JPH1090733A - Light control method and its device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To extract a photo responsiveness of ample magnitude and speed from a photo responsive optical element with a good reproducibility. SOLUTION: Light sources 1, 2 emit control light and signal light respectively. These kinds of light are converged by a condenser lens 7 to irradiate an optical cell 8 packed with photo responsive liquid composition, only the signal light is detected by a photodetector 22 through a light receiving lens 9 and a wavelength selection transmission filter 20. The on/off action of the control light increases/decreases reversibly the transmission factor and/or refractivity of the signal light to realize the intensity modulation of the signal light. By setting the numeral aperture of the light receiving lens 9 at a value substantially smaller than that of the condenser lens 7, the light response of ample magnitude and photo responsiveness can be extracted from a light responsive liquid composition including a dyestuff packed in the optical cell 8.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light control method and a light control method using an optical cell filled with a liquid photoresponsive composition, which is useful in the fields of optoelectronics and photonics such as optical communication and optical information processing. It concerns the device.

[0002]

2. Description of the Related Art In the field of optoelectronics and photonics, which focus on the multiplexing and high density of light for the purpose of transmitting and processing information at an ultra-high speed, light is applied to an optical element prepared by processing an optical material or an optical composition. Of light / light control method that modulates light intensity (amplitude) or frequency (wavelength) without using electronic circuit technology, using changes in transmittance and refractive index caused by irradiating light Development is underway. Also, taking advantage of the characteristics of light,
When parallel optical logic operation or image processing is to be performed, a "spatial light modulator" for performing some type of modulation, such as a change in light intensity distribution, on a cross section of a light beam (ray bundle) is extremely important.
Here too, the application of the light / light control method is expected.

As phenomena that are expected to be applied to light / light control methods, saturable absorption, nonlinear refraction, nonlinear optical effects such as photorefractive effects, and photochromic phenomena have attracted widespread attention.

[0004] On the other hand, there is a phenomenon that molecules excited by light in the first wavelength band newly absorb light in a second wavelength band different from the first wavelength band without changing the molecular structure. It is known and can be referred to as "excited state absorption" or "induced absorption" or "transient absorption".

[0005] Examples of applications of excited state absorption include:
For example, JP-A-53-137888 discloses that a solution or a solid containing a porphyrin-based compound and an electron acceptor is irradiated with at least two kinds of light beams having different wavelengths, and this irradiation causes a light beam having one wavelength to have. A light conversion method is disclosed that transfers information to the wavelength of the other light beam. Also, JP-A-55-100503 and JP-A-55-150503
Japanese Patent Application Laid-Open No. 108603/1993 discloses a method of selecting a propagating light in response to a temporal change of excitation light by utilizing a difference in a spectrum between a ground state and an excited state of an organic compound such as a porphyrin derivative. A liquid core optical fiber is disclosed. JP-A-63-89805 discloses that a core contains an organic compound such as a porphyrin derivative having an absorption corresponding to a transition from a triplet state excited by light to a higher triplet state. A plastic optical fiber is disclosed. Also, JP-A-63-
No. 236013 discloses that after irradiating a crystal of a cyanine dye such as cryptocyanine with light of a first wavelength to optically excite a molecule, the molecule is irradiated with light of a second wavelength different from the first wavelength, There is disclosed an optical functional device that switches transmission or reflection of light of a second wavelength according to a state of light excitation by light of a first wavelength. Also, Japanese Unexamined Patent Publication No.
No. 73326 discloses that a light modulation medium in which a photoinduced electron transfer material such as a porphyrin derivative is dispersed in a matrix material is irradiated with light of first and second wavelengths to absorb molecules between an excited state and a ground state. An optical signal modulation medium that modulates light using a difference in spectrum has been disclosed.

The configurations of the optical devices used in these prior arts are described in JP-A-55-100503, JP-A-55-108603, and JP-A-63-8.
Japanese Patent Application Laid-Open No. 9805 discloses a device configuration in which an optical fiber through which a propagating light propagates is wound around a light source of an excitation light (for example, a flash lamp).
Japanese Patent No. 37884 and Japanese Patent Application Laid-Open No. 64-73326 disclose control light from a direction different from the optical path of the signal light over the entire propagation portion of the light corresponding to the signal light inside the photoresponsive optical element. There is disclosed an apparatus configuration in which light is not converged but rather is diverged and irradiated by means such as a projection lens.

[0007]

However, in the prior art described above, a very high-density optical power is required in order to cause a practically large change in transmittance or refractive index (light response). At present, there is no material that can be practically used because it is required, the response to light irradiation is slow, or the durability of the light-responsive material is low.

The present applicant has solved the above-mentioned problems of the prior art, and has developed a light control method and a light control in which a light response of a sufficient magnitude and speed is obtained from a light-responsive optical element with a light power as low as possible. Invention related to device (Japanese Patent Application No. Hei 7-
Nos. 25618 and 8-151133) and inventions relating to photoresponsive materials (Japanese Patent Application Nos. 7-58413 and 7-584).
No. 14).

The present invention solves the above problems, and further provides a light control method and a light control device for obtaining a light response with a sufficient size and good reproducibility, further improving the above-mentioned application of the present applicant. The purpose is to do.

[0010]

According to a first aspect of the present invention, there is provided a light control method comprising the steps of: providing an optical cell filled with a liquid photoresponsive composition with the photoresponsive; The composition is irradiated with a control light having a wavelength sensitive to the composition, and the signal light transmitted through the optical cell is reversibly changed by changing the transmittance and / or the refractive index of the signal light in a wavelength band different from the control light. An optical control method for performing intensity modulation and / or light flux density modulation, wherein the control light and the signal light are respectively converged and radiated to the optical cell, and near the respective focal points of the control light and the signal light. The optical paths of the control light and the signal light are arranged such that the regions having the highest photon density overlap each other in the photoresponsive composition in the optical cell.

In order to achieve the above object, a light control method according to a second aspect of the present invention is the light control method according to the first aspect, wherein the control light and the signal light are transmitted through the optical cell. Is characterized in that the light is propagated in substantially the same optical path.

Further, in order to achieve the above object, a light control method according to a third aspect of the present invention is the light control method according to the first or second aspect, wherein the light responsive composition in the optical cell is provided. After passing through the object, the signal light beam in a region which has been strongly subjected to the intensity modulation and / or the light beam density modulation is separated and extracted from the diverging signal light beam.

Further, in order to achieve the above object, a light control method according to a fourth aspect of the present invention is the light control method according to the first or second aspect, wherein the light responsive composition in the optical cell is provided. After passing through the object, the divergent signal light beam is taken out in an angle range (opening angle) smaller than the divergence angle of the signal light beam, thereby receiving the intensity modulation and / or the light beam density modulation strongly. And separating and extracting the signal light beam in the region.

In order to achieve the above object, a light control method according to a fifth aspect of the present invention is the light control method according to any one of the first to fourth aspects, wherein the control light and the signal light are provided. By changing the positional relationship between the respective focal positions and the optical cell, the irradiation of the control light reduces the apparent response of the signal light transmitted through the optical cell in a direction in which the apparent intensity of the signal light decreases, and the signal It is characterized in that one of the light response and the light response in which the apparent intensity of light increases is selected and extracted.

Furthermore, in order to achieve the above object, a light control method according to the invention of claim 6 of the present application is the light control method according to any one of claims 1 to 5, wherein Contains a dye.

Further, in order to achieve the above object, a light control device according to the invention of claim 7 of the present application provides a light control device in which an optical cell filled with a liquid photoresponsive composition is sensitive. Control light having a wavelength different from that of the control light, and by reversibly increasing or decreasing the transmittance and / or the refractive index of the signal light in a wavelength band different from the control light, the intensity of the signal light transmitted through the optical cell and / or Or a light control device used in a light control method for performing light flux density modulation, wherein the light control device includes converging means for converging the control light and the signal light, respectively, and focuses each of the converged control light and the signal light. The control light and the optical path of the signal light are respectively arranged so that the regions having the highest photon densities in the vicinity overlap each other, and the liquid photoresponsive composition in the optical cell is the converged liquid photoresponsive composition. Wherein the region of highest photon density in each of the vicinity of the focal point of the control light and the signal light is disposed in overlapping positions.

Further, in order to achieve the above object, a light control device according to the invention of claim 8 of the present application is the light control device according to claim 7, wherein the control light and the signal light are in the optical cell. Is characterized by having an optical path arrangement that propagates in substantially the same optical path.

According to a ninth aspect of the present invention, there is provided a light control apparatus according to the ninth aspect of the present invention, wherein the light responsive composition in the optical cell is provided. It is characterized by having a means for separating and extracting the signal light beam bundle in the region that has been subjected to the intensity modulation and / or the light beam density modulation out of the divergent signal light beam bundles after passing through the object.

