Fig. 7.

Aberration correction over a large area. (a), 2PEF image of a Vectashield-embedded brain slide 150μm below the surface. Scale bar, 100μm. (b) (resp. (c)), map of the Strehl ratio after spatially unresolved aberration correction over the green boxed region in (a)(resp. the entire area in (a)). (d), Strehl ratio in the green boxed region after correction over a region centred on this boxed region and of varying size. The dotted line is the lower limit for diffraction-limited focussing and the solid line is the value achieved after correction over the entire image. (e)–(g), Strehl ratio map after spatially resolved correction over (e), 9; (f), 25; and (g), 64 subregions. (h), percentage of the image area for which the Strehl ratio is above 0.8 as a function of the number of subregions used for spatially resolved correction. (b)–(g) maps share the same colour scale and pixel size (10μm).