JPH02113228A - Thin film waveguide element - Google Patents

Abstract

PURPOSE:To reduce the restriction of a substrate, to facilitate the formation of an optical waveguide, and to realize low cost and high performance by laminating a core layer which performs wavelength conversion by nonlinear optical effect, a 1st clad layer which has a lower refractive index than the core layer, and a 2nd clad layer which has a higher refractive index than the 1st clad layer. CONSTITUTION:The 1st clad layer 3 has the lower refractive index than the core layer 2 at the frequency of a basic wave entered into the core layer 2 and also has a higher refractive index than the core layer 2 at the frequencies of generated higher harmonics. Consequently, the generated higher harmonics can be entered into the 2nd clad layer 4 or other optical waveguides efficiently. The 2nd clad layer 4 is made of a material which is similar to that of the 1st clad layer 3 and has a higher refractive index than the 1st clad layer 3. Consequently, the excellent optical waveguide is easily formed at low cost.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a thin film waveguide element, and more specifically, the present invention relates to a thin film waveguide element, and more specifically, it provides a wavelength conversion function using nonlinear optical effects, as well as demultiplexing, mixing, and polarization. Regarding the provision of active functions such as

[Conventional technology 1 Conventionally, thin film waveguide elements (nonlinear thin film waveguide elements) having a wavelength conversion function using nonlinear optical effects include those that perform phase matching by mode selection and those that perform phase matching by Cerenkov radiation. It has been known. The core layer, which becomes these optical waveguides, has a shape and refractive index designed to match the material of the substrate, and is formed on a substrate of semiconductor, glass, inorganic compound, plastic, or the like by photolithography or the like.

In addition, the thin film waveguide device, which is simply a path for light, has been further advanced and the light can be split into the thin film waveguide device itself.

It is also being considered to provide active functions such as mixing and polarization to create an active thin film waveguide element. For this purpose, a substrate with a large electro-optic effect is required. For example, a leading wavepath is formed on a single crystal such as LiNbO3 by Ti diffusion or H diffusion, and an electrode is further provided to impart the above-mentioned active function. is being attempted.

On the other hand, a resonant reflective thin film waveguide device reported by Ikkokubun et al. is known as a new thin film waveguide device [“
Applied Physical Letters (Appl, Ph
ys, Lett,) J 49.13 (198B)]
The optical waveguide of this thin film waveguide element uses a core layer that has no nonlinear optical effect for a single wavelength.

[Problems to be Solved by the Invention] In general, thin film waveguide devices involve forming an optical waveguide with a high refractive index on a substrate with a low refractive index, so it is necessary to control the refractive index and shape of the optical waveguide with high precision. It is difficult to simply form a desired optical waveguide at low cost. In particular, in order to obtain an active thin film waveguide element, LiNbO
3. It is necessary to perform the above-mentioned highly accurate guiding waveguide formation operation on an expensive material such as a single crystal, and furthermore, it is difficult to obtain an active thin film waveguide element with sufficient performance due to constraints on the formation operation.

In addition to the above-mentioned disadvantages, nonlinear thin film waveguide elements that perform phase matching by mode selection have the problem that film thickness control is extremely strict and correction for temperature changes is difficult. In addition, nonlinear thin film waveguide devices using Cerenkov radiation can correct phase matching due to temperature changes by changing the radiation angle of the harmonics, but since the emitted harmonics are crescent-shaped, the beams can be shaped and focused. The problem is that it is difficult.

On the other hand, in conventional resonant reflective thin film waveguide elements, the incidence efficiency may be insufficient due to severe mode constraints in the core layer that guides the fundamental wave. In addition, it is difficult to make it active, and it is impossible to make it active using an electro-optic crystal such as a LiNbO3 substrate.

[Means and effects for solving the problem] To explain the means for solving the above problem, in the invention of claim 1, as shown in FIG. As a thin film waveguide element in which a core layer 2 that performs wavelength conversion, a first cladding layer 3 having a lower refractive index than the core layer 2, and a second cladding layer 4 having a higher refractive index than the first cladding layer 3 are laminated. It is something that exists. In addition, in the invention of claim 3, as shown in FIG. A second cladding layer 4 having a higher refractive index than the first cladding layer 3 is laminated, and at least one of the core layer 2, the first cladding layer 3, and the second cladding layer 4 is made of a polymer material. This is a thin film waveguide device.

