JP2584680B2 - Organic nonlinear optical material - Google Patents

Description

The present invention relates to an organic nonlinear optical material. More specifically, the present invention relates to an organic nonlinear optical material composed of a phthalocyanine derivative suitable for use in optical elements such as wavelength conversion, optical operation, optical shutter, optical memory, and the like.

[Prior Art] The polarization P induced when light passes through a substance is as follows: When the electric field of light is E, P = χ ⁽¹⁾ E + χ ⁽²⁾ E · E + χ ⁽³⁾ E · E · E +... (1) It is expressed as The first term is called linear polarization, and the second and subsequent terms are called nonlinear polarization. The coefficient χ ⁽ⁿ⁾ (n ≧ 2), which is a measure of the magnitude of the polarization induced at this time, is an nth-order nonlinear susceptibility, and the effect from the polarization based on the term including χ ⁽ⁿ⁾ is the nth order This is called the nonlinear optical effect. χ ⁽ⁿ⁾ is a coefficient that quantitatively expresses the nonlinear optical effect by the (n + 1) th order tensor.
In general, χ ⁽²⁾ , χ ^{(3) and the} like are very small. When the electric field E of the light is small, only the linear effect based on the first term of the equation (1) is recognized, but χ ⁽²⁾ , χ ^{( In} the case of a material having a large value of ^3), a second-order or higher order term cannot be ignored under a strong electric field such as a laser beam, and as a result, a nonlinear optical response appears. The second-order nonlinear optical effects include second harmonic generation (SHG), optical rectification,
Such as parametric amplification and Pockels effects,
Third-order nonlinear optical effects include third harmonic generation, DC induced SHG, Kerr effect, and optical bistability.

Nonlinear optical materials exhibiting these phenomena are being studied for application to new optoelectronic devices. In particular, optical bistability is a case where there are two types of output light that take a stable value with respect to one state of the incident light, and which of the two types is taken is determined by the history of the system. You. That is, hysteresis exists between the two states, and this phenomenon is expected to be applied to optical switches, optical storage elements, optical logic elements, and the like.

Non-linear optical materials having the above properties are described in detail in, for example, the following literature.

`` Nonlinear Optical Properties of Organic Molecu
les and Crystals ”DSChemla, J. Zyss (ACADEMIC PRES
S, INC., 1987), "Organic Nonlinear Optical Materials", edited by Masao Kato and Hachiro Nakanishi (CMC, Inc., 1985) The search for tertiary nonlinear optical materials is thriving in both inorganic and organic compounds. It is being done. Semiconductors such as gallium arsenide and Group III-V compounds are known as inorganic materials. Organic materials reported so far are mainly π-conjugated polymers, and polydiacetylene, polysilane, polyimide, polyacetylene, polythiophene and the like are known. In particular, a kind of polydiacetylene called PTS {2,4-hexadiyne-1,6-bis (p-toluenesulfonate)} is currently known as an organic material having the highest third-order nonlinear susceptibility. Stilbene derivatives (JP-A-1-273022);
Also disclosed are materials in which a π-conjugated compound having a cation in a molecule is dispersed in an ionic polymer (JP-A-1-217328, JP-A-1-217329, etc.). Other organic materials include unsubstituted or alkoxy-free metal-free or metal phthalocyanines (JP-A-1-237626).
No.) is also disclosed. This organic material has a wavelength of 1907 nm
The third harmonic intensity when irradiating the light is smaller than that of the PTS.

In general, in an organic material, the nonlinear response is caused by π electrons in a molecule that is easily polarized. On the other hand, in inorganic materials, electrons related to lattice coupling respond to light. For this reason, the destruction threshold for laser light is larger in an organic material than in an inorganic material. The response speed of inorganic materials does not exceed picoseconds, whereas the response speed of organic materials is as fast as femtoseconds.

For inorganic materials, the third-order nonlinear susceptibility is 10 ^-2 to 10 ^-5 es
u is large but response is slow, about 10GHz. On the other hand, organic materials having a third-order nonlinear susceptibility exceeding 10 ⁻⁸ esu are not known, but have an advantage that a high-speed response of several tens of GHz or more is possible.

When a nonlinear optical material is used for an optical switch, an optical logic element, or the like, high-speed response is an indispensable characteristic. In this sense, the importance of the organic nonlinear optical material in these optical-related technologies is high.

[Problems to be Solved by the Invention] The tertiary organic nonlinear optical materials known so far are characterized by a structure in which π-conjugated systems are linearly or cyclically connected. However, with regard to the nonlinear optical properties, there is no known non-linear optical property exhibiting properties higher than that of PTS, which is a kind of polydiacetylene. Even the PTS has a problem that it is difficult to form a thin film, which is extremely important in making an optical material into an element. In addition, it has a problem that it is easily oxidized and thus unstable in air or thermally unstable.

