The phenomenon of imaging properties of a material model of light intensity waves is analyzed in its various manifestation. (1) In the field of static intensity waves two types of records are considered: volume hologram and selectogram. Unlike the volume hologram, selectogram is not so sensitive to the degree of temporal coherence of recording light. (2) In the field of holographic recording of moving patterns of intensity waves several methods are considered. Doppler hologram presents the dynamic record of the moving pattern of intensity waves resulted from the interference of a reference wave with an object wave that being scattered from the moving object experienced the Doppler shift of its frequency. This hologram is capable of reconstructing the moving image of the object. Second Harmonic Generated hologram (SHG hologram) is recorded in a nonlinear material endowed with the second-order nonlinearity. It is capable of forming high-quality images in the light whose frequency is doubled. The main distinctive feature of SHG hologram is its extremely fast time response that permits one to realize superfast switches. Dynamic 'xi-two' hologram is in fact a particular case of the SHG hologram when the frequencies of an object and reference waves are different.
This paper is entitled Holography Reinvented, because its theme is simply that each of the three best-known names in holography made their discoveries and inventions without knowing about the work of any the others; that is, each of them invented or reinvented holography, as it were. This is largely a presentation of anecdotal remarks drawn from conversations, observations drawn from historical documents, including some from the Museum of Holography files now at the MIT Museum, and observations drawn from the author's own experiences as holography has evolved. As such, any errors of fact or interpretation are entirely the author's own, as is the slant toward imaging or display holography that will be conspicuous. The three main players are Professors Denis Gabor, Emmett Leith, and Juri Denisyuk. A few other names will come into the story as well, notably: Pieter van Heerden (my former colleague at the Polaroid Research Labs) and Hussein M.A. El-Sum, among others.
In 1963 Gordon Rogers published a paper in which he described the formation of optical images in terms of transformations of the coherence function associated with the wave propagating from the object, passing through lenses, and continuing on to the image plane. Of particular importance, he noted (a) that a clear aperture can be treated as the superposition of a large number o pinholes, the pinhole density being so high that they effectively fill the aperture, and (b) that each pair of pinholes produces in the image pl ane a sinusoidal fringe pattern. The superposition of the many fringe patterns then determines the image intensity distribution. In this paper Rogers' concept is extended to include the formation of images of 3D full-color objects and the formation of images in a particular super-resolving imaging system.
A solar photovoltaic energy collection system using a reflection hologram is described herein. The system uses a single-axis tracking system in conjunction with a spectral- splitting holographic element. The hologram accurately focuses the desired regions of the solar spectrum to match the bandgaps of two ro more different solar cells, while diverting unused IR wavelengths away. Other applications for solar holography include daylighting and greenhouses.
In this paper we report on a holographic method used to record fast events in the nanosecond time scale. Several frames of the expansion of shock waves in air and in a polymer sample are recorded holographically in a single shot experiment, using a pulse train generated with a single pulse from a Q-switched Nd:YAG laser. The time resolution is limited by the laser pulse width, which is 5.9 ns. The different frames are recorded on the holographic material using angle multiplexing. Two cavities are used to generate the signal and reference pulses at different angles. We also present a method in which the recording material is replaced by a CCD camera. In this method the holograms are recorded directly on the CCD and digitally reconstructed. The holograms are recorded on a single frame of the CCD camera and then digitally separated and reconstructed.
We demonstrate several nonlinear optical techniques that allow spatial-temporal processing of femtosecond laser pulses. Photorefractive and cascaded second order nonlinear wave mixing is used to convert space domain information into ultrafast temporal waveforms. Spectral domain three wave mixing allows time imaging of femtosecond signals as well as characterization of the signal complex amplitude. Femtosecond pulse interferometry is applied for spatial and temporal characterization of the multimode optical fiber.
