JPH04314034A - Waveguide type wavelength conversion element and production thereof - 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]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a waveguide type wavelength conversion element using a nonlinear organic material as an optical waveguide material and a method for manufacturing the same.

0002

[Prior Art] Currently, research is active in various fields on wavelength conversion elements using nonlinear materials, and in the future optical discs,
It is expected that it will be installed in products such as optical integrated circuits and optical computers. A nonlinear optical phenomenon is that when a light wave hitting a material becomes extremely strong (e.g., laser light) and the electric field becomes large, the following (
As shown in formula 1), P=χ(1) E+χ(2) EE+χ(3) E
EE+... (1) [However, P is polarizability,
E is the electric field, χ (n (n = 1, 2, 3...) is the nonlinear susceptibility) It is no longer possible to ignore the second-order or higher-order components of the electric field E, and the relationship between polarization and electric field in ordinary optical phenomena This means that it is different from the following equation (2), which expresses A typical example of its use is the application of second harmonic generation (SHG). Also, materials that have such a nonlinear optical effect are called nonlinear materials. Conventionally, this type of material is KH2PO4. (KDP), NH4H
Inorganic crystals without central symmetry, such as 2PO4 (ADP) and LiNbO3, have been used. Furthermore, recently, compounds have been discovered in organic crystals that have greater nonlinearity than LiNbO3 and the like. Typical examples include 2-methyl-4-nitroaniline (MNA), meta-nitro-aniline (m-NA), and urea.

0003

[Problems to be Solved by the Invention] Generally, for nonlinear optical phenomena, it is necessary that the energy density of the light waves applied to the material is high, and as one means of increasing the energy density of the light waves, nonlinear optical elements are used as waveguide films. It is very important to However, as mentioned above, this type of material is generally a crystal, and it is difficult to form a waveguide film into a waveguide type nonlinear optical element. In the case of inorganic crystals, it has been successfully made into waveguide films and three-dimensional waveguides using LiNbO3, etc., but this processing process is complicated and the device becomes very expensive. An object of the present invention is to provide a waveguide type wavelength conversion element and a manufacturing method thereof that eliminate these drawbacks.

0004

[Means for Solving the Problems] As a result of intensive study and research in order to solve the above problems, the present inventors have used a side chain-embedded nonlinear material in the core, and a photocurable polymer in the cladding. By using a waveguide made of this material, we succeeded in creating a waveguide-type wavelength conversion element that has high conversion efficiency and does not decrease in conversion efficiency over time. That is, the present invention uses an organic polymer compound containing a nonlinear material,
A method for producing a waveguide type wavelength conversion element, characterized in that the nonlinear material is incorporated into the organic polymer compound to obtain a core material by orienting it while heating, and the core is characterized in that the nonlinear material is added to the organic polymer compound. The present invention provides a waveguide type wavelength conversion element characterized by being made of a material in which a nonlinear material is incorporated into an organic polymer compound while being heated and oriented. The waveguide type wavelength conversion element of the present invention may be composed of the above-mentioned core and a cladding made of a photocurable organic polymer compound.

The present invention involves (1) doping a nonlinear material into an organic polymer and incorporating the nonlinear material into the organic polymer while simultaneously heating and orienting it to obtain a core material; (2) using a photocurable organic polymer as a cladding; It is characterized by the use of molecular compounds.

[0006]

[Operation] The present invention will be explained in detail below with reference to the drawings. FIG. 1 shows an example of manufacturing a thin film waveguide type wavelength conversion element according to the present invention in the order of steps. A photo-curable organic polymer material (hereinafter referred to as ITO) for forming a cladding is placed on an indium-tin-oxide (hereinafter abbreviated as ITO) evaporation substrate 1.
A photocurable cladding material) 21 is provided, and it is irradiated with ultraviolet light [step (a) in FIG. 1]. Next, a photocurable cladding material 22 is further provided, and the portions other than the waveguide portion are masked with a photomask 3, and the portions other than the waveguide portion are irradiated with ultraviolet rays, thereby producing the cladding other than the waveguide portion [step (b) in the same example]. Next, by washing off the uncured resin on the waveguide portion with a solvent, a recess corresponding to the waveguide portion is formed (step (c)). The waveguide portion is coated with a polymeric material 4 containing a nonlinear material. [Step (d) of the same]. Next, a photocurable cladding material 23 is provided on the top of the nonlinear material 4 and the cladding 22, and the cladding is produced by irradiation with ultraviolet rays [Step (e) of the same]. ITO is vapor-deposited on the top of the cladding. Set plate 1 (step (f)). By applying heat and voltage, the nonlinear material of the waveguide portion and the polymeric material are reacted while being oriented, and the nonlinear material forms a chemical bond as a side chain of the polymeric material. A waveguide is made of a side chain-incorporated nonlinear polymer material [step (g)]. Figure 1 shows an alignment method using opposing electrodes, but the alignment method is limited to this. For example, as shown in FIG. 2 as another embodiment of the present invention, the rod-shaped electrode 6 is
Alternatively, the alignment may be performed using a so-called colon-poling technique by using a needle electrode (not shown).

