JPH0682856A - Nonlinear optical material - Google Patents

Abstract

PURPOSE:To provide the novel compd. useful as a nonlinear optical material having high transmittance to blue light by using a specific compd. and the nonlinear optical material having high nonlinear optical responsiveness. CONSTITUTION:The above-mentioned compd. is expressed by formula I and the nonlinear optical material consists of this compd. as a nonlinear optical response material. In the formula I, An denotes an aryl group; X a chalcogen atom and N-R; Am denotes an ammonium group; R denotes a hydrogen atom, alkyl group or aryl group. The compd. expressed by the formula I is preferably the compd. expressed by formula II. In the formula II, R<1> denotes an alkyl group; X<1> denotes an oxygen atom or sulfur atom. Above all, the oxygen atom is more preferable. Am<1> denotes an ammonium group. This compd. has high blue transmittability and sufficient SHG activity as compared with the compds. known generally as org. nonlinear optical materials from heretofore.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a novel compound useful as a nonlinear optical material. The present invention also relates to a nonlinear optical material suitable for use in various elements such as wavelength conversion elements that utilize nonlinear optical effects. Further, the present invention relates to a light wavelength conversion method using a nonlinear optical material. The present invention also relates to a material (hereinafter referred to as “recording material”) for recording various information and thermal history by utilizing the wavelength conversion.

[0002]

2. Description of the Related Art In recent years, a material having a non-linear optical material-a non-linearity between a polarization and an electric field, which appears when a strong optical electric field such as laser light is applied, has been attracting attention. Such materials are generally known as nonlinear optical materials and are described in detail in, for example, the following. "Non-Linear Optical Property De of Organic and Polymeric Material"
C.S. Symposium Series 233 Edited by David Jay Williams (American Chemistry Association 198)
3 years) "" Nonlinear Optical Properties of Organi
c and Polymeric Material "ACS SYMPOSIUM SERIES 2
33 David J. Williams ed. (American Chemical Societ
y, 1983) "," Organic Nonlinear Optical Materials ", supervised by Masao Kato, Hachiro Nakanishi (CMC, 1985)," Nonlinear Optical Properties. "
Of Organic Molecule's and Crystals, "Volumes 1 and 2, DS Schmla and Jay Jess, Ed. (Academic Press 198
7 years) "" Nonlinear Optical Properties of Organic
Molecules and Crystals "vol 1 and 2 DSChemla
and edited by J. Zyss (Academic Press).

One of the applications of the nonlinear optical material is a second harmonic generation (SHG) based on the second-order nonlinear optical effect and a wavelength conversion device using a sum frequency and a difference frequency. So far, those which have been practically used are inorganic perovskites represented by lithium niobate. However, recently, it has become known that a π-electron conjugated organic compound having an electron-donating group and an electron-withdrawing group has various performances as a nonlinear optical material, which greatly exceeds the above-mentioned inorganic substances. In order to form a higher performance non-linear optical material, it is necessary to arrange compounds having a high non-linear susceptibility in a molecular state so as not to generate inversion symmetry. It is known that a compound having a long π-electron conjugated chain is useful for the expression of a high non-linear susceptibility, which is one of them, and various compounds are described in the above-mentioned documents. Obviously, the maximum absorption wavelength becomes longer, and the transmittance of blue light decreases, for example, which hinders the generation of blue light as the second harmonic. This also occurs in the p-nitroaniline derivative, and the fact that the transmittance of the wavelength has a large influence on the efficiency of the second harmonic generation is due to Alain Azema et al., Proceedings of SPII,
Volume 400, New Optical Materials (Alai
n Aze'ma et al., Proceedings of SPIE, Volume 400, Ne
w Optical Materials), (1983) p. 186, FIG.

