阅读说明：本技术 反射型空间光调制器、光观察装置及光照射装置 (Reflection type spatial light modulator, optical observation device, and light irradiation device ) 是由 泷泽国治 田中博 丰田晴义 大林宁 酒井宽人 渡边翼 于 2017-12-05 设计创作，主要内容包括：本发明提供一种反射型空间光调制器,其具备：电光结晶,其具有输入光被输入的输入面和与输入面相对的背面；光输入输出部,其配置于电光结晶的输入面,且具有透射输入光的第一电极；光反射部,其包含包括多个第二电极的基板,且配置于电光结晶的背面侧；驱动电路,其对第一电极与多个第二电极之间施加电场,光输入输出部包含形成于输入面上的第一电荷注入抑制层,光反射部包含形成于背面上的第二电荷注入抑制层。(The present invention provides a reflection type spatial light modulator, comprising: an electro-optical crystal having an input surface to which input light is input and a back surface opposite to the input surface; a light input/output unit which is disposed on an input surface of the electro-optical crystal and has a first electrode for transmitting input light; a light reflection unit including a substrate including a plurality of second electrodes and disposed on a back surface side of the electro-optical crystal; and a drive circuit for applying an electric field between the first electrode and the plurality of second electrodes, wherein the light input/output section includes a first electric-charge-injection inhibiting layer formed on the input surface, and the light reflection section includes a second electric-charge-injection inhibiting layer formed on the back surface.)

1. A reflective spatial light modulator, characterized in that,

is a reflective spatial light modulator that modulates input light and outputs modulated light,

the disclosed device is provided with:

a perovskite-type electro-optical crystal having an input surface to which the input light is input and a back surface facing the input surface, and having a relative dielectric constant of 1000 or more;

an optical input/output unit which is disposed on the input surface of the electro-optical crystal and has a first electrode through which the input light is transmitted;

a light reflecting section including a substrate on which a plurality of second electrodes are arranged, the light reflecting section being arranged on the back surface of the electro-optical crystal and reflecting the input light toward the light input/output section; and

a drive circuit that applies an electric field between the first electrode and the plurality of second electrodes,

the optical input/output section includes a first electric-charge-injection inhibiting layer formed on the input surface, the first electric-charge-injection inhibiting layer inhibiting injection of electric charges from the first electrode into the electro-optical crystal by having a dielectric material in a cured product of a non-conductive adhesive material,

the light reflection unit includes a second electric-charge-injection inhibiting layer formed on the rear surface, and the second electric-charge-injection inhibiting layer inhibits injection of electric charges from the plurality of second electrodes into the electro-optical crystal by having a dielectric material in a cured product of a non-conductive adhesive material.

2. The reflective spatial light modulator of claim 1,

the light reflection unit further includes:

a plurality of third electrodes formed on a surface of the second electric-charge-injection inhibiting layer opposite to the back surface, the third electrodes corresponding to the plurality of second electrodes;

and a plurality of bumps arranged such that the plurality of second electrodes and the plurality of third electrodes corresponding to the plurality of second electrodes are electrically connected to each other.

3. The reflective spatial light modulator of claim 1,

the substrate includes a pixel region in which the plurality of second electrodes are arranged and a peripheral region surrounding the pixel region,

the second electric-charge-injection inhibiting layer has a first region facing the pixel region and a second region surrounding the first region,

the content of the dielectric material in the second region is smaller than the content of the dielectric material in the first region.

4. The reflective spatial light modulator of claim 3,

the boundary of the first region and the second region coincides with the boundary of the pixel region and the peripheral region as viewed from the input direction of the input light.

5. The reflective spatial light modulator of claim 3,

a boundary between the first region and the second region is located closer to the outer edge than a boundary between the pixel region and the peripheral region as viewed from the input direction of the input light.

6. The reflective spatial light modulator of any one of claims 1 to 5,

the light input/output unit further includes a transparent substrate having a first surface on which the input light is input and a second surface that is a surface opposite to the first surface, and the first electrode is disposed on the second surface of the transparent substrate.

