KR20220026361A - Holographic Optical Element and Method For Manufacturing Thereof - Google Patents

Abstract

The present invention relates to a holographic optical element and a manufacturing method thereof, and more specifically, to a holographic optical element and a manufacturing method thereof, which can improve the luminance of an augmented image. The method includes the steps of: a first step of generating the optical element by recording an interference pattern, which is a holographic grating pattern realized by an interference phenomenon between a reference light and an object light, on a photosensitive material; a second step of repeating the first step by predetermined number of times to generate a plurality of the optical elements; a third step of heating the optical element to change an inclination angle of the interference pattern; and a fourth step of combining the plurality of the optical elements to form the holographic optical element.

Description

Holographic Optical Element and Method For Manufacturing Thereof

The present invention relates to a holographic optical device and a manufacturing method thereof, and more particularly, to a holographic optical device capable of improving the luminance of an augmented image and a manufacturing method thereof.

A holographic optical element is an optical element that records an interference pattern on a photosensitive material by interfering an object wave, which is light reflected and diffracted from an object, with another wave reference wave having coherence with the light. Since the photosensitive material on which the interference pattern is recorded reproduces augmented image information by using diffraction instead of reflection or refraction, the photosensitive material is sometimes classified as a type of diffractive optical element.

On the other hand, as described above, the holographic optical device is generally manufactured by irradiating an object wave and a reference wave to a photosensitive material.

The holographic optical device manufactured in this way can be applied to a vehicle HUD (Head Up Display), etc. The augmented image light required for driving can be provided to the user's eye box area.

As such, in order for the user to effectively view the augmented image provided by the HUD (Head Up Display) even in bright daytime, the luminance of the augmented image is important.

However, in the case of a holographic optical device used in a conventional HUD (Head Up Display), an interference pattern having a constant maximum diffraction efficiency angle is formed, so that light with high luminance is emitted only in a certain direction. Most of the light with high luminance is emitted to the area, so there is a problem in that the luminance of the augmented image is lowered.

In addition, as for the light emitted to the user's eye box area by the holographic optical element used in the conventional HUD (Head Up Display), only the light containing information on a specific part of the augmented image has high luminance, so that the user sees it. There is a problem in that the augmented image has different luminance for each part.

One object of the present invention is to solve the problem that augmented image light emitted from a holographic optical device used in a HUD (Head Up Display) and the like is not effectively focused on the user's eye box area.

An object of the present invention is to solve a problem that an augmented image provided to a user's eye box area from a holographic optical device used for a head up display (HUD) or the like does not have uniform luminance for each part.

One object of the present invention is to solve the problem of not being able to easily manufacture a holographic optical device capable of emitting light of an augmented image so that an augmented image provided to a user's eye box area has uniform and high luminance.

The problems of the present invention are not limited to the problems mentioned above, and other problems not mentioned will be clearly understood by those skilled in the art from the following description.

An exemplary embodiment of the present invention includes a first step of generating an optical element by recording an interference pattern, which is a holographic grating pattern realized by an interference phenomenon between a reference light and an object light, on a photosensitive material; a second step of repeating the first step a predetermined number of times to generate a plurality of the optical elements; a third step of heating the optical element to change the inclination angle of the interference pattern; and a fourth step of forming a holographic optical device by combining the plurality of optical devices.

According to an exemplary embodiment of the present invention, in the third step, the plurality of optical elements may be heated to different temperatures.

According to an exemplary embodiment of the present invention, in the fourth step, the plurality of optical elements may be combined such that the inclination angle of the interference pattern recorded on the holographic optical element gradually increases or decreases in a predetermined direction.

An exemplary embodiment of the present invention includes a first step of generating an optical element by recording an interference pattern, which is a holographic grating pattern realized by an interference phenomenon between a reference light and an object light, on a photosensitive material; There is provided a method of manufacturing a holographic optical device comprising a second step of generating a holographic optical device by heating a predetermined portion of the optical device to change the inclination angle of the interference pattern.

According to an exemplary embodiment of the present invention, the optical element may be heated to a different temperature for each portion in which the inclination angle of the interference pattern is to be changed.

According to an exemplary embodiment of the present invention, in the second step, each portion of the optical element for which the inclination angle of the interference pattern is to be changed may be heated to a gradually higher or lower temperature in a predetermined direction.

According to an exemplary embodiment of the present invention, the photosensitive material may be a photopolymer.

