KR100194804B1 - Aromatic polyester-based nonlinear optical polymer compound and optical device manufactured using the same - Google Patents

Abstract

The present invention relates to an aromatic polyester-based nonlinear optical polymer compound and an optical device manufactured using the same, having a glass transition temperature of 160-200 ° C., having sufficient thermal stability necessary for optical device fabrication, and easy synthesis of the material. In addition, an object of the present invention is to provide an aromatic polyester-based nonlinear optical polymer compound exhibiting low light transmission loss due to flexibility of molecular structure and an optical device manufactured using the same. In order to achieve the object of the present invention, a non-linear optoelectronic compound is directly represented by the following general formula (I) and (II) by condensation reaction of an aromatic diecohol monomer covalently bonded to the side chain with an aromatic dialcohol monomer having various substituents. An aromatic polyester-based nonlinear optical polymer compound is prepared, and the upper and lower cladding layers and the core layer are formed using the compound, and polarized, followed by etching the upper electrode along the waveguide to manufacture an optical device.

Here, X is one selected from -C (CF ₃ ) ₂ , -C (CH ₃ ) ₂ , -Si (CH ₃ ) ₂ , -CO, -SO _2- , -O-, -S-, D is one selected from O, NH, alkylamine (NR ₁ : linear alkyl group of R ₁ = C ₁ ~ C ₆ ), B is none or one selected from CH = CH, N = N, C≡C And A is one selected from NO ₂ , tricyanoethylene, CN, and SO ₂ R ₂ (which is a linear alkyl group of R ₂ = C ₁ to C ₆ ), and a and b are mole ratios of the copolymer, a + b = 1 and R is an alkyl group having a straight or branched C ₁ to C ₂₀ . Aromatic polyester-based nonlinear optical polymer compound of the present invention has a large electro-optic coefficient, thermal stability, low light transmission loss, excellent thin film properties, easy multilayer film, prepared using the aromatic polyester-based nonlinear optical polymer compound An optical device has advantages of high reliability and low driving voltage.

Description

Aromatic polyester nonlinear optical polymer compound and optical device manufactured using the same

The present invention relates to an aromatic polyester-based nonlinear optical polymer compound and an optical device manufactured using the same, and more particularly, to a high speed optical modulator, an optical switch, a secondary harmonic wave generator, and the like.

Due to the limitations of pure electronic circuits and transmission systems in broadband, speed, integration, etc., the role of light in communication technology is increasing. Starting with optical fibers for long distance transmission, optical modulators, optical switches, and optical data storage devices are being developed at high speed. Semiconductor, inorganic and organic materials have all been studied as material materials for such optical devices.

Organic optoelectronic polymers have inherent differences in opto-electronic mechanisms (inorganic optoelectronic materials, which are ferromagnetic crystals, whose opto-electronic reactions depend on ion substitution, while organic optoelectronic materials result from changes in the electronic structure of individual molecules) This results in a much faster switching speed (50 picosec vs. 2 nanosec) and a much wider bandwidth (100 GHz vs. 10 GHz) than LiNbO ₃ and semiconductor materials. Organic optoelectronic polymers also have good processability, which means that they can be used in many optical devices such as linear waveguide wiring, phase modulators, Mach-Zehnder interferometers, beam splitters, and directional couplers. It is much easier to integrate X-switch, X-switch, etc., which is very advantageous for optical devices required for next generation.

The practical application of optical devices made of organic polymer materials requires large electro-optic coefficients, low optical transmission loss, and thermal stability.

Side shains, in which optoelectronic organics are covalently bonded to the polymer's backbone using a flexible group, are a new class of organic materials that exhibit very interesting optical properties. The acrylate side chain nonlinear optical polymers developed so far have shown low optical transmission loss due to the large electro-optic coefficient and excellent film properties, but the glass transition temperature of these polymers is lower than 150 ℃, and the thermal stability required for device fabrication is inferior. There was this. Recently, polyimide side chain nonlinear optical polymers with glass transition temperature of more than 200 ° C have been developed to improve the thermal stability, but these materials have solved the thermal stability but due to the reduction of the polling effect due to the rigidity of the molecular structure. The resulting electro-optic coefficient is not large, and also has a disadvantage of having a large optical transmission loss due to large anisotropy.

