JPH08179353A - Optical writing type spatial optical modulation element and its production - Google Patents

Abstract

PURPOSE: To provide an optical writing type spatial optical modulation element capable of increasing the relative modulation rate and contrast ratio. CONSTITUTION: This optical writing type spatial optical modulation element has a first transparent substrate 1 on which a first electrode layer 2 transparent to at least writing light has been formed, a second transparent substrate 10 on which a second electrode layer 9 transparent to at least reading out light has been formed, a photoreceptor layer 3 held between the first and second electrode layers 2, 9, a light shielding body layer 4 and an electro-optic effect layer. The optical writing type spatial optical modulation element described above makes the writing light incident on the photoreceptor layer 3, modulates the incident reading out light on the electro-optic effect layer according to a change in the characteristics of the photoreceptor layer 3 by this writing light and emits the modulated light. The photoreceptor layer 4 is formed out of a segmented structure consisting of packed layer parts 42 having insulating and light shielding characteristics and island layer parts 41 having conductive and light shielding characteristics.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical writing type spatial light modulator for modulating reading light according to writing light.

[0002]

2. Description of the Related Art FIG. 2 shows an optical writing type spatial light modulator (optical writing type Spatial Light Modulator:
It is a sectional view showing an example of the conventional example of "(SLM)". In this figure, 1 is a first transparent substrate made of transparent glass or the like, 2 is a first transparent electrode, 3 is a photosensitive layer made of cadmium sulfide (CdS) or amorphous silicon (α-Si), and 4 is tellurium. Light-shielding layer made of cadmium chloride (CdTe) or the like, 5 is a dielectric mirror, 7 is a liquid crystal layer which is an electro-optical effect layer, 6 and 8 are dielectric layers each acting as a liquid crystal alignment film, and 9 is a second transparent electrode. Reference numeral 10 is a second transparent substrate made of transparent glass or the like.

In the example shown in FIG. 2, the writing light 11 is the first light.
And the read light 12 enters from the second transparent substrate 10 side. A predetermined voltage is applied between the first and second transparent electrodes 2 and 9 by the power supply 14. Here, in the liquid crystal layer 7, liquid crystal molecules are substantially parallel to the substrate surface,
The alignment direction of the molecules on both substrate surfaces of the liquid crystal layer is rotated by 45 degrees (45 degree twist), and is adjusted so as to exhibit both the optical rotation effect and the birefringence effect.

A voltage V having a positive electrode of 9 is applied between the first and second transparent electrodes 2 and 9 by a power source 14, and a photosensitive layer 3, a light-shielding layer 4 and a dielectric mirror constituting an SLM. Since the electric conductivity in the plane direction of the layer 5, the liquid crystal layer 7 and the like is set to be sufficiently low, the layers are in a so-called serially connected state. Assuming that the absolute values of impedances of the photoconductor layer 3, the light shielding layer 4, the dielectric mirror layer 5, and the liquid crystal layer 7 are Z1, Z2, Z3, and Z4, the voltage V4 applied between the liquid crystal layers 7 is approximately

[0005]

[Equation 1]

[0006] When the writing light 11 is not incident from the first transparent substrate 1 side, the impedance Z1 of the photoconductor layer 3 is set to be sufficiently higher than the combined impedance of the light shielding layer 4, the dielectric mirror layer 5, and the liquid crystal layer 7. . By setting the partial pressure V1 applied to the photoconductor layer 3 to be high, a voltage Vh lower than the voltage required for aligning the molecules of the liquid crystal layer in the direction of the electric field is divided between the layers of the liquid crystal layer 7. ing. At this time, the liquid crystal molecules are aligned following the alignment film 6. In this state, when the reading light 12, which is linearly polarized light and includes only the first polarization component, is incident, the incident light is not subjected to the birefringence effect, only the optical rotation effect depending on the twist angle, but due to the dielectric mirror 5. When the liquid crystal layer 7 is reflected, the liquid crystal layer 7 travels in the opposite direction and receives the optical rotation effect in the opposite direction. As a result, linearly polarized light vibrating in exactly the same direction as the incident light is emitted. This emitted light passes through a polarization separation element (not shown) such as a polarization beam splitter, and only the second polarized component that vibrates in the direction perpendicular to the first polarized light is output, but the emitted light contains the second polarized component. The output light that is not reflected becomes zero. This state is a state in which optical writing is not performed.