An object of the present invention is to exhibit nonlinear optical characteristics equal to or higher than that of an existing organic nonlinear optical material, and to be difficult to form a thin film of an existing organic material in practical use, to be unstable to air, heat, and the like. It is an object of the present invention to provide a novel organic nonlinear optical material that solves the above problem.

[Means for Solving the Problems] The present invention provides a compound of the formula [I] Wherein R represents an aliphatic hydrocarbon group having 4 to 24 carbon atoms, and M represents a metal atom or a hydrogen atom which may have a halogen atom or an oxygen atom. The present invention provides an organic nonlinear optical material containing:

The present invention has found that the phthalocyanine of the formula [I] has a third-order nonlinear susceptibility equal to or higher than that of an existing organic nonlinear optical material, and does not have any problems that the existing material has at the time of practical use. It is completed.

In the present invention, examples of the aliphatic hydrocarbon group having 4 to 24 carbon atoms (R) include an n-butyl group, an n-pentyl group, and an n-butyl group.
Linear hydrocarbon groups such as hexyl group, n-heptyl group, n-octyl group and n-nonyl group; branched hydrocarbon groups such as sec-butyl group, t-butyl group and neo-pentyl group; cyclohexyl group And the like, or a combination of these hydrocarbon groups.

Examples of the metal atom (M) which may have a halogen atom or an oxygen atom include copper, iron, beryllium, calcium, cadmium, cobalt, tin, palladium, nickel, zinc, manganese, lead, silicon, magnesium, platinum, AlC
l, InCl, SbCl, Ti = O, V = O, Zr = O, Hr = O, and the like.

The compound of the formula [I] used in the present invention has the formula [II] In the formula, A represents the same meaning as R in the formula [I], and is produced by heating at least one compound alone or together with various metal salts, preferably in an organic solvent.

Preferred examples of the organic solvent include aliphatic organic solvents having a hydroxyl group such as alcohols and glycols.

The method for measuring the nonlinear optical properties of the compound of the formula [I] used in the present invention is as follows.

A thin film of this compound is formed on a quartz substrate. The thickness of the thin film is preferably 1 μm or less, but is not necessarily limited to this range.

When the obtained thin film sample is irradiated with a laser while changing the incident angle, a change in the intensity of the third harmonic, which is the output light, forms a pattern called a maker fringe. From this fringe pattern, a third-order nonlinear susceptibility χ ⁽³⁾ that quantitatively expresses the nonlinear optical effect is obtained.

Examples of the method for forming a thin film include a casting method, a spin coating method, and a vapor deposition method. In the casting method, spin coating method and the like, a solution of the phthalocyanine derivative of the present invention is used. Examples of solvents suitable for use include the following.

Aliphatic saturated hydrocarbons such as n-hexane, n-heptane, n-octane and cyclohexane, ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone, acetate esters, butyl acetate esters, methyl cellosolve and ethyl cellosolve Esters, alcohols such as methyl alcohol, ethyl alcohol, propyl alcohol, isopropyl alcohol and n-butyl alcohol; aromatics such as benzene, toluene and xylene; chlorinated aromatic hydrocarbons such as orthodichlorobenzene and chlorobenzene; chloroform And chlorinated aliphatic hydrocarbons such as dichloromethane and tetrachloroethylene.

Hereinafter, typical examples of the phthalocyanine derivative of the formula [I] that can be used in the present invention will be described.

(Examples) Hereinafter, the present invention will be described more specifically based on examples. In each example, parts are by weight unless otherwise specified.

Example 1 To 131 parts of N, N-dimethylethanolamine, 26.1 parts of 5- (n-hexylthio) -1,3-diiminoisoindoline and 6.6 parts of copper (II) acetylacetonate were added, and the mixture was heated under reflux for 4 hours. And cooled to room temperature. Next, methanol
After adding 262 parts, the mixture was washed with methanol and dried to obtain 19.8 parts of compound (a). Further, the compound (a) was purified by column chromatography using silica gel as a packing material and developed and eluted with chloroform.

An effluent containing the compound (a) is applied on a quartz substrate of 2 cm in length and 6 cm in width by a spin coating method, and is coated with 0.23 μm
A thin film of the compound (a) having a thickness was formed.

The wavelength obtained as the difference frequency between the fundamental wave of the Nd: YAG laser and the wave oscillated by the pumping of the dye laser by the second harmonic of the Nd: YAG laser from the thin film side
Light of 2.1 μm was irradiated while changing the incident angle from −40 degrees to 40 degrees, and the intensity of the generated third harmonic was measured to obtain a maker fringe.