Therefore, an object of the present invention is an aromatic polyester having a glass transition temperature of 160 ℃ ~ 200 ℃ having sufficient thermal stability necessary for the fabrication of optical devices, easy synthesis of the material, showing a low light transmission loss due to the flexibility of the molecular structure It is to provide a non-linear optical polymer compound and an optical device manufactured using the same.

In order to achieve the above object as well as another object that can be easily expressed in the present invention by a direct condensation reaction between the non-linear optoelectronic compound covalently bonded to the side chain aromatic dicarocyclic acid monomers and aromatic dialcohol monomers having various substituents The produced aromatic polyester-based nonlinear optical polymer compound represented by the following general formulas (I) and (II) is provided, and an optical device manufactured by the conventional method using this compound is provided.

Here, X is one selected from -C (CF ₃ ) ₂ , -C (CH ₃ ) ₂ , -Si (CH ₃ ) ₂ , -CO, -SO _2- , -O-, -S-, D is an electron donor group selected from O, NH, and alkylamine (NR ₁ : R ₁ = C ₁ to C ₆ linear alkyl group), and B is a bridging group. CH = CH, N = N, C 1 C selected from A, electron acceptor NO ₂ , tricyanoethylene, CN, SO ₂ R ₂ (R ₂ = C ₁ ~ C ₆ straight line Alkyl group), a and b are a + b = 1 as the molar ratio of the copolymer, and R is an alkyl group having a straight or branched C ₁ to C ₂₀ .

For easy synthesis of the aromatic polyester-based nonlinear optical polymer compound of the above purpose, the non-linear optoelectronic compound of the following general formula (3) is first reacted with an aromatic dicarboxylic acid monomer covalently bonded to the side chain, followed by the reaction of Mizunobu Easily prepared through the Sean reaction.

Here, D is one selected from O, NH, alkylamine (NR ₁ : R ₁ = C ₁ ~ C ₆ is a linear alkyl group), B is none or at CH = CH, N = N, C≡C One is selected and A is one selected from NO ₂ , tricyanoethylene, CN, SO ₂ R ₂ (which is a linear alkyl group of R ₂ = C ₁ to C ₆ ). The present invention will be described in more detail as follows.

As an example of the nonlinear optoelectronic compound, a method for synthesizing an aromatic dicarocyclic acid monomer in which 4-alkylamino-4'-nitro stilbene is covalently bonded to the side chain is as follows. First, 5-hydroxyisophthalate and 4- [N- (n-hydroxyalkyl) -N-methylamino] -4'-nitro stilbene are prepared in the presence of triphenyl phosphine and diethyl azodicarboxylate. Covalently bind using the reaction to obtain DANS-IP. The obtained DANS-IP is reacted with potassium hydroxide (KOH) in ethanol (EtOH) and water (H ₂ O) solvents to obtain DANS-IPA, a dicarboxylic acid.

The reaction is described schematically as follows.

As an example of the nonlinear optoelectronic compound, a method for synthesizing an aromatic dicarocyclic acid monomer in which 4-alkylamino-4'-nitro azobenzene is covalently bonded to the side chain is as follows. Mizunobu reaction of 5-hydroxyisophthalate and 4- [N- (n-hydroxyalkyl) -N-ethylamino] -4'-nitro azobenzene in the presence of triphenyl phosphine and diethyl azodicarboxylate Covalently coupled to obtain DR1-IP. DR1-IP is then reacted with potassium hydroxide in ethanol and water solvent to obtain the dicarboxylic acid DR1-IPA.

The reaction scheme is described as follows.

The synthesis method of the aromatic dicarboxylic acid monomer in which the flexible alkoxy group is covalently bonded to the side chain is as follows. For example, 5-hydroxyisophthalate is covalently bonded to 2-ethylhexyl bromide in the presence of potassium carbonate to form dimethyl-5- (2-ethylhexyloxy) isophthalate, followed by diesteric picionation. 2-ethylhexyloxy) isotalic acid is obtained.

The aromatic dialcohol monomer having various substituents and the aromatic dicarocyclic acid monomer covalently bonded to the side chain of the non-linear optoelectronic compound prepared by the above-described method is subjected to condensation reaction in the presence of thionyl chloride (SOCl ₂ ) and pyridine. Aromatic polyester-based nonlinear optical polymer compounds are synthesized by a very simple production method which is directly polymerized.

