JPH01522A - Nonlinear optical material and its orientation method - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of the Invention] The present invention relates to nonlinear optical materials, and particularly to nonlinear optical materials suitable for thin film or fiber waveguides and methods for orienting the same.

[Prior art]

Conventionally, K D P and L i are used as nonlinear optical materials.
Inorganic single crystals such as N b 03 and organic single crystals such as urea are known and have been used, for example, in wavelength conversion elements of lasers. However, it is technically difficult to obtain such a sufficiently large single crystal, and it is not possible to obtain one at low cost. To address these problems, attempts have been made to obtain large single crystals in the form of thin films or fibers by vapor deposition methods or zone melting in capillaries (Nayay, B.; AC3
sym, 153 (1983)).

However, in this method, second harmonic generation (SHG) and third harmonic generation (THG), which are nonlinear optical effects, are
) It is not easy to control a single crystal in the phase-matched orientation necessary to efficiently obtain it.

Furthermore, instead of using a single crystal, in order to control the crystal structure, a method is known in which a guest compound with a large nonlinear optical constant is introduced into a host molecule, and an electric or magnetic field is applied to orient the guest compound.

For example, attempts have been made to use polymer liquid crystal as a host and polar molecules as guests to align polar molecules using the electric field orientation of polymer liquid crystal, and SHG has been observed by applying voltage [Meredity G-R etc. [Macromolecules J (Meredity.

G, R, et al; Macromolecule
les, 15.1385, 1982].

In addition, as an example of orienting polar molecules in an amorphous polymer, an azo dye is dissolved in polymethyl methacrylate resin to form a thin film, and then heated above the glass transition point.
By applying a voltage to align the azo dye molecules and cooling to fix the structure, 6X10'''esu
A nonlinear optical constant of 1 is observed. [Singer K.D., Thornjie E., Lalama N.J.
, K.D.

5ohn, J.E., and Lalama, S.J.
; Appl, Phys.

Lett, ) 49.248 pages, 1986].

JP-A-57-45519 discloses that a polymeric nonlinear optical substrate can be obtained by adding a nonlinear optically responsive organic compound to a polymeric compound as a substrate. USP44288
73.

In addition, as described in JP-A-62-84139, there is a nonlinear optical substrate in which an acrylamide resin is used as a host polymer and a nonlinear optically responsive organic compound is used as a guest.

Furthermore, JP-A-62-246962 describes the growth of compounds having asymmetric centers in polyoxyalkylene oxide matrices.

Such polymer-based nonlinear optical materials have excellent processability such as thin film formation while maintaining electronic interactions that produce nonlinear optical effects, and are suitable for device production.

[Problem that the invention seeks to solve]

Generally, as the content of guest molecules in the solid solution increases,
The nonlinear optical effect increases in proportion to the amount, but if a large amount of a low-molecular polar compound as a guest is added to a high-molecular polymer,
For example, it is difficult to homogeneously blend at a molecular level of less than 20% by weight, and defects such as partial phase separation of guest molecules and crystallization may occur.

In addition, such blend polymers tend to have a particularly large content of low-molecular-weight polar guest molecules (when this happens, the polymer itself loses its flexibility and its mechanical strength tends to decrease significantly).

Regarding second-order nonlinear optical effects, even if the polarizability β of a single guest molecule is large, if it is a centrosymmetric crystal, even if mixed with a conventional polymer, there is no SHG activity, or even if it shows only a small amount. . Therefore, it is usually necessary to form a film and apply an electric or magnetic field, or to stretch and orient it.

In particular, in the conventional example, as shown in the report by Singer K. D. et al., the energy of the electric field is small compared to the thermal energy, so even if the electric field is applied to the point of dielectric breakdown, good molecular orientation and large nonlinear susceptibility can be achieved. I couldn't get it.

Further, even if a polymeric nonlinear optical substrate was obtained by adding a nonlinear optically responsive organic compound, the nonlinear susceptibility did not exceed the nonlinear susceptibility of the nonlinear optically responsive organic compound alone.

