Abstract: In a speckle imaging process, the contribution of non-uniform, incoherent background illumination is removed via an aperture sampling technique. A pair of uncorrelated speckle images are produced and subtracted from one another to eliminate the non-coherent background contribution. The result of this subtraction is rectified so as to provide a signal which may be displayed on a video display. Disclosed are techniques for real time video display of enhanced speckle images as well as techniques for visualizing vibrational modes and surface roughness mapping.

Abstract: A method for producing multicolor holographic optical elements useful in presentation of multicolor holographic images in a head-up display (HUD) system. Because of restricted geometries, such HUDs should allow for reconstruction of wavefronts employing all readout beams coming from the same direction, with the reconstructed wavefront being cast in a specified direction. A first method for producing a multicolor HOE satisfying these conditions makes all recording at the same wavelength but with varying record geometries. A second method for producing multicolor HOEs employs the same record geometries but uses varying wavelengths of recording light. This allows the recording to be made under conditions where the diffraction efficiency of the resulting HOEs is controlled, as are the displayed colors.