JP4553223B2 - Method for photographing transmission hologram master - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for photographing a transmission hologram master, and more particularly, to a method for photographing a transmission hologram master that is difficult to photograph by ordinary two-beam interference.
[0002]
[Prior art]
Usually, the transmission hologram is photographed by a two-beam interference exposure system using an arrangement as shown in FIG. In this case, the light emitted from the laser 21 is split into two light fluxes by the half mirror 22 via the mirror M1, and the reflected light is enlarged by the beam expanding system 23 and the one light (for example, object light) 25 is expanded. The light transmitted through the half mirror 22 is enlarged by the beam expanding system 24 through the mirrors M2 and M3 to be the other light (for example, reference light) 26, and the two light beams 25 and 26 are mutually transmitted. Photographing is performed by making a predetermined angle incident simultaneously on a volume hologram photosensitive material 30 such as a photopolymer to cause interference.
[0003]
However, such a two-beam interference exposure system is severe in maintaining the coherence of the laser light divided into two, and great care is required to obtain an optical system that can stably shoot ( For example, optical path length difference between two beams, stability of optical components such as an optical vibration isolation table and mirror).
[0004]
In particular, when taking a large-size hologram having a diameter exceeding, for example, φ100 mm, the optical system itself becomes large, and the optical components used are also enlarged, so that it is more difficult to obtain stability of the optical system. become.
[0005]
In order to remove this instability factor, an optical system that performs two-beam interference from one beam as shown in FIG. 5 is also considered. In the case of this arrangement, the beam diameter of the light emitted from the laser 21 is expanded by the beam expanding system 23 via the mirrors M1, M2, and M3, and a part of the diameter is incident on the mirror 27 and reflected by the mirror 27. A portion of the light (for example, object light) 25 and a portion of the light (for example, reference light) 26 not incident on the mirror 27 are simultaneously incident on the volume hologram photosensitive material 30 to cause interference.
[0006]
The imaging system of FIG. 5 has higher optical stability than that of FIG. 4, but the interference area becomes small depending on the imaging conditions (angle of the mirror 27). It cannot be said that it is suitable for photography.
[0007]
By the way, as a large-size hologram, for example, a transmission hologram that forms a uniform diffraction grating is known, such as a hologram for a hologram color filter disclosed in JP-A-10-253955.
[0008]
[Problems to be solved by the invention]
The present invention has been made in view of such problems in the prior art, and its purpose is to produce a large transmissive hologram original plate, particularly a uniform diffraction grating, that is difficult to photograph with ordinary two-beam interference. It is an object to provide a photographing method capable of producing a transmission hologram master in a simple arrangement.
[0009]
[Means for Solving the Problems]
The transmission hologram master imaging method of the present invention that achieves the above object is a transmission hologram master imaging method in which a half mirror is disposed on the back surface side of the hologram photosensitive material, and further on the back surface side of the half mirror surface. An angled reflecting surface is arranged so that light of a predetermined wavelength is incident from the surface side of the hologram photosensitive material, transmitted through the hologram photosensitive material, reflected by the half mirror, and directly incident on the hologram photosensitive material. First interference fringes are recorded by interference with incident light, transmitted through the hologram photosensitive material, transmitted through the half mirror, reflected by the reflecting surface, and incident directly on the hologram photosensitive material. The second interference fringes are simultaneously recorded by the interference of the light, transmitted through the hologram photosensitive material, reflected by the half mirror, and incident on the hologram photosensitive material. A method characterized in that recording the third interference fringe by interference between light reflected by the transmissive reflecting surface the light and the half mirror is incident on the hologram photosensitive material simultaneously.
[0010]
In this case, an antireflection glass or a light absorbing glass is arranged on the surface side of the hologram photosensitive material, and light incident from the back side of the hologram photosensitive material is internally reflected on the surface of the hologram photosensitive material and enters the hologram photosensitive material again. Thus, it is desirable to prevent recording of unnecessary interference fringes.
[0011]
Further, the reflection surface may be provided on the back surface side of the triangular prism, and the triangular prism may be disposed on the back surface side of the half mirror.
[0012]
In that case, a half mirror may be integrally provided on the surface of the triangular prism.
[0013]
The light incident from the surface side of the hologram photosensitive material may be parallel light.
[0014]
In the present invention, the third interference fringes used at the time of replicating the original are combined with the reflection-type first interference fringes and the reflection-type second interference fringes that do not get in the way at the time of replicating the original. Since the image is taken in the same arrangement as that of the reflection type hologram, the transmission hologram master can be easily produced by a simple method of entering one incident light. Moreover, since the hologram can be photographed in an integrated arrangement, the hologram master can be photographed extremely stably. Also, the optical system may be a simple optical system for spreading the incident light, and it is easy to produce a large reflective layer, half mirror, etc., so a large hologram master is photographed. be able to.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a method for photographing a transmission hologram master according to the present invention will be described based on examples.
