Time-domain diffuse optics with 8.6  mm² fast-gated SiPM for extreme light harvesting

Area of Science:

• Biomedical Optics
• Photonics
• Medical Imaging

Background:

• Fast time-gated single-photon detectors offer depth sensitivity for detecting absorption perturbations in scattering media.
• Clinical applications, such as in vivo functional brain imaging, are limited by the small active area (<0.04 mm²) of existing detectors.

Purpose of the Study:

• To demonstrate the performance of a fast-gated digital silicon photomultiplier (SiPM) with a large active area (8.6 mm²).
• To overcome the photon collection limitations of conventional time-gated single-pixel detectors for deep tissue investigations.

Main Methods:

• Utilized a fast-gated digital silicon photomultiplier (SiPM) with an 8.6 mm² active area.
• Evaluated detector performance on phantoms and in vivo.
• Measured depth sensitivity and signal-to-noise ratio at late photon arrival times.

Main Results:

• The digital SiPM demonstrated superior photon collection capability compared to established single-pixel detectors.
• Achieved high depth sensitivity for detecting absorption perturbations within scattering media.
• Enabled deep investigations and high signal-to-noise ratios at late photon arrival times.

Conclusions:

• The large-area fast-gated digital SiPM significantly enhances capabilities for in vivo optical imaging.
• This technology overcomes previous limitations, enabling deeper penetration and improved signal detection in scattering biological tissues.
• Facilitates advanced functional imaging applications, including brain activation studies.