The Experts below are selected from a list of 258 Experts worldwide ranked by ideXlab platform

Ivan Rech - One of the best experts on this subject based on the ideXlab platform.

  • fast fully integrated front end circuit to overcome pile up limits in time correlated single photon counting with single photon Avalanche Diodes
    Optics Express, 2018
    Co-Authors: Giulia Acconcia, M Ghioni, Alessandro Cominelli, Ivan Rech
    Abstract:

    Time-Correlated Single Photon Counting (TCSPC) is an essential tool in many scientific applications, where the recording of optical pulses with picosecond precision is required. Unfortunately, a key issue has to be faced: distortion phenomena can affect TCSPC experiments at high count rates. In order to avoid this problem, TCSPC experiments have been commonly carried out by limiting the maximum operating frequency of a measurement channel below 5% of the excitation frequency, leading to a long acquisition time. Recently, it has been demonstrated that matching the detector dead time to the excitation period allows to keep distortion around zero regardless of the rate of impinging photons. This solution paves the way to unprecedented measurement speed in TCSPC experiments. In this scenario, the front-end circuits that drive the detector play a crucial role in determining the performance of the system, both in terms of measurement speed and timing performance. Here we present two fully integrated front-end circuits for Single Photon Avalanche Diodes (SPADs): a fast Active Quenching Circuit (AQC) and a fully-differential current pick-up circuit. The AQC can apply very fast voltage variations, as short as 1.6ns, to reset external custom-technology SPAD detectors. A fast reset, indeed, is a key parameter to maximize the measurement speed. The current pick-up circuit is based on a fully differential structure which allows unprecedented rejection of disturbances that typically affect SPAD-based systems at the end of the dead time. The circuit permits to sense the current edge resulting from a photon detection with picosecond accuracy and precision even a few picoseconds after the end of the dead time imposed by the AQC. This is a crucial requirement when the system is operated at high rates. Both circuits have been deeply characterized, especially in terms of achievable measurement speed and timing performance.

  • note fully integrated active quenching circuit achieving 100 mhz count rate with custom technology single photon Avalanche Diodes
    Review of Scientific Instruments, 2017
    Co-Authors: Giulia Acconcia, Ivan Rech, Angelo Gulinatti, Ivan Labanca, M Ghioni
    Abstract:

    The minimization of Single Photon Avalanche Diodes (SPADs) dead time is a key factor to speed up photon counting and timing measurements. We present a fully integrated Active Quenching Circuit (AQC) able to provide a count rate as high as 100 MHz with custom technology SPAD detectors. The AQC can also operate the new red enhanced SPAD and provide the timing information with a timing jitter Full Width at Half Maximum (FWHM) as low as 160 ps.

  • silicon photon counting Avalanche Diodes for single molecule fluorescence spectroscopy
    IEEE Journal of Selected Topics in Quantum Electronics, 2014
    Co-Authors: Xavier Michalet, Ivan Rech, Angelo Gulinatti, Piera Maccagnani, Antonino Ingargiola, Ryan A Colyer, Giuseppe Scalia, Shimon Weiss, M Ghioni
    Abstract:

    Solution-based single-molecule fluorescence spectroscopy is a powerful experimental tool with applications in cell biology, biochemistry and biophysics. The basic feature of this technique is to excite and collect light from a very small volume and work in a low concentration regime resulting in rare burst-like events corresponding to the transit of a single molecule. Detecting photon bursts is a challenging task: the small number of emitted photons in each burst calls for high detector sensitivity. Bursts are very brief, requiring detectors with fast response time and capable of sustaining high count rates. Finally, many bursts need to be accumulated to achieve proper statistical accuracy, resulting in long measurement time unless parallelization strategies are implemented to speed up data acquisition. In this paper we will show that silicon single-photon Avalanche Diodes (SPADs) best meet the needs of single-molecule detection. We will review the key SPAD parameters and highlight the issues to be addressed in their design, fabrication and operation. After surveying the state-of-the-art SPAD technologies, we will describe our recent progress towards increasing the throughput of single-molecule fluorescence spectroscopy in solution using parallel arrays of SPADs. The potential of this approach is illustrated with single-molecule Forster resonance energy transfer measurements.

