White light 3-D image plane holography

Abstract

We present a technique for recording and reconstructing an image plane hologram of a 3-D object using a white light source. A diffraction grating is placed in the image plane of a lens in intimate contact with the holographic emulsion. The grating structure is multiplied onto the recorded negative image of the object to serve as a spatial frequency carrier for the holographic image. The substitution of a diffraction grating in place of an external reference beam drastically reduces the temporal coherence requirements for this type of image plane holography. The spatial and temporal coherence requirements are calculated and shown to be consistent with a wide variety of holographic applications involving large 3-D objects. The holographic image reconstruction is accomplished by spatial filtering the optical Fourier transform of the original recorded hologram. The zero spatial frequency diffraction order produces a negative image of the original object while the nonzero diffraction orders produce a positive holographic image which exhibits parallax effects.