JPH02156229A - Nonlinear optical material - Google Patents

Abstract

PURPOSE:To obtain the novel nonlinear optical material which exhibits a high nonlinear optical effect by using a specific carbonyl amidine deriv. CONSTITUTION:The nonlinear optical material useful for electrooptical devices, second harmonic wave generating devices, piezoelectric devices, light guides, etc., or optical memory light sources, laser printer light sources, optical switches, etc., consists of the compd. expressed by formula I. In formula I, Ar1 to Ar3 may be the same or different and denote a substd. or unsubstd. aryl group or arom. group contg. a substd. or unsubstd. hetero atom. The novel high- performance nonlinear optical material is obtd. in this way.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an electro-optical device, a second harmonic generation device,
The present invention relates to novel nonlinear optical materials useful for piezoelectric devices, guiding waveguides, etc., pre-memory light sources, laser printer light sources, optical switches, etc.

[Prior Art] In recent years, materials that exhibit the nonlinear optical effect - a phenomenon in which when intense laser light is incident on a material, an emitted light with a different component from the incident light is obtained due to the interaction - have attracted attention. There is. Such materials are generally known as nonlinear optical materials and are described in detail in, for example:

'Non1iner 0ptical Prope
rties ol' Organicand Po
Lymeric Materials'A CS S
YMPO8IUM! 1ilERIEs 233. Dav
Edited by ld J, Willa Ils (AmericanC
hemlcal S'ociety, published in 1983),
"Organic Nonlinear Optical Materials" edited by Masao Kato and Hebe Nakanishi (CMC Publishing Co., Ltd., 1983); "Organic Electronic Materials" edited by Akio Taniguchi (Science Forum Publishing Co., Ltd., 1983).
(published in 1986).

One of the applications of nonlinear optical materials is second harmonic generation (SHG) based on second-order nonlinear optical effects and wavelength conversion devices using sum frequency and difference frequency. Potassium dihydrogen phosphate (K
DP), ammonium dihydrogen phosphate (ADP), lithium niobate, and the like. However, in recent years, it has become known that π-electron conjugated organic compounds having an electron-donating group and an electron-withdrawing group have various performances as nonlinear optical materials that far exceed those of the above-mentioned inorganic materials.

Generally, in the case of H-ring compounds, each molecule exhibits a nonlinear optical response, and the nonlinear optical performance of the molecule is determined by its molecular hyperpolarizability: β (molecular hyperpolarizability).
Although it depends on the size of P-nitroaniline, even if it exhibits high second-order nonlinear performance in the molecular state (i.e., even if it has a large β), it will not crystallize. Due to the central symmetry of the molecular arrangement, many molecules do not exhibit any second-order nonlinear optical effects in the crystalline state. In addition, a methyl group was introduced at the ortho position of this P-nitroaniline, and the performance of the molecule (i.e., β
MNA (2-methyl-4-nitroaniline), which succeeded in reducing the symmetry of the crystal without decreasing the size of the
I have a large SHG tensor d I+, but [B, P
, Levlne et al., J.

Appl, Phys, 50.2523 (I970)],
Since this component does not satisfy the phase matching condition for efficiently extracting SHG, it is difficult to effectively utilize this large nonlinear optical performance.

Furthermore, single crystal MNA is difficult to obtain (there are many problems in applying it as a device).

In addition, asymmetric carbon atoms are introduced into known SHG active skeletons [
J, L, Oudar, et al, J, Appl Ph.
ys, 48°2899 (I977)], and methods such as dispersing high-performance molecules in polymers and poling them using an electric field (Japanese Patent Application Laid-Open No. 61-186942) have not necessarily yielded good results. Not yet.

[Problems to be Solved by the Invention] In view of the above circumstances, an object of the present invention is to provide a novel nonlinear optical material that exhibits high nonlinear optical effects.

[Means for Solving the Problems] The present inventors have conducted extensive research in order to solve the above problems, and have discovered that a specific carbonylamidine derivative is effective, leading to the present invention.