  • improving the performance of silicon single photon Avalanche Diodes
    Proceedings of SPIE, 2011
    Co-Authors: Angelo Gulinatti, Ivan Rech, Piera Maccagnani, M Ghioni, S Cova
    Abstract:

    Many applications require high performance Single Photon Avalanche Diodes (SPAD) either as single pixels or as small arrays of detectors. Although currently available silicon devices reached remarkable performance, nevertheless further improvements are needed in order to meet the requirements of most demanding time-resolved techniques. In this paper we present a new planar silicon technology for the fabrication of SPAD detectors, aimed at improving the Photon Detection Efficiency (PDE) of classical thin SPAD in the near infrared range while maintaining a good Temporal Resolution (TR). Experimental characterization showed a significant increase in the PDE with a remarkable value of 40% at 800nm; a photon timing jitter as low as 93ps FWHM as been also attained, while other device performances, such as Dark Count Rate (DCR) and Afterpulsing Probability (AP) are essentially unchanged, compared to thin SPAD. Being planar, the new technology is also intrinsically compatible with the fabrication of arrays of detectors.

  • photon timing jitter dependence on injection position in single photon Avalanche Diodes
    IEEE Journal of Quantum Electronics, 2011
    Co-Authors: Mattia Assanelli, Ivan Rech, Angelo Gulinatti, Antonino Ingargiola, M Ghioni
    Abstract:

    In recent years, a growing number of applications demand better timing resolution from single-photon Avalanche Diodes (SPADs). The challenge is pursuing improved timing resolution without impairing other device characteristics such as quantum efficiency and dark count rate. This task requires a clear understanding of the statistical phenomena involved in the Avalanche current growth in order to drive the device engineering process. Past studies state that in Si SPADs the Avalanche injection position statistics is the main contribution to the photon-timing jitter. However, in recent re-engineered devices, this assumption has been questioned. To address this issue, we developed an experimental setup capable of characterizing the photon-timing jitter as a function of the injection position by means of a laser focused on the device active area. The results not only confirmed that the injection position statistics is not the main contribution to photon-timing jitter, but also evidenced interesting dependences of the timing performances on the injection position. Furthermore, we found a relationship between the photon-timing jitter and the specific resistance of the devices, which has been investigated by means of photoluminescence measurements.

M Ghioni - One of the best experts on this subject based on the ideXlab platform.

  • fast fully integrated front end circuit to overcome pile up limits in time correlated single photon counting with single photon Avalanche Diodes
    Optics Express, 2018
    Co-Authors: Giulia Acconcia, M Ghioni, Alessandro Cominelli, Ivan Rech
    Abstract:

    Time-Correlated Single Photon Counting (TCSPC) is an essential tool in many scientific applications, where the recording of optical pulses with picosecond precision is required. Unfortunately, a key issue has to be faced: distortion phenomena can affect TCSPC experiments at high count rates. In order to avoid this problem, TCSPC experiments have been commonly carried out by limiting the maximum operating frequency of a measurement channel below 5% of the excitation frequency, leading to a long acquisition time. Recently, it has been demonstrated that matching the detector dead time to the excitation period allows to keep distortion around zero regardless of the rate of impinging photons. This solution paves the way to unprecedented measurement speed in TCSPC experiments. In this scenario, the front-end circuits that drive the detector play a crucial role in determining the performance of the system, both in terms of measurement speed and timing performance. Here we present two fully integrated front-end circuits for Single Photon Avalanche Diodes (SPADs): a fast Active Quenching Circuit (AQC) and a fully-differential current pick-up circuit. The AQC can apply very fast voltage variations, as short as 1.6ns, to reset external custom-technology SPAD detectors. A fast reset, indeed, is a key parameter to maximize the measurement speed. The current pick-up circuit is based on a fully differential structure which allows unprecedented rejection of disturbances that typically affect SPAD-based systems at the end of the dead time. The circuit permits to sense the current edge resulting from a photon detection with picosecond accuracy and precision even a few picoseconds after the end of the dead time imposed by the AQC. This is a crucial requirement when the system is operated at high rates. Both circuits have been deeply characterized, especially in terms of achievable measurement speed and timing performance.

  • note fully integrated active quenching circuit achieving 100 mhz count rate with custom technology single photon Avalanche Diodes
    Review of Scientific Instruments, 2017
    Co-Authors: Giulia Acconcia, Ivan Rech, Angelo Gulinatti, Ivan Labanca, M Ghioni
    Abstract:

    The minimization of Single Photon Avalanche Diodes (SPADs) dead time is a key factor to speed up photon counting and timing measurements. We present a fully integrated Active Quenching Circuit (AQC) able to provide a count rate as high as 100 MHz with custom technology SPAD detectors. The AQC can also operate the new red enhanced SPAD and provide the timing information with a timing jitter Full Width at Half Maximum (FWHM) as low as 160 ps.

