arXiv subjects

Ge Jin

Publications and source records attributed to Ge Jin.

At least 55 records · Page 3Linked to original sources

arXiv2018

Miniaturized high-frequency sine wave gating InGaAs/InP single-photon detector

High-frequency gating InGaAs/InP single-photon detectors (SPDs) are widely used for applications requiring single-photon detection in the near-infrared region such as quantum key distribution. Reducing SPD size is highly desired for practical use, which is favorable to the implementation of further system integration. Here we present, to the best of our knowledge, the most compact high-frequency sine wave gating (SWG) InGaAs/InP SPD. We design and fabricate an InGaAs/InP single-photon avalanche diode (SPAD) with optimized semiconductor structure, and then encapsulate the SPAD chip and a mini-thermoelectric cooler inside a butterfly package with a size of 12.5 mm $\times$ 22 mm $\times$ 10 mm. Moreover, we implement a monolithic readout circuit for the SWG SPD in order to replace the quenching electronics that is previously designed with board-level integration. Finally, the components of SPAD, monolithic readout circuit and the affiliated circuits are integrated into a single module with a size of 13 cm $\times$ 8 cm $\times$ 4 cm. Compared with the 1.25 GHz SWG InGaAs/InP SPD module (25 cm $\times$ 10 cm $\times$ 33 cm) designed in 2012, the volume of our miniaturized SPD is reduced by 95\%. After the characterization, the SPD exhibits excellent performance with a photon detection efficiency of 30\%, a dark count rate of 2.0 kcps and an afterpulse probability of 8.8\% under the conditions of 1.25 GHz gating rate, 100 ns hold-off time and 243 K. Also, we perform the stability test over one week, and the results show the high reliability of the miniaturized SPD module.

physics.ins-det↗

arXiv2018

An sTGC Prototype Readout System for ATLAS New-Small-Wheel Upgrade

This paper presents a readout system designed for testing the prototype of Small-Strip Thin Gap Chamber (sTGC), which is one of the main detector technologies used for ATLAS New-Small-Wheel Upgrade. This readout system aims at testing one full-size sTGC quadruplet with cosmic muon triggers.

physics.ins-det↗

arXiv2018

The Study of Multi-Layer sTGC Test System for ATLAS Phase-I upgrade

A completely New Small Wheel (NSW) will be constructed for ATLAS Phase-1 upgrade. Small-Strip Thin-Gap-Chamber (sTGC) will devote to the trigger function of NSW. A full-size sTGC quadruplet consists of 4 layers, and will need 4 pad Front-End-Boards and 4 strip Front-End-Boards for sTGC signals readout. The 8 boards should be readout simultaneously at a time. This paper presents the study of multi-layer sTGC test system, a FEB Driver Card (FEBDC) is designed for pFEB and sFEB boards handling. The design and test of FEBDC are described in details.

physics.ins-det↗

arXiv2018

A low power DAQ system with high-speed storage for submersible buoy

Submersible Buoy (SB) is an important apparatus capable of long-term, fixed-point, continuous and multi-directional measurement of acoustic signals and hydrological environment monitoring in the harsh marine environment, providing important information for hydrological environment research, marine organism research and protection. We will describe a real-time data acquisition (DAQ) system with multiple designs to meet low-power consumption and high-speed data transmission.

physics.ins-det↗

arXiv2018

Single Photon Source Driver Designed in ASIC

The single photon source is an important part of the quantum key distribution (QKD) system. At present, the single photon source is large in size and complex in structure for a lot of discrete components which are used. The miniaturization of the photon source is the tendency of the QKD system. We integrate all laser driver electronic module into one single ASIC chip, which can be used to drive the 1550nm DFB laser in random pulse mode and it can greatly reduce the volume of the single photon source. We present the design of the chip named LSD2018 and simulation results before the tape-out. The LSD2018 is fabricated with a 130 nm CMOS process and consists of a discriminator, an adjustable pulse generator, a bandgap reference, an SPI bus, and an amplitude-adjustable current pulse driver. The electronic random pulse from the driver can go 20mA to 120mA in amplitude and 400ps to 4ns in pulse width. The parameters can be set by an SPI bus.

