Fig. 3. Imaging through the thinned skull of a sparsely labelled THY1-YFP mouse 470 μm below the brain surface.

Maximum intensity projection of a 190 × 190 × 80 μm³ volume using conventional 2P (a), pupil F-SHARP (b) and conjugate F-SHARP (c). Images in a–c are presented on the same colour scale and with a saturation corresponding to 0.5 of the maximum signal. The measured E-field PSF at the centre of the image (d) and the corresponding correction pattern assigned to the wavefront shaper (e) demonstrate a PSF that is highly scattered (phase shown in pseudo colour, using a circular HSV colour map). The conjugate F-SHARP module allows us to increase both the signal intensity and the resolution over an extended FOV compared with conventional 2P and F-SHARP. The achieved FOV increases from 15 μm (pupil F-SHARP) to 80 μm (f).