  • silicon photon counting Avalanche Diodes for single molecule fluorescence spectroscopy
    IEEE Journal of Selected Topics in Quantum Electronics, 2014
    Co-Authors: Xavier Michalet, Ivan Rech, Angelo Gulinatti, Piera Maccagnani, Antonino Ingargiola, Ryan A Colyer, Giuseppe Scalia, Shimon Weiss, M Ghioni
    Abstract:

    Solution-based single-molecule fluorescence spectroscopy is a powerful experimental tool with applications in cell biology, biochemistry and biophysics. The basic feature of this technique is to excite and collect light from a very small volume and work in a low concentration regime resulting in rare burst-like events corresponding to the transit of a single molecule. Detecting photon bursts is a challenging task: the small number of emitted photons in each burst calls for high detector sensitivity. Bursts are very brief, requiring detectors with fast response time and capable of sustaining high count rates. Finally, many bursts need to be accumulated to achieve proper statistical accuracy, resulting in long measurement time unless parallelization strategies are implemented to speed up data acquisition. In this paper we will show that silicon single-photon Avalanche Diodes (SPADs) best meet the needs of single-molecule detection. We will review the key SPAD parameters and highlight the issues to be addressed in their design, fabrication and operation. After surveying the state-of-the-art SPAD technologies, we will describe our recent progress towards increasing the throughput of single-molecule fluorescence spectroscopy in solution using parallel arrays of SPADs. The potential of this approach is illustrated with single-molecule Forster resonance energy transfer measurements.

  • improving the performance of silicon single photon Avalanche Diodes
    Proceedings of SPIE, 2011
    Co-Authors: Angelo Gulinatti, Ivan Rech, Piera Maccagnani, M Ghioni, S Cova
    Abstract:

    Many applications require high performance Single Photon Avalanche Diodes (SPAD) either as single pixels or as small arrays of detectors. Although currently available silicon devices reached remarkable performance, nevertheless further improvements are needed in order to meet the requirements of most demanding time-resolved techniques. In this paper we present a new planar silicon technology for the fabrication of SPAD detectors, aimed at improving the Photon Detection Efficiency (PDE) of classical thin SPAD in the near infrared range while maintaining a good Temporal Resolution (TR). Experimental characterization showed a significant increase in the PDE with a remarkable value of 40% at 800nm; a photon timing jitter as low as 93ps FWHM as been also attained, while other device performances, such as Dark Count Rate (DCR) and Afterpulsing Probability (AP) are essentially unchanged, compared to thin SPAD. Being planar, the new technology is also intrinsically compatible with the fabrication of arrays of detectors.

  • photon timing jitter dependence on injection position in single photon Avalanche Diodes
    IEEE Journal of Quantum Electronics, 2011
    Co-Authors: Mattia Assanelli, Ivan Rech, Angelo Gulinatti, Antonino Ingargiola, M Ghioni
    Abstract:

    In recent years, a growing number of applications demand better timing resolution from single-photon Avalanche Diodes (SPADs). The challenge is pursuing improved timing resolution without impairing other device characteristics such as quantum efficiency and dark count rate. This task requires a clear understanding of the statistical phenomena involved in the Avalanche current growth in order to drive the device engineering process. Past studies state that in Si SPADs the Avalanche injection position statistics is the main contribution to the photon-timing jitter. However, in recent re-engineered devices, this assumption has been questioned. To address this issue, we developed an experimental setup capable of characterizing the photon-timing jitter as a function of the injection position by means of a laser focused on the device active area. The results not only confirmed that the injection position statistics is not the main contribution to photon-timing jitter, but also evidenced interesting dependences of the timing performances on the injection position. Furthermore, we found a relationship between the photon-timing jitter and the specific resistance of the devices, which has been investigated by means of photoluminescence measurements.

Mark A. Itzler - One of the best experts on this subject based on the ideXlab platform.