7. The reflective spatial light modulator of any one of claims 1 to 6,

setting the relative dielectric constant of the electro-optic crystal to_xtl，

D represents a thickness from the input surface to the back surface in the electro-optical crystal_xtl，

D represents the total thickness of the first and second electric-charge-injection inhibiting layers_ad，

A maximum voltage V to be an applied voltage generated by the drive circuit_smaxAnd a voltage V applied to the electro-optical crystal to output the modulated light whose phase of the input light is modulated by only 2 pi radians_xtlV of ratio of_xtl/V_smaxIs set to R_sWhen the temperature of the water is higher than the set temperature,

relative dielectric constant of the first and second electric-charge-injection inhibiting layers including the dielectric material_adRepresented by the formula (1),

[ number 1]

8. The reflective spatial light modulator of any one of claims 1 to 7,

the first electrode is formed on the entire surface of the input surface.

9. The reflective spatial light modulator of claim 1,

the light reflecting section further includes a plurality of fourth electrodes disposed on the back surface of the electro-optic crystal so as to face the plurality of second electrodes.

10. The reflective spatial light modulator of claim 9,

the light reflecting section reflects the input light by the plurality of fourth electrodes.

11. The reflective spatial light modulator of any one of claims 1 to 9,

the light reflecting section reflects the input light by the plurality of second electrodes.

12. The reflective spatial light modulator of any one of claims 1 to 11,

the electro-optical crystal is KTa as KTN crystal_1-xNb_xO₃Crystalline form K as K L TN crystal_1-yLi_yTa_1-xNb_xO₃Crystals, or P L ZT crystals, wherein,

at KTa_1-xNb_xO₃In the crystallization, 0 ≦ x ≦ 1,

at K_1-yLi_yTa_1-xNb_xO₃In the crystallization, x is 0 ≦ 1, and y is 0 < 1.

13. The reflective spatial light modulator of any one of claims 1 to 12,

and a temperature control element for controlling the temperature of the electro-optical crystal.

14. A light observation device characterized in that,

comprising:

a light source that outputs the input light;

the reflective spatial light modulator of any one of claims 1 to 13;

an optical system that irradiates the object with the modulated light output from the reflective spatial light modulator; and

and a light detector that detects light output from the object.

15. A light irradiation device characterized in that,

comprising:

a light source that outputs the input light;

the reflective spatial light modulator of any one of claims 1 to 13; and

and an optical system for irradiating the object with the modulated light output from the reflective spatial light modulator.

Technical Field

The present disclosure relates to a reflective spatial light modulator, an optical observation device, and a light irradiation device.

Background

For example, patent documents 1 and 2 disclose an electro-optical element. The electro-optical element includes: substrate, and KTN (KTa) of ferroelectric laminated on substrate_1-xNb_xO₃) The layer, dispose transparent electrode, the metal electrode of disposing behind the KTN layer in the front of the KTN layer. KTN has four crystal structures depending on temperature, and is used as an electro-optical element when it has a perovskite crystal structure. This KTN layer is formed on a seed layer formed on a metal electrode.

Disclosure of Invention

Problems to be solved by the invention

Patent documents 1 and 2 disclose that conductivity is imparted to a seed layer by adding a conductive material to the seed layer. In this case, since the metal electrode is electrically connected to the KTN layer, an electric field can be applied to the KTN layer. However, in such a configuration, when electric charges are injected from the metal electrode to the KTN layer, modulation accuracy may be unstable due to the operation of electrons in the KTN crystal. In particular, when the metal electrodes of the plurality of electro-optical elements are formed in an array, when the seed layer is provided with conductivity, electrical signals input to the plurality of metal electrodes are mixed, and the modulation accuracy may be unstable.

Drawings

Fig. 1 is a block diagram showing a configuration of an optical observation device according to an embodiment.

Fig. 2 is a cross-sectional view showing a spatial light modulator used in the optical observation apparatus of fig. 1.