physics.app-ph↗

arXiv2018

An Ultra-high-Speed Waveform Digitizer Prototype Based on Gigabit Ethernet for Plasma Diagnostics

An ultra-high-speed waveform digitizer prototype based on gigabit Ethernet has been developed. The prototype is designed to read out signals of detectors to realize the accurate measurement of various physical quantities for plasma diagnostics. The prototype includes an ultra-high-speed analog-to-digital converter (ADC) used to realize high speed digitization, a Xilinx Kintex-7 field-programmable gate array (FPGA) used for system configuration and digital signal processing, a DDR3 memory bar for data storage, and a gigabit Ethernet transceiver for interfacing with a computer. The sampling rate of the prototype is up to 5Gsps with 10-b resolution. The features of the prototype are described in detail.

physics.ins-det↗

arXiv2018

Development of FEB Configuration Test Board for ATLAS NSW Upgrade

The FEB(front end board) configuration test board is developed aiming at meeting the requirement of testing the new generation ASIC(application-specific integrated circuit) chips and its configuration system for ATLAS NSW(New Small Wheel) upgrade, In this paper, some functions are developed in terms of the configurations of the key chips on the FEB, VMM3 and TDS2 using GBT-SCA. Additionally, a flexible communication protocol is designed, verifying the whole data link. It provides technical reference for prototype FEB key chip configuration and data readout, as well as the final system configuration.

physics.ins-det↗

arXiv2018

Scanning Test System Prototype of p/sFEB for the ATLAS Phase-I sTGC Trigger Upgrade

The Pad Front End Board (pFEB) and the Strip Front End Board (sFEB) are developed for the ATLAS Phase-I sTGC Trigger Upgrade. The pFEB is used to to gather and analyze pads trigger, and the sFEB is developed to accept the pad trigger to define the regions-of-interest for strips readout. The performance of p/sFEBs must be confirmed before they are mounted on the sTGC detector. We will present the scanning test system prototype which is designed according to the test requirements of the p/sFEB. In this test system prototype, a simulation signal board is developed to generate different types of signal to the p/sFEB. PC software and FPGA XADC cooperate to achieve the scan test of analog parameter.

eess.SP↗

arXiv2018

The Detector System Design for the Grating-based Phase Contrast Imaging CT Prototype

In the hard X rays domain, the phase shift of the wave passing through the soft materials like tissues is typically three orders of magnitude larger than the absorption. Therefore the phase-sensitive X-ray imaging methods can obtain substantially increased contrast over conventional absorption-based imaging. In this paper, we present a detector system design for the computed tomography(CT) prototype which based on the grating-based phase contrast imaging(GBPCI) method. This system consists of 43 Hamamatsu silicon photodiode S12058(X) modules including 16512 pixels. Each module can provide 384(16*24) pixels, which the minimum pixel size is 0.75mm*1mm. The front-end readout electronics(FEE) of each module complete the analog-to-digital conversion, the digital processing, and the data transmission. All digitized data from 43 detector module are transmitted to the control system through the data collection boards. The test result shows that the efficient resolution of the detector system is up to 14.6bit. For all pixels, the integral nonlinearity is no more than 0.1%.

physics.ins-det↗

arXiv2018

A DAQ Prototype for Front-end Waveform Digitization in Intensive Electromagnetic Field Circumstance

A front-end waveform digitization data acquisition system prototype for pulsed magnetic field generator in inertial confinement fusion is described. The pulse magnetic field is created by discharging a high-voltage capacitor through a small wire-wound coil, and the Rogowski coil is used to measure the discharge current which can describe the corresponding magnetic field waveforms. The prototype is designed to measure the signal instead of the oscilloscope through a long-distance coaxial, which is greatly affected by electromagnetic interference caused by high-power loser. The outfield test result shows that the prototype can has a comparable performance as the oscilloscope for pulse magnetic field measurement.

physics.ins-det↗

arXiv2018

A data transmission system for the phase contrast Xray human computed tomography prototype