  • shortwave infrared negative feedback Avalanche Diodes and solid state photomultipliers
    Optical Engineering, 2014
    Co-Authors: Xudong Jiang, Mark A. Itzler, Kevin Odonnell, Mark Entwistle, Krystyna Slomkowski
    Abstract:

    In recent years, significant progress has been made in InP-based Geiger-mode single photon Avalanche Diodes (SPADs), and a variety of circuits for enabling Geiger-mode operation have been proposed and demonstrated. However, due to the inherent positive feedback of the impact ionization Avalanche process, Geiger-mode SPADs are constrained by certain performance limitations, particularly with regard to counting rate and the inability to resolve photon number. To overcome some of the performance limitations of regular SPADs, we have developed negative feedback Avalanche Diodes (NFADs) that employ a negative feedback mechanism to regulate the Avalanche process. The NFAD fabrication process is based on the design platform we use to achieve state-of-the-art performance SPADs and is very flexible. The operation of NFAD devices is also very simple, with only a direct current (DC) bias being required. Various discrete devices and matrices composed of different elements have been designed, fabricated, and characterized. For discrete devices, ∼10% photon detection efficiency has been realized consistent with acceptable afterpulsing probability. The negative feedback mechanism significantly improves the uniformity of the output pulse heights and Avalanche charge per detection event, resulting in a low “charge excess noise” factor. When configured in a matrix format, the NFAD devices were demonstrated to have the ability to resolve photon number and work effectively as solid-state photomultipliers (SSPMs) in the shortwave infrared (SWIR) region. The InGaAs/InP NFAD SSPMs have the potential to replace photomultiplier tubes and provide a solid-state solution in applications where the requirement for single-photon sensitivity in the SWIR region beyond ∼0.9   μ m  cannot be met by silicon photomultipliers. The NFAD devices have been used in various quantum optics and quantum key distribution applications and demonstrated an excellent performance.

  • improved sinusoidal gating with balanced ingaas inp single photon Avalanche Diodes
    Optics Express, 2013
    Co-Authors: Wenlu Sun, Xudong Jiang, Qiugui Zhou, J C Campbell, Mark A. Itzler
    Abstract:

    We report balanced InGaAs/InP single photon Avalanche Diodes (SPADs) operated in sinusoidal gating mode with a tunable phase shifter to reduce common mode noise. This technique enables detection of small Avalanche pulses, which results in reduced afterpulsing. For laser repletion rate of 20 MHz at 240 K, the dark count rate for photon detection efficiency of 10% is 8.9 kHz.

  • pulsed gating with balanced ingaas inp single photon Avalanche Diodes
    IEEE Journal of Quantum Electronics, 2013
    Co-Authors: Wenlu Sun, Xudong Jiang, J C Campbell, Mark A. Itzler
    Abstract:

    We demonstrate balanced InGaAs/InP single photon Avalanche Diodes operated in gated mode for a data transmission rate of up to 20 MHz. The common-mode signal cancellation realized with the balanced configuration enabled detection of small Avalanche pulses. For a laser repletion rate of 20 MHz at 240 K, the dark count probability for a photon detection efficiency of 13% is $1.9\times 10^{-5}$ . The afterpulse probability is 0.3% for a 2 ns pulse width, hold-off time of 20 ns, and 10% PDE, at 240 K.

  • characterization of sinusoidal gating of ingaas inp single photon Avalanche Diodes
    Proceedings of SPIE, 2012
    Co-Authors: Xiaoguang Zheng, Wenlu Sun, Xudong Jiang, J C Campbell, Mark A. Itzler
    Abstract:

    We report sinusoidal gating of InGaAs/InP single photon Avalanche Diodes (SPAD) operated at wavelength of 1310 nm with high photon detection efficiency (PDE) and low dark count rate (DCR). At a gating frequency of 80 MHz and temperature of 240 K the DCR and PDE were 15.5 kHz and 55%, respectively. The slope of DCR versus PDE increases with higher laser repetition rate. There are two mechanisms that contribute to this trend. The first is due to the lower afterpulse probability associated with a lower laser repetition rate. The other is due to the RC effect, which is illustrated by an equivalent circuit that includes a model of the SPAD. We also show that relative to gated passive quenching with active reset (PQAR) for fixed PDE, sinusoidal gating yields lower afterpulsing rates for the same hold-off time. This is explained in terms of the integrated pulse shape and the resultant charge flow. The afterpulse probability, Pa, is related to the hold off time, T, through the power law, PapT-a where a is a measure of the detrapping time in the multiplication region.© (2012) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.

