Resolution enhanced multiphoton microscopy

Problem statements

For decades, optical microscopy has played an important role in the observation of cell biology. In microscopy, as for all imaging optical system, the spatial resolution is limited. Recently, several new approaches have been developed to overcome this limit, particularly in fluorescence microscopy. We investigate the use of saturation of the fluorescence excitation for improving the spatial resolution.

Contributions

At high excitation intensities, saturation of the excitation probability of the fluorophore occurs and induces a strong nonlinear fluorescence response. This can be used to retrieve structural information from a region smaller than the non-saturated excitation point spread function. In this work, we investigate the performances of this technique in the context of multi-photon fluorescence microscopy by temporally modulating the illumination intensity. As a first step, we have tested the technique on 200 nm fluorescent microspheres and we are now applying it to samples of biological interest.