Fig. S3.

Recovery of diffraction-limited resolution. (A) MIP of the raw data used for the deconvolution in Fig. 4. (Scale bar: 5 µm.) (B) Plot of the dendritic spine neck along the dotted white line in A. Before deconvolution, the original diffraction-limited resolution of the microscope is recovered through the intact skull. The black dotted line shows the Gaussian fit with an FWHM of 0.69 µm, agreeing well with the measured system PSF in a clear medium. (C) The Fourier spectrum of A. (D) The same FOV before correction. (E) The Fourier spectrum of D. As a result of severe wavefront distortions, the out-of-focus excitation overwhelmed the ballistic excitation without correction. As the total power of the laser remained the same (phase-only wavefront shaping), after correction, the out-of-focus excitation was reduced, whereas the laser focus became stronger. To quantify the reduced background, we compared the average signal in the magenta dotted squares in A and D and found that the background was reduced by 2.6.