A generalized Fourier optics approach is employed to describe hologram recording and reconstruction in volume media. A compact expression is derived, which is suitable for the treatment of complicated optical signals propagated by arbitrary optical systems. This is in contrast to the existing literature on volume holography that is mainly focused on the derivation of high diffraction efficiency in relatively simple configurations. It is demonstrated that the traditionally accepted Bragg selectivity can be obtained as a first approximation of much more general selectivity, a generalized Bragg selectivity, that describes the deterioration of the hologram reconstruction quality as a function of the deviations from the recording configuration. As a case study, a few simple situations are analyzed in detail and an old experimental result is explained theoretically.
The holographic principle is reinvestigated based on the Wigner distribution function (WDF). We apply the WDF to the analysis of generic optical setups which are used to record and reconstruct image plane holograms, Fourier holograms, and Fresnel holograms. We use the graphical representation of the Wigner chart to derive various important properties, including the required space bandwidth product of the hologram. This allows us to provide an intuitive analysis of the trade-off between the recording schemes.
Experiments with ultrashort laser pulses have indicated that the intersection of a rotational symmetric ellipsoidal by a flat surface at any angle appears circular when studied form one focal point of the ellipsoidal. This statement is mathematically proved for the general case. The spherical coordinate system of an observer that travels at ultrahigh velocity appears transformed into an ellipsoidal coordinate system but this fact is hidden from sight by said statement. If this was not so, his absolute velocity would be visible to the traveling observer in contradiction to Einstein's postulate.
White light interferometry is an extremely powerful tool for optical measurements. This paper discusses the advantages and disadvantages of white light interferometry compared to laser light interferometry. Three different white light interferometers are discussed: 1) diffraction gratin interferometers; 2) vertical scanning or coherence probe interferometers, and 3) white light scatterplate interferometers.
The research of passive and active grating waveguide structures has been ongoing in our group for the last decade. We briefly review recent research activities, emphasizing how such structures can be exploited for optical communication and for biological sensing.
This paper is devoted to a brief analysis on the development of 3D holography for the last 40 years. We also consider how 3D holography has impacted on the modern laser designs. Definitely, in the frame of such a short paper, there is no possibility to discuss many important issues related to this subject. Therefore, the author mainly concentrated on only one type of application. This is nonlinear optical wave interactions, involving 3D holographic grating. Sometimes such interactions are referred to as dynamic holography.
One way of honoring the world's two greatest holographers is to remove from their field the association with the offbeat world of the holographic mind. Basing itself on analogical musings of two very creative scientists who were themselves not holographers, this 'field' of the holographic brain has strayed far from science and into the absurd. So much absurdity has been written by so many people that the one legitimate study of holographic principle in dolphins has been grouped too often with the nonsense. Here is taken most of the 'target statements' form one book. We could not bear to read them all this closely. We will attempt to determine what tidbit of fact led to the statements and to suggest alternative explanations when there is something to explain.
Two imaging techniques are presented which can create remarkable images. The first technique is color holography which provides full parallax 3D color images with a large field of view. The virtual color image recorded in a holographic plate represents the most realistic-looking image of an object that can be obtained today. The extensive field of view adds to the illusion of beholding a real object rather than an image of it. The other technique is interferential color photography or Lippmann photography. This, almost forgotten, one-hundred-year-old photographic technique, is also remarkable. It is the only color recording imaging technique, which can be record the entire visible color spectrum. It is not based on Maxwell's three- color principle, the dominating principle behind most current color imaging techniques. The natural color rendition, make this 2D photographic technique very interesting. The reproduction of human skin and metallic reflections, for example, are very natural looking, which is not possible to record in ordinary photography.
Recent development of high resolution, full-color, full parallax digital holograms are outlined, focusing on a variety of scale-sensitive applications for this technology. This paper details recent improvements in the digital hologram resolution and recording system. The unique capabilities of digital holograms to provide solutions for a variety of applications, and some specific concepts that are being explored, are also outlined.