When the writing light 11 is incident from the first transparent substrate 1 side, electrons and holes are generated in the photosensitive layer 3 at the portion where the writing light 11 is incident. The holes move toward the negative electrode 2 by the electric field and are carried away from the negative electrode 2. Although the electrons move toward the light-shielding layer 4, since the light-shielding layer 4 has a high specific resistance, it stays at the interface, and this charge causes a potential difference between the light-shielding layer 4, the dielectric mirror layer 5, and the liquid crystal layer 7, and the liquid crystal layer 7
Is activated. In other words, the optical carriers generated by the writing light 11 lower the impedance of the photoconductor layer 3 and increase the voltage applied to the liquid crystal layer 7, so that the liquid crystal molecules are aligned in the electric field direction. For this reason SLM
The read light 12, which is linearly polarized light including only the first polarization component that is incident on the SLM, is subjected to the birefringence action while reciprocating through the liquid crystal layer 7, and the polarization direction is rotated according to the degree of alignment of the liquid crystal layer 7, and the SLM Is emitted. The polarization state of the reading light 12 is spatially (that is, two-dimensionally) and real-time modulated according to the distribution and intensity of the writing light 11, and is emitted as modulated light 13. This emitted light passes through a polarization separation element (not shown) such as a polarization beam splitter, and only the second polarized component vibrating in the direction orthogonal to the first polarized light is extracted as output light. This state is a state in which optical writing is performed.

Here, the role of the light shielding layer 4 will be described. The light shielding layer 4 has a role of preventing the read light 12 from reaching the photoconductor layer 3, and secondarily has a role of preventing the write light 11 from mixing with the modulated light 13. In general, the light intensity of the read light 12 is extremely higher than that of the write light 11, so that the dielectric mirror 5 alone transmits 1 to several percent of the light, so that the read light 12 to the photoconductor layer 3 is transmitted. Can not be prevented from permeating. Although it cannot be generally stated because it depends on the photosensitivity of the photoconductor layer 3 and the like, it is required that the light-shielding layer 4 and the dielectric mirror layer 5 together have a light-shielding ability of 1 / million or more. A cadmium telluride film is generally used as the light-shielding layer 4 used for this purpose, but a film thickness of about 3 μm is required.

[0009]

As described above, in the conventional SLM, since the light shield layer 3 is as thick as about 3 μm, the voltage applied to the liquid crystal molecules is the minimum voltage required for the liquid crystal molecules to start rising. Can't be big enough. Therefore, there is a problem that the maximum value of the intensity of the modulated light modulated by the liquid crystal layer cannot be sufficiently increased, and a problem that the contrast ratio of the intensity of the modulated light cannot be increased.

Hereinafter, this problem will be described in detail. The equivalent circuit of the optical writing type SLM has impedances of the photoconductor layer 3, the light shielding layer 4, the dielectric mirror layer 5 and the liquid crystal layer 7, respectively.
When represented by Z1, Z2, Z3, and Z4, they can be represented by these series circuits as shown in FIG. Here, the photosensitive layer 3 is amorphous silicon, the light-shielding layer 4 is cadmium telluride, and the liquid crystal layer 7 is Merck liquid crystal E2100.
, The absolute value of these impedances is generally 1KH _Z , each Z1 is about 300KΩ (dark state), Z2 is about 50K.
Ω and Z4 are about 90KΩ. As the absolute value of the total impedance of the other layers, the dielectric mirror layer 5, and the alignment layers 6 and 8, Z3 will be about 50Ω in the present description, and the generality will not be lost. In operation, the liquid crystal interlayer voltage in the dark state is set to Vh, which generally depends on the required contrast, but is 0.70
It is around V. Here, Vh is defined as the voltage immediately before the liquid crystal molecules start to rise. Therefore, the electrodes 2, 9
3.81V is suitable for the voltage supplied between them. When the writing light 11 is incident in this state, the absolute value of the impedance Z1 of the photoconductor layer usually decreases to about 100 kΩ, depending on the intensity of the writing light 11. At this time, the liquid crystal interlayer voltage V4 is 1.
It rises to 18V. At this time, as can be seen from FIG. 5, the relative modulation rate ((the intensity of the modulated light in which the read light is modulated by the liquid crystal layer / the intensity of the read light) × 100) did not reach the maximum value of 67%, and The brightness is limited. Vh
If it is set to 0.70 V or more and the voltage supplied between the electrodes 2 and 9 is increased, the voltage applied between the liquid crystals is increased, and the intensity of the read light modulated by the liquid crystal layer is certainly increased. It is clear from FIG. 5 that the contrast ratio (relative modulation rate when the liquid crystal voltage is V / relative modulation rate when the liquid crystal voltage is Vh) is reduced.