In an exemplary embodiment of the present invention, in the holographic optical device manufactured by the method for manufacturing the holographic optical device, the interference patterns recorded for each part have the same pitch and different inclination angles, and the inclination angle of the interference pattern in a predetermined direction is An increasing or decreasing holographic optical element is provided.

The holographic optical element according to the present invention is formed by combining a plurality of optical elements having the same pitch and different inclination angles of the interference pattern, so that the augmented image light with high luminance is concentrated and emitted to the user's eye box area. It provides the effect of viewing the augmented image with high luminance.

In addition, since the light including information of each part of the augmented image has a high luminance and is evenly concentrated and emitted to the user's eye box area, it provides an effect that the user can view the augmented image having an even luminance.

In addition, the method for manufacturing a holographic optical device according to the present invention generates a holographic optical device in which an interference pattern having the same pitch and different inclination angles for each position is recorded through a heating process, so that the holographic optical device can be manufactured through a simple and convenient process. It provides an effect that can be manufactured.

1 is a flowchart illustrating a method of manufacturing a holographic optical device according to a first embodiment of the present invention.
2 is a view showing a process of recording an interference pattern on a photosensitive material.
3 is a diagram illustrating a process of heating a plurality of optical elements.
FIG. 4(a) is a diagram illustrating maximum diffraction efficiency angles of a plurality of optical elements having a constant inclination angle of an interference pattern.
FIG. 4(b) is a diagram illustrating maximum diffraction efficiency angles of a plurality of optical elements having different inclination angles of interference patterns.
Figure 5 (a) is a view showing the augmented image light emitted to the user's eye box by a conventional holographic optical element combining a plurality of optical elements of Figure 4 (a).
5 (b) is a view showing the augmented image light emitted to the user's eye box by the holographic optical device according to an embodiment of the present invention combining the plurality of optical devices of Figure 4 (b).
Figure 6 (a) is a view showing an example of the augmented image according to Figure 5 (a) shown to the user.
Figure 6 (b) is a diagram showing an example of the augmented image according to Figure 5 (b) shown to the user.
7 is a flowchart illustrating a method of manufacturing a holographic optical device according to a second embodiment of the present invention.
8 is a view showing a process of heating the optical element for each part.
9 is a view showing a holographic optical device according to an embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings and the content to be described later. However, the present invention is not limited to the embodiments described herein and may be embodied in other forms. Like reference numerals refer to like elements throughout.

Hereinafter, a method for manufacturing the holographic optical device 1 according to the first embodiment of the present invention will be described.

An exemplary embodiment of the present invention includes a first step of generating an optical element by recording an interference pattern, which is a holographic grating pattern realized by an interference phenomenon between a reference light and an object light, on a photosensitive material; a second step of repeating the first step a predetermined number of times to generate a plurality of the optical elements; a third step of heating the optical element to change the inclination angle of the interference pattern; and a fourth step of forming a holographic optical device by combining the plurality of optical devices.

The method for manufacturing a holographic optical device according to an exemplary embodiment of the present invention generates a holographic optical device in which an interference pattern having the same pitch and different inclination angles for each location is recorded through a heating process, so that the holographic optical device is a simple and convenient process. can be manufactured.

1 is a flowchart illustrating a method of manufacturing a holographic optical device according to a first embodiment of the present invention.

Referring to FIG. 1, in the method for manufacturing the holographic optical device 1 according to the first embodiment of the present invention, an interference pattern, which is a holographic grating pattern realized by an interference phenomenon between a reference light and an object light, is recorded on a photosensitive material. a first step of generating an optical device (S100); a second step (S200) of repeating the first step a predetermined number of times to generate a plurality of the optical elements; a third step of heating the optical element to change the inclination angle of the interference pattern (S300); and a fourth step (S400) of combining the plurality of optical elements to form a holographic optical element.

First, the first step (S100) will be described.

The first step ( S100 ) is a step of recording the interference pattern 400 , which is a holographic grating pattern, on the photosensitive material 300 .

According to an exemplary embodiment of the present invention, the photosensitive material may be a photopolymer.

The photosensitive material 300 can record optical information by exposure, and a conventional photosensitive material known in the field of holograms can be used. For example, the photosensitive material 300 may include a photopolymer capable of recording optical information due to a difference in refractive index between the exposed portion and the non-exposed portion.

2 is a view showing a process of recording an interference pattern on a photosensitive material.

