Total internal reflection diffraction grating in conical mounting and its application in planar display

Abstract

Total internal reflection diffraction gratings in conical mounting, where the plane of incidence does not contain the grating vector, are investigated in this paper and the relevant conditions and parameters for such gratings are presented. These are then used to design total internal reflection diffraction gratings in conical mounting that the diffraction angle into the first order is equal to the incidence angle. The applications of such gratings in conical mounting to planar optics configurations, which have at least three gratings and one of them is total internal reflection diffraction grating in conical mounting, are discussed in detail. Also, the diffraction properties of all three gratings in this configuration, especially the grating period which is the most important parameter of gratings, are analyzed. The main condition, on which all the gratings in planar display configuration have the same grating periods, is presented based on theoretical analysis: the turning grating should be in 60 deg conical mounting. The configuration can be used to virtual display or wearable display.