Introduction of microscopy principle for biology students: From Abbe theory to super-resolution microscopy

抄録

Optical microscopes use visible light on the wavelength scale of submicron, comparable to the size of cell structures. Students of basic biology will be convinced that light at this wavelength scale must limit the performance of light microscopes. While this explanation may seem intuitive, it is only one of two major factors that determine microscope’s resolution. The other limiting factor in microscopes may be difficult to fully understand without a background in basic physics and mathematics. Here, I present a two-step process for teachers to help students understand Abbe theory, the most important theory in microscope optics. First, I explain what the Fourier transform of an image is: how a two-dimensional image is decomposed into various stripes with different spacing and angles. I provide a simple yet precise explanation of the mathematics of Fourier transform. Next, I explain wave diffraction and interference, which provides a fundamental understanding of how light waves propagate and interact with observing materials depending on the spacings in striped patterns. I use several drawings to illustrate the concepts. Even students with no prior knowledge of resolution limits will be able to follow the explanations and appreciate the true breakthrough in super-resolution microscopy.