Fresnel holograms

Figure 5. Schematic arrangement for hologram formation with an electron biprism. A plane wave illuminates the specimen placed off-axis. After the object lens a wire is placed between two earthed plates. The wire is the electron optical analog of a Fresnel biprism and causes the unperturbed and perturbed waves forming the electron hologram to interfere. The object phase-shift causes a displacement in the hologram fringes, and is thus observable.

FIGURE 14 Fresnel zone plate (hologram due to a point object). 

In Fresnel-type HOEs, the light distribution in the hologram plane is the Fresnel diffractive image of the object. For radially symmetrical kinoforms (rings and circles), 2D Fourier and Fresnel integrals are reduced to ID Hankel s integrals [146]. 

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