According to the invention of claim 1 above, the light incident on the core layer 2 is totally reflected on the first cladding layer 3, and the seeping light can cause interference on the second cladding layer 4. This makes it possible to confine light in a single mode to the core layer 2. At the same time, by radiating the harmonics whose wavelength has been converted by the core layer 2, which has a nonlinear optical effect, to the second cladding layer 4 or a separately provided leading waveguide, it is possible to perform stable and good phase matching against temperature changes. can. In addition, core layer 2
Because the fundamental wave is confined efficiently and there is little seepage, the optical power density improves and the wavelength conversion efficiency increases. Furthermore, according to the invention of claim 3, the refractive index and the anisotropy of the refractive index of the polymer material are controlled by electric fields, magnetic fields, temperature changes, light, etc., and active functions such as demultiplexing, switching, mode conversion, etc. function can be obtained.

The core layer 2 in the invention of claim 1 exhibits a nonlinear optical effect, and can be formed of a nonlinear optical material that exhibits the effect. Examples of the nonlinear optical material include inorganic crystals, organic crystals, glass, semiconductors, and polymer materials.

(B2 N) 2 CO As an inorganic crystal, For example, LiNbO3, KTiOPO4 (KTP) β-BaB204 etc.

As an organic crystal, For example, something like the following Ru.

(Left below) H2 2N Y@3(HCOOe)3 82PO4e-B20 2N (!8) (2B) Lactose 1/406H6 D R' CI...(l14a) F3 CH...(84d) R' Mouth R ' R R ' 2N- HCOMe OH eO- (+) pseudoephedrine (-) norp
seudoepharine NOH... (77d) As the glass, for example, filter glass such as 5chott or 0G590 can be used.

As the semiconductor, for example, GdS, GaAs, Si, etc. can be used.

As the polymer material, for example, in addition to polydiacetylene, polyacetylene, polythiophene, etc., polymer liquid crystals having a nonlinear optical effect among the polymer liquid crystals described later can be used.

By forming the core layer 2 by applying a solid solution of a nonlinear optical material having a large nonlinear molecular susceptibility to a glass or polymeric material serving as a matrix, the formation of a thin film such as the core layer 2 is facilitated. You can also do that. The nonlinear optical material can be introduced into the matrix by copolymerization or the like. When the core layer 2 is made of glass or polymeric material as a matrix, it is preferable to orient the nonlinear optical material contained therein or to orient the polymeric material.

The glass or polymeric material used as the matrix does not need to be a nonlinear optical material, and in addition to the above-mentioned materials, for example, quartz glass, PbO glass, phosphate glass,
B2O3 glass, polyester, polyamide, polyacrylate, polymethacrylate, polycarbonate, polyvinyl chloride, polyether, polystyrene, polyolefin, etc. can be used.

In addition, the nonlinear optical material introduced into the matrix of glass or polymer material preferably has a structure having at least one of an electron donating group and an electron withdrawing group in the skeleton having a π electron system. There is something like.

(Left below) 0-nitroaniline p-nitroaniline (X0=Io, I(ho, NO3°, CtoCH
-CHCOO8CROa°, BF4°, Re04e
, CH:+OSO3e)NO2 I3 Polygamma-benzyl-glutamic acid The core layer 2 in the invention of claim 3 does not necessarily need to be formed of the above-mentioned nonlinear optical material, but may be formed of a material that does not have a nonlinear optical effect. It can also be formed. in particular,
It can also be formed only from the material used as the matrix of the core layer 2 in the invention of claim 1 above.

In particular, the use of polymeric liquid crystals as the core layer and cladding layer is excellent because the electro-optic effect, thermo-optic effect, etc. can be used as an active waveguide element, and the effect obtained is large and it can be driven with low energy.

The thickness of the core layer 2 is preferably 0.1 to 100H.

If it is less than 0.1μ hazy, it will be difficult for light to enter, and if it is more than 100% intestine, it will be difficult to select a mode for confinement.

A more preferable thickness is 0.5 to 20 mm.

As the first cladding layer 3, a compound having a lower refractive index than the core layer 2 and the second cladding layer 4 is used. It is desirable that the refractive index difference is larger than lXl0-5.

Below lXl0-5, the refractive index difference cannot be controlled due to the temperature difference. More preferably it is lXl0-3 or more.

The thickness is desirably greater than 1/100 of the wavelength of the light used, and in order to extract the light from the core layer 2 and effectively guide it to the second cladding layer 4 or other optical waveguide,
10 times or less the wavelength of the light used, preferably less than the wavelength of the light used, more preferably 1/1/2 of the wavelength of the light used.
2 or less is desirable.