It is an object of the present invention to provide an optical writing type spatial light modulator capable of increasing the relative modulation ratio and the contrast ratio.

[0012]

Therefore, the first aspect of the present invention is to provide a "first transparent substrate having a first electrode layer which is transparent to at least writing light and a first transparent substrate which is transparent to at least reading light. A second transparent substrate on which two electrode layers are formed; and a photoconductor layer, a light shielding layer and an electro-optical effect layer sandwiched between the first and second electrode layers, wherein In a spatial light modulator of optical writing type, which receives writing light, modulates the reading light incident on the electro-optical effect layer and emits modulated light in response to a change in characteristics of the photoconductor layer due to the writing light. The light-shielding space light is characterized in that the light-shielding body layer has a sectional structure composed of a filling layer portion having an insulating property and a light-shielding characteristic and an island layer portion having a conductive property and a light-shielding characteristic. Modulation element (claim 1) " That.

Further, the present invention secondly provides an optical writing type spatial light modulator according to claim 1, wherein the filling layer portion is an insulating cermet film. To do. Further, a third aspect of the present invention is the "optical writing type spatial light modulator according to claim 1, wherein the filling layer portion is a polymer layer in which an insulating pigment is dispersed." provide.

In a fourth aspect of the present invention, "a first transparent substrate having a first electrode layer transparent to at least writing light and a second electrode layer transparent to at least reading light is formed. Second transparent substrate, and the first and second transparent substrates
A photosensitive layer sandwiched between electrode layers, a light shielding layer and an electro-optical effect layer, and the writing light is made incident on the photosensitive layer, and the characteristics of the photosensitive layer are changed by the writing light. In the method of manufacturing the optical writing type spatial light modulator that modulates the read light incident on the electro-optical effect layer and emits the modulated light, at least a transparent first electrode layer is formed on the first transparent substrate. Forming step and the transparent first
A step of forming a photoconductor layer on the electrode layer, and a step of forming a plurality of island layer portions having conductive and light-shielding properties on the photoconductor layer, and then filling the island layer portion with insulating and light-shielding A step of forming a filling layer portion having characteristics, a step of forming a dielectric mirror layer on the light shielding layer from the island layer portion and the filling layer portion, and a transparent second electrode on the second transparent substrate. A method of manufacturing an optical writing type spatial light modulator comprising the steps of forming a layer and forming an electro-optic effect layer between the dielectric mirror and the transparent second electrode layer (claim 4). " provide.

A fifth aspect of the present invention is that "the plurality of island layer portions having the conductive and light-shielding properties are formed by a photolithography method.
A method for manufacturing the above-described optical writing type spatial light modulator (claim 5) "is provided. A sixth aspect of the present invention is that "the plurality of island layer portions having the conductive and light shielding properties are formed by a screen printing method.
A method for manufacturing the above-described optical writing type spatial light modulator (claim 6) "is provided.

[0016]

The light shielding layer 4 is composed of an electrically conductive and light shielding island layer portion 41 and an insulating and light shielding filling layer portion 42. The film thickness of the filling layer portion 42 was set sufficiently thick to block light, and the conductivity was set to a value necessary and sufficient to prevent lateral diffusion of carriers. Usually, the thickness is 1 to 5 μm and the conductivity is 10 ⁻¹⁰ Ω ⁻¹ · cm ⁻¹ or less.