Further, in order to achieve the above object, a light control device according to a tenth aspect of the present invention, in the light control device according to the ninth aspect, strongly receives the intensity modulation and / or the light flux density modulation. As a means for separating and extracting the signal light beam flux in the region where the signal light is converged, the converging means having a numerical aperture smaller than the numerical aperture of the converging means used when the signal light is converged and incident on the optical cell. I do.

Further, in order to achieve the above object, a light control device according to an eleventh aspect of the present invention, in the light control device according to the ninth aspect, strongly receives the intensity modulation and / or the light flux density modulation. An aperture is used as a means for separating and extracting the signal light beam bundle in the region where the light beam has separated.

According to a twelfth aspect of the present invention, there is provided an optical control device according to the twelfth aspect of the present invention, wherein the control light and the signal light are provided. Moving means for changing the positional relationship between each of the focal positions and the optical cell, and by using the moving means, the positional relationship between the respective focal positions of the control light and the signal light and the optical cell. By changing, the optical response in the direction in which the apparent intensity of the signal light transmitted through the optical cell by the irradiation of the control light decreases, and the optical response in which the apparent intensity of the signal light increases. It is characterized in that either one is selected and taken out.

Further, in order to achieve the above object, a light control device according to a thirteenth aspect of the present invention is the light control device according to any one of the seventh to twelfth aspects, wherein It is characterized by having means for separating mixed light of control light and signal light transmitted through the responsive composition into signal light and control light.

In order to achieve the above object, a light control device according to a fourteenth aspect of the present invention is the light control device according to any one of the seventh to thirteenth aspects, wherein the control light and the signal light are different from each other. And / or the intensity modulation and / or the density modulation of the divergent signal light beams after passing through the photoresponsive composition in the optical cell. Means for separating and extracting the signal light beam bundle in the received area, and / or converting the mixed light of the signal light and the control light transmitted through the photoresponsive composition in the optical cell into the signal light and the control light The means for separating has a structure incorporated in the optical cell.

Further, in order to achieve the above object, a light control device according to the invention of claim 15 of the present application is the light control device according to any one of claims 7 to 14, wherein the liquid photoresponsive composition is Contains a volatile solvent.

Furthermore, in order to achieve the above object, a light control device according to the invention of claim 16 of the present application is the light control device according to any one of claims 7 to 15, wherein the liquid photoresponsive composition is Contains a dye.

[Combination of Photoresponsive Composition, Signal Light Wavelength Band, and Control Light Wavelength Band] The photoresponsive composition, signal light wavelength band, and control light used in the light control method of the present invention. As the combination of these wavelength bands, an appropriate combination can be selected and used depending on the purpose of use.

As a specific setting procedure, for example, first, the wavelength or the wavelength band of the signal light is determined according to the purpose of use, and the optimal photoresponsive composition for controlling the wavelength and the wavelength of the control light are determined. A combination can be selected. Alternatively, after determining the combination of the wavelengths of the signal light and the control light according to the purpose of use, a photoresponsive composition suitable for this combination may be selected.

With respect to the composition of the liquid photoresponsive composition used in the present invention, and the optical path lengths of signal light and control light propagating in an optical cell filled with the photoresponsive composition,
These combinations can be set based on the transmittance of control light and signal light transmitted through the optical cell. For example, first, of the composition of the photoresponsive composition, at least the concentration of a component absorbing the control light or the signal light is determined, and then the transmittance of the control light and the signal light passing through the optical cell reaches a specific value. It is possible to set the optical path lengths of the signal light and the control light propagating in the optical cell. Or, first, for example, if necessary in the device design, after setting the optical path length to a specific value, the photoresponsive composition so that the transmittance of control light and signal light transmitted through the optical cell is a specific value Can be adjusted.

The present invention provides a light control method and a light control device which can derive a light response of a sufficient magnitude and speed with a light power as low as possible from an optical cell filled with a liquid photoresponsive composition. The optimal values of the transmittances of the control light and the signal light that pass through the optical cell to achieve this purpose are as follows.

In the light control method and the light control device of the present invention, the control of the concentration and the state of the light absorbing component in the photoresponsive composition so that the transmittance of the control light propagating through the optical cell is 90% or less. It is preferable to set the optical path length.

Here, when an attempt is made to use the optical response in the direction in which the transmittance of the signal light decreases due to the irradiation of the control light,
In the state where control light is not irradiated, control is performed on the concentration and existence state of the light absorbing component in the photoresponsive composition and the setting of the optical path length so that the transmittance of the signal light propagating through the optical cell is at least 10% or more. Is preferred.

[Optical Cell] The optical cell used in the present invention has a function of holding a liquid photoresponsive composition and a function of effectively giving a form to the liquid photoresponsive composition. A function of receiving the converged and irradiated signal light and control light and transmitting the signal light and the control light to the photoresponsive composition, and after passing through the photoresponsive composition, diverging It has the function of propagating and emitting the signal light.

The form of the optical cell used in the present invention is roughly classified into an external form and an internal form.

The external form of the optical cell may be a plate, a rectangular parallelepiped, a column, a semi-column, a quadratic column, a triangular column, or the like depending on the configuration of the light control device of the present invention.

The internal form of the optical cell is a form of a cavity for filling the liquid photoresponsive composition,
It effectively imparts a form to the liquid photoresponsive composition. Depending on the configuration of the light control device of the present invention, the internal form of the optical cell, specifically, for example, a thin film, a thick film, a plate, a rectangular parallelepiped, a column, a semi-column, a quadrangular prism, a triangular prism, It can be appropriately selected from a convex lens shape, a concave lens shape, and the like.

As the structure and material of the optical cell, any material can be used as long as it satisfies the following requirements.

(1) The external form and the internal form as described above can be precisely maintained under use conditions.

(2) Inertness to the liquid photoresponsive composition.

(3) The composition of the liquid photoresponsive composition can be prevented from changing due to emission, transmission and permeation of various components.

(4) The liquid photoresponsive composition can be prevented from being deteriorated by contact with a gas or liquid such as oxygen or water existing in the use environment.

Of the above requirements, the function of preventing a change or deterioration of the composition of the liquid photoresponsive composition only needs to be exerted within the design life of the optical element.

The converging means for converging the control light and the signal light, and / or the intensity of the signal light beam diverging after passing through the photoresponsive composition in the optical cell. Means for separating and extracting a signal light beam in a region that has been strongly subjected to modulation and / or light beam density modulation, and / or mixing light of control light and signal light transmitted through the photoresponsive composition in the optical cell. An optical cell having an integral structure in which the means for separating signal light and control light is incorporated in the optical cell can be used.

[Photo-Responsive Composition] In the present invention, when control light is irradiated, optical control is performed so as to reversibly change the transmittance and / or the refractive index of signal light in a wavelength band different from that of the control light. As the liquid photoresponsive composition used in the method and the light control device, various known ones can be used.

To give a specific example, for example,
GaAs, GaAsP, GaAlAs, InP, InS
b, ultrafine particles of a compound semiconductor such as InAs, PbTe, InGaAsP, and ZnSe, which are colloidally dispersed in a liquid matrix material, a metal halide (for example, potassium bromide, sodium chloride, or the like) doped with a foreign metal ion, or the metal Ultra-fine particles of halides (eg, copper bromide, copper chloride, cobalt chloride, etc.) colloidally dispersed in a liquid matrix material, CdS, CdSe, CdSe doped with foreign metal ions such as copper
Ultrafine particles of cadmium chalcogenide such as S, CdSeTe are colloidally dispersed in a liquid matrix material, ultrafine particles of semiconductor such as silicon, germanium, selenium, tellurium are colloidally dispersed in a liquid matrix material, platinum, gold And ultra-fine particles of noble metals such as palladium and colloidally dispersed in a liquid matrix material, and complexes of metal ions (for example, neodymium ion and erbium ion) dissolved or colloidally dispersed in a liquid matrix material. A material in which a dye is dissolved or colloidally dispersed in a matrix material can be suitably used.

Among these, those obtained by dissolving or colloidally dispersing a dye in a matrix material are particularly preferably used in the present invention because the selection range of the matrix material and the dye is wide and the processing into an optical cell is easy. be able to.

[Dye] In the present invention, known dyes can be used.

Specific examples of the dye which can be used in the present invention include, for example, xanthene dyes such as rhodamine B, rhodamine 6G, eosin and phloxin B, acridine dyes such as acridine orange and acridine red, ethyl red, methyl Azo dyes such as red, porphyrin dyes, phthalocyanine dyes, cyanine dyes such as 3,3′-diethylthiacarbocyanine iodide, 3,3′-diethyloxadicarbocyanine iodide, brilliant green, Victoria Blue R, etc. And the like can be suitably used.

In the present invention, these dyes can be used alone or as a mixture of two or more.