The reaction scheme is described as follows.

In addition, in the present invention, a lower cladding layer is formed by scanning a silicon substrate deposited with gold by using a compound of formula (II), followed by photobleaching the core layer prepared by spin coating a compound of formula (I) on the waveguide. After the side constrained, the upper cladding layer was formed by using the general formula (II) compound on the prepared core layer and the silicon substrate was placed on a hot plate at 150-200 ° C. After polarizing by applying a strong DC voltage of 100 ~ 200V per μm between the upper electrodes, the upper electrode is etched along the waveguide using a microfabrication technique to manufacture an optical waveguide optical device.

The following examples further illustrate the invention, but do not limit the scope of the invention.

Example 1

This example is a synthesis example of an aromatic dicarocyclic acid monomer to which an optoelectronic compound is covalently bonded.

(A) Synthesis of dimethyl-5- [N-methyl-N '-{4- (4'-nitrostyryl) phenyl} ethoxy] isophthalate (DANS-IP)

Into a 250 mL three necked flask, add 2.98 g (10 mmol) of 4- [N- (2-hydroxy ethyl) -N-methylamino] -4'-nitro stilbene and 3.93 g (15 mmol) triphenyl phosphine. Dissolve completely with tetrahydrofuran (THF) solvent. To this solution is added 3.16 g (15 mmol) of dimethyl-5-hydroxyisophthalate. After 5 minutes, diethyl azodicarboxylate (2.61 g, 15 mmol) dissolved in 8 mL of THF was slowly added dropwise to the reaction vessel. After 1 hour the reaction mixture became a solid and an additional 30 mL of THF was added. The reaction mixture is stirred for 12 hours and then heated to 60-70 ° C. for 1 hour. The reaction mixture is stored in the refrigerator for one day. The red product precipitated is filtered off and dried in air. This is recrystallized from chloroform and isopropanol to obtain DANS-IP.

(B) Synthesis of 5- [N-methyl-N '-{4- (4'-nitrostyryl) phenyl} ethoxy] isophthalic acid (DANS-IPA)

6.83 g (122.4 mmol) KOH was added to the flask, and 45 mL of EtOH and 45 mL of H ₂ O were added to dissolve completely. Slowly add 3 g (6.12 mmol) of DANS-IP to the reaction solution. The reaction mixture is refluxed for 24 hours. After checking the progress of the reaction by thin layer chromatography (TLC), the reaction was completely completed, and then the temperature of the reaction solution was lowered and neutralized by adding 10.5 ml of hydrochloric acid. The resulting solid is stored in the refrigerator for 24 hours, filtered and then recrystallized with acetic acid to obtain DANS-IPA.

(C) Synthesis of dimethyl-5- [N-methyl-N '-{4- (4'-nitrophenyl-azo) phenyl} amino] ethyl isophthalate (DR1-IP)

25 g (79.5 mmol) Disperse Red 1 and 25 g (95.4 mmol) triphenyl phosphine are added to a 500 mL three neck flask and completely dissolved in 200 mL of THF solvent. 20.1 g (95.4 mmol) of dimethyl-5-hydroxyisophthalate is added to this solution. After 5 minutes, diethyl azodicarboxylate (16.6 g, 95.4 mmol) dissolved in 30 mL of THF was slowly added dropwise to the reaction vessel. The reaction mixture is stirred for 6 hours. The reaction mixture is stored in a refrigerator for 24 hours, after which the precipitated red product is filtered and dried in air. This is completely dissolved in chloroform and recrystallized with isopropanol to obtain DR1-IP.

(D) Synthesis of 5- [N-ethyl-N '-{4- (4'-nitrophenyl-azo) phenyl} amino] ethyl isophthalic acid (DR1-IPA)

2.29 g (39.4 mmol) of KOH was added to the flask, and 8 mL of EtOH and 8 mL of H ₂ O were added to dissolve it completely. 1 g (1.97 mmol) of DR1-IP is slowly added to the reaction solution. The reaction mixture is refluxed for 6 hours. After confirming the progress of the reaction by TLC, after the reaction was completely completed, the temperature of the reaction solution was lowered and 3.28 ml hydrochloric acid was added thereto. The resulting solid is filtered and then recrystallized with acetic acid to give DR1-IPA.

