Potential approaches for fabricating non-classical ruled diffraction gratings with large apertures

Principles for the design of pendulum-type ruling engines and their potential application for the fabrication of non-classical ruled diffraction gratings with large apertures are considered. For spherical diffraction gratings, the derivation of the analytical dependences for the determination of the geometrical shape of the curvilinear projections of their grooves, their curvature radii, and variable pitch is presented. Expressions for the coefficients of first–third-order aberrations are obtained.