Furthermore, increasing the energy density of incident light has been considered as a method of obtaining a large nonlinear optical effect as a nonlinear optical element. For this purpose, it is necessary to use a high-energy laser for the incident light or to focus the incident light, and the latter is especially important when applying a semiconductor laser to a nonlinear optical element. Focusing of incident light using thin-film or fiber-like waveguides is particularly suitable for this purpose, and large nonlinear optical effects have been reported (T, Tanluchi, JEE, High Tec
hReport.

November, 93 (1986)). However, in order to obtain such a waveguide, for example, LiNbO3
In this method, Ti and H were diffused and exchanged into a single crystal, which took time and was difficult to control.

[Summary of the invention]

An object of the present invention is to provide a nonlinear optical material that can be applied to a waveguide having a sufficient nonlinear optical constant in place of the conventional expensive single-crystal nonlinear optical material as described above. Furthermore, the object of the present invention is to facilitate thinning of the film.
The object of the present invention is to provide a nonlinear optical material that has sufficient mechanical and optical strength and is suitable for device production.

Therefore, in order to solve the problems of the prior art, the present invention aims to easily and uniformly dissolve a guest organic compound having a large nonlinear polarizability in a host polymer compound, and to The third-order nonlinear optical effect does not deteriorate when blended with the host polymer compound, and it has flexibility even when a large amount of guest organic compound is contained, and has excellent mechanical strength and processability. The object of the present invention is to provide a new nonlinear optical material.

Another object of the present invention is that in the second-order nonlinear optical effect, although β is large, the guest organic compound alone is a centrosymmetric crystal, and the guest organic compound that does not exhibit SHG activity is blended with the host polymer compound. The object of the present invention is to provide a nonlinear optical material that can exhibit large SHG activity.

In other words, the present invention is characterized by a nonlinear optical material containing oriented dielectric compounds having electron-donating substituents and electron-withdrawing substituents in a polyoxyalkylene matrix.

[Detailed description of aspects of the invention]

The polyoxyalkylene used in the present invention is represented by the following formula (1)
It is indicated by.

In the formula (1), R represents an alkylene group having 1 to 6 carbon atoms, and n is 10 to 6.
It is 100,000.

As R, an alkylene group having 1 to 6 carbon atoms can be used, but if the number of carbon atoms is 7 or more, the compatibility with a compound having an electron-withdrawing substituent and an electron-donating substituent decreases, so that an excellent It is not possible to obtain a film with physical properties. Among these, polyoxyalkylene in which R has 2 to 4 carbon atoms is particularly preferred.

The polyoxyalkylene is effective even if it is only a part of the matrix, and can also be used by introducing it into other compounds by copolymerization or by mixing it with other compounds by blending.

Examples of the introduction method by copolymerization include the following.

■Used as a side chain of the main chain polymer.

(-A'+-.

In this case, it is sufficient that polyoxyalkylene represented by (=R-0), is bonded to at least a portion of the main chain represented by +A'P-. It may also have a crosslinked structure.

■Used as a main chain (configuring a repeating unit).

A÷R-0arrow, lB÷R-0shi1. C-R-OE)-,
-...A, B, C... may have the same structure or different structures.

(2) The structures (2) and (2) above constitute a cyclic structure and are used.

More specifically, compounds having polyoxyalkylene include the following.

R, Coo(-R-0ji, 1COOR2(R=C,=C
6 shows an alkylene group. Rj + R2=C3~C2
o represents an alkyl group. n=2-10000) CH.

(Represents an alkylene group where R=C, =C6. R3+ R4
=H or a C8-C2o alkyl group. n' and n
, = 2~l OOOO) HO-(child R,-0,). (:R2C)3-1・-
(Mi R3-Of-Ro・H(R+, R2, R3=
Indicates a C+ to C6 alkylene group.

n, n', n' = 2~100000) 1,000 CH2
-C arrow.