[Matrix Material] The matrix material that can be used in the present invention is (1) a liquid material,
(2) high transmittance in the wavelength region of light used in the light control method of the present invention; (3) stable dissolution or colloidal dispersion of the dyes and the like used in the present invention;
(4) Any material can be used as long as it satisfies the condition that the composition as a photoresponsive composition can be kept with good stability.

Examples of the inorganic matrix material include water, water glass (concentrated aqueous solution of alkali silicate),
Hydrochloric acid, sulfuric acid, nitric acid, aqua regia, chlorosulfonic acid, methanesulfonic acid, trifluoromethanesulfonic acid, and the like can be used.

As the organic matrix material, various organic solvents and liquid organic polymer materials can be used.

As the volatile organic solvent, specifically,
Methanol, ethanol, isopropyl alcohol, n
-Alcohols such as butanol, amyl alcohol, cyclohexanol and benzyl alcohol, polyhydric alcohols such as ethylene glycol, diethylene glycol and glycerin, esters such as ethyl acetate, n-butyl acetate, amyl acetate and isopropyl acetate, acetone and methyl ethyl ketone Ketones such as methyl isobutyl ketone and cyclohexanone, ethers such as diethyl ether, dibutyl ether, methoxyethanol, ethoxyethanol, butoxyethanol and carbitol, tetrahydrofuran, 1,4-dioxane, 1,
Cyclic ethers such as 3-dioxolane, halogenated hydrocarbons such as dichloromethane, chloroform, carbon tetrachloride, 1,2-dichloroethane, 1,1,2-trichloroethane, tricrene, bromoform, dibromomethane, diiodomethane, and benzene Aromatic hydrocarbons such as toluene, xylene, chlorobenzene, o-dichlorobenzene, nitrobenzene, anisole and α-chloronaphthalene; aliphatic hydrocarbons such as n-pentane, n-hexane, n-heptane and cyclohexane; , N
Amides such as -dimethylformamide, N, N-dimethylacetamide and hexamethylphosphoric triamide; cyclic amides such as N-methylpyrrolidone; ureas such as tetramethylurea and 1,3-dimethyl-2-imidazolidinone Derivatives, sulfoxides such as dimethyl sulfoxide, carbonates such as ethylene carbonate and propylene carbonate, nitriles such as acetonitrile, propionitrile, benzonitrile, nitrogen-containing heterocyclic compounds such as pyridine and quinoline, triethylamine, triethanol Amine, amines such as diethylamino alcohol and aniline, organic acids such as chloroacetic acid, trichloroacetic acid, trifluoroacetic acid and acetic acid, as well as solvents such as nitromethane, carbon disulfide and sulfolane can be used.

These solvents may be used as a mixture of a plurality of types.

[Dissolution or Colloidal Dispersion of Dye in Matrix Material] A known method can be used to dissolve or colloidally disperse the dye in these matrix materials. For example, a method of dissolving a dye in an organic solvent or water glass, a method of dissolving a dye and a non-volatile liquid matrix material in a common volatile solvent and mixing them, and then removing the solvent by evaporating the liquid, A method of forming a matrix material by polymerizing or polycondensing the monomer after dissolving or dispersing the dye into the raw material monomer of the polymer matrix material, if necessary, using a solvent,
Etc. can be suitably used. It is known that by devising a combination of a dye and a matrix material and devising a processing method, a dye molecule can be aggregated to form a special aggregate called “H aggregate” or “J aggregate”. However, the dye molecules in the matrix material may be used under conditions that form such an aggregated or associated state.

A known method can be used to colloidally disperse the various ultrafine particles in a liquid matrix material. For example, a method in which the ultrafine particles are formed in a liquid matrix material, a chemical vapor deposition method, a sputtering method, an ultrafine particle produced by a gas phase method such as an evaporation method in an inert gas, and a dispersant, if necessary. , A method of trapping in a liquid matrix material, or the like can be suitably used.

The liquid photoresponsive composition used in the present invention may be used within a range that does not impair its function.
In order to improve the stability and durability as an optical element, a known antioxidant, an ultraviolet absorber, a singlet oxygen quencher, a dispersing aid, a dispersion stabilizer, a surfactant and the like may be contained as accessory components. good.

[0057]

Embodiments of the present invention will be described below with reference to the drawings.

[Embodiment 1] FIG. 1 shows a schematic configuration of a light control device of the present embodiment. As shown in FIG. 1, such an optical device configuration and arrangement include a case where a thin film type optical cell 8 is used as an internal form, and a plate-like, rectangular parallelepiped, cylindrical, or semi-cylindrical internal or external form. It can also be suitably used when using an optical cell having a rectangular column shape or the like.

Here, the optical cell 8 having a thin-film internal form has, for example, the following configuration.

(1) Cell 800 made of optical glass or quartz glass (FIG. 2).

(2) An assembling optical cell 810 (FIG. 3) in which two glass sheets are overlapped with a spacer and rubber packing therebetween and held by a metal frame for fixing.

An optical glass or quartz glass cell 800 as shown in FIG.
02, the side glass 803 and 804, and the bottom glass 805, the liquid photoresponsive composition filling portion 808
Is formed. As the glass material, besides quartz glass, optical glass such as soda glass and borosilicate glass can be used, and can be manufactured by a known glass processing technique. In order to obtain the accuracy as an optical cell, it is necessary to maintain a high degree of flatness and parallelism of the entrance / exit surface glasses 801 and 802 during glass processing. The liquid photoresponsive composition is supplied to the inlet 807.
Through the inlet tube 806. The filled liquid photoresponsive composition is sealed in an optical cell by inserting, for example, a polytetrafluoroethylene stopper (not shown) into the inlet 807, or sealing the inlet 807 by glass processing. The requirements of the optical cell can be satisfied. The optical glass or quartz glass cell 800 uses a majority of organic and inorganic matrix materials, except when using a solution that corrodes the glass, such as a strongly alkaline liquid, hydrofluoric acid, or borofluoric acid. When filling the liquid photoresponsive composition, it can be widely used. Particularly, it is useful when an acid such as hydrochloric acid, sulfuric acid, nitric acid, aqua regia, chlorosulfonic acid, methanesulfonic acid, trifluoromethanesulfonic acid, chloroacetic acid, trichloroacetic acid, trifluoroacetic acid, or acetic acid is used as the matrix material.

A form similar to that of the glass optical cell 800 shown in FIG. 2 can be made of a transparent plastic (organic glass) such as polymethyl methacrylate, polystyrene, and polycarbonate, and used as an optical cell. However, in this case, it is necessary to pay attention to the material selection and combination so that the matrix material does not dissolve or invade the plastic.

A prefabricated optical cell 810 as shown in FIG.
Is a method in which a spacer 814 provided with a liquid photoresponsive composition filling portion 818 is sandwiched between two plate-like entrance / exit surfaces 813 and 815, and this is packed with rubber packings 812 and 81.
6, and is fixed in fixing screw holes 824 and 825 using screws (not shown). Introducing pipe 82 attached to fixed frame 817
2 and 823 are introduction holes 82 provided in the fixed frame 817.
1. An introduction hole 820 provided in the rubber packing 816 and then an introduction hole 819 provided in the entrance / exit surface glass 815, and the liquid photoresponsive composition is introduced into the filling section 818 through these introduction paths. Can be. Filling section 81
8, that is, the optical path length that propagates through the photoresponsive composition when the signal light and / or the control light is vertically incident is determined by the thickness of the spacer 814 when assembled. Spacer 814, entrance / exit surface glasses 813 and 815, rubber packings 812 and 815, and
Since the fixing frames 811 and 817 are all in contact with the liquid photoresponsive composition, the fixing frames 811 and 817 need to be made of a material that can withstand the solubility, permeability, permeability, and / or corrosion of the liquid matrix material. Specifically, the material of the spacer 814 is preferably optical glass, quartz glass, polytetrafluoroethylene, butyl rubber, silicon rubber, ethylene propylene rubber, or the like. In particular, a fluorine-based polymer material such as polytetrafluoroethylene is preferably used in order to achieve both the maintenance of the accuracy of the optical path length and the maintenance of the liquid sealing property.

As the entrance / exit surface glasses 813 and 815, optical glass such as synthetic sapphire, soda glass, borosilicate glass and the like can be used in addition to quartz glass. When the matrix material is a liquid that corrodes inorganic glass, an organic glass such as polymethyl methacrylate, polystyrene, or polycarbonate can be used. As the material of the rubber packings 812 and 816, butyl rubber, silicon rubber, ethylene / propylene rubber, radiation-crosslinked fluororesin rubber, or the like can be used. The fixing frames 811 and 817 are preferably made of metal such as stainless steel or gold-plated brass.

