Experimental characterization of an isoplanatic patch in mouse cortex using adaptive optics.

Optical microscopy techniques have become essential tools for studying normal and pathological biological systems. However, in many situations, image quality deteriorates rapidly in the field of view due to optical aberrations and scattering induced by thick tissues. To compensate for these aberrations and restore the microscope's image quality, adaptive optics (AO) techniques have been proposed for the past 15 years. A key parameter for the AO implementation lies in the limited isoplanatic dimension over which the image quality remains uniform. Here, we propose a method for measuring this dimension and deducing the anisoplanatism and intensity transmission of the samples. We apply this approach to fixed slices of mouse cortices as a function of their thickness. We find a typical mid-maximum width of 20 µm for the isoplanatic spot, which is independent of sample thickness.