If a scanning illumination spot is combined with a detector array, we acquire a 4 dimensional signal. Unlike confocal microscopy with a small pinhole, we detect all the light from the object, which is particularly important for fluorescence microscopy, when the signal is weak. The image signal is basically a cross-correlation, and is highly redundant. It has more than sufficient information to reconstruct an improved resolution image. A 2D image can be generated from the measured signal by pixel reassignment. The result is improved resolution and signal strength, the system being called image scanning microscopy. A variety of different signal processing techniques can be used to predict the reassignment and deconvolve the partial images. We use an innovative single-photon avalanche diode (SPAD) array detector of 25 detectors (arranged into a 5× 5 matrix). We can simultaneously acquire 25 partial images and process to calculate the final reconstruction online.

© (2018) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.

Colin J. R. Sheppard, Mauro Buttafava, Marco Castello, Alberto Diaspro, Giorgio Tortarolo, Alberto Tosi, Giuseppe Vicidomini, and Federica Villa, "Image scanning microscopy (ISM) with a single photon avalanche diode (SPAD) array detector," Proc. SPIE 10679, Optics, Photonics, and Digital Technologies for Imaging Applications V, 106790H (Presented at SPIE Photonics Europe: April 24, 2018; Published: 24 May 2018); https://doi.org/10.1117/12.2309825.