Fig. 3 is a diagram showing the relationship between the crystal axis, the light traveling direction, and the electric field in the retardation modulation.

Fig. 4 is a diagram for explaining electrodes of the spatial light modulator of fig. 2.

Fig. 5 is a sectional view taken along line V-V of fig. 2.

Fig. 6 is a cross-sectional view showing a spatial light modulator according to another embodiment.

Fig. 7 is a sectional view taken along line VII-VII of fig. 6.

Fig. 8 is a cross-sectional view showing a spatial light modulator according to still another embodiment.

Fig. 9 is a cross-sectional view showing a spatial light modulator according to still another embodiment.

Fig. 10 is a cross-sectional view showing a spatial light modulator according to still another embodiment.

Fig. 11 is a block diagram showing a configuration of a light irradiation device according to an embodiment.

An object of an embodiment is to provide a reflective spatial light modulator, a light irradiation device, and a light observation device that can suppress mixing of electric signals input to a plurality of electrodes and stabilize modulation accuracy.

Means for solving the problems

One aspect provides a reflective spatial light modulator that modulates input light and outputs modulated light, including: a perovskite-type electro-optical crystal having an input surface to which input light is input and a back surface facing the input surface, and having a relative dielectric constant of 1000 or more; a light input/output unit which is disposed on an input surface of the electro-optical crystal and has a first electrode for transmitting input light; a light reflection unit including a substrate on which a plurality of second electrodes are arranged, arranged on a back surface side of the electro-optical crystal, and configured to reflect input light to the light input/output unit; and a driving circuit for applying an electric field between the first electrode and the plurality of second electrodes, wherein the light input/output section includes a first electric-charge-injection inhibiting layer formed on the input surface for inhibiting injection of electric charges from the first electrode into the electro-optical crystal by having a dielectric material in a cured product of the non-conductive adhesive material, and the light reflection section includes a second electric-charge-injection inhibiting layer formed on the back surface for inhibiting injection of electric charges from the plurality of second electrodes into the electro-optical crystal by having a dielectric material in a cured product of the non-conductive adhesive material.

Another aspect provides an optical observation device including: a light source that outputs input light; the above-described reflective spatial light modulator; an optical system for irradiating the object with the modulated light output from the spatial light modulator; and a light detector for detecting light output from the object.

Another aspect provides a light irradiation device including: a light source that outputs input light; the above-described reflective spatial light modulator; and an optical system for irradiating the object with the modulated light output from the spatial light modulator.

According to such a reflective spatial light modulator, a light irradiation device, and a light observation device, input light is transmitted through the light input/output unit and is input to the input surface of the electro-optical crystal. The input light is reflected by a light reflection unit disposed on the back surface of the electro-optical crystal and can be output from a light input/output unit. At this time, an electrical signal is input between the first electrode provided in the light input/output portion and the plurality of second electrodes provided in the substrate. Thus, an electric field is applied to the electro-optical crystal having a high relative permittivity, and input light can be modulated. In the reflective spatial light modulator, a non-conductive first electric-charge-injection inhibiting layer is formed on an input surface of an electro-optical crystal, and a non-conductive second electric-charge-injection inhibiting layer is formed on a back surface of the electro-optical crystal. This can suppress injection of electric charges from the first and second electric-charge-injection suppressing layers into the electro-optical crystal. In particular, by forming the second electric-charge-injection inhibiting layer, it is difficult for the electric signals input to each of the plurality of second electrodes to diffuse, and mixing of the electric signals with each other is inhibited. Therefore, the modulation accuracy can be stabilized.

In one aspect, the light reflection unit may further include: a plurality of third electrodes formed on a surface opposite to the back surface of the second electric-charge-injection inhibiting layer, the third electrodes corresponding to the plurality of second electrodes; and a plurality of bumps arranged such that the plurality of second electrodes and the plurality of third electrodes corresponding to the plurality of second electrodes are electrically connected to each other. In this configuration, when an electric field is applied to the electro-optical crystal, the electric field can be applied to the plurality of third electrodes individually. Therefore, mixing of the electric signals input to the plurality of electrodes can be suppressed, and modulation accuracy can be further stabilized.