Referring to FIG. 2 , when a reference light 100 such as a laser and an object light 200 are irradiated to the photosensitive material 300 , the reference light 100 and the object light 200 are located inside the photosensitive material 300 . The interference pattern 400, which is a holographic grid pattern formed by the interference phenomenon, is implemented. At this time, the portion where the constructive interference is formed due to the interference phenomenon formed in the photosensitive material 300 is strongly polymerized with the photosensitive material, and the portion where the destructive interference is formed by the interference phenomenon is the portion where the photosensitive material is weakly polymerized to form a refractive index in the photosensitive material. By generating a difference, the interference pattern 400 is recorded in the photosensitive material 300 , thereby creating the optical element 500 .

According to an exemplary embodiment of the present invention, each wavelength of the reference light 100 and the object light 200 is preferably 400 nm or more and 700 nm or less. Specifically, each wavelength of the reference light 100 and the object light 200 is preferably 532 nm.

According to an exemplary embodiment of the present invention, the angle between the reference light 100 and the object light 200 is preferably 45° or more and 80° or less. Specifically, the angle between the reference light 100 and the object light is preferably 60°.

Next, the second step ( S200 ) will be described.

The second step ( S200 ) is a step of generating a plurality of optical devices 500 by repeating the first step ( S100 ) a predetermined number of times. A plurality of optical devices 500 may be generated as many times as the second step (S200) is repeated.

Next, the third step ( S300 ) will be described.

According to an exemplary embodiment of the present invention, in the third step, the plurality of optical elements may be heated to different temperatures.

In the third step (S300), the interference patterns 400 recorded in each optical element 500 generated in the second step (S200) have the same pitch but different inclination angles, so that a plurality of optical This is a step of heating the device 500 .

When the optical device 500 made of a photopolymer or the like is heated, the interference pattern 400 recorded on the optical device 500 due to the shrinkage of the photopolymer, etc. does not change the pitch but changes the inclination angle. In addition, the higher the heating temperature and the longer the heating time, the greater the inclination angle of the interference pattern 400 recorded on the optical element 500 is.

3 is a diagram illustrating a process of heating a plurality of optical elements.

For example, referring to FIG. 3 , by heating a plurality of optical elements 500 to different temperatures, a plurality of optical interference patterns 400 having the same pitch but different inclination angles are recorded. Device 500 may be fabricated.

Next, the fourth step (S400) will be described.

According to an exemplary embodiment of the present invention, in the fourth step, the plurality of optical elements may be combined such that the inclination angle of the interference pattern recorded on the holographic optical element gradually increases or decreases in a predetermined direction.

The fourth step (S400) is a step of forming the holographic optical device (1) by combining the plurality of optical devices (500) heated by the third step (S300).

When the holographic optical element 1 is formed by combining the plurality of optical elements 500, a plurality of optical elements such that the inclination angle of the interference pattern recorded on the holographic optical element 1 gradually increases or decreases in a predetermined direction. The device 500 may be combined.

As such, since the inclination angle of the interference pattern recorded on the holographic optical element 1 is configured differently for each position, the incident angle of the incident beam that can diffract the incident beam with maximum efficiency for each position of the holographic optical element 1 (hereinafter, The 'maximum diffraction efficiency angle') may vary.

FIG. 4A is a diagram illustrating maximum diffraction efficiency angles of a plurality of optical elements having a constant inclination angle of an interference pattern.

For example, referring to FIG. 4( a ), the first optical element 510 , the second optical element 520 , and the third optical element 530 for manufacturing the holographic optical element 1 . When the formed interference patterns 401, 402, 403 have the same pitch and the same inclination angle, the first optical element 510, the second optical element 520, and the third optical element 530 have maximum diffraction The efficiency angle is the same.

Specifically, a first incident beam 10 having a first incident angle, a second incident beam 20 having a second incident angle, and a third incident beam 30 having a third incident angle are applied to the first optical element 510 . When irradiating, the diffraction efficiency of the second incident beam 20 may be the greatest. In this case, when the second optical element 520 and the third optical element 530 also irradiate the first incident beam 10 , the second incident beam 20 , and the third incident beam 30 , the second incident beam The diffraction efficiency of (20) becomes the largest.

FIG. 4(b) is a diagram illustrating maximum diffraction efficiency angles of a plurality of optical elements having different inclination angles of interference patterns.

On the contrary, when described with reference to FIG. 4(b), the fourth optical element 540, the fifth optical element 550, and the sixth optical element 560 for manufacturing the holographic optical element 1 are formed When the interference patterns 404, 405, and 406 have the same pitch but different inclination angles, the fourth optical element 540, the fifth optical element 550, and the sixth optical element 560 have the maximum diffraction efficiency. angle will be different.