Therefore, the advent of a nonlinear optical material having a high transmittance for blue light is desired. Conventionally, it has been studied to replace the carbon atom of the benzene nucleus of nitroaniline with a nitrogen atom etc., but satisfactory results have not always been obtained. In addition, the applicant of the better method,
JP-A-62-210430 and JP-A-62-210
It was disclosed in Japanese Patent No. 432. Further, JP-A-62-599
34, JP-A-62-23136, JP-A-63-26.
No. 638, Japanese Patent Publication No. 63-31768, and Japanese Patent Laid-Open No. 63-1.
63827, JP-A-63-146025, JP-A-6-
3-85526, JP-A-63-239427, JP-A-1-100521, JP-A-64-56425, JP-A-1-102529, JP-A-1-102530,
Many materials are disclosed in JP-A-1-237625, JP-A-1-207724 and the like. However, as described above, in order to be useful as a second-order nonlinear optical material, the performance in the molecular state alone is insufficient, and it is essential that the molecular arrangement in the aggregated state has no inversion symmetry. is there. However, at present, it is extremely difficult to predict the molecular arrangement, and the probability of existence in all organic compounds is not high.

Also, many optical recording materials for laser writing are already known. Typical examples thereof include a substrate on which a metal, a semimetal, or a nonmetal is vapor-deposited or a substrate on which a dye is vapor-deposited or applied. However,
The method of vapor-depositing metal or the like has a problem that productivity is poor and the recording layer is poor in oxidation resistance and hydrolysis resistance. Further, those coated or vapor-deposited with dyes have the drawback of being poor in durability, and these optical recording media are still unsatisfactory in that they have low sensitivity to semiconductor lasers and low stability. It is considered that one of the causes of these problems in durability or sensitivity is that the wavelength of the recording light source and the wavelength of the reproducing light source are the same. Further, as a sensor for heat, although it is very well known that the temperature at a certain point is known like a liquid crystal sensor, a simple method for cumulatively recording heat history is not so well known. Absent.

[0006]

Therefore, a first object of the present invention is to provide a novel compound useful as a nonlinear optical material. The second object is to provide a non-linear optical material exhibiting a high non-linear optical response. A third object is to provide a method utilizing the responsivity related to the conversion of the light wavelength among the non-linear optical responsivities. Further, a fourth object is to provide an optical recording material having excellent sensitivity and durability, and a fifth object is to provide a material capable of cumulatively recording thermal history.

[0007]

Means for Solving the Problems As a result of intensive studies, the present inventors have found that a compound represented by the general formula (I) and a nonlinear optical material containing the compound as a nonlinear optical responsive material
It has been found that the object of the present invention can be achieved. General formula (I)

[0008]

[Chemical 4]

In the formula, Ar represents an aryl group. X is
Represents a chalcogen atom and NR. Am represents an ammonium group. R represents a hydrogen atom, an alkyl group or an aryl group. Among the compounds represented by the general formula (I), the compounds represented by the following general formula (2) are preferable. General formula (2)

[0010]

[Chemical 5]

In the formula, R ¹ represents an alkyl group and X ¹ represents an oxygen atom or a sulfur atom. Of these, oxygen atom is preferable. Am ¹ represents an ammonium group.

It has also been found that the object of the present invention can be achieved by a recording material containing a compound in which the ability to generate a second harmonic appears or disappears due to the formation of a salt. Examples of the combination of the above-mentioned salt-forming compounds include a combination of carboxylic acid and amine, sulfonic acid and amine, phenol and amine, active methyl (or methylene or methine) and amine, thiol and amine, imino and amine. Among the formed salts, the compound represented by the following general formula (3) is excellent. General formula (3)

[0013]

[Chemical 6]

Where Ar³Represents an aryl group. X³
Is a chalcogen atom and NR³Represents Am³Is small
Represents an ammonium group having at least one hydrogen atom
You R ³Represents a hydrogen atom, an alkyl group or an aryl group
You In particular Ar is 4-alkoxyphenyl,
Those in which X is an oxygen atom or a sulfur atom are preferred. Less than
These general formulas will be described in more detail below.

