RU1804640C - Amplitude-to-phase image conversion method - Google Patents

Abstract

The invention relates to photography and can be used in optical information copying systems. SUBSTANCE: method for converting an amplitude image to a phase image consists in forming an intermediate amplitude hologram on a silver halide photo layer, then the dielectric and bichromated gelatins are sequentially applied to the amplitude hologram, exposed from the substrate side by the radiation of a halogen lamp, and displayed in an aqueous or slightly alkaline solution, removed l Unsubstantiated gelatin. 4 ill.

Description

The invention relates to holography and can be used in optical information copying systems.

The purpose of the invention is to simplify the method and improve image quality by reproducing high spatial frequencies with the introduction of layers on which the formation of holograms in contact.

The method is implemented as follows.

Layers of dielectric and dichromous gelatin are sequentially applied to the amplitude hologram, exposed to the radiation of a halogen lamp from the side of the substrate, and are developed in an aqueous or slightly alkaline solution at a temperature of 50 ° C. to remove the undecreased gelatin. A dielectric layer made on the basis of a methacrylic acid copolymer prevents the penetration of ammonium bmhrocate from the deposited layer into the hologram, thereby preserving the amplitude image of the hologram, and prevents swelling of the photo-emulsion layer of the primary hologram during the development of the phase-relief hologram.

After the conversion, the hologram formed as a spatial modulation of the thickness of the gelatin layer is characterized by high diffraction efficiency (20%) and allows the optical information to be copied using the high-performance hot stamping method.

Figure 1 shows the dependence of the thickness of the dielectric layer on the concentration of methacrylic acid copolymer; in FIG.

W

2 - dependence of the thickness of the relief-forming layer on the concentration of gelatin; Fig. 3 shows the dependence of diffraction efficiency on exposure time; Fig. 4 shows the dependence of diffraction efficiency on development temperature.

According to the usual holographic scheme using a helium-neon laser (LGN-215), a hologram was recorded on a VRL type photographic plate. The primary hologram was developed using a standard D-19 developer. After drying (the room temperature was 23 ± 2 ° C), the layers based on the methacrylic acid copolymer (TU 6-01-1070-76) were successively dipped onto the emulsion layer of the hologram, the concentration of the methacrylic acid copolymer being 3%, which corresponded (Fig. 1) to a layer thickness of 0.3-0.4 microns and bichromated gelatin (the gelatin concentration was 200 g / l and the sensitizing additive concentration was 16 g / l). The thickness of the bichromated gelatin layer, according to the relationship shown in Fig. 2, was 2 microns.

A sample of an amplitude hologram with deposited layers was exposed to radiation of a KGM type halogen lamp (150 W, 24 V) for 5 minutes. The exposure time was determined by the dependence of diffraction efficiency on exposure time (Fig. 3). After exposure, a development operation was performed in water or a slightly alkaline solution (for example, 0.1 KOH). According to experimental data (Fig. 4), the best development temperature is 50 ° C. After removal of the undecreased gelatin and drying of the sample

a relief phase hologram was obtained with a diffraction efficiency of 20%.

The depth of modulation of the thickness of the gelatin layer is 0.2 μm, which allows

embossed copying.

claims

A method of converting an amplitude image into a phase image, which consists in exposing the first emulsion layer deposited on a substrate, developing it, as a result of which an amplitude hologram is obtained, converting it into a phase hologram by repeatedly exposing the amplitude hologram to

the second photosensitive layer is also processed in the phase hologram, in that, in order to simplify the method and improve the image quality by reproducing high spatial frequencies, the dielectric layer and the second photosensitive layer are sequentially applied to the amplitude hologram before re-exposure a layer using a bichromated gelatin layer, re-exposure is carried out from the side of the substrate by radiation of a halogen lamp, after which a phase holograph is shown mmu in an aqueous or slightly alkaline solution at 50 ° C and undeveloped gelatin is removed.

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