  • ingaas inp negative feedback Avalanche Diodes nfads
    Proceedings of SPIE, 2011
    Co-Authors: Xudong Jiang, Mark A. Itzler, Kevin Odonnell, Mark Entwistle, Krystyna Slomkowski
    Abstract:

    In recent years substantial effort has been made in material growth, device design and fabrication, and driving circuitry to improve the performance of InGaAs/InP single photon Avalanche Diodes (SPADs) operated in Geiger mode. Despite these efforts, InGaAs/InP SPADs are constrained by certain performance limitations due to the inherent positive feedback involved in the Avalanche process. With the goal of overcoming some of these performance limitations, we have successfully designed and implemented thin film resistors monolithically integrated with InGaAs/InP SPADs to provide a negative feedback mechanism to regulate the Avalanche sizes. The monolithic integration scheme ensures very small parasitic effects, results in fast quenching of Avalanches, and allows for wafer-level integration which facilitates the fabrication of array structures. We will discuss the design and operation of NFAD devices and performance characterization of these devices. Basic characteristics of NFADs such as pulse response, quenching and recovery dynamics will be described. We will also present device performance parameters such as photon detection efficiency (PDE), dark count rate (DCR) and afterpulsing probability (Pap). InGaAs/InP negative feedback Avalanche Diodes with different device sizes and quenching resistances have been designed and fabricated. Devices with ~10% PDE and acceptable Pap has been realized, which provides a simple, practical solution for certain photon-counting applications.

Franco Zappa - One of the best experts on this subject based on the ideXlab platform.

  • single photon Avalanche Diodes in a 0 16 μm bcd technology with sharp timing response and red enhanced sensitivity
    IEEE Journal of Selected Topics in Quantum Electronics, 2018
    Co-Authors: Mirko Sanzaro, Alberto Tosi, Federica Villa, Paolo Gattari, Giuseppe Croce, Franco Zappa
    Abstract:

    CMOS single-photon Avalanche Diodes (SPADs) have recently become an emerging imaging technology for applications requiring high sensitivity and high frame-rate in the visible and near-infrared range. However, a higher photon detection efficiency (PDE), particularly in the 700–950 nm range, is highly desirable for many growing markets, such as eye-safe three-dimensional imaging (LIDAR). In this paper, we report the design and characterization of SPADs fabricated in a 0.16 μ m BCD (Bipolar-CMOS-DMOS) technology. The overall detection performance is among the best reported in the literature: 1) PDE of 60% at 500 nm wavelength and still 12% at 800 nm; 2) very low dark count rate of μ m2 (in counts per second per unit area); 3) < 1% afterpulsing probability with 50 ns dead-time; and 4) temporal response with 30 ps full width at half-maximum and less than 50 ps diffusion tail time constant.

  • charge persistence in ingaas inp single photon Avalanche Diodes
    IEEE Journal of Quantum Electronics, 2016
    Co-Authors: Niccolo Calandri, Alberto Tosi, Mirko Sanzaro, Franco Zappa
    Abstract:

    We present a detailed characterization and modeling of the charge persistence effect that impacts InGaAs/InP single-photon Avalanche Diodes. Such phenomenon is due to holes that pile-up at the heterointerface outside the active area and has two main consequences: 1) higher noise (equivalent to higher dark count rate), not decreasing as expected at low temperature and 2) possible distortion of the acquired time-resolved waveforms (due to such signal-correlated noise). We propose a model that describes: 1) the generation of holes at the detector periphery in the InGaAs layer; 2) their accumulation at the heterointerface; 3) their subsequent diffusion toward the active area within the InGaAs layer; and 4) their resulting drift to the high field depleted InP region, where the unwelcome spurious Avalanche is eventually triggered. We support our model by detailed experimental measurements and simulations. Finally, we propose simple approaches for designing detectors less sensitive to this type of noise.

  • low noise low jitter 32 pixels cmos single photon Avalanche Diodes array for single photon counting from 300 nm to 900 nm
    Review of Scientific Instruments, 2013
    Co-Authors: Carmelo Scarcella, Simone Tisa, Alberto Tosi, Federica Villa, Franco Zappa
    Abstract:

    We developed a single-photon counting multichannel detection system, based on a monolithic linear array of 32 CMOS SPADs (Complementary Metal-Oxide-Semiconductor Single-Photon Avalanche Diodes). All channels achieve a timing resolution of 100 ps (full-width at half maximum) and a photon detection efficiency of 50% at 400 nm. Dark count rate is very low even at room temperature, being about 125 counts/s for 50 μm active area diameter SPADs. Detection performance and microelectronic compactness of this CMOS SPAD array make it the best candidate for ultra-compact time-resolved spectrometers with single-photon sensitivity from 300 nm to 900 nm.