Hereinafter, as the optical cell 8 of FIG. 1, the thickness of the liquid photoresponsive composition (the optical path length when vertically incident) is 50.
The quartz glass cell 8 of FIG.
A case will be described in which a mixture of 00 and a chloroform solution of tetra (t-butyl) copper phthalocyanine (concentration: 5 × 10 ⁻³ mol / liter) is used. FIG. 4 shows the transmittance spectrum of the optical cell 8 in this case. This optical cell 8
Was 0.5% at the control light wavelength (633 nm) and 91% at the signal light wavelength (830 nm).

The light control device of the present invention whose outline is illustrated in FIG. 1 includes a light source 1 for control light, a light source 2 for signal light, an ND filter 3, a shutter 4, a semi-transmissive mirror 5, a light mixer 6, a condenser lens 7, an optical cell 8, a light receiving lens 9, a wavelength selective transmission filter 20, an aperture 19, photodetectors 11 and 22, and an oscilloscope 100.

Of these optical elements or optical components,
The control light source 1, the signal light source 2, the optical mixer 6, the condenser lens 7, the optical cell 8, the light receiving lens 9, and the wavelength selective transmission filter 20 have the light control of the present invention in the apparatus configuration of FIG. It is an essential equipment component to carry out the method. The ND filter 3, shutter 4, semi-transmissive mirror 5, and aperture 19 are provided as needed.
Photodetectors 11 and 22, and oscilloscope 100
Is not necessary for implementing the light control method of the present invention, but is used as necessary as an electronic device for confirming the operation of light control.

Next, the features and operations of the individual components will be described.

A laser device is preferably used as the control light source 1. The oscillation wavelength and output are appropriately selected according to the wavelength of the signal light targeted by the light control method of the present invention and the response characteristics of the photoresponsive composition used. There is no particular limitation on the type of laser oscillation.
Any type can be used according to output, economy, and the like. Further, the wavelength of the light from the laser light source may be converted by a nonlinear optical element before use. Specifically, for example, an argon ion laser (oscillation wavelength 45
7.9 to 514.5 nm), a gas laser such as a helium-neon laser (633 nm), a solid-state laser such as a ruby laser or an Nd: YAG laser, a dye laser, a semiconductor laser, and the like can be suitably used. As the signal light source 2, not only coherent light from a laser light source but also non-coherent light can be used. In addition to light sources that provide monochromatic light, such as laser devices, light-emitting diodes, and neon discharge tubes, continuous spectrum light from tungsten bulbs, metal halide lamps, xenon discharge tubes, and the like can also be used by selecting the wavelength with an optical filter or monochromator. good.

An appropriate combination of the photoresponsive composition, the signal light wavelength band, and the control light wavelength band used in the light control method of the present invention is selected depending on the purpose of use. Used. Hereinafter, a semiconductor laser (oscillation wavelength: 830 nm, continuous oscillation output: 5 mW, Gaussian beam having a diameter of about 8 mm after beam shaping) is used as the signal light source 2, and a helium-neon laser (oscillation wavelength: 633 nm, beam diameter 2 mm) is used as the control light source An embodiment will be described in which a combination of an optical cell 800 filled with the liquid photoresponsive composition as described above and the optical cell 8 is used as the optical cell 8.

Although the ND filter 3 is not always necessary, the ND filter 3 is used to prevent laser light having an unnecessarily high power from entering the optical parts and optical elements constituting the apparatus. In testing response performance, it is useful for increasing or decreasing the light intensity of control light. In this embodiment, several types of ND filters were exchanged for the latter purpose.

When a continuous wave laser is used as control light, the shutter 4 is used for blinking the continuous wave laser in a pulse shape, and is an essential component of the device for implementing the light control method of the present invention. is not. That is, when the light source 1 of the control light is a laser that oscillates pulses and is a type of light source that can control the pulse width and oscillation interval, or when the laser light that has been pulse-modulated in advance by appropriate means is used as the light source 1 The shutter 4 need not be provided.

When the shutter 4 is used, any type can be used, such as an optical chopper, a mechanical shutter, a liquid crystal shutter, an optical Kerr effect shutter, a Pockels cell, an acousto-optic (AO) modulator, and the like. Can be appropriately selected and used in consideration of the operation speed of the shutter itself.

The semi-transmissive mirror 5 is used in this embodiment to constantly estimate the light intensity of the control light when testing the operation of the light control method of the present invention, and the light splitting ratio can be set arbitrarily. It is.

The photodetectors 11 and 22 are provided with the optical detectors of the present invention.
It is used to electrically detect and verify the state of change in light intensity due to light control, and to test the performance of the light control device of the present invention. The types of the photodetectors 11 and 22 are arbitrary, and can be appropriately selected and used in consideration of the response speed of the detector itself. For example, a photomultiplier tube, a photodiode, a phototransistor, or the like is used. Can be.

The light receiving signals of the photodetectors 11 and 22 can be monitored by a combination of an AD converter and a computer (not shown), in addition to the oscilloscope 100 or the like.

The optical mixer 6 is used for adjusting the optical paths of control light and signal light propagating in the optical cell 8, and is important in implementing the light control method and light control device of the present invention. It is one of the important device components. Any of polarizing beam splitter, non-polarizing beam splitter, or dichroic mirror can be used,
The light splitting ratio can also be set arbitrarily.

The condensing lens 7 serves as a common converging means for the signal light and the control light, for converging the signal light and the control light adjusted to have the same optical path and irradiating them to the optical cell 8. This is one of the essential components of the light control method and light control device of the present invention. Any specifications such as the focal length, numerical aperture, F-number, lens configuration, and lens surface coating of the condenser lens 7 can be appropriately used. A condenser lens 7 can also be incorporated in the optical cell.

In this embodiment, a microscope objective lens having a magnification of 40 times, a focal length of 5 mm, and a numerical aperture of 0.65 was used as the condenser lens 7.

The light receiving lens 9 is means for returning the signal light and the control light which have been converged and radiated to the optical cell 8 and transmitted therethrough to a parallel and / or convergent beam. As shown in this embodiment, By using a lens having a numerical aperture smaller than the numerical aperture of the condensing lens 7, it is possible to separate and extract a sufficiently large intensity-modulated and / or light-flux-density-modulated signal light with good reproducibility.

In this embodiment, as the light receiving lens 9, for example, a microscope lens having a magnification of 20 and a numerical aperture of 0.4 is used. That is, the light receiving lens 9 is determined by the numerical aperture of the condenser lens 7.
By reducing the numerical aperture of the signal light, it is possible to separate out the light flux of the area of the signal light that has been strongly subjected to the intensity modulation and / or the light flux density modulation, and to obtain a sufficiently modulated signal. Light can be detected with good reproducibility. Of course, even if the numerical aperture of the lens is large, it is needless to say that the numerical aperture may be substantially reduced by inserting the diaphragm 19 or making the light detector 22 enter only the central portion of the light beam. As will be described later, a concave mirror can be used instead of the condenser lens and the light receiving lens (see Embodiment 4). Further, a light receiving lens 9 can be incorporated in the optical cell 8.

The wavelength selective transmission filter 20 is one of the essential components of the device for implementing the light control method of the present invention with the device configuration of FIG. 1, and propagates along the same optical path in the optical cell 8. It is used as one of means for extracting only the signal light from the mixed light of the signal light and the control light.

As means for separating the signal light and the control light having different wavelengths from each other, a prism, a diffraction grating, a dichroic mirror or the like can be used. These signal light / control light separating means can be incorporated in the optical cell 8.

The wavelength selective transmission filter 20 used in the apparatus configuration shown in FIG. 1 can completely cut off light in the wavelength band of control light, while efficiently transmitting light in the wavelength band of signal light. Any known wavelength selective transmission filter can be used. For example, plastic or glass colored with a dye, glass having a multilayer dielectric film on its surface, or the like can be used.

In the optical device shown in FIG. 1 having the above-described components, the control beam emitted from the light source 1 passes through the ND filter 3 for adjusting the intensity of the transmitted light by adjusting the transmittance. The control light passes through a shutter 4 for blinking the control light in a pulse shape, and is split by a semi-transmissive mirror 5.

A part of the control light split by the semi-transmissive mirror 5 is received by the photodetector 11. Here, light source 2
Is turned off, the light source 1 is turned on, and the shutter 4 is opened, and the relationship between the light intensity at the light beam irradiation position on the optical cell 8 and the signal intensity of the photodetector 11 is measured in advance to create a calibration curve. With this, it is possible to always estimate the light intensity of the control light incident on the optical cell 8 from the signal intensity of the photodetector 11. In this embodiment, the power of the control light incident on the optical cell 8 is adjusted in the range of 0.5 mW to 25 mW by the ND filter 3.

The control light split and reflected by the semi-transmissive mirror 5 is
The light is converged through the optical mixer 6 and the condenser lens 7 and is irradiated to the optical cell 8. The light beam of the control light that has passed through the optical cell 8 passes through the light receiving lens 9 and is then blocked by the wavelength selective transmission filter 20.

