D. F. Chernykh

Formation of random and regular relief-phase structures on silver halide photographic emulsions by holographic methods

The formation of diffusers and microlens rasters on silver halide emulsions by holographic methods is considered. Two techniques for converting amplitude holographic recording to relief-phase recording, selective curing and irradiation of the emulsion gelatin by short-wavelength UV radiation, are compared.

Forming the surface relief of complex holographic structures on photosensitive material PFG-01

This paper presents an analysis of the results of measurements of the surface relief of holographic diffusers obtained on PFG-01 photoemulsions by means of multiplex holograms. The results of the measurements confirm that different methods of converting amplitude holographic structures into relief-phase structures have a substantial effect on the optical characteristics of the diffusers.

Pyrometer unit for GaAs substrate temperature control in an MBE system

An optical pyrometer designed for precision measurement of the GaAs substrate temperature during MBE growth is considered. The pyrometer can be calibrated against a certain characteristic absolute temperature that is visually determined from a change in the RHEED pattern. This enables one to calculate the absolute temperature of the substrate with regard to its radiant emissivity and minimize the inaccuracy of radiation temperature measurement. The inaccuracy is associated with the deposition of growth products on the pyrometer window.

Formation of optical scatterers on silver halide photomaterials using multiplex holograms

A method for formation of optical scatterers based on multiplex holograms is proposed. The synthesis of complicated holographic structures that scatter the incident radiation in a solid angle is theoretically analyzed. A significant effect of the methods for profiling of the surface of the silver halide photolayer on the characteristics of high-efficiency diffusers is experimentally demonstrated.

On-axis diffuse screen based on a reference-free volume hologram

A new type of hologram that elaborates upon the simplest (Gabor) on-axis hologram is suggested. The new approach makes it possible to eliminate the projected image distortions typical of the Gabor hologram. Specifically, based on a reference-free thick hologram, an on-axis holographic screen that does not transmit the zeroth order is prepared. In addition, this screen does not produce a halo and the conjugate image. It allows for recording in one spectral range and reconstruction in another, thereby greatly simplifying the choice of a light-sensitive record medium. With this screen, a color image can be projected.

Imaging properties of a 2D crossed holographic grating on silver halide photoemulsions

A technique is proposed for photochemical processing of photoemulsions, which makes it possible to form lens-shaped focusing elements at the nodes of crossed 2D holographic gratings (2DHGs). The results of experiments on 2DHG recording performed on PFG-01 material using this technique show considerable improvement of imaging properties of 2DHG.

Phase recording for formation of holographic optical elements on silver-halide photographic emulsions

Holographic fabrication methods of regular and nonregular relief-phase structures on silver-halide photographic emulsions are considered. Methods of gelatin photodestruction under short-wave ultra-violet radiation and chemical hardening with the help of dichromated solutions were used as a technique for surface relief formation. The developed techniques permitted us to study specimens of holographic diffusers and microlens rasters with small absorption and high light efficiency.

The phenomenon of light concentration by a speckle screen based on a reference-free volume hologram

It is experimentally demonstrated that a speckle screen based on a reference-free volume hologram is capable of concentrating light in the visibility zone. Holographic speckle screens for the projection of images were formed in a bulk photosensitive material based on glycerol-containing dichromated gelatin (DCG). With such screens formed using radiation with a wavelength (0.442 nm) in the spectral range of DCG photosensitivity, it is possible to obtain high-quality image projections using both coherent radiation with a different wavelength and white light. The projection properties of speckle screens were studied, and their ability to concentrate light in the visibility zone was confirmed.

Microlens rasters and holographic diffusers based on PFG-01 silver halide photographic material

This paper discusses holographic methods for obtaining diffusers and microlens rasters on silver halide photographic emulsions. The gelatin-photolysis method in which short-wavelength UV radiation acts on the photosensitive layer and methods of chemical and photohardening of photographic emulsions processed with dichromate solutions are used as technologies for creating relief-phase structures.

Two-dimensional holographic gratings based on silver halide photographic emulsions for the formation of raster images

This paper discusses a two-dimensional crossed holographic grating as an optical element capable of creating raster images, the recording of which in a photosensitive medium with relief-phase response makes it possible to obtain other optical elements--for example, microlens rasters. The extent to which the photochemical processing of the photographic material affects the optical properties of two-dimensional holographic gratings is investigated.