Depth resolution enhancement using light-field light-sheet fluorescence microscopy

Light sheet fluorescence microscopy (LSFM) utilizes a light sheet to optically section samples, giving it the advantages of high signal-to-noise ratio, low phototoxicity and rapid three-dimensional imaging, which is an ideal tool for long-time microscopic observation of living samples. However, due to the inherent characteristics of Gaussian light sheet, there is a contradiction between the field of view and depth resolution of LSFM. In life science research, high depth resolution is necessary to resolve fine structures of biological systems such as neurons. However, in order to maintain a large field of view, the thickness of Gaussian light sheet is limited. Here, we propose a depth resolution enhancement method for LSFM. The incorporation of light field imaging into LSFM allows the acquirement of light field information within the Gaussian light sheet. By using the light field back projection (LFBP) reconstruction algorithm and depth estimation algorithm, it is possible to obtain the depth information in a light sheet, so as to improve the depth resolution. We built a light field light sheet fluorescence microscope (LFLSFM), and demonstrated it by fluorescent microsphere experiments. The proposed method can achieve a depth resolution of 0.5um when the thickness of the light sheet is kept at 6um to ensure a large field of view. Therefore, the method has potentialities in visualizing neural network of tissues and organs such as mouse brain.