Diffraction gratings - their principles and applications to machine tools

The use of diffraction gratings as measuring elements on machine tools is nowadays an accepted procedure. Part I of this paper therefore sets out to give a brief understanding of the principles of diffraction gratings, and the ways in which they have been utilised commercially. In addition, comparisons are made with other reference elements and some consideration is given to manufacturing techniques. Part II of the paper deals in more detail with the pure theory of crossed diffraction gratings.