The film thickness of the island layer portion 41 is also sufficiently thick to block light, and the conductivity is made sufficiently large so that the charge can easily move from the photoconductor layer 3 to the dielectric mirror layer 5. Normally, this thickness is set to 1 to 5 μm, but in order to make the unevenness of the entire light shielding layer 4 as small as possible, the filling layer portion
It is preferable that the thickness is close to. Conductivity is usually 10 ^-7 Ω ^-1 cm
^-1 or more is sufficient, so it is not necessarily a pure metal.

Since the conductivity of the island layer portion 41 is set high, the impedance in the film thickness direction is negligibly lower than the impedance of the photosensitive layer 3 in the dark state, and the equivalent circuit of the island layer portion 41 is , Can be expressed in the film thickness direction as shown in FIG. When the impedances of the photoconductor layer 3, the liquid crystal layer 7, the dielectric mirror layer 5 and the like are represented by Z1, Z3 and Z4, respectively, the absolute value of the impedance is 1KH _Z and each Z1 is about
300KΩ (dark state), Z3 is about 50KΩ, Z4 is about 90KΩ. When an AC voltage of 3.42V is applied to this portion, the voltage between the liquid crystals becomes 0.70V in the dark state, and since this value is equal to Vh, the liquid crystal molecules do not rise. In the state of being optically written, the photocarriers generated in the photoconductor layer 3 pass through the photoconductor layer 3, pass through the island layer portion of the light shielding layer 4 and reach the boundary surface portion with the dielectric mirror layer 5, where Stay in. Meanwhile, the carriers diffuse due to electric conduction, but do not diffuse to the outside of the island layer portion 41 due to the high resistance of the filling layer portion 42, and remain in the island layer portion 41 with a uniform charge density. At that time, the absolute value of the impedance of the photoconductor layer 3 was reduced to about 100 kΩ at the maximum writing, and 1.28 V was applied between the liquid crystal layers 7.
As a result, the relative modulation rate increases from 67% to 93%, and the contrast ratio increases by 39%, as shown in FIG.

Assuming that the impedance of the filling layer portion 42 is Z2, the equivalent circuit of the filling layer portion 42 is shown in FIG. Although depending on the material, the value of Z2 is usually 50 KΩ or more, so that the relative modulation rate in the maximum written state is 54% or less. However, the width d of the filling layer portion is generally equal to at most about several times the total layer thickness of the dielectric mirror layer 5 and the liquid crystal layer 7, and the exudation of the electric field from the island layer portion 41 cannot be ignored. Therefore, it can be considered that the boundary between the island layer portion 41 and the filling layer portion 42 is not clear as a whole.

Since the filling layer portion 42 in the light shielding layer 4 occupies a very small proportion to the island layer portion 41, the filling layer portion 42 does not lower the relative modulation rate of the SLM as a whole. Virtually no problem. The structure of the light-shielding layer 4 of the present invention was found by a detailed analysis of the operating principle of the SLM, and the dimension of the island layer portion 41 depends on the required resolution, but it is generally 5 to 50 μm square or 5 to 50 μm. The diameter is preferably circular, and the packed bed portion 4
The width of 2 is preferably 1 to 10 μm in relation to the insulating ability.

Hereinafter, the present invention will be described in more detail by way of examples, but the present invention is not limited to these examples.

[0022]

【Example】

[Embodiment 1] FIG. 1 is a sectional view showing Embodiment 1 of an optical writing type SLM according to the present invention. On the first transparent substrate 1,
The film thickness of the first transparent electrode 2 is about 0 by the sputtering method.
A 1 μm ITO film was formed.

On the transparent electrode 2, an amorphous silicon film having a film thickness of about 20 μm was formed as a photoconductor layer 3 by a plasma CVD method using monosilane gas and hydrogen gas as raw materials. The light shielding layer 4 was formed on the photoconductor layer 3 as follows. First, as the island layer portion 41, a conductive resin film was formed by a screen printing method having a porosity only in a portion corresponding to the island pattern, and the island layer portion 41 having a thickness of 5 μm was formed after heating and solidification.

After the island layer portion 41 was thus formed, the pigment-dispersed polymer film having a thickness of 3 μm was formed as the filling layer portion 42 by repeating spin coating and drying a plurality of times. At this time, in order to secure the smoothness of the upper surface, it may be designed to be slightly thicker than the island layer portion 41 and cover the island layer portion 41. In this way, the light shielding layer 4 was formed.