O 0-(-R-0 arrow,, H (represents an alkylene group with R=01 to C6. n = 10
~200000, m = 10~100000, X
represents H-, CH3- or a halogen group. ) (R=C, -C6 alkylene group, n=l O~1
00000R, =C, - CI8 represents an alkylene group, cyclohexylene group, phenylene group, biphenylene group or toluylene group. m = 10~10000)0
.

(R=C,=C6 alkylene group, n=10~],
OO000R, =C, ~CI8 represents an alkylene group, a cyclohexylene group, a phenylene group, a biphenylene group, a terphenylene group, or a toluylene group. m = 10~
1oooo) In addition, the dielectric materials used in the present invention include mono-substituted benzene derivatives, tri-substituted benzene derivatives, tetra-substituted benzene derivatives, mono-substituted biphenyl derivatives, di-substituted biphenyl derivatives, tri-substituted biphenyl derivatives, tetra-substituted biphenyl derivatives, and mono-substituted benzene derivatives. substituted naphthalene derivatives,
Di-substituted naphthalene derivatives, tri-substituted naphthalene derivatives,
Tetra-substituted naphthalene derivatives, mono-substituted pyridine derivatives, di-substituted pyridine derivatives, tri-substituted pyridine derivatives, tetra-substituted pyridine derivatives, mono-substituted pyrazine derivatives, di-substituted pyrazine derivatives, tri-substituted pyrazine derivatives, tetra-substituted pyrazine derivatives, mono-substituted pyrimidine derivatives, Di-substituted pyrimidine derivatives, tri-substituted pyrimidine derivatives, tetra-substituted pyrimidine derivatives, mono-substituted azulene derivatives, di-substituted azulene derivatives, tri-substituted azulene derivatives, tetra-substituted azulene derivatives, mono-substituted pyrrole derivatives, di-substituted pyrrole derivatives, tri-substituted pyrrole derivatives, Tetra-substituted virol derivatives, mono-substituted thiophene derivatives, di-substituted thiophene derivatives, tri-substituted thiophene derivatives, tetra-substituted thiophene derivatives, mono-substituted furan derivatives, di-substituted furan derivatives, tri-substituted furan derivatives, tetra-substituted furan derivatives, mono-substituted pyrylium salt derivatives , di-substituted triazine derivatives, tri-substituted pyrylium salt derivatives, tetra-substituted biryllium salt derivatives, mono-substituted quinoline derivatives, di-substituted quinoline derivatives, tri-substituted quinoline derivatives, tetra-substituted quinoline derivatives, mono-substituted pyridazine derivatives, di-substituted pyridazine derivatives, tri-substituted Pyridazine derivatives, tetra-substituted pyridazine derivatives, mono-substituted triazine derivatives, di-substituted triazine derivatives, tri-substituted triazine derivatives, mono-substituted tetrazine derivatives, di-substituted tetrazine derivatives, mono-substituted anthracene derivatives, di-substituted anthracene derivatives, tri-substituted anthracene derivatives, tetra-substituted Anthracene derivatives can be used.

Electron-donating substituents bonded to these dielectrics include:
Amino group, alkyl group (methyl, ethyl, isopropyl, n-propyl, n-butyl, t-butyl, 5eC-butyl, n-octyl, t-octyl, n-hexyl, cyclohexyl, etc.), alkoxy group (methoxy, ethoxy , propoxy, butoxy), alkylamino (N
-methylamino, N-ethylamino, N-propylamino, N-butylamino, etc.), hydroxyalkylamino groups (N-hydroxymethylamino, N-(2-hydroxyethyl)amino, N-(2-hydroxypropyl) amino, N-(3-hydroxypropyl)amino, N-(4-hydroxy)butylamino, etc.),
dialkylamino group (N, N-dimethylamino, N, N
-diethylamino, N, N-dipropylamino, N, N
-dibutylamino, N-methyl-N-ethylamino, N
-methyl-N-propylamino), hydroxyalkyl-alkylamino groups (N-hydroxymethyl-
N-methylamino, N-hydroxymethyl-N-ditylamino, N-hydroxymethyl-N-ethylamino, N-(2-hydroxyethyl)-N-methylamino, N-(2-hydroxyethyl)-N- methylamino, N-(3-hydroxypropyl)-N-methylamino, N-(2-hydroxypropyl)-N-ethylamino, N-(4-hydroxybutyl)-N-butylamino, etc.), dihydroxyalkyl Amino group (N
.