Example 2

This example is a synthesis example of an aromatic dicarboxylic acid covalently bonded to a flexible alkoxy group.

(A) Dimethyl-5- (2-ethylhexyloxy) isophthalate

Dissolve 21.1 g (0.1 mmol) of dimethyl-5-hydroxyisophthalate and 20.7 g (0.15 mol) of potassium carbonate in 250 mL of dimethylformamide (DMF) in a 500 mL three neck flask. After 10 minutes, 2-ethylhexyl bromide (30 g, 0.15 mol) was slowly added dropwise to the reaction vessel. The reaction mixture is stirred at 80 ° C. for 24 hours. The reaction mixture was poured into cold 600 mL of water, stirred, and the organic layer was extracted using ethyl acetate. The extracted organic layer was washed three times with water, dried over anhydrous magnesium sulfate and filtered. The solvent is removed by evaporation followed by vacuum rectification to obtain dimethyl-5- (2-ethylhexyloxy) isophthalate.

(B) 5- (2-ethylhexyloxy) isophthalic acid

Add 6.9 g (61.56 mmol) of t-BuOK to the flask and add 62 mL of DMSO to dissolve it completely. 0.66 g (1.97 mmol) of dimethyl-5- (2-ethylhexyloxy) isophthalate is slowly added to the reaction solution. After confirming the progress of the reaction by TLC, the reaction mixture was completely finished, poured into the cold ice water and the reaction mixture was neutralized with hydrochloric acid solution. The resulting solid is filtered and then dissolved in acetic acid to recrystallize to obtain 5- (2-ethylhexyloxy) isophthalic acid.

Example 3

This example is an example of the condensation polymerization of an aromatic dicarocarboxylate monomer with an aromatic dialcohol.

(A) Polymerization of DANS-IPA with 4,4 '-(hexafluoroisopropylidene) diphenol (PE-1)

Prepare a cooling condenser and a dropping funnel in a 250 mL three-necked flask and continue to flow dried nitrogen. 10 mL of pyridine is added to the flask and cold thionyl chloride (11 mmol) is slowly added dropwise thereto. After stirring at low temperature for about 30 minutes, 1.2 g (2.5 mmol) of DANS-IPA and 4,4 '-(hexafluoroisopropylidene) diphenol (0.84 g, 2.5 mmol) dissolved in 20 mL of pyridine in the reaction vessel. Drop for 20 minutes. After reaction for 3 hours, the reaction mixture is poured into 100 mL of methanol. The precipitated product is filtered and then removed using the Soxhlet extractor with methanol solvent to remove unreacted monomer or oligomer for 2 days. Then, the obtained polymer is dissolved in THF, reprecipitated in methanol, filtered and dried in a vacuum oven at 10 ° C.

(B) Polymerization of DR1-IPA with 4,4 '-(hexafluoroisopropylidene) diphenol (PE-2)

It carried out similarly to (a) of Example 3 except having used DR1-IPA as an aromatic polyester nonlinear optical high molecular compound.

(C) Copolymerization of DANS-IPA with 5- (2-ethylhexyloxy) isophthalic acid (1: 1) with 4,4 '-(hexafluoroisopropylidene) diphenol (PE-3)

Prepare a cooling condenser and a dropping funnel in a 250 mL three-necked flask and continue to flow dried nitrogen. 20 mL of pyridine is added to the flask and cold thionyl chloride (22 mmol) is slowly added dropwise thereto. After stirring at low temperature for about 30 minutes, 1.2 g (2.5 mmol) DANS-IPA and 0.74 g (2.5 mmol) 5- (2-ethylhexyloxy) isophthalic acid dissolved in 40 mL of pyridine in this reaction vessel, and 4,4 '-(hexafluoroisopropylidene) diphenol (1.68 g, 5.0 mmol) was added dropwise for 20 minutes. After reaction for 3 hours, the reaction mixture is poured into 100 mL of methanol. The precipitated product is filtered and then removed using the Soxhlet extractor with methanol solvent to remove unreacted monomer or oligomer for 2 days. Then, the obtained polymer is dissolved in THF, reprecipitated in methanol, filtered and dried in a vacuum oven at 10 ° C.