The cross section of X-ray phase contrast caused by these low-Z elements is greatly bigger than the absorption. Therefore, in the field of X-ray imaging, the phase shift information can offer better imaging contrast. In this paper, we present a data transmission system for the detectors of a phase contrast X-ray human computed tomography prototype. This system contains 3 data collecting boards (DCB) and one data transmitting board (DTB). A slip ring is used to transmit the data from the rotator side to the stator side over a nowadays commonly used multi-mode fiber (MMF). On the rotator side, 3 DCBs act as the controller of these detectors. The function of the DTB is to store all image data from 3 DCBs and implement the commutation with PC. The test shows that this system can meet the requirement of the prototype.

physics.ins-det↗

arXiv2018

Ultra-precision DC source for Superconducting Quantum Computer

The Superconducting Quantum Computing (SQC) is one of the most promising quantum computing techniques. The SQC requires precise control and acquisition to operate the superconducting qubits. The ultra-precision DC source is used to provide a DC bias for the qubit to work at its operation point. With the development of the multi-qubit processor, to use the commercial precise DC source device is impossible for its large volume occupation. We present our ultra-precision DC source which is designed for SQC experiments in this paper. The DC source contains 12 channels in 1U 19~inch crate. The performances of our DC source strongly beat the commercial devices. The output rang is -7~V to +7~V with 20~mA maximum output current. The Vpp of the output noise is 3~uV, and the standard deviation is 0.497~uV. The temperature coefficient is less than 1~ppm/$^{\circ}$C in 14~V range. The primary results show that the total drift of the output within 48h at an A/C room temperature environment is 40~uV which equal to 2.9~ppm/48h. We are still trying to optimize the channel density and long-term drift / stability.

physics.ins-det↗

arXiv2018

Highly Efficient 8-bit Low Precision Inference of Convolutional Neural Networks with IntelCaffe

High throughput and low latency inference of deep neural networks are critical for the deployment of deep learning applications. This paper presents the efficient inference techniques of IntelCaffe, the first Intel optimized deep learning framework that supports efficient 8-bit low precision inference and model optimization techniques of convolutional neural networks on Intel Xeon Scalable Processors. The 8-bit optimized model is automatically generated with a calibration process from FP32 model without the need of fine-tuning or retraining. We show that the inference throughput and latency with ResNet-50, Inception-v3 and SSD are improved by 1.38X-2.9X and 1.35X-3X respectively with neglectable accuracy loss from IntelCaffe FP32 baseline and by 56X-75X and 26X-37X from BVLC Caffe. All these techniques have been open-sourced on IntelCaffe GitHub1, and the artifact is provided to reproduce the result on Amazon AWS Cloud.

cs.CV↗

arXiv2017

1.25 GHz sine wave gating InGaAs/InP single-photon detector with monolithically integrated readout circuit

InGaAs/InP single-photon detectors (SPDs) are the key devices for applications requiring near-infrared single-photon detection. Gating mode is an effective approach to synchronous single-photon detection. Increasing gating frequency and reducing module size are important challenges for the design of such detector system. Here we present for the first time an InGaAs/InP SPD with 1.25 GHz sine wave gating using a monolithically integrated readout circuit (MIRC). The MIRC has a size of 15 mm * 15 mm and implements the miniaturization of avalanche extraction for high-frequency sine wave gating. In the MIRC, low-pass filters and a low-noise radio frequency amplifier are integrated based on the technique of low temperature co-fired ceramic, which can effectively reduce the parasitic capacitance and extract weak avalanche signals. We then characterize the InGaAs/InP SPD to verify the functionality and reliability of MIRC, and the SPD exhibits excellent performance with 27.5 % photon detection efficiency, 1.2 kcps dark count rate, and 9.1 % afterpulse probability at 223 K and 100 ns hold-off time. With this MIRC, one can further design miniaturized high-frequency SPD modules that are highly required for practical applications.

quant-ph↗

arXiv2016

Development of an ADC Radiation Tolerance Characterization System for the Upgrade of the ATLAS LAr Calorimeter

