Fig. 1. Pattern of aberration caused by refractive index mismatch. (a) Schematic of refraction between two types of media; (b) phase simulation of wavefront with spherical aberration caused by refractive index mismatch (d=200 mm, NA=0.75); (c) intensity distribution of light at O1; (d) intensity distribution of light at O2.

Fig. 2. Schematic of AO TPM system.

Fig. 3. TPM images of fluorescent beads in polyacrylamide gel with or without SA correction. (a) xz maximum intensity projection (MIP) image without SA correction; (b) xz MIP image with SA correction; (c)-(f) magnified images corresponding to Fig. 3(a) and 3(b)

Fig. 4. System resolution at the depth of 500 mm with or without SA correction. (a) Lateral (top) and axial (bottom) views of 0.1 mm fluorescent bead (a2) with and (a1) without SA correction; (b) lateral and (c) axial line profiles as indicated in Fig. 4(a) show the improvement of resolution with SA correction

Fig. 5. AO improves the axial resolution and fluorescence intensity at different depth. (a) Axial resolution at different depth with or without SA correction; (b) statistical results of fluorescence intensity improvement and axial resolution improvement at different depth

Fig. 6. Two-photon microscopic images of clearing Thy1-GFP mouse brain tissue. xz maximum intensity projection images (b) with and (a) without SA correction; xy images (d) with and (c) without SA correction at measurement depth of 190 mm below the surface; (e) intensity line profiles as indicated in Figs. 6(a) and 6(b)