The material used for the first cladding layer 3 may have a refractive index lower than that of the core layer 2, and examples of inorganic materials include SiO2,
MgF, TiO2, GeO2, 5i3es, Aj)
203 etc. are used. In addition, examples of polymeric materials include polyacrylate, polyester, polyether,
Polyvinyl alcohol, polyvinylidene fluoride, polysiloxane, polyamide, polyimide, polyimide amide, polypeptide, polytetrafluoroethylene, polystyrene, polyethylene.

Polyvinyl chloride, polyvinyl acetate, etc. are used. It is preferable that these materials have no absorption property for the fundamental wave used, and particularly in the invention of claim 1, it is preferable that they also have no absorption property for the generated harmonic waves.

In the invention of claim 1, the first cladding layer 3 is more preferably a material having a refractive index lower than that of the core layer 2 at the frequency of the fundamental wave incident on the core layer 2, and having a frequency of harmonics generated. It has a higher refractive index than the core layer 2. Thereby, the generated harmonics can be more efficiently incident on the second cladding layer 4 or other leading waveguide.

As the second cladding layer 4, a material similar to that of the first cladding layer 3 and having a higher refractive index than the first cladding layer 3 is used.

When the thickness of the second cladding layer 4 is larger than the wavelength of the light used, it is advantageous when laminating layers. in particular,
0.1 end@-100 #Lm is preferred.

If it is less than 0.1H4, it is difficult to efficiently select an interference reflection structure, and if it is more than 1001L, it is difficult to control the interference reflection structure sufficiently, and it is disadvantageous to downsizing the thin film waveguide element.

Further, in the invention of claim 1, when the second cladding layer 4 is used as a leading wave path for generated harmonics, it is preferable to adjust the thickness so as to meet the harmonic confinement conditions.

As the substrate 1, glass, plastic, inorganic crystal, semiconductor, metal, etc. are used.

The spread of light within the core layer 2 can be prevented by making the optical waveguide part a rectangular buried type, by providing a ridge part, by strip loading, or by using a striped first or second cladding layer 3.
Alternatively, this can be done by providing 4.

The thin film waveguide element according to the first aspect of the invention may be multilayered as shown in FIG.

That is, in FIG. 2, the second cladding layer 4, the first cladding layer 3, and the core layer 2 are laminated in this order on one substrate l, and on top of that, the first cladding layer 3', the second cladding layer 4', 1st
A cladding layer 3' and a core layer 2' are laminated in this order.

For example, when an incident laser beam with a wave number W is incident on the upper core layer 2', the incident light is confined in the core layer 2' by the first cladding layer 3'' and the second cladding layer 4'. The harmonics generated in the core layer 2' are guided to the core layer 2 below through the first and second cladding layers 3', 3'', 4',
, 4 in the core layer 2.

In the invention of claim 3, it is necessary to use a polymer material for at least one layer among the core layer 2, the first cladding layer 3, and the second cladding layer 4, thereby imparting an active function. Can be done. For this purpose, it is preferable that the polymer material has an electro-optic effect, and in particular, polymer liquid crystal is most suitable. Furthermore, what is the electro-optic effect?
These include electric field Frederick transition, Kerr effect, Pockels effect, etc.

Furthermore, if the above configuration is applied to the invention of claim 1, it is possible to provide an active function at the same time as the wavelength conversion function, and in particular, in the invention of claim 1, the core layer 2 is made of a polymer material. When used, a polymeric material may be used as the matrix described above.

Examples of the polymer liquid crystal include polymer liquid crystal compounds having liquid crystal phases such as a nematic phase, a chiral nematic phase, a smectic phase, a chiral smectic phase, and a discotic phase. Such a polymeric liquid crystal compound exhibits a particularly effective function when used in the core layer 2.

As the polymeric liquid crystalline compound having a chiral nematic phase or chiral smectic phase, a side chain type polymeric liquid crystalline compound, a main chain type polymeric liquid crystalline compound, etc. can be used.