N-dihydroxymethylamino, N, N-di(2-
hydroxyethyl)amino, N, N-di(2-
hydroxypropyl)amino, N,N-di(3-hydroxypropyl)amino, N-hydroxymethyl-
(N-(2-hydroxyethyl)amino, etc.), mercapto group, hydroxy group, or proton group, and as the electron-withdrawing substituent, nitro group,
A cyano group, a halogen atom (chlorine atom, bromine atom), trifluoromethyl group, carboxyl group, carboxyester group, carbonyl group or sulfonyl group can be used.

Specific examples of dielectric compounds used in the present invention are shown below.

(1) 3-nitro-4-hydroxy-3-sodiumcarboxyazobenzene (2) 4-chloro-2-phenylquinazoline (3
) Urea (4) Aminoacetonitrile (5) Aminoacetophenone (6) Aminoacridine (7) Aminoadipic acid (8) Aminoanthracene (9) Aminobiphenyl (10) 2-Amino-5-bromobenzoic acid (11) ) 1-amino-4-bromo-2-methylanthraquinone (12) 1-amino-4-bromonaphthalene (13) 2-amino-5-bromopyridine (14) Aminobutyric acid (15)
Aminochlorobenzene sulfonic acid (16
) 2-amino-4-chlorobenzoic acid (
17) 2-amino-5-chlorobenzoic acid (18) 3-amino-4-chlorobenzoic acid (19) 4-amino-2-chlorobenzoic acid (20) 5-amino-2-chlorobenzoic acid Acid (21) 2-amino-5-chlorobenzonitrile (22) 2-amino-5-chlorobenzophenone (23) Amino-chlorobencitrifluoride (24) 3-amino-6-chloromethyl-2-pyrazine carbonitrile -4-oxide (25) 2-amino-4-chloro-6-methylpyridine (26) l-amino-4-chloronaphthalene (27) 2-amino-3-chloro-1,4-naphthoquinone (28) 2 -amino-4-chloro-5
-Ditrophenol (29) 2-Amino-4-chloro-5-nitrotoluene (30) 2-Amino-
4-chloro-4-phenol (31) N -(2
-amino-4-chlorophenyl) anthranic acid (32) 2-amino-5-chloropurine (33)
2-amino-5-chloropyridine (34)
3-amino-2-chloropyridine (35) 5-amino-2-chloropyridine (36) Aminochrysene (37) 2-amino-p-cresol (38)
3-amino-p-cresol (39) 4-amino-p-cresol (40) 4-amino-m-
Cresol (41) 6-amino-m-cresol (42) 3-aminocrotonitrile (43)
6-Amino-3-cyano-2,4-dimethylpyridine (44) 5-amino-6-dia-2-pyrazinyl acetate (45) 4-[N (2-methyl-3-cyano-5-pyrazinylmethyl) Aminocobenzoic acid (46) 3,5-dinitroaniline (47)
4 (2,4-dinitroanilino)phenol (48
) 2,4-dinitroanisole (49) 2
．． 4-Dinitrobenzaldehyde (50) 2.6
-Dinitrobenzaldehyde (51) 3.5-Dinitrobenzamide- (52) 1.2-Dinitrobenzene (53) 1.3-Dinitrobenzene (5
4) 1,4-dinitrobenzene (55) 3
