conclude that the Pico-PET electronics system provides a practical solution to the long-standing bottleneck problem that has limited the development of potentially advanced nuclear imaging technology using SiPMs.
关键词： silicon photomultiplier (SiPM),readout electronics,Field-programmable gate array (FPGA),nuclear imaging,sigma–delta modulation
更新于2025-09-10 09:29:36
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Towards the large area HVCMOS demonstrator for ATLAS ITk
摘要： High Voltage CMOS (HVCMOS) sensor is a proposed cost effective alternative to the existing hybrid sensors in ATLAS ITk pixel barrel for outer layers. To prove the feasibility of HVCMOS sensors in ATLAS experiment, a large area demonstrator chip is being designed. This work presents the design details of three HVCMOS sensor chips with an overview of the measurement results of ATLASpix1 which is the first large area (1cm×2cm) prototype in 0.18μm process.
关键词： CLIC,ATLAS,Large fill factor,triggered readout,monolithic pixel detector,pixel grouping,HVCMOS,ATLASpix
更新于2025-09-10 09:29:36
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Evaluation of the readout electronics based on the center of gravity method for position sensitive radiation detection
摘要： In the application of position sensitive radiation detection, the center of gravity method is often used to obtain better spatial resolution. In order to obtain the resolution degradation caused by the readout electronics, an evaluation method is put forward in this paper. The principle of the method is to simulate the signal distribution on sense wires of the MWPC (Multiwire Proportional Chamber) detector. The evaluation software quantizes the simulated data and drives the digital to analog converter to generate test signals. The readout electronics is evaluated with these stimulus signals according to the readout scale. An evaluation board based on this method is implemented. Tests are carried out in the laboratory to evaluate a readout circuit for the MWPC detector. The position resolution contributed by the electronics is better than 15 μm when the swtiching frenquency of the switch array is 12.5 MHz. The test results proved that the evaluation method is correct and practical. It can greatly simplify the evaluation of the readout electronics.
关键词： position sensitive radiation detection,center of gravity method,MWPC detector,spatial resolution,readout electronics
更新于2025-09-10 09:29:36
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Single-Shot Single-Gate rf Spin Readout in Silicon
摘要： For solid-state spin qubits, single-gate rf readout can minimize the number of gates required for scale-up since the readout sensor can integrate into the existing gates used to manipulate the qubits. However, state-of-the-art topological error correction codes benefit from the ability to resolve the qubit state within a single shot, that is, without repeated measurements. Here, we demonstrate single-gate, single-shot readout of a singlet-triplet spin state in silicon, with an average readout fidelity of 82.9% at 3.3 kHz measurement bandwidth. We use this technique to measure a triplet T? to singlet S0 relaxation time of 0.62 ms in precision donor quantum dots in silicon. We also show that the use of rf readout does not impact the spin lifetimes (S0 to T? decay remained approximately 2 ms at zero detuning). This establishes single-gate sensing as a viable readout method for spin qubits.
关键词： single-gate rf readout,quantum dots,spin qubits,silicon,singlet-triplet spin state
更新于2025-09-09 09:28:46
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The carbon dots as colorimetric and fluorescent dual-readout probe for 2-nitrophenol and 4-nitrophenol detection
摘要： Herein, the fluorescent carbon dots (CDs) has been synthesized by hydrothermal method by using ethylene diamine tetraacetic acid (EDTA) as a raw materials. The prepared CDs exhibited bright blue fluorscence excited by 340 nm with the quantum yield as high as 52%. The CDs possess special fluorescence responses to 2-nitrophenol (2-NP) and 4-nitrophenol (4-NP), and the slump of fluorescence was demonstrated by CDs solution in the case of 2-nitrophenol and 4-nitrophenol existence. The detection limit of 2-NP and 4-NP was calculated at 77 nM and 60 nM, respectively. Meanwhile, the color response to 2-NP and 4-NP can be observed from achromatic solution to yellow by naked eye. All in all, the obtained CDs can be applied as fluorescence and colorimetric probe in environmental protection.
关键词： Carbon dots,Dual-readout probe,2-nitrophenol,4-nitrophenol,Detection
更新于2025-09-09 09:28:46
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A USB 3.0 readout system for Timepix3 detectors with on-board processing capabilities
摘要： Timepix3 is a high-speed hybrid pixel detector consisting of a 256 × 256 pixel matrix with a maximum data rate of up to 5.12 Gbps (80 MHit/s). The ASIC is equipped with eight data channels that are data driven and zero suppressed making it suitable for particle tracking and spectral imaging. In this paper, we present a USB 3.0-based programmable readout system with online pre-processing capabilities. USB 3.0 is present on all modern computers and can, under real-world conditions, achieve around 320 MB/s, which allows up to 40 MHit/s of raw pixel data. With on-line processing, the proposed readout system is capable of achieving higher transfer rate (approaching Timepix4) since only relevant information rather than raw data will be transmitted. The system is based on an Opal Kelly development board with a Spartan 6 FPGA providing a USB 3.0 interface between FPGA and PC via an FX3 chip. It connects to a CERN Timepix3 chipboard with standard VHDCI connector via a custom designed mezzanine card. The firmware is structured into blocks such as detector interface, USB interface and system control and an interface for data pre-processing. On the PC side, a Qt/C++ multi-platform software library is implemented to control the readout system, providing access to detector functions and handling high-speed USB 3.0 streaming of data from the detector. We demonstrate equalisation, calibration and data acquisition using a Cadmium Telluride sensor and optimise imaging data using simultaneous ToT (Time-over-Threshold) and ToA (Time-of-Arrival) information. The presented readout system is capable of other on-line processing such as analysis and classification of nuclear particles with current or larger FPGAs.
关键词： Front-end electronics for detector readout,Detector control systems,X-ray detectors,Data processing methods
更新于2025-09-09 09:28:46
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Optimal Imaging Parameters for Readout-segmented EPI of the Temporal Bone
摘要： Readout-segmented echo planar imaging (rs-EPI) is a form of multi-shot EPI. rs-EPI is affected less by susceptibility artifacts than single-shot EPI (ss-EPI), which is widely used for diffusion-weighted imaging, so rs-EPI is expected to produce less image distortion. In this study, we compared rs-EPI and conventional ss-EPI of the temporal bone region, which contains abundant amounts of air and frequently exhibits changes in magnetic susceptibility. In addition, we used a phantom to determine the optimum rs-EPI acquisition conditions for clinical use and investigated the clinical utility of rs-EPI in 20 patients (8 men, 12 women, mean age, 54.3 ? 16.7-years-old) with cholesteatoma (mean apparent diffusion coef?cient on ss-EPI, 0.88 ? 1013 ? 0.18 mm2/s). The images of the temporal bone region produced using rs-EPI exhibited less distortion than those obtained with ss-EPI (P < 0.05).
关键词： readout-segmented EPI (rs-EPI),temporal bone region,single-shot EPI (ss-EPI),distortion,susceptibility
更新于2025-09-04 15:30:14