The light beam of the signal light emitted from the light source 2 is mixed by the optical mixer 6 so as to propagate along the same optical path as the control light, and converges on the optical cell 8 via the condenser lens 7. The light that has been irradiated and passed through the element is
After passing through the wavelength selective transmission filter 20 and passing through an aperture 19 provided as necessary, the photodetector 2
The light is received at 2.

An experiment of light control was performed using the optical device of FIG. 1, and a change in light intensity as shown in FIGS. 5 and 6 was observed. 5 and 6, reference numeral 111 denotes a light reception signal of the photodetector 11, and reference numerals 222 and 223 denote light reception signals of the photodetector 22. The difference between the case where the light receiving signal 222 of the photodetector 22 is obtained and the case where 223 is obtained is as follows.

In the apparatus arrangement shown in FIG. 1, the control light and the signal light are converged and made incident on the optical cell 8, but the position (focal point Fc) at which the converged beam diameter becomes minimum is focused on the optical cell 8. When set near the lens 7 (on the light incident side), an optical response 222 is observed in a direction in which the apparent intensity of the signal light transmitted through the optical cell 8 decreases. On the other hand, if the position (focal point Fc) where the convergent beam diameter becomes minimum is set to a position near the light receiving lens 9 of the optical cell 8 (on the light emission side), the apparent intensity of the signal light transmitted through the optical cell 8 becomes An increasing direction of the optical response 223 is observed.

The details of the mechanism by which such a photoresponse occurs are not yet elucidated, and are under intensive study at present. However, the transmittance and refractive index of the photoresponsive composition may change due to control light irradiation. Is presumed to be caused by

Here, as a method for changing the positional relationship between the optical cell and the focal position of the control light and the signal light converged on the same optical path, for example, a mount provided with a fine movement mechanism using a precision screw, and a piezoelectric element actuator are provided. The optical cell 8 is mounted on a pedestal or a pedestal provided with an ultrasonic actuator, and moved as described above. In addition, the condensing lens 7 is made of a material having a large nonlinear refractive index effect, and a control light pulse is generated. How to change the focal position by changing the power density,
A method of changing the focal position by changing the temperature with a heating device using a material having a large thermal expansion coefficient as the material of the condenser lens 7 can be used.

An experiment of light control was performed using the optical device shown in FIG. 1, and changes in light intensity as shown in FIGS. 5 and 6 were observed. The details are as described below.

First, the light beam of the control light and the light beam of the signal light are focused on the focus F in the optical cell 8 or in the same area near the optical cell 8.
The optical paths from the respective light sources, the optical mixer 6, and the condenser lens 7 were adjusted so as to connect c. Next, the function of the wavelength selective transmission filter 20 was checked. That is, it was confirmed that when the light source 1 was turned on while the light source 2 was turned off and the shutter 4 was opened and closed, no response occurred to the photodetector 22 at all.

The minimum position of the convergent beam diameter (focal point Fc)
Is moved on the optical cell 8 by moving the optical cell 8. That is, while the distance (d ₇₈ + d ₈₉ ) between the condenser lens 7 and the light receiving lens 9 is fixed, the distance between the optical cell 8 and the condenser lens 7 is changed, and the control light and the signal light converged on the same optical path. The measurement was performed by changing the positional relationship between the focal position and the optical cell 8.

First, the case where the focal point Fc is placed on the condenser lens 7 of the optical cell 8 will be described. FIG. 5 shows a response waveform 222 of the signal light with respect to the control light waveform 111 in this case.

When the light source 1 of the control light is turned on with the shutter 4 closed, and then the light source 2 is turned on at time t ₁ to irradiate the optical cell 8 with signal light, the signal intensity of the photodetector 22 becomes level C. To level A.

At time t ₂ , the shutter 4 is opened,
When the control light was converged and irradiated on the same optical path as the signal light inside the optical cell 8 was propagating, the signal intensity of the photodetector 22 decreased from level A to level B. That is, an optical response in a direction in which the apparent intensity of the signal light decreases was observed. The response time for this change was less than 2 microseconds.

At time t ₃ , when the shutter 4 was closed and the irradiation of the control light to the optical cell was stopped, the signal intensity of the photodetector 22 returned from the level B to the level A. The response time for this change was less than 3 microseconds.

At time t ₄ , the shutter 4 is opened,
Then, closing at time t _5, the signal intensity of the photodetector 22 decreased from level A to level B, then returns to level A.

When the light source 2 was turned off at time t ₆ , the output of the photodetector 22 decreased and returned to the level C.

Next, a case where the focal point Fc is set on the light receiving lens 9 side of the optical cell 8 will be described. In this case, the response waveform 22 of the signal light with respect to the control light waveform 111
3 is shown in FIG.

When the light source 1 of the control light is turned on with the shutter 4 closed, and then the light source 2 is turned on at time t ₁ to irradiate the optical cell 8 with signal light, the signal intensity of the photodetector 22 becomes level C To level A.

At time t ₂ , the shutter 4 is opened,
When the control light was converged and irradiated on the same optical path as the signal light inside the optical cell 8 was propagating, the signal intensity of the photodetector 22 increased from level A to level D. That is, an optical response in a direction in which the apparent intensity of the signal light increases was observed. The response time for this change was less than 2 microseconds.

At time t ₃ , when the shutter 4 was closed and the control light irradiation to the optical cell was stopped, the signal intensity of the photodetector 22 returned from level D to level A. The response time for this change was less than 3 microseconds.

At time t ₄ , the shutter 4 is opened,
Then, closing at time t _5, the signal intensity of the photodetector 22 increased from level A to level D, and then returns to level A.

When the light source 2 was turned off at time t ₆ , the output of the photodetector 22 decreased and returned to the level C.

In summary, when the optical cell 8 is irradiated with the control light with the time change of the light intensity represented by the waveform 111 in FIG. 5 or FIG. 6, the light intensity of the signal light is monitored. The output waveform of the photodetector 22 shown as shown in FIG. 5 changed reversibly in response to the time change of the light intensity of the control light as shown at 222 in FIG. 5 or 223 in FIG. That is,
Controlling the transmission of signal light by increasing or decreasing or interrupting the light intensity of the control light, that is, controlling light with light (light / light control) or modulating light with light (light / light modulation)
It was confirmed that it was possible.

The degree of change in the light intensity of the signal light corresponding to the intermittent control light is determined by using the output levels A, B, and C of the photodetector 22 as a value ΔT [unit %] Or the value ΔT ′ [unit%] defined below using A, C and D

ΔT = 100 [(AB) / (AC)]

２T ′ = 100 [(DA) / (AC)] can be quantitatively compared. Here, A is the output level of the light detector 22 when the light source 2 of the signal light is turned on with the control light cut off, and B and D are the output levels of the light detector 22 when the signal light and the control light are irradiated simultaneously. The output level C is a photodetector 22 in a state where the signal light source 2 is turned off.
Output level.

In the above example, the incident power of the control light is set to 5
When the direction and the magnitude of the optical response of the signal light were examined by changing the position of the optical cell 8 with respect to the condenser lens 7 and the light receiving lens 9, the magnitude of the response ΔT in the direction in which the signal light intensity decreased was set to mW. The maximum value was 89%, and the maximum value of the response magnitude ΔT ′ in the direction in which the apparent signal light intensity increased was 51%. When the focal position of the control light is set near the incident side of the photoresponsive composition in the optical cell and the control light is irradiated with a pulse width longer than 1 millisecond, the power of the control light is increased by 10 m.
When it was larger than W, the solvent chloroform started boiling at the focal position of the control light. Since the boiling of the solvent occurs very locally, the pressure rise inside the optical cell was very small. When the control light was shut off, the boiling stopped immediately.

By changing the positional relationship between the position (focal point Fc) where the convergent beam diameter is minimum and the optical cell 8 as described above, the direction of the optical response of the signal light is reversed, and the apparent intensity of the signal light decreases. A response in an increasing direction or an increasing direction can be obtained.

