Adrian James Cable

53.1: Real-time Binary Hologram Generation for High-quality Video Projection Applications

Presenting visual information using binary-phase holography has a number of advantages over conventional video projection techniques. However, acceptable image quality for video applications has yet to be realised. In addition, the computational complexity of hologram generation has precluded real-time operation. The authors present a new approach to hologram generation and display which allows high-quality images to be projected holographically, in real time.

Viewing angle enhancement for two- and three-dimensional holographic displays with random superresolution phase masks

Holographic displays employing binary phase modulation have been demonstrated to be attractive on the grounds of efficiency and miniaturization, and they offer a plausible approach to two-dimensional (2D) and three-dimensional (3D) image projection and display. A novel algorithm--one-step phase retrieval--and corresponding hardware architecture have recently been proposed, providing the performance required for real-time holographic display. However, since viewing angle varies inversely with pixel size, very small display pixels are required to achieve a wide field of view. This is particularly problematic for 3D displays, as the requirement for a large display with small pixels has hitherto necessitated an unachievably large electrical bandwidth. We present a novel approach, utilizing fixed random pixelated quaternary phase masks of greater resolution than the displayed hologram, to dramatically increase the viewing angle for 2D and 3D holographic displays without incurring a bandwidth penalty or significantly degrading image quality. Furthermore, an algorithm is presented to generate holograms accounting for the presence of such a phase mask, so that only one mask is required.

73.4: Real-time Diffractive Video Projector Employing Ferroelectric LCOS SLM

A compact, efficient projection system using an LCOS display as a programmable diffractive element is presented. The device accepts DVI data representing 1280 × 1024 pixels at 24 bits per pixel. The holograms required for display on the LCOS device are calculated in real time using specially developed algorithms.

Production of computer-generated holograms on recordable compact disk media using a compact disk writer

It is often necessary in optical experiments to produce computer-generated holograms (CGHs) of reasonable quality for the purpose of routing light. Such holograms are often created using a pressing process that is not normally done in-house and is very expensive for small runs. We present a novel technique for the production of such holograms using a standard compact disk (CD) writer, which is fast and very cost effective, along with an analysis of results obtained using this technique.

Low image reconstruction error using continuous real axis modulation

A method of encoding computer-generated holograms, which is matched to the recently developed one-step phase retrieval (OSPR) algorithm, is described. Continuous amplitude and binary phase modulators are coupled to enable the encoding of the entire Fourier plane real axis, and an implementation using commonly available reflective and transmissive devices is described. It is shown that, if a binary phase spatial light modulator (SLM), employing high switching angle liquid crystal (LC) material, is deployed in such a coupled modulator arrangement, the resultant reconstructed images exhibit signal-to-noise ratios some 3.5 and 15 times greater than those currently achievable with continuous and binary phase modulation, respectively.

Precision measurement with visual feedback using binary phase diffractive optical elements

A novel method for obtaining precision measurements by using two binary diffractive optical elements is presented. The system provides visual feedback of the measurement without the use of electronics.

Precision measurement system using binary phase computer-generated holograms

We present a novel method of obtaining precision measurement using two binary phase diffractive optical elements, termed the hologram, and phase mask. By encoding multiple views into the hologram, each of which corresponds to a horizontal or vertical relative displacement of the phase mask, the system is able to provide a visual feedback of the measurement without the use of electronics. A probabilistic method for detection of the resultant images, matched to the statistical properties of holographic replay, shows promise for enabling a fully automated measurement system.