Two-photon fluorescence microscopy with differential aberration imaging

We report our progress in the development of Differential Aberration Imaging (DAI), a technique that enhances twophoton fluorescence (TPEF) microscopy by improving rejection of out-of-focus background by means of a deformable mirror (DM). The DM is used to intentionally add aberrations to the imaging system, which causes dramatic losses to in-focus signal while preserving the bulk of the out-of-focus background. By taking the difference between TPEF images with and without added aberrations, the out-of-focus portion of the signal is further rejected. We now introduce an implementation of DAI using a new type of DM that can be produced at much lower cost.