．． 4-Dinitrobenzoic acid (56) 3
．． 5-Dinitrobenzoic acid (57) 3
．． 5-Dinitrobenzonitrile (58) 2.6-
Dinitro-p-cresol (59) 4.6-sinitro-cresol (60) 2.4-dinitrodiphenylamine (61) Dinitrodurene (62) 2.4-dinitro-N-ditylaniline (63) 2.7 -Sinitrofluorene (64)
2.4-dinitrofluorobenzene (65)
1.3-Dinitronaphthalene (66) 1.5-Dinitronaphthalene (67) 1.8-Dinitronaphthalene (68) 2.4-Dinitrophenol (6
9) 2,5-dinitrophenol (70)
2.4-dinitrophenylhydrazine (71) 3
．． 5-Dinitrosalicylic acid (72) 2
．． 3-dinitrotoluene (73) 2,4-dinitrotoluene (74) 2,6-dinitrotoluene (
75) 3,4-dinitrotoluene (76)
9-nitroanthracene (77) 4-nitroanthranic acid (78) 2-amino-5-trifluoromethyl-1,3,4-thiazole (79)
7-amino-4-(trifluoromethyl)-coumarin (80) 9-cyanoanthracene (81)
3-cyano-4,6-dimethyl-2-hydroxypyridine (82) 5-cyanoindole (83) 2-cyano-6-methoxybenzothiazole (84) 9-cyanophenanthrene (85)
Cyanolic chloride (86) 1.2-
Diaminoanthraquinone (87) 3.4-Diaminobenzoic acid (88) 3.5-Diaminobenzoic acid (89) 3.4-Diaminobenzophenone (90) 2.4-Diamino-6
-(hydroxymethyl)pteridine (91) 2
．． 6-Diami2-4-nitrotoluene (92) 2
．． 3-dicyanohydroquinone (93) 2.4-
Dinitroaniline (94) 2,6-Dinitroaniline (95) 2-Amino-5-iodobenzoic acid (96) Aminomethanesulfonic acid (97) Aminomethoxybenzoic acid (98) 2-Amino-4-methoxy Benzothiazole (99) 2-amino-6-methoxybenzothiazole (100) 5-amino-2-methoxyphenol (101) 5-amino-2-methoxypyridine (102) 2-amino-3-methylbenzoic acid ( 103) 2-amino-5-methylbenzoic acid (104) 2-amino-6-methylbenzoic acid (105) 3-amino-4-methylbenzoic acid (106) 4-amino-3-methylbenzoic acid (107)
2-amino-4-methylbenzophenone (108)
7-amino-4-methylcoumarin (109) 3-amino-5-methylisoxazole (110) 7-
The second-order micro-nonlinear optical constant (β) of amino-4-methyl-1,8-naphthyridin-2-ol is ω (ng)
: Energy difference between the ground and excited states h Ni blank constant r l (gn) : Base and excited state quantity dipole matrix element e : Electronic charge Δmouth (n) = rl (curve) r! (gg) (Ward, J, F,; Review of
Modern Physics, Volume 37, Page 1,
(1965), compounds with large dipole moments are effective, but in general, compounds with large dipole moments tend to have centers of inversion symmetry in their crystal structures;
In most cases, SHG is not observed.

