Off-axis digital holography typically uses a beam splitter to combine reference and object waves at an angle matched to the sampling period of the sensor array. The beam splitter determines the thickness of the recording system. This paper describes and demonstrates a total internal reflection hologram that replaces the beam splitter and enables hologram recording over a large aperture with a t...

The application of conventional reflector-type compact antenna test ranges (CATR’s) becomes increasingly difficult above 100 GHz. The main problems are the tight surface accuracy requirements for the reflectors and, therefore, the high manufacturing costs. These problems can be overcome by the use of a hologram type of compact range in which a planar hologram structure is used as a collimating ...

We introduce M/# as a metric for characterizing holographic memory systems. M/# is the constant of proportionality between diffraction efficiency and the number of holograms squared. Although M/# is a function of many variables in a holographic recording system, it can be measured from the recording and erasure of a single hologram. We verify experimentally that the diffraction efficiency of mu...

We describe and demonstrate a volume holographic storage system in which a phase-conjugate object beam is reconstructed by the same reference beam that was used for recording. An intermediate hologram is used as a temporary buffer, recorded with its own reference beam and the data-bearing object beam. Reading this buffer hologram with the phase conjugate of its reference beam reconstructs the p...

We present a holographic theory of human memory. According to the theory, a subject's vocabulary resides in a dynamic distributed representation-a hologram. Studying or recalling a word alters both the existing representation of that word in the hologram and all words associated with it. Recall is always prompted by a recall cue (either a start instruction or the word just recalled). Order of r...

A marbled image is generated by performing marbling operations on an image. When the marbled image is recovered to the original image, the parameters of the marbling operations should be known in the decoding process. By embedding these into the marbled image, we can eliminate an additional internet transmission. This paper proposes a watermark algorithm for marbled images based on a linear enh...

The worldsheet of a macroscopic fundamental superstring in the Green-Schwarz light-cone gauge is viewed as a possible boundary hologram of the near horizon region of a small black string. For toroidally compactified strings, the hologram has global symmetries of AdS3 ×Sd−1 ×T8−d (d = 3, . . . , 8), only some of which extend to local conformal symmetries. We construct the bulk string theory in d...

We describe a new application of super-resolution image reconstruction to digital holography which is a technique for threedimensional information recording and reconstruction. Digital holography has suffered from the low resolution of CCD sensors, which significantly limits the size of objects that can be recorded. The existing solution to this problem is to use optics to bandlimit the object ...

In no possible world does a time traveler succeed in killing her earlier self before she ever enters a time machine. So if many, many time travelers went back in time trying to kill their unprotected former selves, the time travelers would fail in many strange, “coincidental” ways, slipping on banana peels, killing the wrong victim, and so on. Such cases produce doubts about time travel. How co...