In order to investigate the mechanism of such a change in the optical response, a change in the light intensity distribution in the cross section of the signal light beam caused by performing the optical control was measured. That is,
In the apparatus shown in FIG. 1, the light receiving lens 9 is changed to one having a numerical aperture (for example, 0.75) larger than the numerical aperture of the condenser lens 7 (0.65 in this embodiment), and the diaphragm 19 is removed. A light intensity distribution measuring device as schematically shown in FIG. 7 is installed in place of the light detector 22, and all the light beams transmitted through the optical cell 8 are received and converged by the light receiving lens 9, and the light intensity distribution measuring device And the light intensity distribution on the cross section of the signal light beam was measured. The measurement results are shown in FIGS. Here, as shown in FIG. 7, the light intensity distribution measuring device has a light receiving section 31 (effective diameter 4 mm).
A first slit 32 having a width of 1 mm is provided, and a second slit 33 having a width of 25 μm is moved at a constant speed in the length direction of the first slit, that is, in the direction from point X to point Y in FIG. 1mm x 25μ made by two slits
This is an apparatus for measuring the intensity of light passing through a rectangular window of m in accordance with the moving position of the window. In order to measure the light intensity corresponding to the moving position of the window, for example, the output of a detector that receives the light passing through the window is placed on a storage oscilloscope synchronized with the moving speed of the second slit 33. Just record it. FIGS. 8 to 10 show the light intensity distribution of the signal beam recorded on the storage oscilloscope with respect to the light beam cross section as described above.
The horizontal axis (position in the light beam cross section) corresponds to the position in the direction from point X to point Y in FIG. 7, and the vertical axis represents light intensity.

FIG. 8 shows that the control light does not enter the optical cell 8 and
5 is a light intensity distribution of a section of the signal light beam when only the signal light is incident. The light intensity distribution in this case is a distribution in which the intensity at the central portion is high and the intensity decreases toward the periphery (approximately “Gaussian distribution”).

FIG. 9 shows that the position (focal point Fc) where the convergent beam diameter becomes the minimum is set at a position close to the condenser lens 7 of the optical cell 8 (on the light incident side), and an apparent signal when the control light is irradiated. It is a light intensity distribution of the signal light beam cross section when the control light is irradiated under the condition that the light response 222 in the direction in which the light intensity decreases is observed. In this case, the light intensity distribution is such that the light intensity in the central portion is weak and the light intensity increases in the periphery. The light intensity at the center of the signal light beam cross section decreases depending on the control light intensity and the positional relationship between the optical cell 8 and the focal point, and approaches zero as the control light intensity increases. Therefore, in this case, when only the central portion of the signal light beam is extracted and the apparent signal light intensity is measured, the optical response 222 in the direction in which the intensity of the signal light decreases in response to the intermittent control light is sufficient. Can be taken out in size.

FIG. 10 shows that the position (focal point Fc) where the convergent beam diameter becomes minimum is set at a position close to the light receiving lens 9 of the optical cell 8 (light emission side), and when the control light is irradiated, the apparent signal light is emitted. It is a light intensity distribution of the cross section of the signal light beam when the control light is irradiated under the condition that the optical response 223 in the direction in which the intensity increases is observed. In this case, the light intensity at the central portion is higher than the light intensity at the central portion when control light is not irradiated (FIG. 8). In this case, the light intensity at the central portion of the signal light beam cross section depends on the relationship between the control light intensity and the focal position of the optical cell 8, but reaches several times that when the control light is not irradiated. Therefore, in this case, when only the central part of the signal light beam is extracted and the apparent signal light intensity is measured, the optical response 223 in the direction in which the signal light intensity increases in response to the intermittent control light is sufficiently large. You can take it out.

From the above experiment, it can be seen that the light intensity modulation (light response) of the signal light due to the intermittent control light occurs particularly at the center of the cross section of the signal light beam (light flux). Therefore, contrary to the gist of the present invention, the numerical aperture of the light receiving lens 9 is made larger than the numerical aperture of the condenser lens 7 so that the optical cell 8
When all of the signal light transmitted through the optical detector is captured and received by the photodetector, the detected optical response is significantly smaller than that in the case of the present invention. In addition, noise components other than the portion subjected to the light modulation by the control light are taken into the photodetector, and the S / N ratio is significantly deteriorated.

[Embodiment 2] In the light control light method and light control apparatus of the present invention, in order to increase the light response, the control light and the signal light are respectively converged and irradiated to the optical cell, and The optical paths of the control light and the signal light may be arranged so that regions having the highest photon densities in the vicinity of the respective focal points of the control light and the signal light overlap with each other in the optical cell. It is preferable that the light and the control light propagate in substantially the same optical path. In the case of a Gaussian beam in which the amplitude distribution of the electric field of the control light and the signal light is a Gaussian distribution, the light beam and the wavefront near the focal point Fc when converging at an opening angle 2θ by the condenser lens 7 or the like. FIG. 11 shows the state of No. 30. Here, the position where the diameter 2ω ₀ of the Gaussian beam having the wavelength λ is minimum, that is, the radius ω _{0 of the} beam waist is expressed by the following equation.

[0119]

Ω ₀ = λ / (π · θ) For example, the condensing lens (focal length 5 m
m, numerical aperture 0.65), wavelength 633 nm, beam diameter 1
mm waist radius ω when converging control light of mm
₀ is 2.02 μm, and similarly, the radius ω ₀ of the beam waist when converging the signal light having the wavelength of 830 nm and the beam diameter of 8 mm is calculated to be 0.392 μm (substantially the diffraction limit).

As shown in FIG. 12, the signal light and the control light can be regarded as “substantially the same optical path” in the following cases: 1) The optical axis of the control light and the signal light Are parallel to each other, and in the optical path of the control light, for example, the section L ₀₂ (radius r ₂ ), the optical path of the signal light, for example, the section L ₊₁ , L ₀₁ , or L ₋₁ (radius r ₁ ;
r ₁ ≦ r ₂ ), 2) the control light and the signal light have their optical axes parallel to each other, and the control light and the signal light have an optical path, for example, in the section L ₀₂ (radius r ₂ ). The optical path, for example, the cross section L ₊₁ , L ₀₁ or L _-1 (radius r ₁ ;
r ₁ ≦ r ₂ ), and 3) the optical axes of the control light and the signal light are parallel to each other (distance l ₊₁ , l ₋₁ , or l ₊₁ + l ₋₁ between the optical axes). And the optical path of the control light is any of the cross sections L ₊₁ , L ₀₁ , or L ₋₁ , and the optical path of the signal light is also one of the cross sections L ₊₁ , L ₀₁ , or L ₋₁ .

The data shown in Table 1 is used as an example in the first embodiment.
In the apparatus of the above, the numerical aperture 0.65
A microscope objective lens having a numerical aperture of 0.4 is used as the light receiving lens 9 and a position (focal point) where the convergent beam diameter is minimum is located near the condenser lens 7 of the optical cell 8 (light). The optical path of the signal light is fixed to the cross section L ₀₂ (diameter 8 mm) under the condition that the optical response 222 in the direction in which the signal light transmitted through the optical cell decreases is observed. _The signal light when the optical path (optical axis) of the control light of ₊₁ , L ₀₁ , or L _-1 (diameter 1 mm) is translated by ± 1.2 mm as the distance l ₊₁ or l _-1 between the optical axes. 9 shows a change in the magnitude ΔT of the optical response. The optical response is maximum when the optical axes of the signal light and the control light are completely coincident. However, even if the distance l _{+ 1} or l- ₁ between the optical axes is shifted by about ± 0.6 mm, the optical response is The magnitude ΔT only changes by about 7 points.

That is, the control light is adjusted such that regions (beam waist) having the highest photon density near the respective focal points of the converged signal light and control light overlap with each other in the photoresponsive composition in the optical cell. And the optical path of the signal light is arranged, respectively, when the overlap of these areas is maximum, that is, the optical response is maximum when the optical axes of the control light and the signal light are completely coincident, It has been found that when the optical paths of the control light and the signal light are substantially the same, a sufficiently large optical response can be obtained.

[0123]

[Table 1] [Comparative Example 1] To perform a comparative experiment based on the conventional technology,
JP-A-53-137888, JP-A-63-231
According to the description in Japanese Patent Application Laid-Open No. 424 and Japanese Patent Application Laid-Open No. Sho 64-73326, light control was attempted using an apparatus having a configuration as schematically shown in FIG. That is, a 1 cm optical path length quartz solution cell 27 is irradiated with semiconductor laser light (wavelength 830 nm) from the light source 2 of the signal light passing through the diaphragm 19 and the transmitted light is detected through the wavelength selective transmission filter 20. The control light was diffused using a projection lens 26 from the direction orthogonal to the signal light, and was irradiated onto the entire optical path of the signal light passing through the solution cell 27 while being received by the detector 22. In the device configuration of FIG. 13, the light source 1 (wavelength 633 nm) of signal light, N
D filter 3, shutter 4, semi-transmissive mirror 5, and
The role and specifications of the photodetector 11 are the same as in the first embodiment. The wavelength selective transmission filter 20 is for preventing the control light scattered from the solution cell 27 from being incident on the photodetector 22, and may be the same as that used in the first embodiment.