Examples of the aryl group represented by Ar and Ar ³ include a phenyl group, a naphthyl group, a 2-pyridyl group, a 3-pyridyl group, a 4-pyridyl group, a 2-pyrimidyl group, a 2-furyl group and a 3-furyl group. , 2-thienyl group, 3
A thienyl group. Preferred are a phenyl group and a 2-pyridyl group. For example, they may be substituted with the groups shown below, and as the substituent, for example, an alkyl group having 1 to 24 carbon atoms, preferably 1 to 10 carbon atoms, more preferably 1 to 5 carbon atoms (eg, methyl, ethyl,
Propyl, i-propyl, butyl, t-butyl, pentyl, sec-pentyl), an alkoxy group having 1 to 24 carbon atoms, preferably 1 to 10 carbon atoms, more preferably 1 to 5 carbon atoms (eg methoxy, ethoxypropoxy, benzyloxy). ), Carbon numbers 1 to 24, preferably 1 to 1
0, more preferably 1 to 5 acylamino groups (eg acetylamino, propionylamino, pivaloylamino, methanesulfonylamino, benzoylamino),
An acyloxy group having 1 to 24 carbon atoms, preferably 1 to 10 and more preferably 1 to 5 (for example, acetyloxy, propionyloxy, benzoyloxy, benzenesulfonyloxy),

An alkoxycarbonyl group having an alkyl group having 1 to 24 carbon atoms, preferably 1 to 10, and more preferably 1 to 5 carbon atoms (eg, methoxycarbonyl,
(Ethoxycarbonyl, propoxycarbonyl), an N-alkylcarbamoyl group having an alkyl group having 1 to 24 carbon atoms, preferably 1 to 10 carbon atoms, more preferably 1 to 5 carbon atoms (for example, N-methylcarbamoyl, N, N-dimethylcarbamoyl, N). -Ethylcarbamoyl), an acyl group having 1 to 24 carbon atoms, preferably 1 to 10 carbon atoms, more preferably 1 to 5 carbon atoms (eg acetyl, propionyl, pivaloyl, methanesulfonyl, benzoyl),
Further, the above alkyl group may be substituted with, for example, alkoxy, acylamino, acyloxy, alkoxycarbonyl, N-alkylcarbamoyl or acyl.

Further, an aryl group having 6 to 20 carbon atoms, preferably 6 to 10 carbon atoms (eg, phenyl, tolyl, 1-).
Naphthyl, 2-naphthyl), a 5- to 8-membered, preferably 5- or 6-membered heterocycle (eg 2-pyridyl, 3-pyridyl, 4-pyridyl, 2-pyrimidyl, 2-furyl, 3).
-Furyl, 2-thienyl, 3-thienyl, 1-pyrrolyl, 1-pyrazolyl, 1-imidazolyl, 1-triazolyl, 1-benzimidazolyl, pyrrolidyl, piperazinyl, morpholinyl), hydroxy group, carboxy group,
Examples thereof include amino groups (for example, amino, methylamino, dimethylamino, cyclohexylamiki, n-octylamino) and halogen atoms (fluorine, chlorine, bromine, iodine).

Of these, a substituent having a substituent constant σ _{+ p} > 0 is particularly preferable, and a substituent at the 4-position is more preferable. The above-mentioned substituent constants are described in "Structural Activity-Relationship of Drugs-Guideline for Drug Design and Study of Mechanism of Action" in Sensation No. 122 edited by Structure-Activity-Relationship Association, pages 95-111, published by Nankodo and Corbin.・ Hansyu (Corwin ・ Hansch),
Albert Leo, "Substitute Constants for Correlation
Analysis in Chemistry and Biology "(Substituent Constants for Correlation Analys
is in Chemistry and Biology) 69-161 John ・
Represents the values given in John Wiley and Sons.

