Two-photon bi-functional refractive Index and fluorescence microscopy (2P-BRIEF)

This is the authors' abstract. We don't add key points for this paper.

Understanding the dynamic interaction between fluorescence-labeled and label-free structures is important. The two types of signals are conventionally collected by fluorescence and phase microscopy, respectively. Recently, we developed a one-photon bi-functional microscopy system for simultaneous imaging of fluorescence and refractive index. However, it cannot reconstruct the refractive index of highly scattering samples with dense fluorophores. To solve this challenge, we develop new two-photon multimodal microscopy that reconstructs the 3D refractive index and fluorescence from multiple two-photon fluorescence images with a multi-slice model. We validated this method using a sample consisting of a mixture of fluorescence and glass beads.