KR101071490B1 - Light modulator and method of light modulation - Google Patents

Abstract

An optical modulator and a light modulation method are disclosed. An optical modulator using surface plasmon resonance by an optical refractive diffraction grating can be manufactured. When the modulated light is irradiated to the diffraction grating engraved by the photorefractive phenomenon, surface plasmon resonance occurs as light of a specific wavelength is absorbed at the interface between the metal layer and the photorefractive layer. The period of the diffraction grating can be adjusted by the angle at which two lights of constant wavelength are irradiated, and by adjusting the period of the diffraction grating, the wavelength of light absorbed from the irradiated modulated light can be adjusted.

Optical modulator, surface plasmon resonance, diffraction grating, photorefractive

Description

LIGHT MODULATOR AND METHOD OF LIGHT MODULATION

The present invention relates to an optical modulator, and more particularly, to an optical modulator using surface plasmon resonance.

An optical modulator is a device that can be used as a display device, a light source, or an optical information processing device that realizes color display without using a color filter or a color light source.

The conventional optical modulator uses a prism-coupled surface plasmon resonance and uses a high refractive prism to optically excite the plasmon wave. Since the conventional optical modulator uses an expensive high refractive prism, there have been difficulties in miniaturization and high directivity of the device.

In addition, there is a disadvantage that the wavelength absorbed by the plasmon resonance is fixed, so that the wavelength band of the modulated light cannot be varied.

It is an object of the present invention to provide an optical modulator capable of varying the wavelength band of modulated light.

Another object of the present invention is to provide an optical modulation method capable of varying a wavelength band of modulated light.

Optical modulator according to an embodiment of the present invention for achieving the above object is a lower electrode, a metal layer positioned on the lower electrode, an organic light refractive layer located on the metal layer, the light transmission layer located on the light refractive layer An optical modulator comprising an upper electrode as an electrode, and a diffraction grating generating light source unit generating a diffraction grating in the photorefractive layer by cross irradiating a pair of lights to the photorefractive layer of the optical modulator.

According to another aspect of the present invention, there is provided a light modulation method according to another embodiment of the present invention, a lower electrode, a metal layer positioned on the lower electrode, an organic light refractive layer positioned on the metal layer, and a light refractive layer positioned on the metal refractive layer. Providing an optical modulator comprising an upper electrode as a light transmitting electrode, and cross irradiating a pair of lights having a first inter-angle to the optical refraction layer of the optical modulator to form a first grating gap in the optical refraction layer. Generating a first diffraction grating having a first diffraction grating, irradiating the modulated light to an optical refraction layer in which the first diffraction grating is formed on the upper electrode, and first modulated light reflected from the optical refraction layer and the metal layer interface Detecting a step.

Specific details of other embodiments are included in the detailed description and drawings.

According to the optical modulator of the present invention as described above has the following effects.

First, it is possible to control the wavelength of the light absorbed from the irradiated to-be-modulated light by adjusting the diffraction grating spacing formed in the photorefractive layer.

Second, by blocking any one of the interference light irradiated at a constant wavelength it can be reversibly generated / dissipated grating in the optical refraction layer.

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

Advantages and features of the present invention and methods for achieving them will be apparent with reference to the embodiments described below in detail with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but may be embodied in various different forms, and the present embodiments merely make the disclosure of the present invention complete, and are common in the art to which the present invention pertains. It is provided to fully inform those skilled in the art of the scope of the invention, which is to be defined only by the scope of the claims. Like reference numerals refer to like elements throughout.

Hereinafter, an optical modulator according to a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings. In the following description, well-known functions or constructions are not described in detail to avoid unnecessarily obscuring the subject matter of the present invention.

1 is a perspective view showing a light modulator device constituting an optical modulator according to an embodiment of the present invention.

Referring to FIG. 1, the optical modulation device includes a lower electrode 10, a metal layer 20 positioned on the lower electrode 10, and a pair of spacers 30 spaced apart from each other on the metal layer 20. ), The organic photorefractive layer 40 positioned between the pair of spacers 30, the pair of spacers 30, and the upper electrode 50 positioned on the organic photorefractive layer 40. It includes.