On the other hand, when polyoxyalkylene is used in the nonlinear optical element of the present invention, it is possible to obtain a nonlinear optical effect.

Therefore, in the present invention, the center of inversion symmetry of a compound having such a large dipole moment can be removed by the presence of a polyoxyalkylene matrix. This cancellation of the center of inversion symmetry is thought to be because polyoxyalkylene forms a helical structure in its crystalline state, and the dielectric compound described above is uniaxially oriented between the helices.

Because the dielectric compound interacts with the helical structure of the polyoxyalkylene matrix and is uniaxially oriented, phase separation and non-conformity occur even when a large amount of the aforementioned dielectric compound is contained. Does not cause uniform crystallization. Similarly, since the helical structure of the polyoxyalkylene matrix is maintained, the nonlinear optical material of the present invention has good flexibility and mechanical strength, and is suitable for use in the form of a thin film or fiber.

In addition, in the nonlinear optical material of the present invention, the polyoxyalkylene matrix and the dielectric compound have a special orientation due to interaction, and the above-mentioned meridian G.R. It is possible to obtain a high degree of orientation, which cannot be obtained in principle in the reports of Koro and Singer K.D., and it becomes possible to develop extremely excellent nonlinear optical effects.

As such an alignment treatment method, the aforementioned polyoxyalkylene matrix and dielectric compound are heated above their melting point, which is a temperature at which no interaction occurs, and an electric field is applied in the same direction as the optical electric field of the incident light used for the nonlinear optical effect. It is desirable to cool down to below the melting point. At this time, the rate of interaction between the polyoxyalkylene matrix and the dielectric compound is reduced to 100 degrees/see or less, more preferably 10 degrees/sec or less, so that the interaction with the electric field is maximized. By doing so, an extremely excellent nonlinear optical effect can be obtained.

Figure 1 shows typical model examples of the composition dependence under a constant electric field and the electric field dependence at a constant composition when the polyoxyalkylene matrix and the above-mentioned dielectric compound interact and are oriented. Shown in the second recapture.

In the nonlinear optical material of the present invention, by such a treatment method, it is possible to form an electron-donating substituent and an electron-withdrawing substituent (
By aligning the dipole moment of the table force in the direction of the electric field, it becomes possible to align the largest micro-nonlinear optical constant β perpendicularly to the film plane, and as a thin film waveguide,
The nonlinear optical effect can be used most effectively.

Similarly, molecular alignment can be obtained by applying a magnetic field above the melting point and cooling to below the melting point. Further, stretching treatment is also effective for orientation.

The nonlinear optical element of the present invention can be obtained by adding a compound having an electron-donating substituent and an electron-withdrawing substituent to a polyoxyalkylene solution, casting the homogeneous solution, and then drying it. At this time, by heating to 40 to 120°C, a good film is obtained in which the compound having an electron-donating substituent and an electron-withdrawing substituent and the polyoxyalkylene do not separate.

Further, better performance can be obtained by applying a direct current electric field to this film at a temperature above the melting point and cooling it to below the melting point while the field is being applied. As a method of applying a DC electric field, electrodes may be provided on both sides of the film, or corona discharge or the like may be used.

FIG. 1 is a sectional view of a nonlinear optical element 1 according to the present invention. In the figure, 11 is a substrate made of glass, plastic, etc.
A lower electrode 12 is made of a conductor such as ITO (indium tin oxide), tin oxide, indium oxide, gold, silver, copper, or aluminum. 13 is a low refractive index layer which can be formed of an organic thin film or an inorganic thin film, and specifically, vinylidene fluoride-trifluoroethylene copolymer, 5i02, etc. are used. 14 is a waveguide formed of the nonlinear optical material of the present invention. Reference numeral 15 denotes an upper electrode made of aluminum.

The wavelength λ towards the nonlinear optical element l according to the invention.

When a laser with a wavelength of λo/2 is oscillated from the laser light source 16, a laser with a wavelength of λo/2 is output from the nonlinear optical element l. In addition, FIG. 17 shows an optical modulation device such as an optical switching element or an optical knitting device, and 18 is a condenser lens.

The present invention will be explained in detail below.

[Example 1] MEK of vinylidene fluoride-trifluoroethylene copolymer was applied to a glass substrate sputtered with ITO.
(Methyl ethyl ketone) solution (5 wt%) was spin-coded and evaporated to dryness. 1.03 g (23 mmol) of polyoxyethylene with a molecular weight of 5 million and 2-
Methyl-4-nitroaniline 0.30g (2mmo'
1) was dissolved in 10 ml of benzene for 5 hours, spin-coded, and evaporated to dryness while maintaining the temperature at 60 to 80°C. A uniform film was obtained. Furthermore, aluminum was vapor-deposited to obtain a waveguide type nonlinear optical element. This element is 8
The temperature was raised to 0°C, and an electric field was applied to the ITO electrode and the aluminum electrode while cooling at room temperature. This nonlinear optical element has N
When d-YAG laser (wavelength 1.064 μm) was focused and irradiated, the second harmonic of light (wavelength 0.532 μm) was detected.
The occurrence of was observed using a photomultiplier.