Examples of the ammonium group represented by Am, Am ¹ and Am ³ include ammonium, alkylammonium (eg, methylammonium, ethylammonium, cyclohexylammonium, 1-phenylethylammonium), dialkylammonium (eg, dimethylammonium, diethyl). Ammonium, pyrrolidinium, piperidinium, morpholinium, piperazinemonoammonium, piperazinebisammonium), trialkylammonium (for example, trimethylammonium, triethylammonium, triethylenediaminemonoammonium, triethylenediaminebisammonium), tetraalkylammonium ( For example, tetramethyl ammonium, tetraethyl ammonium, benzyl trimethyl Rumonium), arylammonium (eg, anilinium, N-methylanilinium, N, N-diethylanilinium), pyridinium (pyridinium, 2-picolinium, 3-picolinium, 4-picolinium, 4-N, N-dimethylamino). Pyridinium), 1,8-diazabicyclo [5,4,0]
-7-Undecenium can be mentioned. However, Am ³ is not a quaternary ammonium.

The alkyl group represented by R, R ¹ and R ³ is, for example, a straight-chain or branched alkyl group having 1 to 30 carbon atoms, preferably 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms (eg, Methyl, ethyl, propyl, i-propyl, hexyl, cyclohexyl), which may be substituted, for example, with the following groups. An alkoxy group having 1 to 24 carbon atoms, preferably 1 to 10, more preferably 1 to 5 carbon atoms (eg, methoxy, ethoxypropoxy, benzyloxy), 1 to 24 carbon atoms, preferably 1 to 10, more preferably 1
To 5 acylamino groups (eg acetylamino, propionylamino, pivaloylamino, methanesulfonylamino, benzoylamino), 1 to 24 carbon atoms,
Preferably 1 to 10, more preferably 1 to 5 acyloxy groups (eg acetyloxy, propionyloxy, benzoyloxy, benzenesulfonyloxy),

An alkoxycarbonyl group having an alkyl group having 1 to 24 carbon atoms, preferably 1 to 10 carbon atoms, more preferably 1 to 5 carbon atoms (eg, methoxycarbonyl group,
(Ethoxycarbonyl, propoxycarbonyl), an N-alkylcarbamoyl group having an alkyl group having 1 to 24 carbon atoms, preferably 1 to 10 carbon atoms, more preferably 1 to 5 carbon atoms (for example, N-methylcarbamoyl, N, N-dimethylcarbamoyl, N). -Ethylcarbamoyl), an acyl group having 1 to 24 carbon atoms, preferably 1 to 10 carbon atoms, more preferably 1 to 5 carbon atoms (eg acetyl, propionyl, pivaloyl, menthasulfonyl, benzoyl),
Further, the above alkyl group may be substituted with, for example, alkoxy, acylamino, acyloxy, alkoxycarbonyl, N-alkylcarbamoyl, or acyl.

An aryl group having 6 to 20 carbon atoms, preferably 6 to 10 carbon atoms (for example, phenyl, tolyl, 1-naphthyl, 2-naphthyl), a 5- to 8-membered, preferably 5- or 6-membered heterocycle (for example, 2- Pyridyl, 3-pyridyl, 4-pyridyl, 2-pyrimidyl, 2-furyl, 3-
Furyl, 2-thienyl, 3-thienyl, 1-pyrrolyl,
1-pyrazolyl, 1-imidazolyl, 1-triazolyl, 1-benzimidazolyl, pyrrolidyl, piperazinyl, morpholinyl), hydroxy group, carboxy group, amino group (for example, amino, methylamino, dimethylamino, cyclohexylamino, n-octylamino) ) And halogen atoms (fluorine, chlorine, bromine, iodine).

Specific examples of the compounds used in the present invention are shown below, but the scope of the present invention is not limited to these.

