Advanced illumination techniques for high-contrast highresolution fluorescence and scattering microscopy

In light microscopy an object is illuminated with a lamp or a laser and the transmitted,
reflected or fluorescent light is detected to get information on the object. In the project two approaches will be developed to study small particles and their interaction with living cells: Light Sheet Fluorescence Microscopy and Complex Beam Scattering Microscopy.
In standard fluorescence microscopy the entire sample is illuminated and there is an important background arising from fluorescent material that is out of focus. In this project we will illuminate the sample with a sheet of light that coincides with the focal plane of the microscope, so that only that part of the sample that is in focus is illuminated. This can be realized with an optical fiber or by illuminating through the microscope objective lens onto an inclined mirror mounted on the sample holder. These solutions should be inexpensive and compatible with existing microscopes.
For the study of small sub-resolution features in a sample we plan to scan specially designed focused laser beams near the object of interest and to detect the scattered light. The images of the scattered light are rich in information about the optical properties of the object of interest, such as size, shape and refractive index. In the project we will build a setup to scan different focused laser beams along an object, simulate scattering images for known objects and estimate the properties of unknown sub-resolution objects based on the scattering images.