  • spice modeling of single photon Avalanche Diodes
    Sensors and Actuators A-physical, 2009
    Co-Authors: Franco Zappa, Alberto Tosi, Dalla A Mora, Simone Tisa
    Abstract:

    Abstract In this paper we present a comprehensive circuit model for single photon Avalanche Diodes (SPADs), implemented into two different CAD circuit simulation environments (PSpice and Spectre), that fully describes detector behavior in the above-breakdown (Geiger-mode) operation. In particular, the SPICE modeling accurately simulates the ignition of the detector due to a photon absorption, the fast Avalanche current build-up, the self-sustaining charge-multiplication process, and the self-quenching of the Avalanche pulse. The model works within both passive and active quenching circuits and it deals correctly with both single-photon and photon-burst excitation. We show how to experimentally extract the required model parameters from any SPAD detector and how to input them into the circuit simulators. We discuss different operating regimes and we present various case studies that validate the modeling and quantitatively prove its accuracy.

  • ingaas inp single photon Avalanche Diodes show low dark counts and require moderate cooling
    Proceedings of SPIE the International Society for Optical Engineering, 2009
    Co-Authors: Alberto Tosi, Franco Zappa, Mark A. Itzler, S Cova, Dalla A Mora, Xudong Jiang
    Abstract:

    ABSTRACT InGaAs/InP devices suitable as Single-Photon Avalanche Diodes (SPADs) for photon counting and photon timing applications in the near-infrared provide good detection efficiency and low time jitter, together with fairly low dark-count rate at moderately low temperatures. However, their pe rformance is still severely limite d by the afterpulsing effect, caused by carriers trapped into deep levels during the Avalanche current flow and later released. We present preliminary experimental ch aracterization of recently-developed InGa As/InP detectors that can promisingly be operated slightly cooled. We investigate the primary da rk-count rate, taking into account both thermal generation in the InGaAs absorption layer and trap-assisted tunnelling in the InP multiplication layer. We report on improvements obtainable by selecting the proper operating conditions and electronic circuit solutions. The fundamental role played by the front-end circuits in minimizing the effects of afterpulsing is assessed and demonstrated. We report the performance of a 25 µm-diameter InGaAs/InP SPAD at 1550 nm wavelength, with dark count rate of 400 cps (count per seconds) at 175 K and just 2000 cps at 225 K, with afterpulsing showing off only below T

Angelo Gulinatti - One of the best experts on this subject based on the ideXlab platform.

  • note fully integrated active quenching circuit achieving 100 mhz count rate with custom technology single photon Avalanche Diodes
    Review of Scientific Instruments, 2017
    Co-Authors: Giulia Acconcia, Ivan Rech, Angelo Gulinatti, Ivan Labanca, M Ghioni
    Abstract:

    The minimization of Single Photon Avalanche Diodes (SPADs) dead time is a key factor to speed up photon counting and timing measurements. We present a fully integrated Active Quenching Circuit (AQC) able to provide a count rate as high as 100 MHz with custom technology SPAD detectors. The AQC can also operate the new red enhanced SPAD and provide the timing information with a timing jitter Full Width at Half Maximum (FWHM) as low as 160 ps.

  • silicon photon counting Avalanche Diodes for single molecule fluorescence spectroscopy
    IEEE Journal of Selected Topics in Quantum Electronics, 2014
    Co-Authors: Xavier Michalet, Ivan Rech, Angelo Gulinatti, Piera Maccagnani, Antonino Ingargiola, Ryan A Colyer, Giuseppe Scalia, Shimon Weiss, M Ghioni
    Abstract:

    Solution-based single-molecule fluorescence spectroscopy is a powerful experimental tool with applications in cell biology, biochemistry and biophysics. The basic feature of this technique is to excite and collect light from a very small volume and work in a low concentration regime resulting in rare burst-like events corresponding to the transit of a single molecule. Detecting photon bursts is a challenging task: the small number of emitted photons in each burst calls for high detector sensitivity. Bursts are very brief, requiring detectors with fast response time and capable of sustaining high count rates. Finally, many bursts need to be accumulated to achieve proper statistical accuracy, resulting in long measurement time unless parallelization strategies are implemented to speed up data acquisition. In this paper we will show that silicon single-photon Avalanche Diodes (SPADs) best meet the needs of single-molecule detection. We will review the key SPAD parameters and highlight the issues to be addressed in their design, fabrication and operation. After surveying the state-of-the-art SPAD technologies, we will describe our recent progress towards increasing the throughput of single-molecule fluorescence spectroscopy in solution using parallel arrays of SPADs. The potential of this approach is illustrated with single-molecule Forster resonance energy transfer measurements.

