By Topic

# 1993 Fourth International Conference on Holographic Systems, Components and Applications

## Filter Results

Displaying Results 1 - 25 of 54
• ### Photorefractive adaptive transmission system: all optical signal modulation and amplified phase conjugation

Publication Year: 1993, Page(s):180 - 185
Cited by:  Papers (1)
| | PDF (267 KB)

The operational principles of an adaptive transmitter system based on the combined action of two photorefractive crystals, an amplifier and a phase conjugator have been presented. The system is capable of generating amplified, phase-modulated, phase-conjugate signals of low-intensity probe signal fields. The generation of amplified PC replicas is seen to be limited to within a specific range of lo... View full abstract»

• ### Multiplexed static and dynamic photorefraction at 780 nm in Bi12SiO20

Publication Year: 1993, Page(s):174 - 179
| | PDF (160 KB)

The authors report preliminary results on the observation of multiplexed dynamic and static photorefractive behavior in the diffusion regime, at 780 nm in BSO. In the present case the dynamic gratings follow the expected response but the static gratings exhibit a lifetime which is nearly four orders of magnitude larger than the dynamic gratings at quite high erasing beam intensities. In addition b... View full abstract»

• ### The self-focusing Fresnel-Dammann grating and the Fresnel binary CGH for compact 2-D light spot array generation

Publication Year: 1993, Page(s):147 - 152
Cited by:  Patents (1)
| | PDF (396 KB)

The authors have described the design and demonstrated the performance of two types of lensless array generator. The Self-focusing Fresnel-Dammann grating (SFD), and the Fresnel hologram. The SFD is based on a conventional Dammann grating, but obviates the need for extraneous Fourier transform lenses, by combining the grating with a Fresnel zone plate, in an exclusive-OR fashion. No alignment is r... View full abstract»

• ### Full natural colour 3D optical models by integral imaging

Publication Year: 1993, Page(s):237 - 242
| | PDF (324 KB)

Improvements in both lateral and angular resolution can be effected by adopting two tier optics. In systems employing two tier optics for primary pseudoscopic images improved lateral resolution at and around the screen plane is achieved, however, increasingly remote planes contain increasing defocus due to diffraction effects and reduced angular resolution. These deficiencies can be overcome by ad... View full abstract»

• ### Optical optimization of binary phase fan-out elements

Publication Year: 1993, Page(s):129 - 134
| | PDF (312 KB)

Binary phase fan-out elements, often referred to as Dammann gratings, produce a two-dimensional array of beams. In some cases the multiple beams have to be uniform in intensity, while in others a varied distribution of intensities is desired. In all cases, these elements need to be efficient, so to avoid losses. The authors apply an optical parallel processor to perform the simulated annealing sta... View full abstract»

• ### White-light colour-encoded photography for rendering hold-images in a diffractive screen

Publication Year: 1993, Page(s):153 - 156
| | PDF (108 KB)

The capability of color-encoding the continuous sequence of views from a scene was demonstrated previously by the author (1990). In the present work, the scheme for this process is shown where white light from a black and white object is diffracted at a diffraction grating and then photographed on colour film. Two rays of different wavelengths reaching the plane of the color photographic film dete... View full abstract»

• ### Programmable computer generated holograms with large space bandwidth product

Publication Year: 1993, Page(s):216 - 221
| | PDF (272 KB)

The key to programmable binary phase computer generated holograms (CGHs) is a controllable recording media with a robust phase modulation scheme. Magneto-optic and ferroelectric liquid crystal (FELC) devices have intrinsically robust π phase modulation schemes and FELC devices have produced high quality electrically programmable holograms. FELCs offer a means to create CGHs which are dynamic bu... View full abstract»

• ### Two-dimensional arrays of diffractive microlenses for optical interconnects

Publication Year: 1993, Page(s):41 - 46
Cited by:  Patents (2)
| | PDF (372 KB)

