Holographic Head-Up Displays (HUDs) have major operational advantages over displays employing only conventional optics : principal among these are high display brightness for little attenuation of the outside world and the ability to cover wide angular fields of view. In addition, diffractive power can be used to give the effect of a shape other than that of the substrate on which the hologram is formed. There are limitations, however, particularly with regard to the amount of diffractive power that can be employed, the obliquity at which the hologram can operate and the vertical head movement over which high display brightness can be achieved. The paper considers both advantages and disadvantages of holographic HUDs and the application of this type of system to aircraft and, possibly, automobiles.
Philip J. Rogers,
"Holographic Head-Up Displays For Air And Ground Applications", Proc. SPIE 1013, Optical Design Methods, Applications and Large Optics, (13 April 1989); doi: 10.1117/12.949372; https://doi.org/10.1117/12.949372