As the dielectric mirror layer 5, eleven layers of titanium dioxide and magnesium fluoride were alternately formed on the light shielding layer 4 by the electron beam evaporation method to form a mirror for the reading light 12. On the second transparent substrate 10, an ITO film having a thickness of about 0.1 μm was formed as the second transparent electrode 9 by the sputtering method.

Next, a polyimide film having a thickness of 0.05 μm is formed as an alignment film on the dielectric mirror layer 5 of the first substrate and the ITO film of the second substrate by a spin coating method to a predetermined thickness. It was formed by rubbing treatment. These substrates are TN type liquid crystals, which are sprayed with a predetermined spacer at a predetermined density and then bonded together while adjusting the parallelism and the spacing.
Adeka Kiracol 7561 was injected. The twist angle of the alignment of liquid crystal molecules was 45 degrees, and the liquid crystal layer thickness was adjusted to 4 μm.

The SLM manufactured as described above has a large relative modulation ratio and a large contrast ratio. Example 2 The same method as in Example 1 was carried out except that a polymer film in which carbon particles were dispersed was used as the filling layer portion 42 instead of the pigment-dispersed polymer film. Example 3 An ITO film having a thickness of about 0.1 μm was formed as the first transparent electrode 2 on the first transparent substrate 1 by the sputtering method.

An amorphous silicon film having a thickness of about 20 μm was formed on the transparent electrode 2 as a photosensitive layer 3 by a plasma CVD method using monosilane gas and hydrogen gas as raw materials. The light-shielding layer 4 was formed on the photoconductor layer 3 as follows. First, in order to form the island layer portion 41, an aluminum film was formed to a thickness of about 0.3 μm by a vacuum evaporation method. After this, a photoresist is applied, the mask pattern of the island layer portion 41 is exposed, and development etching is performed to expose the island layer portion 4
1 was formed.

After the island layer portion 41 was thus formed, spin coating and drying were repeated a plurality of times as the filling layer portion 42 to form a pigment-dispersed polymer film having a thickness of 3 μm. At this time, in order to secure the smoothness of the upper surface, it may be designed to be slightly thicker than the island layer portion 41 and cover the island layer portion 41. In this way, the light shielding layer 4 was formed.

As the dielectric mirror layer 5, eleven layers of titanium dioxide film and magnesium fluoride film were alternately formed on the light shielding layer 4 by the electron beam evaporation method to form a mirror for the reading light 12. On the second transparent substrate 10, as the second transparent electrode 9, an IT film having a thickness of about 0.1 μm is formed by a sputtering method.
An O 2 film was formed.

Next, a polyimide film having a thickness of 0.05 μm is formed as an alignment film on the dielectric mirror layer 5 of the first substrate and the ITO film of the second substrate by a spin coating method, and the predetermined film is formed. It was formed by rubbing treatment. These substrates are TN type liquid crystals, which are sprayed with a predetermined spacer at a predetermined density and then bonded together while adjusting the parallelism and the spacing.
Adeka Kiracol 7561 was injected. The twist angle of the alignment of liquid crystal molecules was 45 degrees, and the liquid crystal layer thickness was adjusted to 4 μm.

The SLM manufactured as described above has a large relative modulation rate and a large contrast ratio. [Example 4] The same method as in Example 3 was carried out except that a polymer film in which carbon particles were dispersed was used as the filling layer portion 42 instead of the pigment-dispersed polymer film. Example 5 An ITO film having a thickness of about 0.1 μm was formed as the first transparent electrode 2 on the first transparent substrate 1 by the sputtering method.

On the transparent electrode 2, an amorphous silicon film having a film thickness of about 20 μm was formed as a photoconductor layer 3 by a plasma CVD method using monosilane gas and hydrogen gas as raw materials. The light shielding layer 4 was formed on the photoconductor layer 3 as follows. First, as the island layer portion 41, a conductive resin film was formed by a screen printing method having a porosity only in the portion corresponding to the island pattern, and the island layer portion 41 having a thickness of 3 μm was formed after heating and solidification.