Arrays of 16×16 diffractive optical microlenses are presented that are used in free space interconnection networks of electronic switching stages. They have been fabricated as binary optical elements' in glass substrates by microstructuring techniques. Individual elements have a diameter of 2 mm and 200 μm and 16 levels per zone. Arrays with different F-number lenses for the two waveleng... View full abstract»

• ### Diffractive optical elements for high power CO2 laser applications

Publication Year: 1993, Page(s):243 - 248
| | PDF (312 KB)

High power CO2 lasers are of great importance in manufacturing industry where they find use as cutting, welding, annealing and marking tools. Beamshaping elements for CO2 light based on refraction are commonly implemented using semiconductor materials. Refractive elements are inherently lossy and difficult to cool effectively. Diffractive optical elements (DOEs) offer several... View full abstract»

• ### A direct search method for the computer design of holograms

Publication Year: 1993, Page(s):96 - 99
| | PDF (260 KB)

A new optimisation technique for the computer design of holograms has been developed. It has much in common with simulated annealing but requires less computational effort. Additionally the technique is not restricted to any particular holographic set up such as Fourier transform holograms. The method has been used to design phase holograms for laser machining at CO2 wavelengths. To eva... View full abstract»

• ### Tomographic reconstruction techniques for the analysis of holographic interferograms

Publication Year: 1993, Page(s):135 - 140
| | PDF (284 KB)

The authors describe the development of tomographic techniques suited to the reconstruction of data obtained from holographic interferograms, and some initial results. The principle development discussed is the treatment of the data in three dimensions rather than the conventional approach of simplifying the problem to the reconstruction of a series of layered two dimensional slices. A discussion ... View full abstract»

• ### Construction of a matrix-matrix crossbar optical interconnect employing diffractive fan-out and fan-in elements

Publication Year: 1993, Page(s):31 - 34
Cited by:  Patents (2)
| | PDF (268 KB)

An optical cross-bar interconnect incorporating diffractive/holographic optics and capable of providing high-bandwidth fully non-blocking links between 64 independent electronic processors is the goal of the authors project: Optically Connected Parallel Machines'. To test a number of new concepts a prototype 16×16 interconnect has been assembled as a first step. The optical arrangement of t... View full abstract»

• ### Volume holographic interconnection and copying architectures based on incoherent/coherent source arrays

Publication Year: 1993, Page(s):21 - 26
Cited by:  Patents (1)
| | PDF (468 KB)

An incoherent/coherent double angularly multiplexed interconnection system that uses a multiplexed volume holographic element and an array of individually coherent but mutually incoherent sources to interconnect 2-D arrays of input and output nodes for neural network and digital interconnection applications is described. A number of important properties of this system have been verified by means o... View full abstract»

• ### Optoelectronic interconnects with high packing densities

Publication Year: 1993, Page(s):10 - 14
| | PDF (204 KB)

Optical board-to-board interconnections are presented. A typically some 5-10 mm thick light-guiding plate is used for confinement and transport of the optical signals. The plate is equipped with grating couplers fabricated as volume phase holograms in dichromated gelatin. The apertures of the optoelectronic transmitters are imaged onto the apertures of the receivers by aspheric field lenses or mir... View full abstract»

• ### Photopolymer replication-a new technique for 0.25 μm phase shifted DFB-LD grating manufacture?

Publication Year: 1993, Page(s):186 - 191
| | PDF (404 KB)

The photomask self interference (PSI) method utilises the interference field generated by the first and transmitted orders of a high precision grating. The authors describe a low cost replication process for PSI mask manufacture, and development to date, on an entirely new approach involving embossing directly into a thin film on the fragile semiconductor substrate. In both the techniques the aim ... View full abstract»

• ### Design and fabrication of synthetic diffractive optical elements for high power laser applications

Publication Year: 1993, Page(s):157 - 162
| | PDF (368 KB)

The design and fabrication of various Fourier and Fresnel domain diffractive optical elements for use with high power Nd glass laser systems is described. Components discussed include focusing beam sampling elements, low-loss harmonic separation filters and far field beam apodizers, which produce a uniform intensity profile View full abstract»