[0024]

[Chemical 7]

[0025]

[Chemical 8]

[0026]

[Chemical 9]

The synthesis of these compounds is basically possible by adding the amine required for conversion to the ammonium salt to a solution of the compound of the general formula (I) in which Am = H. Therefore, if desired, it is also possible to first form a highly soluble ammonium salt and then add the desired amine. The compound of the general formula (I) in which Am = H can be synthesized by the so-called Knoevenagel reaction. About Knoevenagel reaction, BP Mandy, MG Ellard (BPMundy, MGEllerd), Name Reactions and Reagents
Organic Synthesis (Name Reactions and Reagent
s in Organic Syntesis), John Wiley and Sons, 1988.

As the solvent used in the reaction, water, N, N-
It can be selected from a range from polar solvents such as dimethylformamide (DMF) and dimethylsulfoxide (DMSO) to nonpolar solvents such as benzene and hexane.
Polar solvents such as DMF and N, N-dimethylacetamide, alcohols such as methanol and ethanol, ethers such as tetrahydrofuran and 1,2-dimethoxyethane are preferable, alcohols are more preferable, and mixed solvents of the above are preferable. Can be used.
The reaction temperature can be selected from the range of -80 ° to 150 ° C. A range of -10 ° to 100 ° C is preferred,
The range of 10 ° C to 50 ° C is more preferable.

The compounds according to the invention are, for example, in the form of powders, inclusions of molecules in the host lattice (polymers, inclusion compounds, solid solutions, liquid crystals), in the form of thin layers deposited on a support (Langmere. (Blodgett film etc.), single crystal form, solution form and the like, and can be used as the nonlinear optical material. Further, the compound of the present invention is a polymer in the form of a pendant,
It can also be used by binding to polydiacetylene or the like. For more on these methods, see DJ Williams above.
It is described in the edition of the book.

When the compound of the present invention is used as a wavelength conversion element, for example, the following method is possible. 1. Single crystal of the above compound in the core of the fiber,
It is possible to create a wavelength conversion element using glass as a clad material and input YAG laser light to generate the second harmonic. Further, as another method, it is possible to generate a second harmonic wave by forming a waveguide type wavelength conversion element in the same manner. As the phase matching method at this time, the Thierenkov radiation method is used. However, the present invention is not limited to these, and waveguide-guided phase matching is also possible.

2. Next, the above compound can be made into a single crystal, a bulk single crystal can be cut out therefrom, and a YAG laser beam can be inputted to generate a second harmonic thereof. Angle phase matching is used as the phase matching method at this time. These bulk single crystals can be used not only outside the cavity of the laser but also inside the cavity of a solid-state laser such as an LD pumped solid-state laser to improve the wavelength conversion efficiency. Further, the wavelength conversion efficiency can be improved also by disposing it in the resonator of the external resonator type LD.

For the above single crystallization, the Bridgman method, the solvent evaporation method and the like are used. The wavelength-converted wave is not limited to the second harmonic, but is also used for generating the third harmonic and the sum difference frequency. As a laser light source used as a fundamental wave at the time of wavelength conversion, for example, those shown in Table 1 can be mentioned. The wavelength of the fundamental wave is not limited except for the influence of the absorption of the above-mentioned material. This is what Laser & Optronics 59 does.
It is clear from the page (published in November 1987).

[0033]

[Table 1]

The recording material of the present invention is basically
At the time of reproducing or detecting recording, the presence or absence of recording is detected by the second harmonic of the light with which the recording material is irradiated. The recording material of the present invention basically comprises a substrate and a recording layer, but an undercoat layer may be provided on the substrate and a protective layer may be provided on the recording layer depending on the purpose.

The substrate in the present invention is preferably transparent to the laser used during recording and reproduction and the second harmonic during reproduction. In addition, known ones can be arbitrarily used. Typical examples thereof include glass or plastic, and as the plastic, acrylic, polycarbonate, polysulfone, polyimide, or the like is used. Various shapes such as a disk shape, a card shape, a sheet shape, and a roll film shape are possible.
A guide groove may be formed on the glass or plastic substrate to facilitate tracking during recording. A glass binder or a plastic substrate may be provided with a plastic binder or an undercoat layer such as an inorganic oxide or an inorganic sulfide. An undercoat layer having a lower thermal conductivity than that of the substrate is preferable.