An optical modulator according to an embodiment of the present invention includes a lower electrode 10, a metal layer 20 positioned on the lower electrode 10, an organic light refractive layer 40 positioned on the metal layer 20, and A pair of lights 131 and 133 may be applied to the optical modulation device 100 including the upper electrode 50, which is a light transmitting electrode positioned on the optical refraction layer, and the optical refraction layer 40 of the optical modulation 100 device. It includes a diffraction grating generating light source unit for generating a diffraction grating in the light refractive layer 40 by cross irradiation.

The lower electrode 10 may be made of aluminum (Al), gold (Au), and indium tin oxide (ITO). However, the lower electrode 10 may be any electrode of a transparent material, and preferably made of indium tin oxide (ITO). Can be.

The upper electrode 50 is made of an electrode of the same material as the lower electrode 10.

The metal layer 20 is formed on the lower electrode 10 in a thin film form, and the material may be at least one selected from gold, silver, copper, and aluminum.

The organic photorefractive layer 40 may be made of a photorefractive material. The photorefractive material is a material whose refractive index changes depending on the intensity of light when irradiated with light, and has both photoconductivity that generates charge in proportion to the intensity of light and electro-optic property of which the refractive index is changed by an external voltage. .

One example of the material of the photorefractive layer 40 may be a composite material of a photoconductive polymer, a nonlinear optical dye, and a photosensitizer, and may further include a plasticizer. have.

Photoconductive polymers include poly-N-vinylcarbazole (PVK), poly [methyl-3- (9-carbazolyl) propylsiloxane] (PSX-Cz), tetraphenyldiamino-biphenol (TPD), and poly [1,4-phenylene (DBOP-PPV). -1,2-di (4-benzyloxyphenyl) vinylene]), triphenylaminedimer-polyphenylenevinylene (TPD-PPV) and PSX-Hz (poly [4- (diphenyl-hydrazonomethyl) -phenyl]-[3- (methoxy-dimethyl-silanyl ) -propyl] -methyl-amine).

Nonlinear optical pigments include DMNPAA (2,5-dimethyl-4- (p-phenylazo) anisole), AODCST (4-di (2-methoxyethyl) aminobenzylidene malononitrile), DB-IP-DC (2- {3-[(E ) -2- (dibu-tylamino) -1-ethenyl] -5,5-dimethyl-2-cyclohexenyliden} malononitrile), DBDC (3- (N, N-di-n-butylaniline-4-yl) -1- dicyanomethylidene-2-cyclohexene), DCDHF (2-dicyanomethylene-3-cyano-2,5-dihydrofuran) -6, DHADC-MPN (2, N, N-dihexylamino-7-dicyanomethylidenyl-3,4,5,6, 10-pentahydronaphthalene), ATOP (amino-thienyl-dioxocyano-pyridine) -3, Lemke-E ((3- (2- (4- (N, N-diethylamino) phenyl) ethenyl) -5,5-dimethyl-1 , 2-cyclohexenylidene) propanedinitrile), BDMNPAB (1-n-butoxyl-2,5-dimethyl-4- (4′-nitrophenylazo) benzene) and DMHNAB (2,5-dimethyl-4- (2-hydroxyethoxy) -4 '-Nitroazobenzene) may be at least one selected.

The photosensitizers were TNF (2,4,7-trinitro-9-fluorenone), TNFM ((2,4,7-trinitro-9- fluorenylidene) malononitrile), C ₆₀ , [6,6] PCBM ([6, 6] -phenyl-C61-butyric acid methyl ester), TNF (2,4,7-trinitrofluorenone) -C ₆₀ and DBM (2- [2- {5- [4- (di-n-butylamino) phenyl]- 2,4-pentadienylidene} -1,1-dioxido-1-benzothien-3 (2H) -ylidene] malononitrile).

Plasticizers are at least selected from benzylbuthyl phthalate (BPB), diphenyl phthalate (DPP), dioctyl phthalate (DOP), N-ethylcarbazole (ECZ) and EHMPA (n- (2-ethylhexyl) -n- (3-methylphenyl) -aniline) Can be one.

By adding a plasticizer, the glass transition temperature of the organic photorefractive layer 40 can be reduced, thereby generating a photorefractive diffraction grating at room temperature.

The diffraction grating formed in the light refractive layer 40 is formed at or above the glass transition temperature of the light refractive layer 40.

In the present invention, the material of the preferred photorefractive layer may be composed of PSX-Hz, DB-IP-DC, TNF and BBP.