As the dye, tetra (t-butyl) copper phthalocyanine was used in the same manner as in the first embodiment, and a chloroform solution was filled in the solution cell 27 for testing. Regarding the dye concentration, taking into account the difference in the optical path length, that is, the optical path length of 1 cm, which is 200 times that of the optical path length of 50 μm in the first embodiment, the density (1/2) in the case of the first embodiment (2 .5 × 10 ⁻⁵ mol / l) and adjusted so that the effective transmittance was equivalent to that of the first embodiment. As in the case of the first embodiment, the power of the control light incident on the optical element (solution cell 27) is adjusted in the range of 0.5 mW to 25 mW by the ND filter 3, and the control light is flickered using the shutter 4. Was. However, a result was obtained in which the intensity of the signal light incident on the photodetector 22 did not change at all even when the power of the control light was maximized. That is, as long as the power of the control light is adjusted in the range of 0.5 mW to 25 mW, light / light control cannot be realized in the device configuration / device arrangement of FIG.

Embodiment 3 Instead of tetra (t-butyl) copper phthalocyanine in Embodiment 1, tetra (t-butyl) oxyvanadium phthalocyanine was used as a dye. The other conditions were the same as in the method described in Embodiment 1, and the optical cell 8 made of quartz glass was filled with the liquid photoresponsive composition. FIG. 14 shows the transmittance spectrum in this case. The transmittance of this film was 3.4% at the wavelength of control light (633 nm) and 78% at the wavelength of signal light (780 nm).

The film type optical element is mounted on the same light control device (FIG. 1) as in the first embodiment, and the position (focus Fc) at which the convergent beam diameter of the control light and the signal light is minimized and the position of the optical cell 8 While changing the positional relationship, the direction and magnitude of the optical response of the signal light corresponding to the intermittent control light were examined in the same manner as in the first embodiment. However, a semiconductor laser (oscillation wavelength 780 nm, continuous oscillation output 6) was used as the signal light source 2.
mW, Gaussian beam with a diameter of about 8 mm after beam shaping)
A helium-neon laser (Gaussian beam having an oscillation wavelength of 633 nm and a beam diameter of 2 mm) as a control light source 1, a magnification of 20 times, and a numerical aperture of 0.4 as a condenser lens 7.
Microscope lens as a light receiving lens 9 magnification 10 times,
Using a microscope objective lens with a numerical aperture of 0.3, the distance between the optical cell 8 and the condenser lens 7 is changed while the distance (d ₇₈ + d ₈₉ ) between the condenser lens 7 and the light receiving lens 9 is fixed, and the same This was performed by changing the positional relationship between the focus position of the control light and the signal light converged on the optical path and the optical cell 8.

When the incident power of the control light is 5 mW, the maximum value of the response magnitude ΔT in the direction in which the signal light intensity decreases is 82
%, The maximum value of the response magnitude ΔT ′ in the direction in which the apparent signal light intensity increases was 54%.

[Fourth Embodiment] FIG. 15 shows a schematic configuration of a light control device according to a fourth embodiment. Such an optical device configuration and arrangement include, in addition to the thin-film type optical cell 8 illustrated in FIG. 15, the external and external configurations are plate-like, rectangular parallelepiped, cylindrical, semi-cylindrical, and quadrangular prism-like. It can also be suitably used when an optical cell such as the above is used.

Light sources 1 and 2, ND filter 3, shutter 4, photodetectors 11 and 22, optical cell 8, wavelength selective transmission filter 20, and oscilloscope 100
, The same as in Embodiment 1 (FIG. 1) was used in the same manner.

By using the dichroic mirror 21 in the arrangement shown in FIG. 15, the control light is divided and the light intensity is monitored by the photodetector 11, and at the same time, the optical paths of the control light and the signal light are overlapped. The optical mixer 6 required in the arrangement of FIG. 1 can be omitted. However, in the arrangement of FIG. 15, in order to complement the wavelength selective transmission and reflection of the dichroic mirror 21, the wavelength selective transmission filter 10 that completely blocks the signal light and transmits only the control light is connected to the photodetector 11. It is preferably provided before. Further, in order to prevent the signal light and / or the control light from returning to the light sources 1 and 2 and adversely affecting the light source device,
If necessary, the optical isolators 13 and 14 may be provided before the light sources 1 and 2, respectively.

As a light convergence means for irradiating the optical cell 8 with the signal light and the control light whose optical paths are matched together, instead of the condenser lens 7 and the light receiving lens 9, FIG.
In such an arrangement, concave mirrors 15 and 16 can be used. When a lens is used as a common converging means for the signal light and the control light, there is a problem that the focal length varies strictly depending on the wavelength, but there is no concern with a concave mirror.

In the light control device of the present invention as exemplified in FIG. 15, after passing through the optical element, of the diverging signal light beam, the intensity modulation and / or the light beam density modulation was strongly received. The following method can be employed to separate and extract the signal light beam in the region.

(1) A method of providing the stop 19 in front of the photodetector 22.

(2) A method in which the opening angle of the concave mirror 16 on the light receiving side is smaller than the opening angle of the concave mirror 15 on the irradiation side.

(3) A method in which the opening angle of the concave mirror 16 on the light receiving side is made smaller than the opening angle of the concave mirror 15 on the irradiation side, and a stop 19 is provided in front of the photodetector 22.

As shown in FIG. 15, the essential components of the light control device of the present invention include light sources 1 and 2, a dichroic mirror 21, and a wavelength selective transmission filter 2.
0, concave mirrors 15 and 16 and optical cell 8. Note that a polarized or non-polarized beam splitter may be used instead of the dichroic mirror 21 in FIG.

As a procedure for performing the light control method of the present invention with an apparatus as shown in FIG. 15, first, control light (light source 1)
And the optical path of the signal light (light source 2) coincides with the common focal point Fc.
The light source 1 and the light source 2 are alternately turned on to check the functions of the dichroic mirror 21 and the wavelength selective transmission filters 10 and 20 so that the optical element 8 is arranged at the (beam waist) position. When only the light source 2 is turned on (the shutter 4 is opened), there is no response to the light detector 22, and when only the light source 2 is turned on, the light detector 11 is turned off.
Confirmed that there was no response.

The light / light control method using the optical cell 8 was carried out in the same manner as in the first embodiment, and the same experimental results as in the first embodiment were obtained.

[0139]

As described above in detail, according to the light control method and the light control device of the present invention, for example, the laser light in the visible region is used as the control light, and the signal light in the near infrared region is efficiently used. Good modulation can be achieved with a very simple optical device at a practically sufficient response speed without using any electronic circuit or the like.

Further, by filling the optical cell with the liquid photoresponsive composition and using it, it is possible to provide an optical device which can reduce optical scattering and exhibit a large optical response with the smallest possible power. it can.

Further, when a liquid photoresponsive composition is prepared using a volatile solvent, when the control light having excessive power is incident, the solvent boils to generate bubbles, and as a result, the control is performed. The light can be blocked to prevent the optical element from being damaged.

Even if the dye near the focal point of the control light irradiated into the photoresponsive composition is deteriorated, mass transfer by diffusion causes a longer period of time than when the photoresponsive composition is not liquid.
Functions can be demonstrated.

The replacement of the photoresponsive composition in the optical cell can be easily performed.

The converging means for converging the control light and the signal light in the optical cell, and / or the intensity modulation of the divergent signal light flux after passing through the photoresponsive composition in the optical cell. And / or means for separating and extracting a signal light beam in a region which has been strongly subjected to light beam density modulation, and / or mixed light of signal light and control light transmitted through the photoresponsive composition in an optical cell, By incorporating means for separating signal light and control light, an extremely simple and compact light control device can be provided.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a first embodiment illustrating a device configuration used in carrying out the present invention.

FIG. 2 is a schematic view illustrating an optical cell made of optical glass or quartz glass.

FIG. 3 is a schematic view exemplifying constituent parts of an assembling optical cell.

FIG. 4 is a transmittance spectrum of an optical cell filled with the photoresponsive composition of Embodiment 1.

FIG. 5 is a diagram exemplifying a change over time in light intensity of control light and signal light.

FIG. 6 is a diagram exemplifying a change over time in light intensity of control light and signal light.

FIG. 7 is a diagram showing a relationship between a slit and a light beam used for light intensity distribution measurement.

FIG. 8 is a diagram illustrating a light intensity distribution of a beam cross section of a signal light.

FIG. 9 is a diagram illustrating a light intensity distribution of a beam cross section of a signal light.

FIG. 10 is a diagram illustrating a light intensity distribution of a beam cross section of a signal light.

FIG. 11 is a schematic diagram showing a state near a focal point of a Gaussian beam converged by a condenser lens or the like.

FIG. 12 shows optical paths (and optical axes) of control light and signal light.
FIG. 3 is a diagram illustrating the relationship of FIG.

FIG. 13 is a configuration diagram illustrating a device configuration used in the related art.

FIG. 14 is a transmittance spectrum of an optical cell filled with the photoresponsive composition of Embodiment 3.

FIG. 15 is a configuration diagram illustrating a device configuration of a fourth embodiment used when carrying out the present invention.