Examples of the side chain type polymeric liquid crystal compound include those shown in the following formula. (However, in the formula, zero indicates an asymmetric carbon center, and n = 5 to 1000) (Left below) (+24) (+52 = 2 to 15) (12El) (Set = 2 to 10) (I + 2 = 2 ~15) (13r) CH3 -G CH2-C→- " (Peng?= 2-15) (m2 = 2-15) (m2=2-15) (x+y-1, q= 1-10.P2= 1 to 15) In addition, examples of main chain polymeric liquid crystalline compounds having a chiral nematic phase or chiral smectic phase include mesogen groups, flexible chains, and optically active groups, such as ester bonds, amide bonds, peptide bonds, and urethane bonds. Examples include compounds made into polymers by bonds, ether bonds, etc.

Preferably, it is a compound polymerized by an ester bond.

Specific compounds that can be used as mesogen groups include terphenyldicarboxylic acid, P-terephthalic acid,
naphthalene dicarboxylic acid, biphenyl dicarboxylic acid, stilbene dicarboxylic acid, azobenzenedicarboxylic acid, azoxybenzenedicarboxylic acid, cyclobenzenedicarboxylic acid, biphenylether dicarboxylic acid, biphenoxyethane dicarboxylic acid, biphenylethanedicarboxylic acid,
Dicarboxylic acids such as carboxycinnamic acid, hydroquinone, dihydroxybiphenyl, dihydroxyterphenyl, dihydroxyazobenzene, dihydroxyazoxybenzene, dihydroxydimethylazobenzene, dihydroxydimethylazoxybenzene, dihydroxybyridazine, dihydroxynaphthalene , dihydroxyphenyl ether, bis(hydroxyphenoxy)ethane, and other diols; hydroxybenzoic acid, hydroxybiphenylcarboxylic acid, hydroxyterphenylcarboxylic acid, hydroxycinnamic acid, and hydroxyazobenzenecarboxylic acid.

Hydroxycarboxylic acids such as hydroxyazoxybenzenecarboxylic acid and hydroxystilbenecarboxylic acid can be used.

Raw materials for flexible chains include methylene glycol,
Ethylene glycol, propanediol, butanediol, bentanediol, hexanediol, heptanediol, octanediol, nonanediol, decanediol, undecanediol, dodecanediol, tridecanediol, tetradecanediol, pentadecanediol, diethylene glycol, triethylene glycol, tetra Diols such as ethylene glycol, nonaethylene gelicol, and tridecaethylene glycol, and dicarboxylic acids such as malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, speric acid, azelaic acid, and sebacic acid can be used.

The optically active group is preferably difunctional, specifically, (÷)-3-methyl-1,8-hexanediol (-)
-3-Methyl-1,6-hexanediol (◆)-3-
Methylazibic acid (-)-3-methylazibic acid (D)-manito-) (D-+wanni
tol) (L)-mannitol (L-mannitol
)(◆)-Pantothenic acid (,)-1,2-4-trihydroxy-3,3-dimethylbutane (-)-1,2-propanediol (÷)-1,2-propanediol (10)- Lactic acid (-)-Lactic acid (2S, 5S)-2-methyl-3-oxahexane-
Mesogenic groups, flexible chains such as 1,5-diol (2S, 5S, 8S)-2,5-dimethyl-3,8-dioxanonan-1,8-diol and above.

By polycondensing optically active groups, a main chain polymeric liquid crystal compound having a chiral nematic phase or a chiral smectic phase can be obtained. At this time, by using a catalyst, it is possible to improve the degree of polymerization and reduce impurities caused by side reactions, etc., but after the polycondensation is completed, it is desirable to remove them by a reprecipitation method or the like.

Specifically, the following compounds can be mentioned.

(The following is a margin) (13B) (The following is n2=5 to 1000) R3=-CH3CN-+CH2→-Ra = -f C
H2→-(x+V=1.s+2=2~15) (m2=2~15.x+y=1) R1= CH3 -CH? CH20H-e CH2→- (x+y=1.Amount?=2~15)R2=-f
CH2→- (x+y=1.12=2~15) (s3=1~5) (14B) (14?) (m5=0~5) (Intestine 5=θ~5) Furthermore, it has a nematic phase and a smectic phase. Examples of polymeric liquid crystalline compounds include side chain type polymeric liquid crystalline compounds and main chain type polymeric liquid crystalline compounds.

in particular, Examples include compounds represented by the following formulas.

m=1. n=2 Tg=110°C, TC1=140°C ('J11 CH3 n=1~12 (15B) x=1~12.n=1~12 n=CHz-, CToO-, CR-, H-x= 3, n
=3, n=H- Tg=5℃ TCR=114℃ x+y=1.0 m=1-12x=0.1
, y=0.9, m=2Tg=117℃, TC
R=184°C n=1 to 18 n=8 TCR=220°C m=text=l, n=11 Tg=39°C TGR=74°C When the polymeric liquid crystal compound has a glass transition point or melting point above room temperature In order to control switching and the like, a desired waveguide state can be achieved by heating the glass to a temperature above the glass transition point or melting point and then returning the glass to room temperature.