Chemical structures of the PSX-Hz, DB-IP-DC, TNF, and BBP are shown in FIGS. 2A to 2D.

The optical modulator according to the present invention further includes at least one pair of spacers 30 spaced apart from each other between the metal layer 20 and the upper electrode 50. In this case, the organic light refraction layer 40 is positioned between the pair of spacers 30.

The spacers 30 are used to uniformly adjust the thickness of the photorefractive layer and to form the same in the formation of the organic photorefractive layer 40.

The spacers 30 may be any insulating plastic material, and preferably Teflon may be used.

The diffraction grating light source unit cross irradiates a pair of lights 131 and 133 to the photorefraction layer 40 of the light modulation device 100 to generate a diffraction grating in the light refraction layer 40.

The diffraction grating light source generating unit includes a short wavelength light source 120 and an optical splitter 140 that splits the light 130 from the light source 120 into a pair of matched lights 131 and 133.

The diffraction grating generating light source unit further includes a shutter 160 capable of blocking or passing any one of the pair of matched lights 131 and 133.

An optical modulator according to an embodiment of the present invention may include at least one light source for generating a diffraction grating in the light refractive layer.

By using a plurality of light sources, a plurality of diffraction gratings can be formed in the same device.

The optical modulator according to the exemplary embodiment of the present invention further includes an electric field applying unit for applying an electric field between the lower electrode 10 and the upper electrode 50.

The diffraction grating formed in the optical refraction layer is based on the premise that an electric field is applied to the optical modulation device 100.

Hereinafter, the operation principle of the optical modulator according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

<Operation principle of optical modulator>

3 is a view showing the operating principle of the optical modulator according to an embodiment of the present invention.

는 진공에서의 파 벡터의 계수(modulus)이며

,

는 플라즈몬 파의 전파 상수

,

는 백색광의 입사각,

는 두 간섭광 간 사이각의 반각,

는 브래그 회절격자의 주기이다.In Figure 3,

Is the modulus of the wave vector in vacuum

,

Is the propagation constant of the plasmon wave

,

Is the incident angle of white light,

Is the half angle of the angle between the two interfering lights,

Is the period of Bragg diffraction grating.

3 is based on the premise that an electric field by an external power source is applied to the optical modulation device.

When two coherent lights of the same wavelength are irradiated to the optical modulator under a constant external electric field, the diffraction gratings are formed in the optical refraction layer constituting the optical modulator by interference.

In more detail, a charge carrier is generated in a bright portion where constructive interference is caused by interfering light in the photorefraction layer, and the generated charges are optically activated while drift by an external electric field and move to a dark place.

The moving charges are trapped by traps (such as impurities or structural defects in the material) present in the material, which causes the distribution of charges in the material to be uneven and the redistribution of charges thus induced is repeated internal space charge ( create a space-charge field.

By the internal space charge generated as described above, the refractive index of the material having the electro-optic properties is changed and has a diffraction grating structure.

)는 아래 식과 같이 브래그(Bragg) 조건에 의해 입사되는 간섭광의 파장 및 두 개의 광(빛) 사이각의 반각에 의해 결정된다.The diffraction grating spacing (

) Is determined by the wavelength of the interfering light incident by Bragg conditions and the half angle of the angle between the two lights (light) as shown in the following equation.

···식(1)

Formula (1)

는 간섭광의 파장,

은 재료의 굴절률,

는 두 간섭광의 here,

Is the wavelength of the interfering light,

The refractive index of the material,

Of two interfering light

Half of the angle.

The diffraction grating formed inside the photorefractive layer is extinguished by blocking any one of the two lights or blocking an electric field applied from the outside. Using this property, the diffraction grating can be reversibly generated / dissipated in tens of milliseconds.

Subsequently, when modulated light such as white light is irradiated onto the light modulator in which the diffraction grating is formed, a part of the modulated light that is incident is coupled to the surface plasmon resonance at the metal layer-light refractive layer interface.

do.

More specifically, when the modulated light is irradiated to the diffraction grating from an external light source, surface plasmon resonance occurs at the interface between the metal layer and the dielectric photorefractive layer while absorbing light of a specific wavelength. Surface plasmons are modes of electromagnetic fields that can travel along a metal-dielectric interface, and are referred to as charge density oscillations that occur as a result of the energy of incident light excited free electrons in the metal.

