  We present a laser scanning reflection-matrix microscopy combining the
scanning of laser focus and the wide-field mapping of the electric field of the
backscattered waves for eliminating higher-order aberrations even in the
presence of strong multiple light scattering noise. Unlike conventional
confocal laser scanning microscopy, we record the amplitude and phase maps of
reflected waves from the sample not only at the confocal pinhole, but also at
other non-confocal points. These additional measurements lead us to
constructing a time-resolved reflection matrix, with which the sample-induced
aberrations for the illumination and detection pathways are separately
identified and corrected. We realized in vivo reflectance imaging of myelinated
axons through an intact skull of a living mouse with the spatial resolution
close to the ideal diffraction limit. Furthermore, we demonstrated
near-diffraction-limited multiphoton imaging through an intact skull by
physically correcting the aberrations identified from the reflection matrix.
The proposed method is expected to extend the range of applications, where the
knowledge of the detailed microscopic information deep within biological
tissues is critical.