• ### Encoding optimization of synthetic holograms recorded on a parallel access optical disk

Publication Year: 1993, Page(s):222 - 227
| | PDF (340 KB)

First the optical system and the disk data encoding method are presented. Then the different encoding algorithms and their performances are described, allowing the choice of an optimal encoding View full abstract»

• ### Potential of holographically recorded fan-out elements

Publication Year: 1993, Page(s):198 - 203
Cited by:  Papers (1)
| | PDF (284 KB)

The paper investigates the recording of efficient off-axis fan-out elements for optical interconnections. The analysis of fan-out elements recorded in volume holograms (coupled wave theory) shows that high efficiency (>90%) and uniformity can be achieved by simultaneous and sequential recording of N object beams. Experimentally, we have achieved 94% efficiency (uniformity error ±5%). The... View full abstract»

• ### Relation between angles of diffraction and diffraction efficiency of diffractive elements

Publication Year: 1993, Page(s):80 - 84
| | PDF (228 KB)

The authors have attempted to provide some information on diffractive optics between the resonance and the paraxial domain. Two simple considerations, which are based on specific assumptions, have been described. In the first gedanken experiment it was shown that it is only possible to obtain a diffraction efficiency near 100% in the resonance domain, i.e. if α≈90°. The assumption was... View full abstract»

• ### Fourth International Conference on Holographic Systems, Components and Applications (Conf. Publ. No.379)

Publication Year: 1993
| | PDF (76 KB)

The following topics were dealt with: interconnects; materials and fabrication; diffractive HOE; applications View full abstract»

• ### Production and control of refractive and diffractive microlenses

Publication Year: 1993, Page(s):47 - 53
| | PDF (376 KB)

The authors discuss two examples of microlenses where the generation process and the interferometric control are strongly interwoven. For refractive lenses they use lenses melted in photoresist and also reactive ion etched samples. The control is done with the help of a phase shifting interference microscope of the Mach-Zehnder type. An evaluation software was developed under windows. The other ty... View full abstract»

• ### Novel methods for the creation of silver free images in holography using conventional silver-halide emulsions

Publication Year: 1993, Page(s):271 - 274
| | PDF (236 KB)

The authors discuss the area of silver halide process technology associated with the formation of voided gelatin conventionally known as silver halide sensitized gelatin (SHSG). Comparative studies have shown that this method is capable of creating master holograms (in transmission mode) that are virtually free of the grain scattering noise that besets conventional silver halide gelatin (SHG) holo... View full abstract»

• ### Binary synthetic Bragg holograms: fabrication issues and first results

Publication Year: 1993, Page(s):62 - 65
| | PDF (240 KB)

The high transverse resolution available with modern microfabrication also allows the manufacture of binary surface relief gratings with subwavelength features. Previous authors have proposed that by employing pulse width modulation these grating could attain the high diffraction efficiencies of multi-level diffractive elements. The major disadvantage of this modulation scheme, however, is the hig... View full abstract»

• ### A binary phase zone plate array for laser beam spatial intensity distribution conversion

Publication Year: 1993, Page(s):249 - 254
Cited by:  Patents (1)
| | PDF (304 KB)

The phase zone plate combines the simplicity of design and fabrication of the random phase plates with the advantage of near field target placement. The flexibility of design allows the cell structure to be easily modified to produce different focal spot shapes. The components are not specific to a particular near field intensity pattern provided several elements can be encompassed by the beam and... View full abstract»

• ### Diffractive waveguide lenses with optimized high-efficiency structures

Publication Year: 1993, Page(s):100 - 103
| | PDF (204 KB)

The effective-index modulation profiles of waveguide diffraction gratings with maximized first-order efficiency are applied to construct gradient-thickness diffractive waveguide lenses with improved overall efficiency. A high-numerical-aperture lens contains regions with significantly different structures. Such lenses are analyzed with the thin grating decomposition method View full abstract»