The recording layer of the present invention is divided into a layer composed of the above compound alone or a combination thereof with another material itself, or a layer composed of a reflective layer and a light absorbing layer containing the compound. The recording layer constituted by the compound alone or in combination with other materials, the compound is dissolved in a solvent and applied, a method of vapor deposition on a substrate, a method of applying by mixing with a resin solution,
It is formed by a method of applying a mixed solution with another dye, a method of dissolving and applying it in a resin solution together with another dye, and the like.

As the resin, PVA, PVP, polyvinyl butyral, polycarbonate, nitrocellulose,
Known materials such as polyvinyl formal, methyl vinyl ether, maleic anhydride copolymer, and styrene-butadiene copolymer are used, and the weight ratio of the compound to the resin is preferably 0.01 or more. When other dyes such as triarylmethane dyes, merocyanine dyes, cyanine dyes, azo dyes, and anthraquinone dyes having absorption other than the wavelength range of the semiconductor laser are used together, not only the semiconductor laser but also the He-Ne laser and the like can be obtained. It is suitable because it can be recorded.

In the present invention, this recording layer is one layer or two layers.
Provide more than one layer. The thickness of the recording layer is usually 0.01 μm to 1
μm, preferably 0.08 to 0.8 μm.
In the case of reflection reading, it is particularly preferably an odd multiple of 1/4 of the laser wavelength used for reading. When a reflective layer such as a semiconductor laser or a He-Ne laser is provided, a reflective layer is provided on the substrate, and the recording layer is formed of the above compound alone or in combination with other materials by the above-mentioned method on the reflective layer. Or by providing a recording layer on the substrate and then providing a reflective layer thereon.

The reflective layer can be formed by the following method in addition to the vapor deposition method, the sputtering method, the ion plating method and the like. For example, water-soluble resin (PVP, PV
(A etc.), a metal salt or a metal complex salt is dissolved, and a solution containing a reducing agent is applied to the substrate, and the temperature is 50 ° C to 15 ° C.
It is formed by heating and drying at 0 ° C, preferably 60 ° C to 100 ° C. The weight ratio of the metal salt or metal complex salt to the resin is 0.1-10, preferably 0.5-.
It is 1.5. At this time, the thickness of the recording layer is 0.01 to 0.1 μm for the metal particle reflection layer and 0.0 for the light absorption layer.
A range of 1 to 1 μm is suitable.

As the metal salt or metal complex salt, silver nitrate,
Silver potassium cyanide, potassium gold cyanide, silver ammine complex, silver cyan complex, gold salt or gold cyan complex can be used. As the reducing agent, formalin, tartaric acid, tartaric acid salt, reducing agent, hypophosphite, sodium borohydride, dimethylamine borane and the like can be used. The reducing agent can be used in an amount of 0.2 to 10 mol, preferably 0.5 to 4 mol, per 1 mol of the metal salt or metal complex salt.

When the material of the present invention is used as an optical recording material, information is recorded by irradiating the recording layer with a high energy beam in the form of a spot such as a laser through the substrate or from the side opposite to the substrate. The light absorbed by is converted into heat, and the second harmonic generation rate of the compound in the recording layer changes. When used as a thermal recording material, similar changes occur due to direct heat. Information is read by irradiating a laser beam with a low output below the value energy of recording and detecting it by the change of the second harmonic intensity of the recording part and the non-recording part.

[0042]

EXAMPLES The present invention will now be described in detail based on examples. Example 1 Synthesis of Compound 1 5- (4-methoxybenzylidene) thiazolidine-2,
Isopropanol (25 ml) and triethylamine (1.5 ml) were added to 4-dione (1.0 g), and the mixture was slightly heated to form a uniform solution. Morpholine (2 ml) was added to this solution and the mixture was left at room temperature. Crystals started to precipitate after a few minutes. After standing overnight, the crystals were collected by filtration. Yield 1.2g. Various compounds could be obtained by changing the benzylidene compound or amine depending on the purpose. ¹ H in Table 2 for some compounds
-Indicates NMR data.