From this fringe pattern, the third-order nonlinear susceptibility χ ⁽³⁾
1.7 × 10 ⁻¹¹ esu was obtained.

Example 2 To 147 parts of N, N-dimethylethanolamine, 29.3 parts of 5- (n-octylthio) -1,3-diiminoisoindoline and 6.6 parts of vanadyl acetylacetonate were added, and the mixture was refluxed for 4 hours and then heated to room temperature. Cool. Next, methanol
After adding 294 parts, the mixture was washed with methanol and dried to obtain 22.3 parts of compound (b). Further, the compound (b) was purified by column chromatography using silica gel as a packing material and developed and eluted with chloroform.

An effluent containing the compound (b) is applied on a quartz substrate having a length of 2 cm and a width of 6 cm by a spin coating method, and is coated with 0.20 μm
A thin film of the compound (b) having a thickness was formed.

The wavelength obtained as the difference frequency between the fundamental wave of the Nd: YAG laser and the wave oscillated by the pumping of the dye laser by the second harmonic of the Nd: YAG laser from the thin film side
Light of 2.1 μm was irradiated while changing the incident angle from −30 ° to 30 °, and the intensity of the generated third harmonic was measured to obtain a maker fringe.

From this fringe pattern, the third-order nonlinear susceptibility χ ⁽³⁾
3.1 × 10 ^-11 esu was obtained.

Example 3 To 147 parts of N, N-dimethylethanolamine, 29.3 parts of 5- (n-octylthio) -1,3-diiminoisoindoline and 6.6 parts of copper acetylacetonate were added, and the mixture was heated under reflux for 4 hours and then to room temperature. Cool. Next, 294 parts of methanol was added, and the mixture was washed with methanol and dried to obtain 22.8 parts of compound (c). Further, the compound (c) was purified by developing and eluted with chloroform using column chromatography using silica gel as a packing material.

An effluent containing the compound (c) is applied on a quartz substrate of 2 cm in length and 6 cm in width by a spin coating method to obtain a 0.30 μm
A thin film of the compound (c) having a thickness was formed.

The wavelength obtained as the difference frequency between the fundamental wave of the Nd: YAG laser and the wave oscillated by the pumping of the dye laser by the second harmonic of the Nd: YAG laser from the thin film side
Light of 2.1 μm was irradiated while changing the incident angle from −40 degrees to 40 degrees, and the intensity of the generated third harmonic was measured to obtain a maker fringe.

From this fringe pattern, the third-order nonlinear susceptibility χ ⁽³⁾
5.0 × 10 ^-11 esu was obtained.

Examples 4 to 8 Compounds (d), (e), (f), (g) and (h)
Compounds (d) to (h) were produced in the same manner as in Example 1 except that a compound of the formula (II) and a metal compound corresponding to were used and N, N-dimethylethanolamine was used as a solvent.

The compound (d) ~ a in the same manner as in Example 1 (h), the thickness of the thin film shown in Table 1, respectively formed on a quartz substrate, in the same manner as in Example 1 chi ⁽³⁾ Was measured.

 Table 1 shows the measurement results.

[Effects of the Invention] According to the present invention, as compared with conventional organic nonlinear optical materials,
An organic nonlinear optical material having a third-order nonlinear susceptibility equal to or higher than these is provided.

ADVANTAGE OF THE INVENTION According to this invention, since it is extremely stable in air and has heat resistance stability, an organic nonlinear optical material which is easy to store and handle is provided.

According to the present invention, there is provided an organic nonlinear optical material in which a thin film can be easily formed and the film thickness can be easily controlled.

Further, according to the present invention, there is provided an organic nonlinear optical material applicable as various elements in the field of optoelectronics, as a nonlinear optical material having a high response speed.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Yasumasa Suda 2-3-13 Kyobashi, Chuo-ku, Tokyo Toyo Ink Manufacturing Co., Ltd. (72) Inventor Shigeyuki Ebashi 2-3-13 Kyobashi, Chuo-ku, Tokyo Toyo Inside Ink Manufacturing Co., Ltd. (72) Inventor Atsutaka Shigehara 2-1 Hirosawa, Wako-shi, Saitama Pref., Japan (72) Inventor Akira Yamada 2-1 Hirosawa, Wako-shi, Saitama Pref.

Claims (1)

(57) [Claims] [1] The formula [I] Wherein R represents an aliphatic hydrocarbon group having 4 to 24 carbon atoms, and M represents a metal atom or a hydrogen atom which may have a halogen atom or an oxygen atom. Organic nonlinear optical material contained as a component.