The photocurable cladding material used in the present invention is preferably one with a low refractive index, such as silicone (
Examples include meth)acrylate, fluorinated (meth)acrylate, and ladder-type siliconization.

The host material monomers for constituting the nonlinear material of the waveguide portion of the present invention include polymerizable unsaturated bonds such as vinyl groups, acryloyl groups, methacryloyl groups, allyl groups, etc. in the polymer component molecules. It is desirable to have a functional group (for example, an epoxy group, an isocyanate group, etc.) that reacts with the nonlinear material (guest material), and examples thereof include the following compounds. Compound (a)

[Chemical formula 1] Compound (b)

[Case 2] Compound (c)

[Chemical formula 3] Compound (d)

[C4] compound (e)

[C5] compound (f)

[C6] compound (g)

[C7] Compound (chi)

[Chemical formula 8] compound (li)

[Chemical formula 9] Compound (nu)

[Chemical formula 10] compound (le)

[Chemical formula 11] Compound (wo)

embedded image In addition to the above-mentioned monomers, monomers having polymerizable double bonds such as acrylic acid and methacrylic acid can also be used as the host material of the present invention.

[0009] As the guest material used in the present invention, an organic material having a nonlinear optical effect is preferably one that chemically bonds with an epoxy group and/or an isocyanate group, and the following may be mentioned.・4-hydroxymethyl(methyl)amino-4'-nitrostilbene (referred to as compound (wa)) ・4-hydroxyethyl(methyl)amino-4'-nitrostilbene ・4-hydroxypropyl(methyl)amino-4'- Nitrostilbene/4-hydroxybutyl(methyl)amino-4'-nitrostilbene/4-hydroxypentyl(methyl)amino-4'-nitrostilbene/4-hydroxyhexyl(methyl)amino-4'-nitrostilbene/4- Hydroxymethyl(ethyl)amino-4'-nitrostilbene (referred to as compound (ka)) 4-hydroxyethyl(ethyl)amino-4'-nitrostilbene 4-hydroxypropyl(ethyl)amino-4'-nitrostilbene 4-hydroxybutyl(ethyl)amino-4'-nitrostilbene, 4-hydroxypentyl(ethyl)amino-4'-nitrostilbene, 4-hydroxyhexyl(ethyl)amino-4'-nitrostilbene, 4-hydroxymethyl( Propyl)amino-4'-nitrostilbene, 4-hydroxyethyl(propyl)amino-4'-nitrostilbene, 4-hydroxypropyl(propyl)amino-4'-
Nitrostilbene/4-hydroxybutyl(propyl)amino-4'-nitrostilbene/4-hydroxypentyl(propyl)amino-4'-
Nitrostilbene 4-hydroxyhexyl(propyl)amino-4'-
Nitrostilbene/4-hydroxymethyl(butyl)amino-4'-nitrostilbene/4-hydroxyethyl(butyl)amino-4'-nitrostilbene/4-hydroxypropyl(butyl)amino-4'-nitrostilbene/4- Hydroxybutyl (butyl)amino-4'-nitrostilbene, 4-hydroxypentyl (butyl)amino-4'-nitrostilbene, 4-hydroxyhexyl (butyl)amino-4'-nitrostilbene, 4-hydroxymethyl (pentyl) Amino-4'-nitrostilbene/4-hydroxyethyl(pentyl)amino-4'-nitrostilbene/4-hydroxypropyl(pentyl)amino-4'-
Nitrostilbene/4-hydroxybutyl(pentyl)amino-4'-nitrostilbene/4-hydroxypentyl(pentyl)amino-4'-
Nitrostilbene 4-hydroxyhexyl(pentyl)amino-4'-
Nitrostilbene/4-hydroxymethyl(hexyl)amino-4'-nitrostilbene/4-hydroxyethyl(hexyl)amino-4'-nitrostilbene/4-hydroxypropyl(hexyl)amino-4'-
Nitrostilbene/4-hydroxybutyl(hexyl)amino-4'-nitrostilbene/4-hydroxypentyl(hexyl)amino-4'-
