Television Transmission of Holograms With Reduced Resolution Requirements on the Camera Tube

Abstract

This paper proposes a technique for the television transmission of a hologram of a two‐dimensional transparency. The spatial resolution required on the camera tube is reduced by a factor of four compared with the transmission of a conventional off‐axis reference beam hologram. The resolution required is therefore no higher than that required for the direct transmission of the transparency itself. Implementation of the proposed arrangement should be easy. Three holograms formed with an on‐axis reference beam are transmitted. The phase of the reference beam assumes the values 0°, 120°, and 240° for the first, second, and third hologram, respectively. The carrier‐frequency hologram is “synthesized” from these three on‐axis holograms at the receiver. The technique has the further advantage that the undesirable zero‐order terms are eliminated.

Review on the State-of-the-Art Technologies for Acquisition and Display of Digital Holograms

“…The diffracted object wave is then sequentially mixed with M (where 2 ≤ M ≤ 4) different phase shifted versions of the reference beam, and the interference patterns (each referred to an interferogram) are summed up to give the complex hologram of the 3-D object. The pioneering work dates back to [14], demonstrating the electronic transmission of holographic signals captured by camera tubes. The realization of PSH system with modern digital camera has been reported in [15].…”

Holographic bandwidth compression using spatial subsampling

“…Burckhardt and Enloe 14,17 reduced the information recorded in a hologram by exposing an array of small regularly spaced areas. This work was equivalent to spatially subsampling the hologram.…”

Considerations of Television Holography

“…One method of video storage involves the sequential display of the three on-axis holograms on a cathode-ray tube which are then photographed on a single frame of film [18,19]. This does not, however, provide the desired electrical hologram signal which can be transmitted and then used to derive a real-time reproducer.…”

“…Storage cameras, such as vidicons and image orthicons, are significantly more efficient since they integrate the light for an entire frame interval. These cameras can be used without the inefficiencies of spatial offset by properly combining an array of holograms with an on-axis reference [5,[17][18][19]. This is accomplished by recording three frames, each with a different static phase shift in the path of the reference beam.…”