Theoretical research on electron optics

This paper summarizes theoretical research on electron optics in the field of electron microscopy that has been carried out by the author and his colleagues over a long period of time. The main topics to be discussed include the rotationally symmetrical imaging system and its aberrations; the method of matrix algebraic calculation and its applications to electron optics; new developments in scanning electron beam systems, i.e., the combined electromagnetic focusing-deflection system with superimposed fields; the electromagnetic multipole system and its aberrations; the ion optical system with a curvilinear axis and its aberrations; and the phase retrieval in Fourier electron microscopy. This review may help to promote a better understanding of the present state of, and trends in, Chinese electron optics research.