Those starting to study electron optics, or charge-particle optics, now are very fortunate indeed; the three-volume encyclopedic text book of Hawkes and Kasper, 1989a, Hawkes and Kasper, 1989b, 1994) is available to show the various aspects of the subject in proper perspective, presenting thorough and comprehensive analysis with detailed guidance to the literature. In particular, in a single volume (Hawkes and Kasper, 1994) we find a detailed and up-to-date account of the fundamentals of the developments of the past three decades in" electron wave optics" where in whole branches of the subject have emerged since the appearance of the late Walter Glaser's classical article (Glaser, 1956), which was the last attempt to cover systematically the whole of electron optics.

The present chapter is a modest attempt to supplement the excellent survey of the analytic treatment of the scalar theory of electron wave optics …