This surface plasmon is a transverse magnetic polarization wave traveling along the interface, showing a maximum value at the interface between the two metals and the dielectric material and decreasing exponentially in the direction perpendicular to the metal surface.

) 와 일치하는 조건에서 일어난다.Surface plasmon resonance is characterized by the transverse magnetic wave vector of incident light being the wave vector of the surface plasmon (

) Occurs under conditions matching

)은 아래 식(2)와 같이 phase-matching 조건을 만족시켜야 한다.When surface plasmon resonance occurs at the metal-dielectric interface, the surface plasmon resonance coupling wavelength (

) Must satisfy the phase-matching condition as shown in Equation (2) below.

···식(2)

Formula (2)

은 유전체(광굴절층)의 유전상수,

는 금속의 유전상수,

는 피변조광(백색광)의 입사각,

는 회절격자의 주기,

은 회절차수이다.here,

Is the dielectric constant of the dielectric (photorefractive layer),

Is the dielectric constant of the metal,

Is the incident angle of the modulated light (white light),

Is the period of the diffraction grating,

Is the diffraction order.

According to Equation (2), it can be seen that the surface plasmon resonance coupling wavelength is largely dependent on the period of the diffraction grating.

A portion of incident light is absorbed and scattered by surface plasmon resonance, and light that is not absorbed is reflected and sensed by a detector to generate a light modulation phenomenon.

4A to 4C are schematic views illustrating a light modulation method according to another exemplary embodiment of the present invention.

FIG. 4A is a view schematically illustrating that light of any one of the pair of lights 131 and 133 is irradiated to the light modulator through the mirror.

FIG. 4B is a view schematically illustrating that a diffraction grating is formed in a photorefractive layer by irradiating a light modulator with a pair of lights 131 and 133.

According to another embodiment of the present invention, a light modulation method includes a lower electrode 10, a metal layer 20 disposed on the lower electrode 10, an organic photorefractive layer 40 disposed on the metal layer 20, And providing an optical modulation device 100 including an upper electrode 50, which is a light transmitting electrode positioned on the optical refractive layer, between the first and second optical refraction layers 40 of the optical modulation device 100. Irradiating a pair of lights 131 and 133 having an angle to generate a first diffraction grating having a first lattice spacing in the optical refraction layer 40, wherein the first diffraction grating is disposed on the upper electrode 50. Irradiating the modulated light 180 to the generated photorefractive layer 40, and detecting the first modulated light 190 reflected from the optical refraction layer and the metal layer 20 interface.

The optical modulation device 100 provided in the step of providing the optical modulation device 100 includes a lower electrode 10, a metal layer 20, an organic photorefractive layer 40, and an upper electrode 50.

The lower electrode 10 may be made of aluminum (Al), gold (Au), and indium tin oxide (ITO). However, the lower electrode 10 may be any electrode of a transparent material, and preferably made of indium tin oxide (ITO). Can be.

The upper electrode 50 is made of an electrode of the same material as the lower electrode 10.

As the metal layer 20 of the optical modulation device 100, at least one material selected from gold, silver, copper, and aluminum may be used.

The organic photorefractive layer 40 constituting the optical modulation device 100 contains a photoconductive polymer, a nonlinear optical dye, and a photosensitive body. In addition, the organic photorefractive layer 40 may further contain a plasticizer.

By adding a plasticizer, the glass transition temperature of the organic photorefractive layer 40 can be reduced, thereby generating a photorefractive diffraction grating at room temperature.

The diffraction grating formed in the light refraction layer described below is formed at or above the glass transition temperature of the light refraction layer.

The generating of the first diffraction grating may include cross-irradiating a pair of lights 131 and 133 having a first angle to the photorefractive layer of the optical modulation device 100 to have a first lattice spacing in the photorefractive layer. 1 to produce a diffraction grating.

More specifically, in the step of generating the first diffraction grating, the forming of the pair of lights 131 and 133 having the first interangular angle may include the short wavelength light 130 generated from the short wavelength light source 120 between the first and the first diffraction gratings. Dividing into a pair of matched lights to have an angle.

The divided lights 131 and 133 are irradiated to the light modulator 100 through mirrors 151 and 153, respectively.