[Example 2] Molecular fi on a glass substrate with aluminum vapor deposited
5 million polyoxyethylene 2.03g (40mm
ol) and 0.38 g of 1-amino-4-nitronaphthalene
(2 mmol) was dissolved in 5 ml of benzene for 5 hours, spin-coded, and evaporated to dryness while maintaining the temperature at 60 to 80°C, resulting in a uniform film. Furthermore, aluminum was vapor-deposited to obtain a waveguide type nonlinear optical element. This device was heated to 80° C. and cooled to room temperature while applying an electric field to the upper and lower aluminum electrodes. When this nonlinear optical element was focused and irradiated with a Nd-YAG laser (wavelength: 1.064 μm), the second harmonic of light (wavelength: 0.532 μm) was detected.
The occurrence of m) was observed using a photomultiplier.

[Example 3] A MEK solution (5 wt %) of vinylidene fluoride-tetrafluoroethylene copolymer was spin-coded onto a glass substrate on which aluminum was vapor-deposited and evaporated to dryness. To this glass substrate, polyoxyethylene 1 with a molecular weight of 5 million,
03 g (23 m mol) and 2,4-dinitrophenylhydrazine 0,20 g (1 m mol)
1) was dissolved in 10 ml of acetonitrile, spin-coded, and evaporated to dryness while maintaining the temperature at 60 to 80°C. A uniform film was obtained. Furthermore, aluminum was vapor-deposited to obtain a waveguide type nonlinear optical element. When this element was heated to 80°C and an electric field was applied to the upper and lower aluminum poles, a focused Nd-YAG laser (wavelength 1.064 μm) was irradiated onto this nonlinear optical element. (wavelength: 0.532 μm) was observed using a photomultiplier.

Furthermore, after this nonlinear optical element was cooled to room temperature and the electric field was removed, it was irradiated with an Nd-YGA laser, and optical second harmonics were similarly observed.

[Example 4] Polyethylene glycol distearate having an average molecular weight of 1500 as shown below 1. Og and PCOO(CH
2CH20) nCOORR=Nistearate Manufactured by Kao ■
Emanone 3299 and 0.2 g of 4-nitro-4'-iodobiphenyl
0mj! of methanol and heated to dissolve for 1 hour.

Cast this solution on a Petri dish to a thickness of approximately 200 μm.
A uniform film of m was obtained.

Aluminum foil was closely attached to both sides of this film, and while applying a DC electric field of 1000 V, the temperature was raised to 80° C. and slowly cooled to room temperature. Remove the electrode from this film and
When irradiated with a -YAG laser (wavelength: 1.064 .mu.m), the generation of optical second harmonics (wavelength: 0.532 .mu.m) was observed using a photomultiplier with an intensity about three times that of urea produced by the powder method.

[Example 5] 1.0 g of a polyethylene glycol derivative with an average molecular weight of 345 as shown below and 0.2 g of H3 NOF DA-350F 4-methoxy-4''-cyanoterphenyl were added to 20 rrl of ethanol. The mixture was heated and dissolved for 1 hour.

Cast this solution on a Petri dish to a thickness of approximately 200 μm.
A uniform film was obtained.

Aluminum foil was closely attached to both sides of this film, and while applying a DC electric field of 1000 V, the temperature was raised to 80° C. and slowly cooled to room temperature. Remove the electrode from this film and
- When a YAG laser (wavelength: 1.064 μm) was irradiated, the generation of optical second harmonics (wavelength: 0.532 μm) was observed using a photomultiplier with an intensity approximately 4 times that of urea produced using the powder method. .

[Example 6] 1.0 g of a block copolymer of ethylene oxide and propylene oxide as shown below: HO÷c2H4o), 1(C3Ha 0)Ill (
C2H40) It H Molecular weight M = 3250 Echopol PE-68 manufactured by Sanyo Kasei and 2-(4'-aminophenyl)5.6 dicyanol 1
゜4 Pyrazine 0.2g with 20ml benzene and 10ml
j' was heated and dissolved in a mixed solvent of methanol.