[0043]

[Table 2]

Example 2 Measurement of the second harmonic generation was carried out by SK Kurt.
z), by TTPerry, Journal of Applied Physics (J.Appl.Phys.) 3.
According to the method described in Volume 9, page 3798 (published in 1968), the compound 6 of the present invention and the powder of the comparative compound A were used. The measurement was performed by the apparatus shown in FIG. That is, in the measurement, pulsed YAG laser light (λ = 1.064 μm, beam diameter ≈1 mmφ, peak power ≈10 Mw / cm ² ) was used for the fundamental wave, and the second harmonic of the second harmonic was measured by the evaluation device shown in FIG. The strength was measured. The measurement is
Relative comparison with the intensity of the second harmonic of urea. When the strength was weak, visual observation was performed. In particular,
Light emission due to two-photon absorption of the fundamental wave (mainly yellow and red light emission)
In order to distinguish between and the second harmonic, a spectroscope was inserted and only the second harmonic was measured. Further, the measurement by the powder method is mainly for judging the presence or absence of non-linearity of the substance, and the intensity ratio is a reference value of the magnitude of non-linearity. The results are shown in Table 3.

[0045]

[Table 3]

From Table 3, the compound of the present invention is capable of generating the second harmonic by forming an ammonium salt.
It is also clear that the whiteness of the powder is improved. Therefore, it is understood that the compound of the present invention is useful as a nonlinear optical material and capable of wavelength conversion.

Example 3 50 mg of 100 mg of the powder of Compound 1 having a particle size of 100 to 120 μm was placed on a slide glass and heated at 103 to 105 ° C.
After heating for 2 hours, the remaining 50 mg was stored without heating. Heated powder and unheated powder are treated as S.K.
K. Kurtz), TT Perry, Journal of Applied Physics (J.Appl.P)
hys.) Vol. 39, page 3798 (published in 1968), the second harmonic intensity was measured by the apparatus shown in FIG. That is, the measurement was performed using pulsed YAG laser light (λ = 1.064 μm, beam diameter ≈5
mmφ, peak power≈10 Mw / cm ² ) was used as the fundamental wave, and the intensity of the second harmonic was measured by the evaluation apparatus shown in FIG. The measurement was performed by relative comparison with the intensity of the second harmonic of urea. The unheated sample did not generate any second harmonic, whereas the heated sample generated 12 times the second harmonic of urea. This result shows that the material of the present invention can detect the presence or absence of thermal history.

Example 4 Five kinds of samples similar to those in Example 3 were prepared, and 80 ° C. each was prepared.
At 0, 10, 20, 30, 40 minutes.
The second harmonic intensity of the obtained sample was measured in the same manner as in Example 3. As a result, 0, 2, 4, 6, 8 of urea, respectively
It showed double the strength. From this result, it is understood that the material of the present invention can record the thermal history.

Example 5 Exemplified Compound 1 50 mg Dye P 5 mg Polymethylmethacrylate (Amipex B MM Sumitomo Chemical Co., Ltd.) 445 mg Dichloromethane 9.5 g A solution of the above composition was spin coated on a glass plate at 2000 rpm and dried at 40 ° C. A recording layer having a thickness of 0.40 μm was obtained. The recording material thus obtained was irradiated with a He—Ne laser at the irradiation surface at 10 mW and a beam diameter of 10 μm for 10 μs per spot. This recording material was irradiated with a semiconductor laser of 840 nm at the irradiation surface at 5 mW and a beam diameter of 3 μm, and when the second harmonic of 420 nm was detected, it was detected in the recording portion and was not detected in the non-recording portion. Also, 84
When the semiconductor laser of 0 nm was continuously irradiated for 1 hour and then the second harmonic was detected again, the same result as that before the continuous irradiation was obtained. Furthermore, the recording material was stored for one month at a temperature of 60 ° C. and in a room light at a humidity of 90%, but there was no change in recording and reading characteristics.

