Wide-field time-gated SPAD imager for phasor-based FLIM applications

Area of Science:

• Biophotonics
• Optical Imaging
• Fluorescence Spectroscopy

Background:

• Fluorescence Lifetime Imaging Microscopy (FLIM) is a powerful technique for analyzing biological samples.
• High-throughput FLIM requires sensitive and fast detectors.
• Single-Photon Avalanche Diode (SPAD) arrays offer potential for advanced FLIM applications.

Purpose of the Study:

• To evaluate the performance of a novel wide-area time-gated SPAD array for phasor-FLIM.
• To investigate the impact of gate length, gate number, and signal intensity on lifetime measurements.
• To assess the suitability of the phasor approach for large-format SPAD sensors.

Main Methods:

• Characterization of a 512x512 pixel time-gated SPAD array.
• Phasor analysis applied to FLIM data acquired with varying experimental parameters.
• Assessment of lifetime accuracy and precision under different signal conditions.

Main Results:

• The SPAD array demonstrated performance close to the ideal shot-noise limit.
• Accurate and precise fluorescence lifetime measurements were achieved.
• Video-rate FLIM acquisition is feasible with this detector technology.
• The phasor approach effectively managed large datasets from the 512x512 sensor.

Conclusions:

• The wide-area time-gated SPAD array is a capable sensor for high-speed FLIM.
• Phasor analysis is well-suited for processing data from large SPAD arrays, even with limited photons.
• This technology advances the potential for rapid, quantitative biological imaging.