Wide-Field Multiphoton Imaging Through Scattering Media Without Correction.

Optical approaches to fluorescent, spectroscopic and morphological imaging have made exceptional advances in the last decade. Super-resolution imaging and wide-field multiphoton imaging are now underpinning major advances across the biomedical sciences. Whilst the advances have been startling, the key unmet challenge to date in all forms of optical imaging is to penetrate deeper. Conventional thinking has implemented the areas of aberration correction and the use of complex photonics to address this need. In contrast, here we break this paradigm by implementing a scheme that requires no \textit{a priori} information about the media nor its properties. Exploiting temporal focusing and single-pixel detection in our innovative scheme we obtain wide-field two-photon images through various turbid media including a scattering phantom and tissue, at depths up to 540~$\mu$m. We anticipate this major advance becoming a mainstay for two- and three-photon imaging as well as super-resolution imaging at depth.