That is, the present invention is a nonlinear optical material characterized by comprising a compound represented by the following general formula (I).

General formula <1) (In the formula, Arc, Arz, and Ar3 may be the same or different and represent a substituted or unsubstituted aryl group or a substituted or unsubstituted aromatic group containing a heteroatom) The above aryl Examples of the group include a phenyl group, a naphthyl group, an anthryl group, etc., and examples of the aromatic group containing a hetero atom include a pyrrolyl group, a pyridyl group, a pyridazinyl group, a quinolyl group, and the like.

Further, as substituents for the above-mentioned aryl group and aromatic group containing a heteroatom, for example, a dialkylamino group, a diarylamino group, an alkoxy group, an aryloxy group, a hydroxy group, an alkylthio group, an arylthio group, a mercapto group, an alkyl group, Examples include a halogen atom, a carboxyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, a cyano group, and a nitro group.

Next, preferred examples of compounds in the present invention are shown below. However, the present invention is not limited to these.

[Compound Examples] - Can be obtained by the method published in 1155 (I985).

[Example] The present invention will be explained in more detail according to examples.

N,N'-dibenzoylbenzamidine (Compound Example 1)
Preparation of 100 mg of monobenzoylbenzamidine is dissolved in 51 of benzene and 100 B of benzoic anhydride is added. The solution is refluxed for 2.1 hours and the solvent is removed under reduced pressure using a rotary evaporator. The residue was recrystallized from ethanol to obtain 74 mg of colorless crystals with a melting point of 139-140°C.

Preparation of N,N'-dibenzoyl-P-dimethylaminobenzamidine (Compound Example 2) When N-benzoyl-P-dimethylamino-benzamidine and benzoic anhydride were synthesized in the same manner as in Compound Example 1, the melting point was 177-178. Orange needle-shaped crystals were obtained.

Chemical Example 1. The nonlinear optical performance of the compound of 2nd grade was measured.

There are various nonlinear optical effects exhibited by nonlinear optical materials, but if we focus on second harmonic generation (SHG), which is a typical second-order nonlinear optical effect, SHG
It is obvious that materials with high performance can be widely used in the above-mentioned SHG devices, electro-optical devices, and the like.

Therefore, we define the n1 constant of the SHG performance of the present invention as S, and K
urtz and T, T, Perry are J, Appl, phy
s.

39.3798 (I968).

In this method, the compound powder to be measured is irradiated with a strong laser tip, and the intensity of the generated SHG is measured at 71p1 compared to the reference material.
This is a method for estimating the approximate second-order nonlinear performance.

We used a high-power Nd":YAG laser (250 mJ/pulse, pulse width ~20 ns) as the light source laser. (The oscillation wavelength of the Nd":YAG laser is 1.0
84 μm, and when this light is irradiated onto an SHG-active material, 532 nm green SHG is obtained) SHG from the sample filled in the quartz glass cell is scattered both forward and backward with respect to the laser beam traveling direction. Since it is observed,
SHG intensity was measured on both the anterior and posterior sides. The detector at this time was a photomultiplier tube, the laser beam was cut with an infrared absorption filter, and only the 5320- SHG was taken out with an interference filter.

At this time, the particle size of the sample was not sieved, and (zero NH
As is clear from the examples, the compound of the present invention is effective as a nonlinear optical material. For example, by forming this material into an ili product, it can be used in an SHG device as shown in Figure 1. Can be applied.

[Effects] As explained above, the present invention makes it possible to provide a novel high-performance nonlinear optical material.

[Brief explanation of the drawing]

FIG. 1 is a diagram schematically showing an example of an SHG device using the nonlinear optical material of the present invention. ■...Semiconductor laser, 2...Single crystal of the material of the present invention.

Claims (1)

[Claims] A nonlinear optical material comprising a compound represented by the following general formula (I). General formula (I) ▲ Numerical formulas, chemical formulas, tables, etc. (represents an aromatic group containing)