Coded ultrafast optical pulses can be treated as onedimensional (1-D) images in the time domain. We have converted space-domain images into time-domain images using diffraction from dynamic holograms inside a Fourier pulse shaper, with photorefractive quantum wells (QW’s) used as the dynamic holographic medium. We present several examples, in which amplitude or phase modulation of the hologram ...

A two-block X-ray Fresnel zone plate system forms two-beams - a plane wave and a spherical wave - which interfere at the focal distance of the virtual source of the spherical wave. An object placed in the path of the plane wave forms an object wave and the spherical wave is the reference wave. The recorded intensity distribution is the Fourier transform hologram of the object. Analytical and nu...

We show here that through an adaptive deformation of digital holograms it is possible to manage the depth of focus in 3D imaging reconstruction. Deformation is applied to the original hologram with the aim to put simultaneously in focus, and in one reconstructed image plane, different objects lying at different distances from the hologram plane (i.e., CCD sensor). In the same way, by adapting t...

The Gröbner fan of an ideal I ⊂ k[x1, . . . , xn], defined by Mora and Robbiano, is a complex of polyhedral cones in Rn. The maximal cones of the fan are in bijection with the distinct monomial initial ideals of I as the term order varies. If I is homogeneous the Gröbner fan is complete and is the normal fan of the state polytope of I. In general the Gröbner fan is not complete and therefore no...

A new method for resolution control in numerical reconstruction of digital holography is proposed. The wave field on a tilted or vertical plane can be reconstructed without being subject to the minimum object-to-hologram distance requirement, and the pixel resolution can be easily controlled by adjusting the position of a transitional plane. The proposed method solves the problem of pixel resol...

Conventional metasurface holograms relying on metal antennas for phase manipulation suffer from strong Ohmic loss and incomplete polarization conversion. The efficiency is limited to rather small values when operating in transmission mode. Here, we implement a high-efficiency transmissive metasurface hologram by leveraging the recently developed Huygens' metasurface to construct an electric and...

We suggest a method for coding high-resolution computer-generated volume holograms. It involves splitting the computer-generated hologram into multiple holograms, their individual recording as volume holograms by use of the maximal resolution available from the spatial light modulator, and subsequent simultaneous reconstruction. We demonstrate the recording and the reconstruction of a computer-...

The storage capacity of holographic associative memories is estimated. An argument based on the available degrees of freedom shows that the number of patterns that can be stored is limited by the space-bandwidth product of the hologram divided by the number of pixels in each pattern. A statistical calculation shows that if we attempt to store associations by multiply exposing the hologram, the ...

We present multiple-image encryption (MIE) based on compressive holography. In the encryption, a holographic technique is employed to record multiple images simultaneously to form a hologram. The two-dimensional Fourier data of the hologram are then compressed by nonuniform sampling, which gives rise to compressive encryption. Decryption of individual images is cast into a minimization problem....