The interval between the first diffraction gratings is determined by the half angle of the first interangle angle and the wavelength of the irradiated light by Equation (1), which is the Bragg diffraction equation described above.

When any one of the pair of lights 131 and 133 is blocked, the first diffraction grating disappears.

FIG. 4C is a diagram schematically illustrating that the modulated light is irradiated to the detector 200 after the modulated light 180 is irradiated to the light refractive layer on which the diffraction grating is formed.

The irradiating the modulated light 180 is irradiating the modulated light 180 to the light refractive layer on which the first diffraction grating is formed, and the irradiated modulated light 180 includes a specific wavelength to be modulated. Say mania.

Detecting the first modulated light 190 excludes light having a wavelength absorbed by surface plasmon resonance at the interface of the photorefractive layer and the metal layer 20 by the modulated light 180 irradiated to the photorefractive layer. And detecting externally reflected light, that is, modulated light.

The optical modulation method according to another embodiment of the present invention, after detecting the first modulated light 190, the step of extinction of the first diffraction grating generated in the optical refractive layer of the optical modulation device 100, the light Irradiating the light refractive layer of the modulation device 100 with a pair of lights 131 and 133 having a second angle to generate a second diffraction grating having a second grating spacing in the light refractive layer 40; Irradiating the modulated light 180 to the photorefractive layer 40 in which the second diffraction grating is generated on the upper electrode 50, and a second reflected from an interface of the photorefractive layer and the metal layer 20. The method further includes detecting the modulated light 190.

Annihilating the first diffraction grating may include performing blocking of one of the pair of matched lights 131 and 133 and irradiating the other light to the photorefractive layer.

In other words, the first diffraction grating is assumed to be irradiated with a pair of matched lights 131 and 133 simultaneously.

Forming the pair of lights 131, 133 having the second inter-angle in the step of generating the second diffraction grating pairs the short-wavelength light 130 generated from the short-wavelength light source 120 to have the second inter-angle. Splitting into coherent lights 131, 133.

As described above, in the optical modulation method according to the present invention, the first diffraction grating formed in the optical modulator 100 may be extinguished and the second diffraction grating may be generated to reversibly generate or extinguish various periods of the diffraction grating. .

The short wavelength light source 120 may be at least one, and thus the number of diffraction gratings formed in the light modulation device 100 may be changed.

The light modulation method according to another embodiment of the present invention further includes an electric field applying step of applying an electric field between the lower electrode 10 and the upper electrode 50.

The generation of the diffraction grating is possible in a state in which an electric field is applied from the external power source 110 to the optical modulation element 100, and the diffraction grating is also extinguished when the electric field is extinguished.

Hereinafter, an example of manufacturing an optical modulation device using surface plasmon resonance by a photorefractive diffraction grating is provided to help understanding of the present invention. However, the following preparation examples are merely to aid the understanding of the present invention, and the present invention is not limited by the following preparation examples.

Preparation Example: Optical Modulation Device

The photorefractive layer specimen composed of the polymer composite was anisotropic optical pigment DB-IP-DC (2- {3-[(E) -2- (dibutylamino) -1-ethenyl] -5,5-dimethyl-2-cyclohexenyliden} malononitrile) PSX-Hz (Poly [4- (diphenyl-hydrazonomethyl) -phenyl]-[3- (), a photoconductive polymer matrix sensitized by TNF (2,4,7-trinitro-9-fluorenone) methoxy-dimethyl-silanyl) -propyl] -methyl-amine) was prepared by doping.

TNF is described by Kanto Chem. Co. Inc. It was a product and used after purification.

The polymer composite was prepared by adding 5 weight percent BBP to a 69 weight percent PSX-Hz, 30 weight percent DB-IP-DC and 1 weight percent TNF mixture.

Benzylbuthyl phtalate (BBP) is a plasticizer that reduces the glass transition temperature to ensure rotation of the optical pigment. The composite of this composition had a glass transition temperature of 30 ° C.

Since the glass transition temperature is 30 ° C, the photorefractive diffraction grating can be generated / dissipated at room temperature.

To prepare the specimen, the mixture (100 mg total) was dissolved in 400 mg of dichloromethane and the solution was filtered through a 0.2 μm membrane.

The composite was coated on a gold-coated indium tin oxide (ITO) glass substrate and then slowly dried at room temperature for 12 hours and then heated in an oven at 90 ° C. for 24 hours to remove residual solvent.