Specifically, when irradiating the first incident beam 10 , the second incident beam 20 , and the third incident beam 30 to the fourth optical element 540 , the diffraction efficiency of the third incident beam 30 is the highest. can be large In addition, the first incident beam 10 and the second incident beam ( 20), when the third incident beam 30 is irradiated, the diffraction efficiency of the second incident beam 20 may be the greatest.

In addition, the first incident beam 10 and the second incident beam ( 20), when the third incident beam 30 is irradiated, the diffraction efficiency of the first incident beam 10 may be the greatest.

In this way, the holographic optical element 1 manufactured by combining a plurality of optical elements 500 so that the angle of maximum diffraction efficiency is different for each position can be applied to a vehicle head-up display (HUD) or the like.

Figure 5 (a) is a view showing the augmented image light emitted to the user's eye box by a conventional holographic optical element combining a plurality of optical elements of Figure 4 (a).

For example, referring to FIG. 5A , the emission-side optical device 500 - 2 of FIG. 5A has the same pitch and inclination angle of the interference patterns 401 , 402 and 403 . The first optical element 510 , the second optical element 520 , and the third optical element 530 are combined to form it.

When the first incident beam 10, the second incident beam 20, and the third incident beam 30 are irradiated to the inlet-side optical element 500-1, the irradiated light is transmitted through total reflection to the outgoing optical element 500- 2) can be reached. When the diffraction efficiency of the second incident beam 20 among the light reaching the first optical element 510 constituting the emission-side optical element 500 - 2 is the greatest, the second optical element 520 and the third optical element The diffraction efficiency of the second incident beam 20 is the greatest even for light reaching the element 530 .

Therefore, most of the light having the maximum diffraction efficiency among the incident beams emitted from the emitting-side optical element 500 - 2 is emitted to an area other than the user's eye box area. In addition, only the second incident beam 20 containing information of a specific part of the augmented image is diffracted with maximum diffraction efficiency of the light containing information of the augmented image flowing into the user's eye box, and then emitted to the user's eye box.

Figure 5 (b) is a view showing the augmented image light emitted to the user's eye box by the holographic optical element according to an embodiment of the present invention combining a plurality of optical elements of Figure 4 (b).

On the other hand, referring to FIG. 5(b), in the emission-side optical element 500-4 of FIG. 5(b), the interference patterns 404, 405, and 406 have the same pitch but different inclination angles. The fourth optical element 540 , the fifth optical element 550 , and the sixth optical element 560 are combined to form it.

When the first incident beam 10, the second incident beam 20, and the third incident beam 30 are irradiated to the inlet-side optical element 500-3, the irradiated light is transmitted through total reflection to the outgoing optical element 500- 4) can be reached. In this case, the diffraction efficiency of the third incident beam 30 among the light reaching the fourth optical element 540 may be the greatest.

And, the light reaching the fifth optical element 550 in which the interference pattern 405 having a larger inclination angle than the interference pattern 404 of the fourth optical element 540 is recorded is diffraction of the second incident beam 20 . The efficiency may be greatest, and the light reaching the sixth optical element 560 in which the interference pattern 406 having a larger inclination angle than the interference pattern 405 of the fifth optical element 550 is recorded is the first incident beam. (10) may have the greatest diffraction efficiency.

Therefore, most of the light having the maximum diffraction efficiency among the light emitted from the emission-side optical element 500 - 4 is emitted to the user's eye box area. In addition, the light containing information of the augmented image flowing into the user's eye box includes the first incident beam 10 , the second incident beam 20 , and the third incident beam 30 containing information on each part of the augmented image. ) is evenly diffracted with the maximum diffraction efficiency and emitted to the user's eye box area.

Figure 6 (a) is a view showing an example of the augmented image according to Figure 5 (a) shown to the user.

Referring to FIG. 6(a), when only the second incident beam 20 is diffracted with maximum diffraction efficiency and emitted to the user's eye box as shown in FIG. 5(a), the augmented image seen by the user is a specific part But the luminance is high.

Figure 6 (b) is a diagram showing an example of the augmented image according to Figure 5 (b) shown to the user.

Referring to FIG. 6(b), as shown in FIG. 5(b), the first incident beam 10, the second incident beam 20, and the third incident beam 30 are diffracted with maximum diffraction efficiency, so that the user's In the case of being uniformly emitted to the eye box, the luminance of the augmented image viewed by the user is higher overall than in the case of FIG.