[Explanation of symbols]

1 light source for control light, 2 light source for signal light, 3 ND filter, 4 shutter, 5 transflective mirror, 6 optical mixer,
7 condensing lens, 8 optical cell filled with liquid photoresponsive composition, 9 light receiving lens, 10 wavelength selective transmission filter (for blocking signal light), 11 photodetector, 13 optical isolator (for control light), 14 Optical isolator (for signal light), 15 concave mirror, 16 concave mirror, 19 diaphragm,
20 wavelength selective transmission filter (for blocking control light), 21
Dichroic mirror, 22 photodetector (for detecting light intensity of signal light), 26 projection lens, 27 solution cell made of quartz (optical path length 1 cm), 30 wavefront, 31 light receiving part of light intensity distribution measuring device (effective diameter 4 mm), 32 first slit (width 1 mm), 33 second slit (width 25 μm),
100 oscilloscope, 111 Signal from light detector 11 (light intensity time change curve of control light), 222 and 2
23 Signal from light detector 22 (light intensity time change curve of signal light), 800 glass optical cell, 801 incident
Outgoing surface glass, 802 Incident / outgoing surface glass, 803
Side glass, 804 side glass, 805 bottom glass, 806 inlet tube, 807 inlet, 808 liquid photoresponsive composition filling section, 810 assembly optical cell, 811
Fixed frame, 812 rubber packing, 813 entrance / exit surface glass, 814 spacer, 815 entrance / exit surface glass (with introduction hole), 816 rubber packing (with introduction hole), 817 fixed frame (with introduction tube), 818 Liquid light Responsive composition filling section, 819 introduction hole, 820 introduction hole,
821 introduction hole, 822 introduction pipe, 823 introduction pipe, 8
24 fixing screw hole, 825 fixing screw hole, A The output level of the photodetector 22 when the light source of the signal light is turned on while the control light is cut off, and the B focus Fc are set on the condenser lens side of the optical cell 8. And the output level of the photodetector 22 when the control light is irradiated while the signal light source is turned on, the output level of the photodetector 22 when the signal light is turned off, and the D focus Fc are optical. The output level of the photodetector 22 when it is set on the light receiving lens side of the cell 8 and when the control light is irradiated with the light source of the signal light turned on, d ₇₈
Length of the condenser lens 7 and the optical cell 8, d ₈₉ length of the optical cell 8 and the light-receiving lens 9, Fc _{focus, L 01, L +1, L} -1 and L ₀₂ signal light or control light of the light beam cross-section, l ₊₁ and l _-1 translation distance of optical axis of signal light or control light,
The radius of the light beam cross section L ₀₁ , L ₊₁ or L ₋₁ of the r ₁ signal light or control light, the radius of the light beam cross section L ₀₂ of the r ₂ signal light or control light, and the time when the light source of the t ₁ signal light is turned on. ,
The time when the shutter that blocked the t ₂ control light was opened, the time when the t ₃ control light was blocked again by the shutter, t
₍₄ ) The time at which the shutter that blocked the control light was opened, t
₅ control light the time was again blocked by the shutter, the time that turns off the light source of the t ₆ the signal light, the angle at which the outer peripheral portion makes with the optical axis of the light beam is converged by θ condenser lens, it is converged at omega ₀ converging lens Beam waist (beam radius at focal position) of Gaussian beam.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Shigeru Takarada 1-9-4 Horinouchi, Adachi-ku, Tokyo Dainichi Seika Kogyo Co., Ltd. Tokyo Manufacturing Office (72) Inventor Hiromitsu Yanagimoto 1-chome Horinouchi, Adachi-ku, Tokyo No. 9-4 Dainichi Seika Kogyo Co., Ltd. Tokyo Manufacturing Office (72) Inventor Masakatsu Kai 3-12-12 Moriyacho, Kanagawa-ku, Yokohama-shi, Kanagawa Japan Victor Company of Japan, Ltd. (72) Inventor Ichiro Ueno Yokohama, Kanagawa 3-12 Moriyacho, Kanagawa-ku, Japan

Claims (16)

[Claims] An optical cell filled with a liquid photoresponsive composition is irradiated with control light having a wavelength sensitive to the photoresponsive composition, and the transmittance of signal light in a wavelength band different from the control light is provided. And / or intensity modulation of the signal light passing through the optical cell by reversibly changing the refractive index and / or
Or a light control method for performing light flux density modulation, wherein the control light and the signal light are respectively converged and radiated to the optical cell, and the photon density of the control light and the signal light in the vicinity of the respective focal points is reduced. An optical control method, wherein the optical paths of the control light and the signal light are arranged such that the highest region overlaps with each other in the photoresponsive composition in the optical cell. 2. The light control method according to claim 1, wherein the control light and the signal light are propagated in substantially the same optical path in the optical cell. 3. The light control method according to claim 1, wherein the intensity modulation and / or intensity of the signal light beam diverging after passing through the photoresponsive composition in the optical cell.
Alternatively, a light control method characterized by separating and extracting a signal light beam in a region that has been strongly subjected to light beam density modulation. 4. The light control method according to claim 1, wherein the signal light flux diverging after passing through the photoresponsive composition in the optical cell is diverged from the signal light flux. A light control method, wherein a signal light beam in a region which has been strongly subjected to the intensity modulation and / or the light beam density modulation is separated and taken out by taking out in an angle range (opening angle) smaller than the angle. 5. The light control method according to claim 1, wherein the control light is changed by changing a positional relationship between a focus position of each of the control light and the signal light and the optical cell. By irradiating, the optical response in the direction in which the apparent intensity of the signal light transmitted through the optical cell decreases and the optical response in which the apparent intensity of the signal light increases are selectively selected and extracted. A light control method characterized by the above-mentioned. 6. The light control method according to claim 1, wherein the liquid photoresponsive composition contains a dye. 7. An optical cell filled with a liquid photoresponsive composition is irradiated with control light having a wavelength sensitive to the photoresponsive composition, and a transmittance of signal light in a wavelength band different from the control light is provided. And / or intensity modulation of the signal light passing through the optical cell by reversibly increasing and decreasing the refractive index and / or
Or a light control device used in a light control method for performing light flux density modulation, comprising converging means for converging each of the control light and the signal light, and a focus of each of the converged control light and the signal light. The optical paths of the control light and the signal light are arranged so that the regions having the highest photon densities in the vicinity overlap each other, and the liquid photoresponsive composition in the optical cell is the converged control light. And a region where the signal light has the highest photon density in the vicinity of the focal point of each of the signal lights is disposed at a position where the regions overlap each other. 8. The optical control device according to claim 7, wherein the optical control device has an optical path arrangement such that the control light and the signal light propagate in substantially the same optical path in the optical cell. . 9. The light control device according to claim 7, wherein, of the signal light beam diverging after passing through the photoresponsive composition in the optical cell, the intensity modulation and / or
Alternatively, a light control device comprising means for separating and extracting a signal light beam in an area which has been strongly subjected to light beam density modulation. 10. The light control device according to claim 9, wherein the signal light is converged on the optical cell as means for separating and extracting a signal light beam in a region that has been strongly subjected to the intensity modulation and / or the light beam density modulation. A light control device characterized by using a convergence means having a numerical aperture smaller than the numerical aperture of the convergence means used when the light is made incident. 11. The light control device according to claim 9, wherein an aperture is used as means for separating and extracting a signal light beam in a region which has been strongly subjected to the intensity modulation and / or the light beam density modulation. Control device. 12. The light control device according to claim 7, further comprising a moving unit configured to change a positional relationship between a focal position of each of the control light and the signal light and the optical cell, By using the moving means, by changing the positional relationship between the focus position of the control light and the signal light and the optical cell, the signal light transmitted through the optical cell by the irradiation of the control light An optical control device, wherein either one of an optical response in a direction in which the apparent intensity decreases and an optical response in which the apparent intensity of the signal light increases increases is selected and extracted. 13. The light control device according to claim 7, wherein a mixed light of the signal light and the control light transmitted through the photoresponsive composition in the optical cell is controlled to be a signal light. A light control device comprising means for separating light and light. 14. The light control device according to claim 7, wherein the converging unit converges the control light and the signal light, and / or the photoresponsive composition in the optical cell. Of the signal light flux that diverges after passing through
Means for separating and extracting a signal light beam in a region which has been strongly subjected to the intensity modulation and / or light beam density modulation; and / or
Alternatively, means for separating mixed light of signal light and control light transmitted through the photoresponsive composition in the optical cell into signal light and control light has a structure incorporated in the optical cell. Characteristic light control device. 15. The light control device according to claim 7, wherein the liquid photoresponsive composition contains a volatile solvent. 16. The light control device according to claim 7, wherein the liquid photoresponsive composition contains a dye.