Wide-field multiphoton imaging with TRAFIX

Abstract

Optical approaches have broadened their impact in recent years with innovations in both wide-field and super-resolution imaging, which now underpin biological and medical sciences. Whilst these advances have been remarkable, to date, the ongoing challenge in optical imaging is to penetrate deeper. TRAFIX is an innovative approach that combines temporal focusing illumination with single-pixel detection to obtain wide-field multiphoton images of fluorescent microscopic samples deep through scattering media without correction. It has been shown that it can image through biological samples such as rat brain or human colon tissue up to a depth of seven scattering mean-free-path lengths. Comparisons of TRAFIX with standard point-scanning two-photon microscopy show that the former can yield a five-fold higher signal-to-background ratio while signifcantly reducing photo bleaching of the specimen. Here, we show the first preliminary demonstration of TRAFIX with three-photon excitation imaging dielectric beads. We discuss the advantages of the TRAFIX approach combined with compressive sensing for biomedicine.