After forming the island layer portion in this manner, the filling layer portion 4 is formed.
As shown in Fig. ₂ , multiple holes were made in the SiO ₂ target, and Cu was placed there.
Alternatively, Au powder was added and the target was sputtered to form a cermet film of 3 μm. The specific resistance is 1
Concentration in such a way that 0 ⁸ Ω · cm, the film formation rate was adjusted a base temperature. At this time, in order to secure the smoothness of the upper surface,
A design in which the island layer portion 41 is thicker than the island layer portion 41 and covers the island layer portion 41 is also conceivable. In this way, the light shielding layer 4 was formed.

As the dielectric mirror layer 5, eleven layers of titanium dioxide film and magnesium fluoride film were alternately formed on the light shielding layer 4 by the electron beam evaporation method to form a mirror for the reading light 12. On the second transparent substrate 10, as the second transparent electrode 9, an IT film having a thickness of about 0.1 μm is formed by a sputtering method.
An O 2 film was formed.

Next, a polyimide film having a thickness of 0.05 μm is formed as an alignment film on the dielectric mirror layer 5 of the first substrate and the ITO film of the second substrate by a spin coating method, and the predetermined film is formed. It was formed by rubbing treatment. These substrates are TN type liquid crystals, which are sprayed with a predetermined spacer at a predetermined density and then bonded together while adjusting the parallelism and the spacing.
Adeka Kiracol 7561 was injected. The twist angle of the alignment of liquid crystal molecules was 45 degrees, and the liquid crystal layer thickness was adjusted to 4 μm.

The SLM manufactured as described above has a large relative modulation rate and a large contrast ratio. Example 6 An ITO film having a thickness of about 0.1 μm was formed as the first transparent electrode 2 on the first transparent substrate 1 by the sputtering method.

On the transparent electrode 2, an amorphous silicon film having a film thickness of about 20 μm was formed as a photoconductor layer 3 by a plasma CVD method using monosilane gas and hydrogen gas as raw materials. The light shielding layer 4 was formed on the photoconductor layer 3 as follows. First, in order to form the island layer portion 41, an aluminum film having a thickness of 0.3 μm was formed by a vacuum evaporation method. After that, a photoresist is applied, the mask pattern of the island layer portion 41 is exposed, and development etching is performed to etch the island layer portion 41.
Was formed.

After the island layer portion is thus formed, the filling layer portion 4 is formed.
As shown in Fig. ₂ , multiple holes were made in the SiO ₂ target, and Cu was placed there.
Alternatively, Au powder was added and the target was sputtered to form a cermet film of 3 μm. The specific resistance is 1
Concentration in such a way that 0 ⁸ Ω · cm, the film formation rate was adjusted a base temperature. At this time, in order to secure the smoothness of the upper surface,
A design in which the island layer portion 41 is thicker than the island layer portion 41 and covers the island layer portion 41 is also conceivable. In this way, the light shielding layer 4 was formed.

As the dielectric mirror layer 5, eleven layers of titanium dioxide film and magnesium fluoride film were alternately formed on the light shielding layer 4 by the electron beam evaporation method to form a mirror for the reading light 12. On the second transparent substrate 10, as the second transparent electrode 9, an IT film having a thickness of about 0.1 μm is formed by a sputtering method.
An O 2 film was formed.

Then, a polyimide film having a thickness of 0.05 μm is formed as an alignment film on the dielectric mirror layer 5 of the first substrate and the ITO film of the second substrate by a spin coating method, and the predetermined film is formed. It was formed by rubbing treatment. These substrates are TN type liquid crystals, which are sprayed with a predetermined spacer at a predetermined density and then bonded together while adjusting the parallelism and the spacing.
Adeka Kiracol 7561 was injected. The twist angle of the alignment of liquid crystal molecules was 45 degrees, and the liquid crystal layer thickness was adjusted to 4 μm.

The SLM manufactured as described above has a large relative modulation ratio and a large contrast ratio.

[0043]

As described above in detail, according to the present invention, the light shielding layer is divided into the island layer portion and the filling layer portion, and the filling layer portion in the light shielding layer is occupied by the island layer portion. By making the ratio very small relative to the occupied ratio and setting the conductivity of the island layer part high enough, the impedance in the film thickness direction of the island layer part can be made so small that it can be practically ignored. The decrease in the relative modulation rate due to the portion is practically insignificant. As a result, we were able to obtain an optical writing type SLM with significantly improved relative modulation and contrast.

