ABSTRACT
This chapter points to the synergy between optics and mechanics citing the relevant example of the early days of electron optics when the analogy with light optics provided much guidance. The inspiration for the spinor theory of charged particle beam optics also came from the studies on the optics of polarized light! It is recalled that the formalism of quantum charged particle beam optics in turn has recently led to a similar approach, called quantum methodology, to the Helmholtz scalar and the Maxwell vector optics. In future, developments in technology would certainly require quantum theory for the purposes of design and operation of various kinds of charged particle beam devices. This chapter lists several remarks on the necessity for the use of quantum charged particle beam optics in future charged particle beam devices and particle accelerators, and the main problems to be addressed in the future development of the quantum charged particle beam optics.