[0050]

[Chemical 10]

Example 6 A sample was prepared in the same manner as in Example 5 except that Exemplified Compound 1 was replaced with Exemplified Compound 6. Using this, the same experiment as in Example 5 was performed. The same result as in Example 3 was obtained, except that the second harmonic was not detected in the recording portion and was detected in the non-recording portion.

Comparative Example 1 Dye F 50 mg Polymethylmethacrylate (Amipex B MM Sumitomo Chemical Co., Ltd.) 450 mg Dichloromethane 9.5 g The same recording layer was obtained by the same procedure as in Example 5 using the solution having the above composition. 84 for both recording and reading
A 0 nm semiconductor laser was used (recording: 10 m on the irradiation surface
W, beam diameter 10 μm, 10 μsec per location, read:
1 mW on irradiation surface, beam diameter 1.6 μm). Recording and reading were possible when the sample immediately after preparation was used, but recording and reading were not possible with the sample after irradiation with 840 nm light and after storage for 1 month as in Example 5. It was

[0053]

[Chemical 11]

[0054]

From the above examples, the compound of the present invention has a higher blue light transmittance and a sufficient SHG activity as compared with the compounds generally known as organic nonlinear optical materials. I understand. Therefore, the compound of the present invention is considered to be useful as a material for a wavelength conversion element, especially as a material for generating blue light.

However, the application of the non-linear optical material of the present invention is not limited to the wavelength conversion element, and it can be used for any element as long as it utilizes the non-linear optical effect. As specific examples of the element in which the nonlinear optical material of the present invention can be used, in addition to the wavelength conversion element, an optical bistable element (optical storage element, optical pulse waveform control element, optical limiter, differential amplification element, optical transistor, A / D) is used. Conversion element, optical logic element, optical multivibrator, optical flip-flop circuit, etc.), optical modulation element, and phase conjugate optical element. It is also found that the material of the present invention is useful as a recording material.

[Brief description of drawings]

FIG. 1 shows an apparatus for measuring SHG intensity by a powder method.

[Explanation of symbols]

 1 powder sample 2 fundamental wave cut filter 3 spectroscope 4 photomultiplier tube 5 amplifier 6 (11) wavelength 1.064 μm 7 (12) wavelength 0.532 μm

Claims (8)

[Claims] 1. A non-linear optical material containing a compound represented by the following general formula (I). General formula (I) In the formula, Ar represents an aryl group. X represents a chalcogen atom and NR. Am represents an ammonium group. R represents a hydrogen atom, an alkyl group or an aryl group. 2. A compound represented by the following general formula (2).
General formula (2) In the formula, R ¹ represents an alkyl group, and X ¹ represents an oxygen atom or a sulfur atom. Am ¹ represents an ammonium group. 3. A nonlinear optical material containing the compound according to claim 2. 4. A method of converting an optical wavelength using a compound according to claim 1, which has no inversion symmetry as the nonlinear optical material when converting the optical wavelength using a laser beam and a nonlinear optical material. 5. The method for converting a light wavelength according to claim 4, wherein the nonlinear optical material is the material according to claim 3 having no inversion symmetry. 6. A recording material comprising a compound in which the ability to generate a second harmonic appears or disappears due to the formation of a salt. 7. A recording material according to claim 6, wherein the salt of the compound is represented by the following general formula (I).
General formula (3) In the formula, Ar ³ represents an aryl group. X ³ represents a chalcogen atom and N-R ^3. Am ³ represents an ammonium group having at least one hydrogen atom. R ³ represents a hydrogen atom, an alkyl group or an aryl group. 8. The recording material according to claim 7, wherein Ar ³ is 4-alkoxyphenyl and X ³ is an oxygen atom or a sulfur atom.