Search results
Results from the WOW.Com Content Network
Computer-generated holography (CGH) is a technique that uses computer algorithms to generate holograms.It involves generating holographic interference patterns.A computer-generated hologram can be displayed on a dynamic holographic display, or it can be printed onto a mask or film using lithography. [1]
The hologram keeps the information on the amplitude and phase of the field. Several holograms may keep information about the same distribution of light, emitted to various directions. The numerical analysis of such holograms allows one to emulate large numerical aperture, which, in turn, enables enhancement of the resolution of optical microscopy.
This is important because two waves of different frequencies do not produce a stable interference pattern. The coherence length of the laser determines the depth of field which can be recorded in the scene. A good holography laser will typically have a coherence length of several meters, ample for a deep hologram.
Digital holography is the acquisition and processing of holograms with a digital sensor array, [1] [2] typically a CCD camera or a similar device. Image rendering, or reconstruction of object data is performed numerically from digitized interferograms.
[1] [2] The essence of the DPH technology is embedding computer designed digital holograms inside a planar waveguide. Light propagates through the plane of the hologram instead of perpendicularly, allowing for a long interaction path. Benefits of a long interaction path have long been used by volume or thick holograms. Planar configuration of ...
A hogel (a portmanteau of the words holographic and element) is a part of a light-field hologram, in particular a computer-generated one. It is considered a small holographic optical element or HOE and that its total effect to that of a standard hologram only that the resolution is lower and it involves a pixelated structure. [1]
Since its introduction, vibrometry by holographic interferometry has become commonplace. Powell and Stetson have shown that the fringes of the time-averaged hologram of a vibrating object correspond to the zeros of the Bessel function (), where (,) is the modulation depth of the phase modulation of the optical field at , on the object. [1]
At the heart of this new memory lies a novel bi-modal representation of pattern and a hologram-like complex spherical weight state-space. Besides the usual advantages of associative computing, this technique also has excellent potential for fast optical realization because the underlying hyper-spherical computations can be naturally implemented ...