The thickness of the coated gold layer was about 50 nm.

The composite was softened on a hot plate at 100 ° C. and then placed between two Teflon spacers of 100 μm thickness, on an ITO glass, to form a uniformly thick film, and then another ITO glass was placed on two spacers and the composite. After placing it on, a constant pressure was applied to make a photorefractive element. The thickness of the light refractive layer (composite) of the device was about 100 μm.

5 is a graph showing photorefractive diffraction efficiency with time.

FIG. 5 shows the formation of the photorefractive diffraction grating over time. The half angle between the two interfering light beams was 30 ° and the external electric field was 40 V / µm.

The diffraction grating is generated by irradiation of two coincidence laser light and is reversibly erased by canceling either light.

As shown in FIG. 5, the diffraction efficiency was increased when the interference light I ₂ was opened at t = 150 s.

This increase in diffraction efficiency adequately demonstrates the formation of diffraction gratings in organic photorefractive specimens. The generation time of the photorefractive grating was 2.1 seconds.

The diffraction grating efficiency drastically decreased when interfering light I ₂ was blocked at t = 300 s. The extinction time of the photorefractive grating was 4.8 seconds.

Very important for real-time applications such as real-time imaging and real-time data processing, photorefractive grating formation rates are spaces that involve the generation of photocharges of charges, their redistribution and the modulation of refractive index through electro-optic effects Consists of the formation of a charge field.

As a result, the lattice generation time of the photorefractive composite at low glass transition temperature is limited by the directional mobility of photoconductivity and optical pigment.

Since the photoconductivity as well as the directional mobility of the optical pigment increases with the electric field and temperature, the increased external electric field and temperature can result in faster lattice formation in the photorefractive composite.

5 is a graph showing the relationship between the half angle of the angle between two interference lights and the period of the diffraction grating.

The period of the diffraction grating in the organic photorefractive layer is controlled by the half angle of the angle between the two interfering light beams. The period of the diffraction grating decreases with increasing half-angle of the angle between the two interfering light beams. When the half angles of the angles are 20 °, 30 °, and 40 °, respectively, diffraction gratings having periods of 0.541, 0.370, and 0.288 µm are generated in the photorefractive composite through the photorefractive effect.

FIG. 6 is a graph showing a shift of the surface plasmon resonance wavelength according to the period of the diffraction grating.

As shown in FIG. 6, when the period of the diffraction grating is 0.541 μm, the surface plasma resonance occurs at 453 nm and after blue is absorbed and scattered in the organic photorefractive specimen, the reflected light is yellow.

When the period of the diffraction grating was reduced to 0.370 mu m, the surface plasma resonance shifted to 335 nm and purple was absorbed and scattered.

Further, when the period of the diffraction grating is 0.288 mu m, the surface plasma resonance shifts to 286 nm, whereby near ultraviolet rays are absorbed and scattered.

As described above, by changing the period of the diffraction grating from 0.541 to 0.288㎛ it can be seen that the surface plasmon resonance is displaced more than 167nm range.

The optical modulator according to the present invention can absorb light of an unwanted color and reflect light of a desired color from an incident light source by forming a diffraction grating having a reversibly desired interval in the light refractive layer.

As described above, the optical modulator manufactured by the present invention can filter light having a desired wavelength from modulated light such as a white light source, and thus can be widely applied to display fields, optical attenuators, wavelength filters, and the like, which require a color light source.

Although embodiments of the present invention have been described above with reference to the accompanying drawings, those skilled in the art to which the present invention pertains may implement the present invention in other specific forms without changing the technical spirit or essential features thereof. I can understand that.

It is therefore to be understood that the above-described embodiments are illustrative in all aspects and not restrictive. The scope of the present invention is shown by the following claims rather than the detailed description, and all changes or modifications derived from the meaning and scope of the claims and their equivalents should be construed as being included in the scope of the present invention. .

1 is a perspective view showing the structure of an optical modulator constituting an optical modulator according to an embodiment of the present invention.

2A is a diagram showing the chemical structure of PSX-Hz (Poly [4- (diphenyl-hydrazonomethyl) -phenyl]-[3- (methoxy-dimethyl-silanyl) -propyl] -methyl-amine).

