Microscopy through turbid layers using wave front shaping

Abstract

Microscopy through turbid layers is of great interest for biological applications. We present a setup, based on wave front shaping, which allows to image a fluorescent structure behind a turbid layer at diffraction-limited resolution. In this work we address three main problems. We first propose two methods to create a focus behind a turbid layer: the first based on the direct feedback of a detector placed behind the turbid layer, while the second, without direct access, allows to focus on a fluorescent nanobead. We then show how to move the focus in three dimensions, through memory effect, allowing to obtain an image of the structure behind the turbid layer through the measurement of the fluorescence emitted. Finally we propose an experimental attempt to enhance the contours of the image, based on a second scanning performed with a ring shaped focus.