Hereinafter, a method for manufacturing the holographic optical device 1 according to a second embodiment of the present invention will be described.

7 is a flowchart illustrating a method of manufacturing a holographic optical device according to a second embodiment of the present invention.

Referring to FIG. 7, in the method for manufacturing the holographic optical device 1 according to the second embodiment of the present invention, an interference pattern, which is a holographic grating pattern realized by an interference phenomenon between a reference light and an object light, is recorded on a photosensitive material. a first step of generating an optical device (S100-1); and a second step (S200-1) of generating a holographic optical element by heating a predetermined portion to change the inclination angle of the interference pattern of the optical element.

First, the first step (S100-1) of the method for manufacturing the holographic optical device 1 according to the second embodiment of the present invention is to manufacture the holographic optical device 1 according to the first embodiment of the present invention. Since it is the same as the first step ( S100 ) of the method, the following description will be omitted.

Next, the second step ( S200 - 1 ) will be described.

According to an exemplary embodiment of the present invention, in the second step, the optical element may be heated to a different temperature for each portion in which the inclination angle of the interference pattern is to be changed.

The second step (S200-1) is a step of heating the optical element 500 generated in the first step (S300-1) for each part, and the heated optical element 500 forms the holographic optical element 1 . will do

8 is a view showing a process of heating the optical element for each part.

For example, referring to FIG. 8 , the first portion 501 of the optical element 500 is heated to 120° C., and the second portion 502 adjacent to the first portion 501 is heated to 100° C. can be heated In addition, other parts of the optical element 500 except for the first part 501 and the second part 502 may also be heated to a specific temperature.

In this way, when the optical element 500 is heated to a different temperature for each part, the optical element 500 is formed with an interference pattern 400 having the same pitch but different inclination angles for each part. At this time, as described above, the higher the heating temperature and the longer the heating time, the greater the inclination angle of the interference pattern 400 recorded on the optical element 500 may be.

According to an exemplary embodiment of the present invention, in the second step, each portion of the optical element for which the inclination angle of the interference pattern is to be changed may be heated to a gradually higher or lower temperature in a predetermined direction. Specifically, the optical element 500 may be heated for each part so that the inclination angle of the interference pattern recorded on the holographic optical element 1 gradually increases or decreases gradually in a predetermined direction. For example, if described, the holographic optical element 1 may be heated for each part to a temperature gradually higher or lower in a predetermined direction.

As such, the optical element 500 is heated so that the inclination angle of the interference pattern recorded on the holographic optical element 1 is different for each position, so that the incident beam can be diffracted with maximum efficiency for each position of the holographic optical element 1 The incident angle of the incident beam (hereinafter, referred to as 'maximum diffraction efficiency angle') may vary.

The maximum diffraction efficiency angle of the holographic optical element 1 according to the inclination angle of the interference pattern, the action of the holographic optical element 1 applied to a vehicle HUD (Head Up Display), etc. Since it is the same as described in the manufacturing method of the graphic optical device 1, the following description will be omitted.

Hereinafter, the holographic optical device 1 according to an embodiment of the present invention will be described.

9 is a view showing a holographic optical device according to an embodiment of the present invention.

Referring to FIG. 9 , the holographic optical device 1 according to an embodiment of the present invention is configured by combining a plurality of optical devices 500 , and is recorded on each optical device 540 , 550 , 560 . The interfering patterns 404 , 405 , and 406 may have the same pitch but different inclination angles.

In addition, the plurality of optical elements 540 , 550 , and 560 may be coupled to gradually increase or decrease the inclination angle of the interference patterns 404 , 405 , and 406 in a predetermined direction.

Meanwhile, the holographic optical device 1 according to an embodiment of the present invention may be manufactured by the above-described method for manufacturing the holographic optical device 1 according to the embodiment of the present invention, but may be manufactured by another method. there is.

Hereinafter, the operation and effect of the holographic optical device 1 and the manufacturing method thereof of the present invention will be described in detail.

In an exemplary embodiment of the present invention, in the holographic optical device manufactured by the method for manufacturing the holographic optical device, the interference patterns recorded for each part have the same pitch and different inclination angles, and the inclination angle of the interference pattern in a predetermined direction is An increasing or decreasing, holographic optical device is provided.

The holographic optical element according to the present invention is formed by combining a plurality of optical elements having the same pitch and different inclination angles of the interference pattern, so that the augmented image light with high luminance is concentrated and emitted to the user's eye box area. It provides the effect of viewing the augmented image with high luminance.