Example 4

This embodiment is a method of manufacturing an optical device using an aromatic polyester-based nonlinear optical polymer compound.

(A) Fabrication of optical device using PE-1

Each polymer of Example 3 was dissolved in a cyclohexanone solvent at 20% by weight and then filtered through a 0.2 μm Teflon filter. The filtered PE-3 polymer solution is injected onto a silicon substrate previously deposited with gold, and then spin coated to prepare a lower cladding layer of the optical waveguide. At this time, the thickness of the lower cladding layer is adjusted by the number of revolutions. The core layer on the cladding layer is spin-coated with a mixture of PE-1 of Example 3 in a cyclohexanone solvent at 20% by weight, and then placed in a oven at 180 ° C. for 2 hours to form a thin core layer. The photobleaching is used to confine the waveguide. The core layered PE-3 is spin coated with the upper cladding, and then placed in an oven at 180 ° C. for 1 hour. The gold is then vacuum deposited on the thin film for the upper electrode and then polized to maximize the electro-optic effect. Polarization is achieved by placing a silicon substrate on a hot plate at 150 ° C to 200 ° C and applying a strong DC voltage of 100-200V per μm between the lower electrode on the silicon substrate and the upper electrode on the polymer thin film. After polarization, the upper electrode is etched along the waveguide using a conventional microfabrication technique to manufacture an optical waveguide optical device.

(B) Fabrication of optical device using PE-2

It carried out similarly to (a) of Example 4 except having used PE-2 instead of PE-1.

The aromatic polyester-based nonlinear optical polymer compound prepared by the above-described method has a very large value of electro-optic coefficient and has a glass transition temperature of 160 ° C. or higher, which is thermally very stable, has low optical transmission loss, excellent thin film properties, and multilayer thin film. It is easy to manufacture, and the optical device manufactured using the aromatic polyester-based nonlinear optical polymer compound has excellent reliability and is driven at a low driving voltage.

The present invention described above is capable of various substitutions, modifications, and changes without departing from the technical spirit of the present invention for those skilled in the art to which the present invention pertains. It is not limited to the drawings shown.

Claims (3)

Aromatic polyester-based nonlinear optical polymer compound represented by the following general formula (I) Here, X is one selected from -C (CF ₃ ) ₂ , -C (CH ₃ ) ₂ , -Si (CH ₃ ) ₂ , -CO, -SO _2- , -O-, -S-, D is one selected from O, NH, alkylamine (NR ₁ : R ₁ = C ₁ ~ C ₆ linear alkyl group), B is none or one selected from CH = CH, N = N, C≡C And A is one selected from NO ₂ , tricyanoethylene, CN, and SO ₂ R ₂ (which is a linear alkyl group having R ₂ = C ₁ to C ₆ ). Aromatic polyester-based nonlinear optical polymer compound represented by the following general formula (II) Here, X is one selected from -C (CF ₃ ) ₂ , -C (CH ₃ ) ₂ , -Si (CH ₃ ) ₂ , -CO, -SO _2- , -O-, -S-, D is one selected from O, NH, alkylamine (NR ₁ : R ₁ = C ₁ ~ C ₆ linear alkyl group), B is none or one selected from CH = CH, N = N, C≡C And A is one selected from NO ₂ , tricyanoethylene, CN, and SO ₂ R ₂ (which is a linear alkyl group of R ₂ = C ₁ to C ₆ ), and a and b are a + b = as the molar ratio of the copolymer. 1 and R is an alkyl group having a straight or branched C ₁ to C ₂₀ . In manufacturing an optical device using a nonlinear optical polymer, a lower cladding layer is formed of the aromatic polyester nonlinear optical polymer compound according to claim 2, and the core layer is formed of the aromatic polyester nonlinear optical polymer compound according to claim 1 thereon. And forming an upper cladding layer with the aromatic polyester nonlinear optical polymer compound according to claim 2 thereon, and then placing a silicon substrate on a hot plate at 150 to 200 ° C. according to a conventional method. And polarizing by applying a strong DC voltage of 100 to 200 V per μm between the upper electrode and the upper electrode on the polymer thin film, and then etching the upper electrode along the waveguide by using a microfabrication technique.