In one embodiment, the substrate may include a pixel region in which the plurality of second electrodes are arranged and a peripheral region surrounding the pixel region, the second electric-charge-injection inhibiting layer may include a first region facing the pixel region and a second region surrounding the first region, and a content of the dielectric material in the second region may be smaller than a content of the dielectric material in the first region. In this configuration, the second region can fix the substrate to the back surface of the electro-optical crystal with a larger adhesive force than the first region. This suppresses the substrate from falling off the electro-optical crystal.

In one embodiment, a boundary between the first region and the second region may coincide with a boundary between the pixel region and the peripheral region when viewed from the input direction of the input light. In this structure, the electro-optical crystal and the substrate can be bonded more firmly.

In one embodiment, a boundary between the first region and the second region may be located on the outer edge side with respect to a boundary between the pixel region and the peripheral region as viewed in the input direction of the input light. In this configuration, the first region can be reliably disposed between the electro-optical crystal and the pixel region.

In one embodiment, the light input/output unit may further include a transparent substrate having a first surface on which input light is input and a second surface opposite to the first surface, and the first electrode may be disposed on the second surface of the transparent substrate. In such a spatial light modulator, even when the thickness of the electro-optical crystal in the optical axis direction is formed to be thin, the electro-optical crystal can be protected from external impact or the like by the transparent substrate.

In one embodiment, the relative permittivity of the electro-optical crystal may be set to_xtlD represents a thickness from the input surface to the back surface of the electro-optical crystal_xtlD represents the total thickness of the first and second electric-charge-injection inhibiting layers_adAnd V which is the maximum voltage of the applied voltage generated by the driving circuit_smaxAnd a voltage V applied to the electro-optical crystal for phase modulation or delay modulation of the input light by only 2 pi radians_xtlV of ratio of_xtl/V_smaxWhen Rs is set, the relative dielectric constants of the first charge injection inhibiting layer and the second charge injection inhibiting layer containing a dielectric material_adCan be represented by formula 1. In this case, a voltage sufficient to perform phase modulation or delay modulation of the input light by only 2 pi radians can be applied to the electro-optical crystal.

[ number 1]

In one embodiment, the first electrode may be formed on the entire input surface. For example, when a plurality of first electrodes are provided corresponding to a plurality of second electrodes, it is difficult to align the positions of the first electrodes and the second electrodes. In the above structure, it is not necessary to perform the position alignment of the first electrode and the second electrode.

In one embodiment, the light reflecting section may further include a plurality of third electrodes disposed on the back surface of the electro-optical crystal so as to face the plurality of second electrodes. According to this configuration, the plurality of third electrodes can prevent the electric signal transmitted as electric field lines from spreading.

In one embodiment, the light reflecting section may reflect the input light by the plurality of third electrodes. In one embodiment, the light reflecting section may reflect the input light by the plurality of second electrodes. According to these structures, it is not necessary to additionally provide a reflective layer or the like on the second electrode side.

In one embodiment, the electro-optic crystal may be KTa_1-xNb_xO₃(0 ≦ x ≦ 1) crystal, K_1-yLi_yTa_{1- x}Nb_xO₃(0 ≦ x ≦ 1, 0 < y < 1) crystal or P L ZT crystal, and this structure enables to easily realize an electro-optical crystal having a high relative dielectric constant.

In one embodiment, the electro-optical device may further include a temperature control element for controlling a temperature of the electro-optical crystal. According to this configuration, the modulation accuracy can be further stabilized by fixedly maintaining the temperature of the electro-optical crystal.

Effects of the invention

According to the reflective spatial light modulator, the light irradiation device, and the optical observation device of the embodiments, it is possible to suppress mixing of electric signals input to the plurality of electrodes and stabilize modulation accuracy.