Nitrostilbene 4-hydroxyhexyl(hexyl)amino-4'-
Nitrostilbene 2-[ethyl[4-[(4-nitrophenyl)azo]
phenyl]aminoethanol (abbreviated as red1, compound (yo)) ・2-[methyl[4-[(4-nitrophenyl)azo]
phenyl]aminoethanol (referred to as compound (ta))
・2-[Propyl[4-[(4-nitrophenyl)azo]phenyl]aminoethanol ・2-[Butyl[4-[(4-nitrophenyl)azo]
Phenyl]aminoethanol, 2-[pentyl[4-[(4-nitrophenyl)azo]phenyl]aminoethanol, 2-[hexyl[4-[(4-nitrophenyl)azo]phenyl]aminoethanol, 2-[ Ethyl [4-[(4-nitrophenyl)azo]
phenyl]aminomethanol・2-[ethyl[4-[(4-nitrophenyl)azo]
Phenyl]aminopropanol・2-[ethyl[4-[(4-nitrophenyl)azo]
Phenyl]aminobutanol・2-[ethyl[4-[(4-nitrophenyl)azo]
Phenyl]aminopentanol・2-[ethyl[4-[(4-nitrophenyl)azo]
Phenyl]aminohexanol 2-[(4-[(4-nitrophenyl)azo]phenyl]aminomethanol 2-[(4-[(4-nitrophenyl)azo]phenyl]aminopropanol 2-[(4 -[(4-nitrophenyl)azo]phenyl]aminobutanol, 2-[(4-[(4-nitrophenyl)azo]phenyl]aminopentanol, 2-[(4-[(4-nitrophenyl)azo) [Phenyl]aminohexanol・2-[methyl[4-[(4-nitrophenyl)azo]
phenyl]aminomethanol・2-[methyl[4-[(4-nitrophenyl)azo]
Phenyl]aminopropanol・2-[methyl[4-[(4-nitrophenyl)azo]
Phenyl]aminobutanol・2-[methyl[4-[(4-nitrophenyl)azo]
Phenyl]aminopentanol・2-[methyl[4-[(4-nitrophenyl)azo]
Phenyl]aminohexanol, 2-[propyl 4- (4-nitrophenyl)azo]phenyl]aminomethanol, 2-[propyl 4- (4-nitrophenyl)azo]phenyl]aminopropanol, 2-[propyl 4- ( 4-Nitrophenyl)azo]phenyl]aminobutanol/2-[propyl 4-(4-nitrophenyl)azo]phenyl]aminopentanol/2-[propyl 4-(4-nitrophenyl)azo]phenyl]aminohexanol・2-[Butyl[4-[(4-nitrophenyl)azo]
phenyl]aminomethanol・2-[butyl[4-[(4-nitrophenyl)azo]
Phenyl]aminopropanol・2-[butyl[4-[(4-nitrophenyl)azo]
Phenyl]aminobutanol・2-[butyl[4-[(4-nitrophenyl)azo]
Phenyl]aminopentanol・2-[butyl[4-[(4-nitrophenyl)azo]
Phenyl]aminohexanol, 2-[pentyl 4- (4-nitrophenyl)azo]phenyl]aminomethanol, 2-[pentyl 4- (4-nitrophenyl)azo]phenyl]aminopropanol, 2-[pentyl 4- ( 4-Nitrophenyl)azo]phenyl]aminobutanol/2-[pentyl 4-(4-nitrophenyl)azo]phenyl]aminopentanol/2-[pentyl 4-(4-nitrophenyl)azo]phenyl]aminohexanol・2-[hexyl 4- (4-nitrophenyl)azo]phenyl]aminomethanol ・2-[hexyl 4- (4-nitrophenyl)azo]phenyl]aminopropanol ・2-[hexyl 4- (4-nitrophenyl) ) azo]phenyl]aminobutanol, 2-[hexyl 4- (4-nitrophenyl)azo]phenyl]aminopentanol, 2-[hexyl 4- (4-nitrophenyl)azo]phenyl]aminohexanol, and the like.

The waveguide type wavelength conversion element of the present invention has the following advantages due to its shape, materials used, and manufacturing method. ■Since it is a waveguide type, it is easier to control the film thickness than the fiber type. ■Because the orientation is performed using an electric field orientation method, it is possible to achieve orientation regardless of the crystallinity of the nonlinear material. ■Since the nonlinear material is oriented and incorporated into the side chains of the polymer compound, the amount added can be increased, increasing the proportion of molecules that are oriented and incorporated (chemically bonded). ), so orientation relaxation is difficult to occur. Therefore, the waveguide type wavelength conversion element of the present invention can maintain excellent conversion efficiency for a long time.