[0016]
FIG. 1 is a diagram showing an arrangement for photographing a transmission hologram master according to an embodiment of the present invention. In this example, when light having a predetermined wavelength is incident at an incident angle α, the diffraction angle is 0 °. It is assumed that a transmission hologram master for copying a transmission hologram constituting a large uniform diffraction grating having a characteristic of diffracting to the transmission side is taken.
[0017]
For this reason, the half mirror 2 is disposed in close contact with the transmission side of the volume type hologram photosensitive material 1 such as a photopolymer via a refractive index matching liquid 5 such as xylene, and the refractive index such as xylene is further provided on the transmission side. A triangular prism 3 having an apex angle θ is disposed in close contact with the matching liquid 5. Although not necessarily essential, an antireflection glass or a light absorption glass 6 is similarly disposed on the reflection side of the hologram photosensitive material 1 via a refractive index matching liquid 5 such as xylene. A reflective layer 4 is provided on the surface of the triangular prism 3 opposite to the half mirror 2, and a light absorption layer 7 is provided on the side surface thereof.
[0018]
With this arrangement, when parallel light 11 having a predetermined wavelength is incident vertically from the antireflection glass or light absorption glass 6 side, the light transmitted through the antireflection glass or light absorption glass 6 and the hologram photosensitive material 1 is half. The light is partially reflected in the opposite direction by the mirror 2 and enters the hologram photosensitive material 1 as parallel light 12 perpendicularly from the back side. The component transmitted through the half mirror 2 enters the triangular prism 3, is reflected by the reflection layer 4 on the opposite surface, and the component transmitted through the half mirror 2 in the reflected light is obliquely incident on the hologram photosensitive material 1. The light enters the hologram photosensitive material 1 from the back side as parallel light 13 at α. On the other hand, the component 14 reflected by the reflective layer 4 and reflected by the half mirror 2 enters the triangular prism 3 again to become stray light, and is finally absorbed by the light absorbing layer 7 provided on the side surface of the triangular prism 3. .
[0019]
As apparent from the above, the incident light 11 is incident on the hologram photosensitive material 1 perpendicularly from the front surface side, and the reflected light 12 from the half mirror 2 is perpendicular to the rear surface side, and the triangular prism 3 is incident at an incident angle α. Since the reflected light 13 reflected by the reflective layer 4 is incident, the hologram photosensitive material 1 has interference fringes A of the transmission hologram formed by the reflected light 12 and the reflected light 13, and reflected by the incident light 11 and the reflected light 12. Three interference fringes of the interference fringe B of the type hologram and the interference fringe C of the reflection type hologram by the incident light 11 and the reflected light 13 are recorded.
[0020]
The hologram 1 ′ triple-recorded on the hologram photosensitive material 1 in this way is the transmission hologram master according to the present invention. As shown in FIG. 2, the transmission type hologram master 1 ′ receives parallel light 33 having the same wavelength as that of recording from the incident direction of the reflected light 13 at the time of recording in FIG. 1 (FIG. 2 shows FIG. 1). Is rotated within a 180 ° plane), and zero-order transmitted light 33 ′ is generated on the transmission side, and transmission in the transmission direction of the reflected light 12 at the time of recording is generated by the interference fringes A. Diffracted light 32 is generated perpendicularly to the transmission side of the hologram master 1 ′. Further, the interference fringes C generate diffracted light 31 perpendicularly to the reflection side of the transmission hologram master 1 ′, which is the transmission direction of the incident light 11 during recording. However, in the case of the reproduction illumination light 33, the interference fringes B do not generate any diffracted light.
[0021]
Therefore, when another hologram photosensitive material 10 is placed in close contact with the transmission side of the transmission type hologram master 1 ′ and the above reproduction is performed, the diffracted light 32 is incident on the hologram photosensitive material 10 and the incident angle α Since the zero-order transmitted light 33 ′ is incident, the two parallel lights 32 and 33 ′ interfere with each other, and a hologram composed of the interference fringes similar to the interference fringes A can be duplicated. As shown in FIG. 3, when the parallel light 43 having the same wavelength as that at the time of replication is incident on the hologram 10 ′ from the incident direction of the 0th-order transmitted light 33 ′ at the incident angle α, the 0th-order transmitted light 43 is incident on the transmission side. , And diffracted light 42 traveling in the same vertical direction as the diffracted light 32 at the time of duplication is generated on the transmission side. In other words, the transmission hologram that forms a diffraction grating with a uniform characteristic of diffracting to the transmission side at a diffraction angle of 0 ° when light having a predetermined wavelength is incident at an incident angle α is duplicated.
[0022]
As described above, in the present invention, it is possible to produce the transmission hologram master 1 ′ by a simple method in which one incident light 11 is incident. Moreover, as is apparent from the arrangement of FIG. 1, the hologram can be photographed in an integrated arrangement, so that the hologram can be photographed extremely stably. Further, the optical system may be a simple optical system for spreading the incident light 11, and the triangular prism 3, the half mirror 2, and the reflective layer 4 can be easily manufactured in a large size. The hologram can be stably photographed.
