Label-free multimodal femtosecond fiber laser microscopy of organoids with acousto-optic deflectors

Ultracompact femtosecond fiber lasers have become versatile tools for two-photon imaging and 3D lithography. In this study, we report on the application of an 80 MHz Er:doped fiber laser for both non-scanning ultrafast microscopic imaging as well as nonlinear scanning microscopy. Illumination was achieved either through x/y scanning beam or structured illumination using two acousto-optic deflectors integrated into a Mach-Zehnder interferometer module. A single-point detector with high temporal resolution (avalanche diode/photomultiplier) and a fast camera were employed. The combined imaging approach was tested on live, beating heart tissue organoids.