Figure 2b is a diagram showing the chemical structure of DB-IP-DC (2- {3-[(E) -2- (dibutylamino) -1-ethenyl] -5,5-dimethyl-2-cyclohexenyliden} malononitrile).

Figure 2c is a view showing the chemical structure of TNF (2,4,7-trinitro-9-fluorenone).

Figure 2d is a diagram showing the chemical structure of benzylbuthyl phtalate (BPB).

3 is a view showing the operating principle of the optical modulator according to an embodiment of the present invention.

4A to 4C are schematic views illustrating a light modulation method according to another embodiment of the present invention.

5 is a graph showing photorefractive diffraction efficiency with time. The graph drawn inside is a graph showing the relationship between the half angle of the angle between the two interfering light and the period of the diffraction grating.

6 is a graph showing variation of the surface plasmon resonance wavelength according to the period of the diffraction grating.

<Description of Symbols for Main Parts of Drawings>

10: lower electrode 20: metal layer

30 spacer 40 organic light refractive layer

50: upper electrode 100: optical modulation device

110: external power 120: short wavelength light source

130: short wavelength light 131, 133: a pair of light

140: optical splitter 151, 153: mirror

160: shutter 170: external light source

180: modulated light 190: modulated light
200: detector

Claims (14)

An upper electrode which is a lower electrode, a metal layer positioned on the lower electrode, an organic light refractive layer disposed on the metal layer and containing a photoconductive polymer, a nonlinear optical dye and a photosensitive member, and a light transmitting electrode positioned on the light refractive layer. An optical modulator comprising an electrode; And And a diffraction grating generating light source unit generating a diffraction grating in the light refractive layer by cross irradiating a pair of light to the light refractive layer of the optical modulation device. The method of claim 1, The metal layer is an optical modulator, characterized in that at least one selected from gold (Au), silver (Ag), copper (Cu) and aluminum (Al). delete The method of claim 1, And at least one pair of spacers spaced apart from each other between the metal layer and the upper electrode, wherein the organic photorefractive layer is positioned between the pair of spacers. The method of claim 1, And the diffraction grating generating light source unit comprises a short wavelength light source and an optical splitter that splits the light from the light source into a pair of matched lights. The method of claim 5, The light diffraction grating generating light source unit further comprises a shutter capable of blocking or passing any one of the pair of matched lights. The method of claim 1, And an electric field applying unit configured to apply an electric field between the lower electrode and the upper electrode. An upper electrode which is a lower electrode, a metal layer positioned on the lower electrode, an organic light refractive layer disposed on the metal layer and containing a photoconductive polymer, a nonlinear optical dye and a photosensitive member, and a light transmitting electrode positioned on the light refractive layer. Providing an optical modulator comprising an electrode; Irradiating a pair of lights having a first angle between the photorefractive layer of the optical modulation device to generate a first diffraction grating having a first lattice spacing in the photorefractive layer; Irradiating the modulated light onto the photorefractive layer in which the first diffraction grating is generated on the upper electrode; And And detecting the first modulated light reflected from the optical refraction layer and the metal layer interface. The method of claim 8, Forming the pair of lights having the first inter-angle in generating the first diffraction grating comprises dividing the short wavelength light generated from the short-wavelength light source into a pair of coherent lights having the first inter-angle. Light modulation method comprising. The method of claim 8, After detecting the first modulated light, extinguishing the first diffraction grating generated in the light refractive layer of the light modulator; Irradiating a pair of lights having a second angle to the photorefractive layer of the optical modulation device to generate a second diffraction grating having a second grating spacing in the photorefractive layer; Irradiating the modulated light onto the photorefractive layer in which the second diffraction grating is formed on the upper electrode; And And detecting second modulated light reflected from the light refractive layer and the metal layer interface. 11. The method of claim 10, The extinction of the first diffraction grating includes performing blocking the light of any one of the pair of matched lights and irradiating the other light to the photorefractive layer. Forming the pair of lights having the second inter-angle in generating the second diffraction grating comprises dividing the short wavelength light generated from the short-wavelength light source into a pair of coherent lights having the second inter-angle. Light modulation method comprising. The method of claim 8, And an electric field applying step of applying an electric field between the lower electrode and the upper electrode. delete The method of claim 8, The metal layer is a light modulation method, characterized in that at least one selected from gold (Au), silver (Ag), copper (Cu) and aluminum (Al).

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