First, by irradiating the reference light 100 and the object light 200 with the photosensitive material 300 to record the interference pattern 400, which is a holographic grating pattern, on the photosensitive material 300, the interference pattern 400 is recorded optical Create device 500 .

By using the optical element 500, it is possible to manufacture the holographic optical element 1 in which the inclination angle of the interference pattern 400 is recorded differently for each part.

For example, a plurality of optical elements 500 are generated, and the optical elements 500 are heated to different temperatures so that the respective optical elements 500 have the same pitch and different inclination angles. After having 400 , the holographic optical device 1 may be manufactured by combining a plurality of optical devices 500 .

As another example, by heating the optical element 500 to a different temperature for each part, the interference pattern 400 for each part has the same pitch and different inclination angles to manufacture the holographic optical element 1 . may be

At this time, the holographic optical device 1 may be manufactured so that the inclination angle of the interference pattern 400 recorded on the holographic optical device 1 gradually increases or decreases in a predetermined direction.

When the generated holographic optical element 1 is applied to a vehicle HUD (Head Up Display), etc., the holographic optical element 1 has a different maximum diffraction efficiency angle for each position, so information of each part of the augmented image The light containing the light is evenly diffracted with the maximum diffraction efficiency, and is focused and emitted to the user's eye box area.

As such, the holographic optical element according to the present invention is formed by combining a plurality of optical elements having the same pitch and different inclination angles of the interference pattern, so that the augmented image light with high luminance is concentrated and emitted to the user's eye box area, It provides the effect that the user can see the augmented image with high luminance.

In addition, since the light including information of each part of the augmented image is focused and emitted evenly to the user's eye box area with high luminance, the user can view the augmented image having an even luminance.

In addition, the method for manufacturing a holographic optical device according to the present invention generates a holographic optical device in which an interference pattern having the same pitch and different inclination angles for each position is recorded through a heating process, so that the holographic optical device can be manufactured through a simple and convenient process. It provides an effect that can be manufactured.

Although the present invention has been described in detail through representative embodiments above, those of ordinary skill in the art to which the present invention pertains can make various modifications to the above-described embodiments without departing from the scope of the present invention. will understand Therefore, the scope of the present invention should not be limited to the described embodiments, and should be defined by all changes or modifications derived from the claims and equivalent concepts as well as the claims to be described later.

1: holographic optical element 10: first incident beam
20: second incident beam 30: third incident beam
100: reference light 200: object light
300: photosensitive material 400: interference pattern
500: optical element

Claims (8)

A first step of generating an optical element by recording an interference pattern, which is a holographic grating pattern realized by an interference phenomenon between a reference light and an object light, on a photosensitive material;
a second step of repeating the first step a predetermined number of times to generate a plurality of the optical elements;
a third step of heating the optical element to change the inclination angle of the interference pattern; and
A fourth step of forming a holographic optical element by combining a plurality of the optical elements,
A method for manufacturing a holographic optical device.
According to claim 1,
The third step is
heating the plurality of optical elements to different temperatures,
A method for manufacturing a holographic optical device.
3. The method of claim 2,
The fourth step is
Combining a plurality of the optical elements so that the inclination angle of the interference pattern recorded on the holographic optical element gradually increases or decreases in a predetermined direction,
A method for manufacturing a holographic optical device.
A first step of generating an optical element by recording an interference pattern, which is a holographic grating pattern realized by an interference phenomenon between a reference light and an object light, on a photosensitive material; and
Including a second step of generating a holographic optical element by heating a predetermined portion to change the inclination angle of the interference pattern of the optical element,
A method for manufacturing a holographic optical device.
5. The method of claim 4,
The second step is
Heating the optical element to a different temperature for each part to change the inclination angle of the interference pattern,
A method for manufacturing a holographic optical device.
6. The method of claim 5,
The second step is
Heating to a gradually higher or lower temperature in a predetermined direction for each part to change the inclination angle of the interference pattern of the optical element,
A method for manufacturing a holographic optical device.
7. The method according to any one of claims 1 to 6,
The photosensitive material is a photopolymer,
A method for manufacturing a holographic optical device.
[Claim 7] In the holographic optical device manufactured by the method for manufacturing the holographic optical device of any one of claims 3 or 6,
Interference patterns recorded for each part have the same pitch and different inclination angles,
A holographic optical device in which the inclination angle of the interference pattern gradually increases or decreases in a predetermined direction.

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