Gated STED microscopy with time-gated single-photon avalanche diode

Area of Science:

• Optical microscopy
• Super-resolution imaging
• Biophysics

Background:

• Stimulated emission depletion (STED) microscopy offers sub-diffraction resolution imaging.
• Time-gated detection in STED microscopy reduced complexity and illumination intensity but decreased signal.
• Maximizing photon flux within the time gate is crucial for high-quality STED images.

Purpose of the Study:

• To investigate the use of a fast-gated single-photon avalanche diode (SPAD) for improving gated STED microscopy.
• To enhance the signal-to-noise ratio (SNR) of STED images obtained with time-gated detection.
• To assess the impact of SPADs on system complexity and performance in STED microscopy.

Main Methods:

• Implementation of a fast-gated single-photon avalanche diode (SPAD) in a STED microscope setup.
• Utilizing a continuous-wave (CW) STED beam for gated detection experiments.
• Testing the system on calibration samples and biological specimens.

Main Results:

• The fast-gated SPAD significantly improved the signal-to-noise ratio (SNR) of gated STED images.
• The use of SPADs reduced the overall complexity of the STED microscopy system.
• Demonstrated enhanced imaging performance on both calibration and biological samples.

Conclusions:

• Fast-gated SPADs are effective in enhancing SNR for gated STED microscopy.
• SPAD integration simplifies STED system design while improving image quality.
• This technology is compatible with both continuous-wave (CW) and pulsed STED implementations.