ATLAS LAr calorimeter will perform its Phase-I upgrade during the long shut down (LS2) in 2018, a new LAr Trigger Digitizer Board (LTDB) will be designed and installed. Several commercial-off-the-shelf (COTS) multichannel high-speed ADCs have been selected as possible backups of the radiation tolerant ADC ASICs for LTDB. In order to evaluate the radiation tolerance of these back up commercial ADCs, we developed an ADC radiation tolerance characterization system, which includes the ADC boards, data acquisition (DAQ) board, signal generator, external power supplies and a host computer. The ADC board is custom designed for different ADCs, which has ADC driver and clock distribution circuits integrated on board. The Xilinx ZC706 FPGA development board is used as DAQ board. The data from ADC are routed to the FPGA through the FMC (FPGA Mezzanine Card) connector, de-serialized and monitored by the FPGA, and then transmitted to the host computer through the Gigabit Ethernet. A software program has been developed with Python, and all the commands are sent to the DAQ board through Gigabit Ethernet by this program. Two ADC boards have been designed for the TI ADS52J90 and ADI AD9249 respectively. TID test of both ADCs have been performed at BNL, and SEE test for ADS52J90 has been performed at Massachusetts General Hospital (MGH). Test results have been analyzed and presented. The test results demonstrate that our test system is very versatile, and working well for the radiation tolerance characterization of commercial multi-channel high-speed ADC for the upgrade of the ATLAS LAr calorimeter. It is applicable to other collider physics experiments where radiation tolerance is required as well.

physics.ins-det↗

arXiv2016

Design considerations of high-performance InGaAs/InP single-photon avalanche diodes for quantum key distribution

InGaAs/InP single-photon avalanche diodes (SPADs) are widely used in practical applications requiring near-infrared photon counting such as quantum key distribution (QKD). Photon detection efficiency and dark count rate are the intrinsic parameters of InGaAs/InP SPADs, due to the fact that their performances cannot be improved using different quenching electronics given the same operation conditions. After modeling these parameters and developing a simulation platform for InGaAs/InP SPADs, we investigate the semiconductor structure design and optimization. The parameters of photon detection efficiency and dark count rate highly depend on the variables of absorption layer thickness, multiplication layer thickness, excess bias voltage and temperature. By evaluating the decoy-state QKD performance, the variables for SPAD design and operation can be globally optimized. Such optimization from the perspective of specific applications can provide an effective approach to design high-performance InGaAs/InP SPADs.

quant-ph↗

arXiv2015

High-efficiency and low-jitter Silicon single-photon avalanche diodes based on nanophotonic absorption enhancement

Silicon single-photon avalanche diode (SPAD) is a core device for single-photon detection in the visible and the near-infrared range, and widely used in many applications. However, due to limits of the structure design and device fabrication for current silicon SPADs, the key parameters of detection befficiency and timing jitter are often forced to compromise. Here, we propose a nanostructured silicon SPAD, which achieves high detection efficiency with excellent timing jitter simultaneously over a broad spectral range. The optical and electric simulations show significant performance enhancement compared with conventional silicon SPAD devices. This nanostructured devices can be easily fabricated and thus well suited for practical applications.

physics.ins-det↗

arXiv2014

The velocity distribution in the solar neighbourhood from the LAMOST pilot survey

We use about 15,000 F/G nearby dwarf stars selected from the LAMOST pilot survey to map the U-V velocity distribution in the solar neighbourhood. An extreme deconvolution algorithm is applied to reconstruct an empirical multi-Gaussian model. In addition to the well known substructures, e.g., Sirius, Coma Berenices, Hyades-Pleiades over-densities, several new substructures are unveiled. A ripple-like structure from (U, V) = (-120, -5) to (103, -32)km/s is clearly seen in the U-V distribution. This structure seems associated with resonance induced by the Galactic bar, since it is extended in U while having a small dispersion in V at the same time. A ridge structure between (U, V) = (-60, 40) and (-15, 15) km/s is also found. Although similar substructures have been seen in the Hipparcos data, their origin is still unclear. Another compact over-density is seen at (U, V) = (-102, -24). With this large data sample, we find that the substructure located at V~70 km/s and the Arcturus group are essentially parallel in V, which may indicate that they originate from an unrelaxed disk component perturbed by the rotating bar.

astro-ph.GA↗