Executive Summary : | This project aims to develop a new light-sheet microscopy instrument for biological imaging applications. Light-sheet microscopy is a variant of dark-field microscopy, where an illumination beam is shaped like a thin sheet of light, which illuminates or optically sections a sample's plane of interest. This illuminated plane is then imaged directly on an image sensor array using a widefield microscope placed in the orthogonal orientation. Despite its simplicity and long history, light-sheet microscopy has been limited to a small community of microscope builders due to high costs and limited commercial options. Commercial light-sheet systems are restricted to high resolution, low field of view imaging that acquires large 3D volumes by stitching multiple images together. However, this method has drawbacks such as high cost, large data volume, and physical limitations on object size. The project focuses on imaging large samples, such as neuronal or vascular resolution imaging in zebrafish larvae and other tens of millimeter scale small samples. The core idea is to convert low-cost dry/air microscope objectives into immersion objectives and use them to build the light-sheet system. A custom designed external cap will make the microscope objective water (or other media) immersible, increasing the working distance and spherical aberrations of the objective lens. This will help with easy focusing of the optically sectioned plane. A method for suppressing stripe artefacts in light-sheet systems will be combined with a galvo scanner and a beam shaping element to generate angularly diverse light-sheet illumination, resulting in more uniform illumination around absorption centers. With extensive experience in light-sheet microscopy systems, the project is confident in delivering a complete light-sheet microscopy system capable of cellular resolution fluorescence imaging in small organisms. |