[Brief description of drawings]

FIG. 1 is a sectional view showing an optical writing type spatial light modulator that is Embodiments 1 to 6 of the present invention.

FIG. 2A is a plan view showing a structure of a light shielding layer of an optical writing type light modulation element of Examples 1 to 6 of the present invention. This figure shows an example in which the island layer portion has a square shape. Figure 2
(B) is a plan view showing the structure of the light shielding layer of the optical writing type light modulation elements of Examples 1 to 6 of the present invention. This figure is an example in which the island layer portion has a circular shape.

FIG. 3 is an equivalent circuit of a conventional optical writing type spatial light modulator and a filling layer portion of the present invention.

FIG. 4 is an equivalent circuit of an island layer portion of the optical writing type spatial light modulator of the present invention.

FIG. 5 is a graph showing a voltage relative modulation rate applied between liquid crystal layers.

FIG. 6 is a sectional view showing an example of a conventional optical writing type spatial light modulator.

[Explanation of symbols]

 1 1st transparent substrate 2 1st transparent electrode 3 Photosensitive layer 4 Light-shielding layer 5 Dielectric mirror layer 6 Dielectric alignment layer 7 Liquid crystal layer 8 Dielectric alignment layer 9 Second transparent electrode 10 Second transparent substrate 11 Write light 12 Read light 13 Modulated light 15 Island layer portion 39 Filling layer portion d Filling layer portion width V SLM driving power supply Z1 Impedance of photoconductor layer Z2 Impedance of light shield layer Z3 Impedance of liquid crystal layer Z4 Dielectric mirror and alignment film Total impedance of

Claims (6)

[Claims] 1. A first transparent substrate on which a first electrode layer transparent to at least writing light is formed, and a second transparent substrate on which a second electrode layer transparent to at least reading light is formed. A photosensitive layer sandwiched between the first and second electrode layers, a light shielding layer and an electro-optical effect layer, the writing light being incident on the photosensitive layer, and the photosensitive layer being exposed to the writing light. In the spatial light modulator of the optical writing type that modulates the reading light incident on the electro-optical effect layer and emits the modulated light according to the characteristic change of the body layer, the light-shielding body layer is an insulating and light-shielding material. An optical writing type spatial light modulator, which has a sectional structure composed of a filling layer portion having characteristics and an island layer portion having conductivity and light shielding characteristics. 2. The optical write type spatial light modulator according to claim 1, wherein the filling layer portion is an insulating cermet film. 3. The optical writing type spatial light modulator according to claim 1, wherein the filling layer portion is a polymer layer in which an insulating pigment is dispersed. 4. A first transparent substrate on which a first electrode layer transparent to at least writing light is formed, and a second transparent substrate on which a second electrode layer transparent to at least reading light is formed. A photosensitive layer sandwiched between the first and second electrode layers, a light shielding layer and an electro-optical effect layer, the writing light being incident on the photosensitive layer, and the photosensitive layer being exposed to the writing light. In a method of manufacturing a spatial light modulator for optical writing type, which modulates read light incident on the electro-optical effect layer and emits modulated light in accordance with a change in characteristics of a body layer, at least on a first transparent substrate. A step of forming a transparent first electrode layer, a step of forming a photosensitive layer on the transparent first electrode layer, and a plurality of island layer portions having conductive and light-shielding properties on the photosensitive layer After forming, the island layer is filled with insulation and light shielding Forming a filling layer portion having the above characteristics, forming a dielectric mirror layer on the light shielding layer from the island layer portion and the filling layer portion, and forming a transparent second layer on the second transparent substrate. A method of manufacturing a photo-writing type spatial light modulator comprising the steps of forming an electrode layer and forming an electro-optical effect layer between the dielectric mirror and the transparent second electrode layer. 5. The method of manufacturing a spatial light modulator of optical writing type according to claim 4, wherein the plurality of island layer portions having conductive and light-shielding properties are formed by a photolithography method. 6. The method of manufacturing an optical writing type spatial light modulator according to claim 4, wherein the plurality of island layer portions having the conductive and light-shielding properties are formed by a screen printing method.