Adaptive optical two-photon microscopy using autofluorescent guide stars.

We demonstrate a fast, direct wavefront-sensing method for dynamic in vivo adaptive optical two-photon microscopy. By using a Shack-Hartmann wavefront sensor and open-loop control, the system provides high-speed wavefront measurement and correction. To measure the wavefront in the middle of a Drosophila embryo at early stages, autofluorescence from endogenous fluorophores in the yolk were used as reference guide stars. The method was tested through live imaging of a Drosophila embryo. The aberration in the middle of the embryo was measured directly for the first time. After correction, the contrast and signal intensity of the structure in the middle of the embryo was improved.