JPH0216589A - Production of volume phase hologram - Google Patents

Abstract

PURPOSE:To improve stability to light and heat and to obtain high sensitivity even to an Ar laser by incorporating a vinyl carbazole polymer and org. halogen compd. into a photosensitive material film and exposing the photosensitive material film to a gaseous halogen atmosphere prior to exposing. CONSTITUTION:The photosensitive material film contains the vinyl carbazole polymer and the org. halogen compd. This photosensitive material film is exposed to the gaseous halogen atmosphere prior to exposing. The org. halogen compd. is added to the polymer at 1-100wt.%, more preferably 3-25wt.% ratio of said polymer. The sensitivity of the photosensitive material film is enhanced by sensitization in two stages and in a gaseous phase in such a manner, by which the hologram having the sensitivity even to the wavelength region of the Ar laser as the film for hologram recording is easily obtd.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a volume phase hologram that allows a three-dimensional image to be observed on, for example, a flat film. Relating to a manufacturing method.

[Conventional technology]

In holography, an object is irradiated with light waves with good coherence, such as a laser, and the reflected or transmitted light, whose amplitude and phase are modulated according to the shape of the object, is received and recorded using a sensitive material. , is a technique for reproducing an optical image of an object recorded using light irradiated onto a formed hologram. For example, it is possible to observe a stereoscopic optical image on a flat film.

With the progress of research on holography, the requirements for sensitizers have become quite clear. Many materials are known as sensitizers that can be used in holography, such as bleached silver salts, photoresists, thermoplastics, dichromate gelatin, acid-free glass materials, and ferroelectric materials, and their suitability for holder roughness is known. is being further researched.

Characteristics that a sensitizer for forming holograms should have include, for example, (1) laser sensitivity, especially laser sensitivity in the visible light region, and high sensitivity; (2) high resolution; (3) The diffraction efficiency of the obtained hologram is high (4
) The hologram has little noise, (5) the hologram is stable, and (6) recording and reproducing operations are easy.

By the way, with the progress of holography technology, it is becoming possible to form holograms that can withstand practical use, and holograms are being used in a variety of ways, such as enjoying the image itself and using it to decorate and decorate various items. It has been expanded to.

[Problem that the invention seeks to solve]

Vinyl carbazole polymers are hologram recording media that are superior to dichromate gelatin and silver salt films in terms of sensitivity, resolution, diffraction efficiency, environmental resistance, and the like.

JP-A-60-52889 describes that a recording medium is formed from poly-N-vinylcarbazole and carbon tetraiodide.

However, carbon tetraiodide, which is a sensitizer, has extremely poor photostability and thermal stability, so a high degree of skill and equipment are required to handle carbon tetraiodide and recording media containing it. .

Therefore, it has been impossible to preserve recording media containing carbon tetraiodide for a long period of time.

In order to eliminate this drawback, when carbon tetrabromide or iodoform, which is stable against light and heat, is used instead of carbon tetraiodide, Ar laser (488 nm 1514
A new problem arises in that a highly sensitive hologram recording medium cannot be obtained because the absorption is small for wavelengths such as nm).

Therefore, the present invention solves these problems and provides a novel method for manufacturing a volume phase hologram using a hologram recording medium that has improved stability against light and heat and is highly sensitive to Ar laser. The purpose is to

[Means for solving problems]

The above object is achieved by the present invention as follows. That is, the present invention provides a method for manufacturing a volume phase hologram by exposing and developing a light-sensitive film, wherein the light-sensitive film contains a vinylcarbazole polymer and an organic halogen compound, and the light-sensitive film is exposed to light and developed before exposure. This is a method for producing a volume phase hologram, which is characterized by exposing a film to a halogen gas atmosphere.

[Effect]

As a result of a detailed study of the effects of organic halogen compounds on polyvinylcarbazole, the present inventor found that iodoform, which is more stable than carbon tetraiodide against heat and light, and tetraodor By using a halogen compound such as carboxycarbonate as a crosslinking agent and adding a halogen such as iodine or bromine to the recording medium in addition to this crosslinking agent, the absorption of the charge transfer complex of carbazole and an organic halogen compound is small. They discovered that even in the laser wavelength range, the photosensitive range was expanded and the sensitivity increased, and the present invention was completed.

This carbazole-based polymer refers to polyvinyl carbazole, alkyl-substituted polyvinyl carbazole, halogen-substituted derivatives of polyvinyl carbazole, acrylic acid derivatives having carbazole groups in their side chains, vinyl acetate derivatives, and polymers mainly composed of these. Depending on the situation, one or more of them can be used. Specifically, for example, polyvinylcarbazole, 3-chlorovinylcarbazole polymer, 3-bromvinylcarbazole polymer, 3-iodovinylcarbazole polymer, 3-methylvinylcarbazole polymer, 3-ethylvinylcarbazole polymer,
Chlorinated polyvinyl carbazole, brominated polyvinyl carbazole and the following structural formula (■).

Polymers formed by (II) and the like can be used.

CH2=C-R (I) (II) Among these, unsubstituted polyvinylcarbazole is practically preferred because it is easily available and the performance of the obtained hologram is particularly excellent.

