We present a theoretical model that describes holographic ionic fixing and storage dynamics in photorefractive crystals. Holographic gratings that are based on charge redistribution inevitably decay because of ionic and electronic conduction. Relevant decay rates and transient hologram field expressions are derived. Ionic gratings are partially screened by trapped electrons on readout. The life...

Wendy Plesniak MIT Media Laboratory Spatial Imaging Group Cambridge, Massachusetts 02139 Abstract. We describe the incremental computing method for making localized changes to a computer-generated hologram to rapidly modify the 3-D image it reconstructs. The method populates a scene with holographic primitives, tracks scene-based changes, and updates the diffractive contributions of only affect...

The protection of the contents of digital products is referred to as content authentication. In some applications, to be able to authenticate a digital product could be extremely essential. For example, if a digital product is used as a piece of evidence in the court, its integrity could mean life or death of the accused. Generally, the problem of content authentication can be solved using semi...

We demonstrate an in-line digital holographic microscopy using a consumer scanner. The consumer scanner can scan an image with 4,800 dpi. The pixel pitch is approximately 5.29 μm. The system using a consumer scanner has a simple structure, compared with synthetic aperture digital holography using a camera mounted on a two-dimensional moving stage. In this demonstration, we captured an in-line h...

A neural-network architecture of multifaceted planar interconnection holograms and optoelectronic neurons is analyzed. Various computer-generated hologram techniques are analyzed and tested for their ability to produce an interconnection hologram with high-accuracy interconnects and high diffraction efficiency. A new technique is developed by using the Gerchberg-Saxton algorithm, followed by a ...

Received May 9, 1991; revised manuscript received February 14, 1992; accepted February 25, 1992 The mismatch in the number of degrees of freedom supported by volume holograms and the boundary fields that control them limits the dynamic range of recorded holograms. For holograms controlled by using fractal sampling grids, the maximum dynamic range falls inversely with the minimum number of expos...

We describe new techniques of synthesizing three types of computer-generated hologram (CGH); Fourier, Fresnel and image CGHs. These holograms, aimed to reconstruct three-dimensional (3-D) objects, are synthesized by means of a unique algorithm of fusing multiple perspective views of the observed scene. The hologram is initially generated in the computer as a Fourier hologram. Then, it can be co...

A three-dimensional (3D) object reconstruction technique that uses only phase information of a phase-shifting digital hologram and a phase-only spatial-light modulator is proposed. It is well known that a digital hologram can store both amplitude and phase information of an optical electric field and can reconstruct the original 3D object in a computer. We demonstrate that it is possible to rec...

Holography is a method for three-dimensional imaging of objects. In this paper we present an approach for the generation of holograms, exploiting standard graphics rendering methods and hardware. We focus on the visualization of objects composed of line segments, which allow for certain simplifications, and thus hologram generation speed-up. Our method is based on the derivation of a holographi...

Different optical imaging techniques are based on different characteristics of light. By controlling the abrupt phase discontinuities with different polarized incident light, a metasurface can host a phase-only and helicity-dependent hologram. In contrast, ghost imaging (GI) is an indirect imaging modality to retrieve the object information from the correlation of the light intensity fluctuatio...