Cast this solution on a Petri dish to a thickness of approximately 100 μm.
A uniform film was obtained.

Aluminum foil was closely attached to both sides of this film, and the temperature was raised to 80° C. while applying a DC electric field of 1000 V, and then slowly cooled to room temperature. The electrodes of this film were removed and Nd-
When irradiated with a YAG laser (wavelength: 1.064 pm), the generation of an optical second harmonic (wavelength: 0.532 .mu.m) was observed using a photomultiplier with an intensity about twice that of urea produced by the powder method.

[Example 7] 1.0 g of polyoxyethylene with a molecular weight of 5 million, 0.25 g of butyral resin (BL-1 manufactured by Block Chemical Co., Ltd.), and l-
Amino-4-nitronaphthalene 0.25 g to 20mj
! of benzene and 10 m j! was heated and dissolved in a mixed solvent of methanol.

Cast this solution on a Petri dish to a thickness of approximately 200 μm.
A uniform film was obtained.

Aluminum foil was attached to both sides of this film, and the temperature was raised to 80°C while applying a DC electric field of 1000V, and then cooled to room temperature.The electrodes of this film were removed and the Nd-
When irradiated with a YAG laser (wavelength: 1.064 .mu.m), generation of optical second harmonics (wavelength: 0.532 .mu.m) was observed using a photomultiplier with an intensity about three times that of urea produced by the powder method.

[Example 8] 1.0 g of polyoxytetramethylene glycol with a molecular weight of 3000 (manufactured by Sanyo Chemical Co., Ltd. PTMG3000) and 0.2 g of 2methyl-4-nitroaniline were mixed with 30 ml of benzene and lomj! was heated and dissolved in a mixed solvent consisting of methanol.

Cast this solution on a Petri dish to a thickness of approximately 300 μm.
A uniform film was obtained.

Aluminum foil was closely attached to both sides of this film, and while applying a 1000V DC electric field, the temperature was raised to 70°C and slowly cooled to 5°C.The electrodes of this film were removed and the Nd
When irradiated with -YAG laser (wavelength: 1.064 pm), the second light beam was about 5 times more intense than urea produced by the powder method.
Generation of harmonics (wavelength: 0.532 μm) was observed using a photomultiplier.

[Explanation of effects]

As described above, the nonlinear optical element of the present invention makes it possible to form a thin film-like or fiber-like waveguide using a very simple method.

Furthermore, the nonlinear optical element of the present invention makes it possible to obtain a large nonlinear optical effect with a simple configuration as described above.

The above effects have facilitated the application of nonlinear optical elements to optical integrated circuits and optoelectronic integrated circuits.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a nonlinear optical element according to the present invention. Figures 1 and 2 are diagrams for explaining the composition dependence of nonlinear optical effects. FIG. 1 is a diagram illustrating the electric field dependence of the nonlinear optical effect.

Claims (4)

[Claims] (1) A nonlinear optical material characterized by containing a compound having an electron-donating substituent and an electron-withdrawing substituent in a polyoxyalkylene matrix. (2) the electron donating substituent is an amino group, an alkyl group,
Nonlinear optics according to claim 1, which is an alkoxy group, an alkylamino group, a hydroxyalkylamino group, a dialkylamino group, a hydroxyalkyl-alkylamino group, a dihydroxyalkylamino group, a mercapto group, a hydroxy group, or a proton group. material. (3) the electron-withdrawing substituent is a nitro group, a cyano group, a halogen atom, a trifluoromethyl group, a carboxyl group,
The nonlinear optical material according to claim 1, which is a carboxyester group, a carbonyl group, or a sulfonyl group. (4) A nonlinear optical material in which a polyoxyalkylene matrix contains a compound having an electron-donating substituent and an electron-withdrawing substituent is heated above the melting point, and cooled to below the melting point while applying a DC electric field. Orientation processing method for nonlinear optical materials.