The vinyl carbazole polymer may be copolymerized with other monomers as necessary, for example, in order to control properties such as strength and flexibility when formed into a film. Other monomers that can be used for such purposes include, in addition to the vinyl carbazoles mentioned above, vinyl esters such as vinyl acetate, esters of acrylic acid and methacrylic acid, styrene and styrene derivatives, and polymerizable vinyls such as ethylene. monomers can be mentioned. It can also be used by blending or grafting with other polymers as long as a hologram image can be recorded.

Incidentally, these are used by selecting the addition ratio so as to obtain the desired characteristics.

Examples of organic halogen compounds constituting the sensitive material in the present invention include iodine such as iodoform, ethylene tetraiodide, triiodoethane, tetraiodoethane, pentayodoethane, hexaiodoethane, carbon tetrabromide, and ethylene tetrabromide; Bromine compounds are mentioned, l-10 for polymers.
It is added in a proportion of 0% by weight, preferably 3 to 25% by weight.

The thickness of the carbazole polymer film with the above structure is
The film preferably has a thickness of 1 to 20 μm, and the film may be formed on an inorganic or organic transparent substrate such as glass or transparent polymer that does not absorb the wavelength of the coherent light used for exposure, or it may simply be in the form of a film. It's okay to have one.

When fixed on a transparent substrate, halogen molecules diffuse into the sensitive material film only from one side and tend to exhibit non-uniformity (concentration gradient), so doping takes time.

On the other hand, a single film is preferable because it allows diffusion from both sides, which increases uniformity and substantially improves sensitivity. Further, halogens to be added include iodine, bromine, etc., and are 0.01 to 100% by weight based on the polymer.
, preferably in a proportion of 0.05 to 60% by weight.

As for the specific doping method, bromine is a gas at room temperature,
Since iodine is a solid, it is preferable to heat the solid as necessary to sublimate it to reach an equilibrium concentration.

After exposure, the developing method described in Japanese Unexamined Patent Publication No. 53-15153 is applied.

〔Example〕

The present invention will be specifically explained below with reference to Examples.

Example 1 A solution prepared by dissolving 6 g of polyvinylcarbazole and 0.6 g of iodoform in 30 ml of monochlorobenzene was coated on a glass substrate using a spinner to form a film with a thickness of 10 μm. The polyvinyl carbazole film on the glass substrate was immersed in warm water to be peeled off from the glass substrate, then scooped up with a stainless steel mesh and dried. Thereafter, the polymer film was held in a desiccator with solid iodine installed at the bottom and brought into contact with iodine vapor to dope iodine into the polymer film.

Further, the doped film was transferred and held on a transparent substrate again in a dark place, and then exposed to an argon laser at a wavelength of 488 nm. Development was performed according to the following procedure.

■28℃, immersed in trichlorethylene for 2 minutes, ■28℃
, after being immersed in n ~ penta for 2 minutes and dried, the obtained hologram has approximately 3000 lines per 488 nm wavelength light.
It has a spatial frequency of mm and a diffraction efficiency of 60%,
It was a volume phase type hologram with a transmittance of 85%.

Example 2 6 g of polyvinyl carbazole and 0.0 g of carbon tetrabromide in a dark place.
6g to 30mj of dioxane! Using a spinner, a solution dissolved in the above was applied onto a transparent substrate made of diethylene glycol diacrylate to form a film with a thickness of 11 μm. The polyvinyl carbazole on the polymer substrate was peeled off by immersing it in hot water, and was scooped out with a stainless steel mesh. After doping with iodine in the same manner as in Example 1, it was held on a glass plate and exposed to light.

When developed in the same manner as in Example 1, a volume phase hologram with a diffraction efficiency of 71% and a transmittance of 85% at 490 nm was obtained.

Example 3 After leaving the polyvinylcarbazole-carbon tetrabromide film prepared in Example 2 at 20° C. for one week, a hologram was prepared in the same manner as in Example 2. As a result, a volume phase hologram with a diffraction efficiency of 71% and a transmittance of 85% was obtained.

Furthermore, the characteristics of the hologram remained almost unchanged even after two weeks.

Comparative Example 1 A sensitive material layer was formed on a glass substrate by dissolving 5 g of polyvinylcarbazole and 0.4 g of carbon tetraiodide in chlorobenzene in the same manner as in Example 1, and immediately exposed to light. The same development process as in Example 1 was carried out using what was left to stand and then exposed.

The diffraction efficiency of the hologram when exposed immediately after is 88%,
Those exposed after one week were 13%.

〔effect〕

Although sensitive materials made of polyvinylcarbazole polymers and organic iodine compounds are highly sensitive, they have the drawback of poor stability and are extremely difficult to handle. By increasing the sensitivity of a sensitive film by doping with a phase, there is an advantage that a hologram sensitive to the Ar laser wavelength range can be easily produced as a hologram recording film.

Patent applicant: Canon Co., Ltd.

Claims (1)

[Claims] (1) In the method of manufacturing a volume phase hologram by exposing and developing a light-sensitive film, the light-sensitive film contains a vinylcarbazole polymer and an organic halogen compound, and the light-sensitive film is processed prior to exposure. A method for producing a volume phase hologram, the method comprising exposing it to a halogen gas atmosphere.