[0023]
In the above description, the antireflection glass or light absorbing glass 6 disposed on the incident side (reflection side) of the hologram photosensitive material 1 is such that the reflected lights 12, 13 and the like incident from the back side of the hologram photosensitive material 1 are again generated by the hologram photosensitive material. It is arranged to prevent the unwanted interference fringes from being recorded by being internally reflected by the surface of 1 and entering the hologram photosensitive material 1 again.
[0024]
Furthermore, the incident angle of the incident light 11 and the apex angle of the triangular prism 3 can be arbitrarily set according to the incident angle characteristic and diffraction angle characteristic of the transmission hologram to be produced.
[0025]
In the above arrangement, an air layer having a predetermined apex angle may be used instead of the triangular prism 3, and the half mirror 2 is omitted, and Cr, instead of Cr, A thin half mirror surface such as Al may be provided by means of vapor deposition or the like, and the half mirror surface may be provided on the triangular prism 3 itself.
[0026]
The method for photographing a hologram master according to the present invention has been described above based on the embodiments. However, the present invention is not limited to these embodiments, and various modifications can be made.
【The invention's effect】
As is apparent from the above description, according to the transmission hologram master imaging method of the present invention, the third interference fringes used at the time of replicating the master are used as the reflection-type first that does not interfere with the master replica. Since the image is taken in the same arrangement as that of the reflection hologram of Dennischuk together with the interference fringe and the reflection type second interference fringe, the transmission hologram original plate can be obtained by a simple method of entering one incident light. Can be easily produced. Moreover, since the hologram can be photographed in an integrated arrangement, the hologram master can be photographed extremely stably. Also, the optical system may be a simple optical system for spreading the incident light, and it is easy to produce a large reflective layer, half mirror, etc., so a large hologram master is photographed. be able to.
[Brief description of the drawings]
FIG. 1 is a diagram showing an arrangement for photographing a transmission hologram master according to one embodiment of the present invention.
FIG. 2 is a diagram for explaining the characteristics of a transmission hologram master imaged in the arrangement shown in FIG. 1 and hologram replication using the original material.
FIG. 3 is a diagram for explaining the characteristics of a transmission hologram copied from a transmission hologram master imaged in the arrangement of FIG. 1;
FIG. 4 is a diagram for explaining a transmission hologram photographing method using a two-beam interference exposure system;
FIG. 5 is a diagram for explaining a method of photographing a transmission hologram from one beam by two-beam interference.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Hologram photosensitive material 1 '... Transmission type hologram master 2 ... Half mirror 3 ... Triangular prism 4 ... Reflective layer 5 ... Refractive index matching liquid 6 ... Antireflection glass or light absorption glass 7 ... Light absorption layer 10 ... Hologram photosensitive material 10 '... Replicated transmission hologram 11 ... incident light 12 ... reflected light 13 ... reflected light 14 ... reflected light (stray light component)
DESCRIPTION OF SYMBOLS 21 ... Laser 22 ... Half mirror 23, 24 ... Beam expansion system 25 ... Object beam 26 ... Reference beam 27 ... Mirror 30 ... Volume type hologram photosensitive material 31 ... Diffraction beam 32 ... Diffraction beam 33 ... Incident beam 33 '... Zero order transmission Light 42 ... Diffracted light 43 ... Incident light 43 '... Zero-order transmitted light M1, M2, M3 ... Mirror

Claims (5)

  In the method for photographing a transmissive hologram master, a half mirror is disposed on the back side of the hologram photosensitive material, and a reflective surface that forms an angle with respect to the surface of the half mirror is further disposed on the back side of the hologram photosensitive material. A light having a predetermined wavelength is incident, the first interference fringes are recorded by the interference between the light that is transmitted through the hologram photosensitive material, reflected by the half mirror, and incident on the hologram photosensitive material, and the light that is directly incident on the hologram photosensitive material. The second interference fringes are simultaneously recorded by the interference between the light that is transmitted through the photosensitive material, is transmitted through the half mirror, is reflected by the reflection surface, and is incident on the hologram photosensitive material, and the light that is directly incident on the hologram photosensitive material. The hologram photosensitive material that is transmitted and reflected by the half mirror and incident on the hologram photosensitive material is transmitted through the half mirror and reflected by the reflecting surface. The method of imaging transmission hologram original plate, characterized in that to record the third interference fringe by interference between incident light at the same time.   An antireflection glass or a light absorbing glass is arranged on the surface side of the hologram photosensitive material, and light incident from the back side of the hologram photosensitive material is internally reflected by the surface of the hologram photosensitive material and enters the hologram photosensitive material again. 2. The method according to claim 1, wherein recording of unwanted interference fringes by incidence is prevented. The triangular prism is disposed on the opposite side of the half mirror to the hologram photosensitive material, and the reflective surface is provided on the opposite side of the triangular prism from the half mirror side. 3. A method of photographing a transmission hologram master according to 2.   4. The method for photographing a transmission hologram master according to claim 3, wherein the half mirror is integrally provided on a surface of the triangular prism.   The method for photographing a transmission hologram master according to any one of claims 1 to 4, wherein the light incident from the surface side of the hologram photosensitive material is parallel light.

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