Background Rejection in Two-Photon Fluorescence Image Scanning Microscopy
Colin J. R. Sheppard, Marco Castello, Giorgio Tortarolo, Alessandro Zunino, Eli Slenders, Paolo Bianchini, Giuseppe Vicidomini, and Alberto Diaspro (see publication in Journal )Abstract
We discuss the properties of signal strength and integrated intensity in two-photon excitation confocal microscopy and image scanning microscopy. The resolution, optical sectioning and background rejection are all improved over nonconfocal two-photon microscopy. Replacing the pinhole of confocal two-photon microscopy with a detector array increases the peak intensity of the point spread function. The outer pixels of a detector array give signals from defocused regions, and thus the processing of these, such as through subtraction, can further improve optical sectioning and background rejection.