Time-zoomable FRET spectroscopy with a 512 x16 SPAD line sensor

Ahmet T. Erdogan, Gareth O.S. Williams, Andrea Usai, Nikola Krstajic, Neil Finlayson, Andrew Beavil, Rebecca Beavil, Robert K. Henderson

    Research output: Chapter in Book/Report/Conference proceedingConference contribution

    3 Citations (Scopus)
    193 Downloads (Pure)


    We demonstrate a new 512x16 single photon avalanche diode (SPAD) based line sensor with per-pixel TCSPC histogramming for time-resolved, time-zoomable, FRET spectroscopy. The line sensor can operate in single photon counting (SPC) mode as well as time-correlated single photon counting (TCSPC) and per-pixel histogramming modes. TCSPC has been the preferred method for fluorescence lifetime measurements due to its collection of full decays as a histogram of arrival times. However, TCSPC is slow due to only capturing one photon per exposure and large timestamp data transfer requirements for offline histogramming. On-chip histogramming improves the data rate by allowing multiple SPAD pulses (up to one pulse per laser period) to be processed in each exposure cycle, along with secondly reducing the I/O bottleneck as only the final histogram is transferred. This can enable 50x higher acquisition rates (up to 10 billion counts per second), along with time-zoomable histogramming operation from 1.6ns to 205ns with 50ps resolution. A broad spectral range can be interrogated with the sensor (450-900nm). Overall, these sensors provide a unique combination of light sensing capabilities for use in high speed, sensitive, optical instrumentation in the time/wavelength domain. We test the sensor performance by observation of fluorescence resonance energy transfer (FRET) between FAM and TAMRA and between EGFP and RFP FRET standards.

    Original languageEnglish
    Title of host publicationBiophysics, Biology and Biophotonics III
    Subtitle of host publicationThe Crossroads
    EditorsAdam Wax, Vadim Backman
    PublisherSPIE-International Society for Optical Engineering
    ISBN (Electronic)9781510614932
    Publication statusPublished - 20 Feb 2018
    EventBiophysics, Biology and Biophotonics III: The Crossroads 2018 - San Francisco, United States
    Duration: 28 Jan 201828 Jan 2018

    Publication series

    ISSN (Print)0277-786X


    ConferenceBiophysics, Biology and Biophotonics III: The Crossroads 2018
    Country/TerritoryUnited States
    CitySan Francisco


    • CMOS
    • Fluorescence lifetime
    • FRET
    • Histogram
    • Single Photon Counting
    • SPAD
    • Spectroscopy
    • TCSPC

    ASJC Scopus subject areas

    • Electronic, Optical and Magnetic Materials
    • Biomaterials
    • Atomic and Molecular Physics, and Optics
    • Radiology Nuclear Medicine and imaging


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