Characterization of the angular memory effect of scattered light in biological tissues.

This is the final version of the article. Available via open access from Optical Society of America via the DOI in this record.High resolution optical microscopy is essential in neuroscience but suffers from scattering in biological tissues and therefore grants access to superficial brain layers only. Recently developed techniques use scattered photons for imaging by exploiting angular correlations in transmitted light and could potentially increase imaging depths. But those correlations ('angular memory effect') are of a very short range and should theoretically be only present behind and not inside scattering media. From measurements on neural tissues and complementary simulations, we find that strong forward scattering in biological tissues can enhance the memory effect range and thus the possible field-of-view by more than an order of magnitude compared to isotropic scattering for ∼1 mm thick tissue layers.This work was funded by European Research Council Grant 278025 and the Agence Nationale de la Recherche (Investissements d’Avenir ANR-10-LABX-54 MEMO LIFE, ANR-11-IDEX- 0001-02 PSL* Research University). We thank Prof. Georg Maret for enabling Sam Schott’s stay at institut Langevin and his support of the project and David Martina for technical help in the development of the experimental setup