New advances in high-resolution optical microscopy

Laburpena

Microscopy is the science which aim is to view objects that can not be distinguished with the naked eye because the size of those objects are not within its resolution range. A microscope produces an enlarged image of a sample under research. Since microscopy is an essential tool for live and material sciences, this Thesis is devoted to study thoroughly optical microscopy. Optical microscopes can be performed in different ways to provide resulting images with different features. The simplest optical microscope is the widefield microscope. However it presents some limitations that needs to be overcome to obtain high-quality images. Among these limitations we find: axial mechanical scanning to provide the whole structure of a sample, the presence of spherical aberration due to the refractive-index mismatches between the immersion medium of the microscope objective, the coverglass and the specimen, the limitation of spatial resolution imposed by diffraction and the inability of obtaining quantitative phase images. Such limitations are analyzed in this Thesis and some solutions are proposed in order to provide better microscopic images. In particular, we have achieved: (1) a fast-axial scanning of thick samples in real time and without any mechanical movement, (2) an SA-invariant imaging system, (3) images with high lateral resolution and optical sectioning and (4) accurate quantitative phase images and without deteriorating the resolution limit imposed by diffraction. All these findings have been verified both theoretically and experimentally.