Imaging approaches (A–D) Schematic representations of utilisation of Adaptive Optics for gaining depth in imaging. (A) Without adaptive optics, deeper imaging quality suffers from both distortions in the excitation as well as the emission wavefronts. (B) Ideal situation with deformable motors correcting both excitation profiles and emission wavefronts for best-case scenario. (C) Wavefront correction parameters fed into deformable mirrors by inferring the corrections required by sensing wavefront from a ‘guide-star’ emission created by a multiphoton spot excitation. (D) Metrics based parameter iterative optimisation to feed aberration correction to deformable mirrors. (E) An overview of different techniques plotted with x-axis representing lateral resolution (nm), and y-axis the imaging depth (μm). The area of the squares for each technique corresponds to the field of view as scaled to the red length bar (μm). Together with the imaging depth, the ‘view-volume’ can be approximated. The bottom plot represents the axial resolution of the techniques (μm). Single objective light sheet (SOLS) [110], 3D structured illumination microscopy (3D SIM) [111,112], spinning disk (SD) [113], widefield (WF) [114,115], lattice light sheet microscopy (LLSM) [116,117], dual inverted selective plane illumination microscopy (diSPIM) [118], axially swept light sheet microscopy (ASLM) [119], swept confocally-aligned planar excitation (SCAPE) [120], IsoView [121], 2-photon/3-photon Bessel light sheet [122], raster adaptive optics polyscope (RAO-polyscope) [123], 2-photon random access mesoscope (2P RAM) [124], mesolens-widefield [125], 2-photon planar Airy [126].