[0011]

[Examples] The present invention will be specifically explained below with reference to Examples, but these are not intended to limit the scope of the present invention. Example 1 A silicone acrylate resin was used as a non-linear curable cladding material, spin-coated on ITO-deposited glass, and exposed to ultraviolet light of 500 mJ/c using a metal halide lamp.
m2 was irradiated to form a cladding layer with a thickness of about 10 μm. After forming a cladding layer of the same thickness on top of that, the cladding part was cured by irradiating 500 mJ/cm2 of ultraviolet light using a metal halide lamp using a photomask, and then the resin on the waveguide part was washed off. . Next, the refractive index difference △n=2 between the nonlinear polymer material with compound (a) and compound (wa) dissolved in a solvent and the cladding.
%, applied to the waveguide part by dipping method, and dried. After that, a cladding layer was further applied and ultraviolet light was applied at 500 mJ/cm using a metal halide lamp.
2 A waveguide was fabricated by irradiating and curing. ITO vapor-deposited glass was set on the top of this waveguide, and 10
A voltage of 10,000 V/cm was applied and the film was oriented while being heated to 150°C. At this time, the solubility of the nonlinear material (guest material) in the host material was 30% by weight or more.

[0012] Regarding the waveguide obtained above, the SHG (second harmonic generation) intensity was measured according to the following method. The conversion efficiency (%) at this time is shown in Table 1 below. SHG
Intensity measurement method: Takagen uses a Nd:YAG laser and passes the light emitted from the sample through a monochromator to perform SHG
The intensity of only the light (0.532 μm) was detected using a photomultiplier. The cladding material used, nonlinear polymer material (host material and guest material), SHG strength, conversion efficiency, and conversion efficiency after one month (initial value is 100) are shown.

[0013]

[Table 1]

Comparative Example 1 In a waveguide type wavelength conversion element similar to Example 1, a polymer of methyl methacrylate was used as the host material, and the nonlinear material [compound (wa) used in Example 1] was used as the guest material.
, (F), (Y), (T)] to dissolve in the solvent,
A core portion was formed by a dipping method. Thereafter, a cladding portion was formed, and a voltage was applied at a temperature higher than the glass transition point of the host material for orientation. Thereafter, a waveguide type wavelength conversion element was obtained by lowering the temperature while applying a voltage. At this time, the solubility of the nonlinear material (guest material) in the host material is about 10% by weight at most, and the conversion efficiency is poor and may decrease over time.

Comparative Example 2 Using 2-ethylhexyl acrylate instead of methyl methacrylate in Comparative Example 1, a core portion was formed by the dipping method in the same manner as in Comparative Example 1, and after forming a cladding portion, the temperature was increased to a temperature higher than the glass transition point. A voltage was applied at a temperature of Thereafter, a waveguide type wavelength conversion element was obtained by lowering the temperature while applying a voltage. At this time, the solubility of the nonlinear material (guest material) in the host material is at most 1
It was about 0% by weight, and the conversion efficiency was poor and sometimes decreased over time.

The cladding material, host material, guest material, conversion efficiency, and conversion efficiency after one month (initial value is 100) of Comparative Example 1 and Comparative Example 2 are summarized in Table 2 below.

[0017]

[Table 2]

[0018]

Effects of the Invention The waveguide type wavelength conversion element of the present invention has a core formed by doping a nonlinear material into a polymer compound and incorporating it into a side chain by reacting the nonlinear material with the polymer compound while heating and orienting it. Since we create a nonlinear material (
The content of guest material) in the core can be increased. Therefore, it is possible to obtain high conversion efficiency. Furthermore, the device of the present invention has little change in conversion efficiency over time.

[Brief explanation of drawings]

FIG. 1 is a schematic explanatory diagram showing, in order of steps, one embodiment of manufacturing a waveguide type wavelength conversion element of the present invention by a facing electrode type alignment method.

FIG. 2 is a schematic explanatory diagram of an example in which a corona polling technique is used as another embodiment of the present invention.

[Explanation of symbols]

1 ITO vapor deposition substrate 21 Photo-curable cladding material 22 Photo-curable cladding material 23 Photo-curable cladding material 3 Photomask 4. Nonlinear materials 5 Power supply 6 Rod-shaped battery

Claims (3)

[Claims] 1. A waveguide type wavelength waveguide, characterized in that a core material is obtained by incorporating a nonlinear material into an organic polymer compound by orienting the mixture while heating the organic polymer compound. Method for manufacturing a conversion element. 2. A waveguide type wavelength conversion element characterized in that the core is made of a material in which a nonlinear material is added to an organic polymer compound and the nonlinear material is incorporated into the organic polymer compound while being heated and orientated. 3. The core is made of a material in which a nonlinear material is added to an organic polymer compound and the nonlinear material is incorporated into the organic polymer compound while heating and orientation, and the cladding is made of a photocurable organic polymer compound. The waveguide type wavelength conversion element according to claim 2, characterized in that: