Avalanche Photodiode Focal Plane Arrays and Their Application to Laser Detection and Ranging

Focal-plane avalanche photodiodes (APDs) are being more and more widely and deeply studied to satisfy the requirement in weak light and single photon imaging. The progresses of this worldwide study, especially the distinctive researches and achievements in Southwest Institute of Technical Physics and University of Electronic Science and Technology of China are reviewed in this chapter. We successfully fabricated up to 64 × 1 linear-mode Si APD arrays, and 32 × 32–64 × 64 Si single-photon avalanche detector (SPAD) arrays, and applied them in Laser Detection and Ranging (LADAR) platforms like driverless vehicles. Also, we developed 32 × 32–64 × 64 InGaAsP/InP SPAD arrays, and constructed three-dimensional imaging LADAR using them. Together with the progresses of other groups and other materials, we see a prospective future for the development and application of focal-plane APDs

Single Photon Counting Detectors for Low Light Level Imaging Applications

This dissertation presents the current state-of-the-art of semiconductor-based photon counting detector technologies. HgCdTe linear-mode avalanche photodiodes (LM-APDs), silicon Geiger-mode avalanche photodiodes (GM-APDs), and electron-multiplying CCDs (EMCCDs) are compared via their present and future performance in various astronomy applications. LM-APDs are studied in theory, based on work done at the University of Hawaii. EMCCDs are studied in theory and experimentally, with a device at NASA\u27s Jet Propulsion Lab. The emphasis of the research is on GM-APD imaging arrays, developed at MIT Lincoln Laboratory and tested at the RIT Center for Detectors. The GM-APD research includes a theoretical analysis of SNR and various performance metrics, including dark count rate, afterpulsing, photon detection efficiency, and intrapixel sensitivity. The effects of radiation damage on the GM-APD were also characterized by introducing a cumulative dose of 50 krad(Si) via 60 MeV protons. Extensive development of Monte Carlo simulations and practical observation simulations was completed, including simulated astronomical imaging and adaptive optics wavefront sensing. Based on theoretical models and experimental testing, both the current state-of-the-art performance and projected future performance of each detector are compared for various applications. LM-APD performance is currently not competitive with other photon counting technologies, and are left out of the application-based comparisons. In the current state-of-the-art, EMCCDs in photon counting mode out-perform GM-APDs for long exposure scenarios, though GM-APDs are better for short exposure scenarios (fast readout) due to clock-induced-charge (CIC) in EMCCDs. In the long term, small improvements in GM-APD dark current will make them superior in both long and short exposure scenarios for extremely low flux. The efficiency of GM-APDs will likely always be less than EMCCDs, however, which is particularly disadvantageous for moderate to high flux rates where dark noise and CIC are insignificant noise sources. Research into decreasing the dark count rate of GM-APDs will lead to development of imaging arrays that are competitive for low light level imaging and spectroscopy applications in the near future

Development of ASIC for SiPM sensor readout

L'abstract è presente nell'allegato / the abstract is in the attachmen

Characterization of silicon Geiger-mode avalanche photodiodes with novel device architecture

Geiger-mode avalanche photodiode (GM APD) detectors are capable of counting single photons, measuring arrival times with high resolution, and generating zero read noise (when operated with a CMOS digital readout circuit) due to their unique internal gain characteristics. These capabilities make them exceptionally suited to tasks that require precise arrival time measurements or characterization of faint signals (low photon flux). Laser ranging systems use their arrival time measurement capabilities to build three-dimensional images, while adaptive optics applications have recently begun to capitalize on their low noise and high-speed operation for correcting wavefront imperfections due to atmospheric interference. There is now growing interest in using GM APDs for imaging applications where accurate measurements of faint signals are necessary, such as in astronomy. MIT Lincoln Laboratory and the RIT Center for Detectors have developed silicon GM APDs with unique architecture, utilizing scupper regions to minimize detector noise. This thesis investigates the performance of these detectors in terms of dark count rate (DCR). There are a number of mechanisms that produce dark counts, the most prominent being thermal excitation of carriers. Thermal carrier generation rates are generally only dependent on the temperature of the diode and may be constant under certain controlled conditions. Afterpulsing results from the release of carriers trapped in intermediate energy states (states with energy in the band gap of the material). Unlike thermal carrier generation, afterpulsing is dependent on the quenching time of the device (during which the device is unable to detect a carrier). Another mechanism, called self re-triggering, occurs when relaxing carriers emit photons during an avalanche. These photons can be absorbed in the substrate and generate dark carriers. Self-retriggering is also dependent on the quenching time of the device. Theories for afterpulsing and self-retriggering are discussed. Specialized test circuitry is used with a customized data acquisition technique, and the author develops a method for parameter extraction from the raw data. Device characteristics derived from experimental results are examined. The author also develops a simulation program to approximate the dark count rate (among other parameters) of a device based on semiconductor characteristics and testing conditions. This thesis makes conclusions about the dependence of DCR on device architecture and how individual carrier generation mechanisms affect device performance

A Bulk Driven Transimpedance CMOS Amplifier for SiPM Based Detection

The contribution of this work lies in the development of a bulk driven operationaltransconducctance amplifier which can be integrated with other analog circuits andphotodetectors in the same chip for compactness, miniaturization and reducing thepower. Silicon photomultipliers, also known as SiPMs, when coupled with scintillator materials are used in many imaging applications including nuclear detection. This thesis discuss the design of a bulk-driven transimpedance amplifier suitable for detectors where the front end is a SiPM. The amplifier was design and fabricated in a standard standard CMOS process and is suitable for integration with CMOS based SiPMs and commercially available SiPMs. Specifically, the amplifier was verified in simulations and experiment using circuit models for the SiPM. The bulk-driven amplifier’s performance, was compared to a commerciallyavailable amplifier with approximately the same open loop gain (70dB). Bothamplifiers were verified with two different light sources, a scintillator and a SiPM.The energy resolution using the bulk driven amplifier was 8.6% and was 14.2% forthe commercial amplifier indicating the suitability of the amplifier design for portable systems

Technical Design Report for PANDA Electromagnetic Calorimeter (EMC)

This document presents the technical layout and the envisaged performance of the Electromagnetic Calorimeter (EMC) for the PANDA target spectrometer. The EMC has been designed to meet the physics goals of the PANDA experiment. The performance figures are based on extensive prototype tests and radiation hardness studies. The document shows that the EMC is ready for construction up to the front-end electronics interface

The BrightEyes-TTM: an open-source time-tagging module for fluorescence lifetime imaging microscopy applications

The aim of this Ph.D. work is to reason and show how an open-source multi-channel and standalone time-tagging device was developed, validated and used in combination with a new generation of single-photon array detectors to pursue super-resolved time-resolved fluorescence lifetime imaging measurements. Within the compound of time-resolved fluorescence laser scanning microscopy (LSM) techniques, fluorescence lifetime imaging microscopy (FLIM) plays a relevant role in the life-sciences field, thanks to its ability of detecting functional changes within the cellular micro-environment. The recent advancements in photon detection technologies, such as the introduction of asynchronous read-out single-photon avalanche diode (SPAD) array detectors, allow to image a fluorescent sample with spatial resolution below the diffraction limit, at the same time, yield the possibility of accessing the single-photon information content allowing for time-resolved FLIM measurements. Thus, super-resolved FLIM experiments can be accomplished using SPAD array detectors in combination with pulsed laser sources and special data acquisition systems (DAQs), capable of handling a multiplicity of inputs and dealing with the single-photons readouts generated by SPAD array detectors. Nowadays, the commercial market lacks a true standalone, multi-channel, single-board, time-tagging and affordable DAQ device specifically designed for super-resolved FLIM experiments. Moreover, in the scientific community, no-efforts have been placed yet in building a device that can compensate such absence. That is why, within this Ph.D. project, an open-source and low-cost device, the so-called BrightEyes-TTM (time tagging module), was developed and validated both for fluorescence lifetime and time-resolved measurements in general. The BrightEyes-TTM belongs to a niche of DAQ devices called time-to-digital converters (TDCs). The field-gate programmable array (FPGA) technology was chosen for implementing the BrightEyes-TTM thanks to its reprogrammability and low cost features. The literature reports several different FPGA-based TDC architectures. Particularly, the differential delay-line TDC architecture turned out to be the most suitable for this Ph.D. project as it offers an optimal trade-off between temporal precision, temporal range, temporal resolution, dead-time, linearity, and FPGA resources, which are all crucial characteristics for a TDC device. The goal of the project of pursuing a cost-effective and further-upgradable open-source time-tagging device was achieved as the BrigthEyes-TTM was developed and assembled using low-cost commercially available electronic development kits, thus allowing for the architecture to be easily reproduced. BrightEyes-TTM was deployed on a FPGA development board which was equipped with a USB 3.0 chip for communicating with a host-processing unit and a multi-input/output custom-built interface card for interconnecting the TTM with the outside world. Licence-free softwares were used for acquiring, reconstructing and analyzing the BrightEyes-TTM time-resolved data. In order to characterize the BrightEyes-TTM performances and, at the same time, validate the developed multi-channel TDC architecture, the TTM was firstly tested on a bench and then integrated into a fluorescent LSM system. Yielding a 30 ps single-shot precision and linearity performances that allows to be employed for actual FLIM measurements, the BrightEyes-TTM, which also proved to acquire data from many channels in parallel, was ultimately used with a SPAD array detector to perform fluorescence imaging and spectroscopy on biological systems. As output of the Ph.D. work, the BrightEyes-TTM was released on GitHub as a fully open-source project with two aims. The principal aim is to give to any microscopy and life science laboratory the possibility to implement and further develop single-photon-based time-resolved microscopy techniques. The second aim is to trigger the interest of the microscopy community, and establish the BrigthEyes-TTM as a new standard for single-photon FLSM and FLIM experiments