  • improving the performance of silicon single photon Avalanche Diodes
    Proceedings of SPIE, 2011
    Co-Authors: Angelo Gulinatti, Ivan Rech, Piera Maccagnani, M Ghioni, S Cova
    Abstract:

    Many applications require high performance Single Photon Avalanche Diodes (SPAD) either as single pixels or as small arrays of detectors. Although currently available silicon devices reached remarkable performance, nevertheless further improvements are needed in order to meet the requirements of most demanding time-resolved techniques. In this paper we present a new planar silicon technology for the fabrication of SPAD detectors, aimed at improving the Photon Detection Efficiency (PDE) of classical thin SPAD in the near infrared range while maintaining a good Temporal Resolution (TR). Experimental characterization showed a significant increase in the PDE with a remarkable value of 40% at 800nm; a photon timing jitter as low as 93ps FWHM as been also attained, while other device performances, such as Dark Count Rate (DCR) and Afterpulsing Probability (AP) are essentially unchanged, compared to thin SPAD. Being planar, the new technology is also intrinsically compatible with the fabrication of arrays of detectors.

  • photon timing jitter dependence on injection position in single photon Avalanche Diodes
    IEEE Journal of Quantum Electronics, 2011
    Co-Authors: Mattia Assanelli, Ivan Rech, Angelo Gulinatti, Antonino Ingargiola, M Ghioni
    Abstract:

    In recent years, a growing number of applications demand better timing resolution from single-photon Avalanche Diodes (SPADs). The challenge is pursuing improved timing resolution without impairing other device characteristics such as quantum efficiency and dark count rate. This task requires a clear understanding of the statistical phenomena involved in the Avalanche current growth in order to drive the device engineering process. Past studies state that in Si SPADs the Avalanche injection position statistics is the main contribution to the photon-timing jitter. However, in recent re-engineered devices, this assumption has been questioned. To address this issue, we developed an experimental setup capable of characterizing the photon-timing jitter as a function of the injection position by means of a laser focused on the device active area. The results not only confirmed that the injection position statistics is not the main contribution to photon-timing jitter, but also evidenced interesting dependences of the timing performances on the injection position. Furthermore, we found a relationship between the photon-timing jitter and the specific resistance of the devices, which has been investigated by means of photoluminescence measurements.

  • large area low jitter silicon single photon Avalanche Diodes
    Proceedings of SPIE the International Society for Optical Engineering, 2008
    Co-Authors: M Ghioni, Ivan Rech, Angelo Gulinatti, Piera Maccagnani, S Cova
    Abstract:

    Single photon counting (SPC) and time correlated single photon counting (TCSPC) techniques have been developed in the past four decades relying on photomultiplier tubes (PMT), but interesting alternatives are nowadays provided by solid-state single photon detectors. In particular, silicon Single Photon Avalanche Diodes (SPAD) fabricated in planar technology join the typical advantages of microelectronic devices (small size, ruggedness, low operating voltage and low power dissipation, etc.) with remarkable basic performance, such as high photon detection efficiency over a broad spectral range up to 1 μm wavelength, low dark count rate and photon timing jitter of a few tens of picoseconds. In recent years detector modules employing planar SPAD devices with diameter up to 50 µm have become commercially available. SPADs with larger active areas would greatly simplify the design of optical coupling systems, thus making these devices more competitive in a broader range of applications. By exploiting an improved SPAD technology, we have fabricated planar devices with diameter of 200 μm having low dark count rate (1500 c/s typical @ -25 °C). A photon timing jitter of 35 ps FWHM is obtained at room temperature by using a special pulse pick-up network for processing the Avalanche current. The state-of-the-art of large-area SPADs will be reviewed and prospects of further progress will be discussed pointing out the challenging issues that must be faced in the design and technology of SPAD devices and associated quenching and timing circuits.