Abstract. We examine some fundamental theoretical limits on the ability of practical digital holography ͑DH͒ systems to resolve detail in an image. Unlike conventional diffraction-limited imaging systems, where a projected image of the limiting aperture is used to define the system performance, there are at least three major effects that determine the performance of a DH system: ͑i͒ The spacing between adjacent pixels on the CCD, ͑ii͒ an averaging effect introduced by the finite size of these pixels, and ͑iii͒ the finite extent of the camera face itself. Using a theoretical model, we define a single expression that accounts for all these physical effects. With this model, we explore several different DH recording techniques: off-axis and inline, considering both the dc terms, as well as the real and twin images that are features of the holographic recording process. Our analysis shows that the imaging operation is shift variant and we demonstrate this using a simple example. We examine how our theoretical model can be used to optimize CCD design for lensless DH capture. We present a series of experimental results to confirm the validity of our theoretical model, demonstrating recovery of superNyquist frequencies for the first time. © 2009 Society of Photo-Optical Instrumentation Engineers.

This paper presents an extended viewing angle holographic display for reconstruction of real world objects in which the capture and display systems are decoupled. This is achieved by employing multiple tilted spatial light modulators (SLMs) arranged in a circular configuration. In order to prove the proper reconstruction and visual perception of holographic images the Wigner distribution function is employed. We describe both the capture system using a single static camera with a rotating object and a holographic display utilizing six tilted SLMs. The experimental results based on the reconstruction of computer generated and real world scenes are presented. The coherent noise removal procedure is described and implemented. The experiments prove the possibility to view images reconstructed in the display binocularly and with good quality.

Digital holography is an imaging technique that enables recovery of topographic 3D information about an object under investigation. In digital holography, an interference pattern is recorded on a digital camera. Therefore, quantization of the recorded hologram is an integral part of the imaging process. We study the influence of quantization error in the recorded holograms on the fidelity of both the intensity and phase of the reconstructed image. We limit our analysis to the case of lensless Fourier off-axis digital holograms. We derive a theoretical model to predict the effect of quantization noise and we validate this model using experimental results. Based on this, we also show how the resultant noise in the reconstructed image, as well as the speckle that is inherent in digital holography, can be conveniently suppressed by standard speckle reduction techniques. We show that high-quality images can be obtained from binary holograms when speckle reduction is performed.

The application of digital holography as a viable solution to 3D capture and display technology is examined. A review of the current state of the field is presented in which some of the major challenges involved in a digital holographic solution are highlighted. These challenges include (i) the removal of the DC and conjugate image terms, which are features of the holographic recording process, (ii) the reduction of speckle noise, a characteristic of a coherent imaging process, (iii) increasing the angular range of perspective of digital holograms (iv) and replaying captured and/or processed digital holograms using spatial light modulators. Each of these challenges are examined theoretically and several solutions are put forward. Experimental results are presented that demonstrate the validity of the theoretical solutions.

Acrylamide-based photopolymerizable nanocomposites containing three types of nanosized crystals with controlled microporosity, Silicalite-1 (MFI-structure), AlPO-18 (AEI-structure) and Beta (BEA-structure) are studied. The influence of the porous nanoparticles on the average refractive index, optical scattering and holographic recording properties of the nanocomposite are characterized. The redistribution of nanoparticles as a result of the holographic recording in the layers is investigated by Raman spectroscopy. It is observed that in all three nanocomposites the nanoparticles are redistributed according to the illuminating light pattern. This redistribution improves the refractive index modulation only in the case of the MFI nanoparticles, while no improvement is observed in AEI and BEA doped layers. The results can be explained by the hydrophobic/hydrophilic nature of the nanoparticles and their interactions, or absence of interactions, with the host photopolymer.