The above effect can also be obtained by maintaining the temperature at a predetermined temperature.

The polymer liquid crystal may be a polymer liquid crystal composition in which other components are added to the polymer liquid crystal compound. For example, the polymer liquid crystal composition may be a polymer liquid crystal composition in which a polymer liquid crystal compound and a low molecular liquid crystal compound are mixed. Examples include those obtained by heating and dissolving or dissolving in a common solvent.

The polymer liquid crystal compound and the polymer liquid crystal composition may be used alone in the form of a film, or may be used as an M layer on a support substrate.

To form a thin film using polymer liquid crystal, polymer liquid crystal is heated and melted or dissolved in a solvent to make it into a liquid state, and the method is spin code method, casting method, dipping method, bar code method, roll coating method, and gravure coating method.

This can be done by applying it to the surface on which the thin film is to be formed using a doctor blade method or the like. Furthermore, in order to pattern and apply the polymer liquid crystal in stripes or the like, a screen printing method, patterning using a photoresist, or the like can be used. These methods are also used to form thin films using polymeric materials other than polymeric liquid crystals.

When imparting active functions using polymeric liquid crystals, it is preferable to perform horizontal alignment or vertical alignment treatment.

Horizontal and vertical alignment treatments include stretching by mechanical force, roll stretching, shearing, electric field/magnetic field, and interface control. When using a support substrate, horizontal or vertical alignment treatment by interface control is particularly preferred.

Specific examples of horizontal alignment processing based on interface control include the following.

■ Rubbing method By solution coating, vapor deposition, sputtering, etc., on the substrate, for example, - oxide, oxygen dioxide, aluminum oxide, zirconia, magnesium fluoride, cerium oxide, cerium fluoride, silicon nitride, silicon carbide, boron nitride. Inorganic insulating materials such as objects, polyvinyl alcohol, polyimide, polyamideimide, polyesterimide, polyparaxylerin, polyester, polycarbonate, polyvinyl acetal, polyvinyl chloride, polyamide, polystyrene, cellulose resin, melamine resin, Yurya resin, acrylic resin, etc. It is possible to provide an alignment control film formed using an organic insulating material.

This orientation control film is formed by forming a film of an inorganic insulating material or an organic insulating material as described above, and then rubbing the surface of the film in one direction with velvet, cloth, or paper.

■Oblique evaporation method Oxide such as SiO or fluoride or Au, Aj+
Metals such as metals and their oxides are deposited from an oblique angle on the substrate.

(2) Oblique etching method The organic or inorganic insulating film shown in (2) is etched by obliquely irradiating it with an ion beam or oxygen plasma.

(2) Use of stretched polymer membranes Membranes obtained by stretching polymer membranes such as polyester or polyvinyl alcohol also exhibit good orientation.

■Grating method N can also be formed by forming grooves on the substrate surface using photolithography, stamper, or injection.
The liquid crystal is aligned in the direction of the groove.

In addition, specific vertical alignment treatments based on interface treatments include the following.

■ Form a vertical alignment film.

A vertically aligned layer of organic silane, lecithin, PTFE, or the like is formed on the surface of the substrate.

(2) Oblique Vapor Deposition Vertical alignment can be provided by appropriately selecting the deposition angle while rotating the substrate in the oblique vapor deposition method. Further, after oblique vapor deposition, a vertical alignment agent shown in (2) may be applied.

In the above alignment process, each alignment means may be used alone or in combination of two or more means.

Examples of polymer materials other than polymer liquid crystals for imparting functionality include polyvinylidene fluoride, P(VDF-↑rF
E) Copolymers etc. can be used.

When a polymeric material is used to impart functionality, as shown in FIG. 3, upper and lower electrodes 5a and 5b can be provided, and these electrodes 5a and 5b can also be patterned. In addition, an electrode 5 is placed between the leading waveguides using a polymer material.
a, 5b, or a heat insulating layer or light absorption layer.

Also in the case of the invention of claim 3, multi-layering is possible as shown in FIG. Electrode 5a shown in FIG.
Reference numeral 5b denotes a matrix electrode, in which a low refractive index interference layer 6 is provided under the upper electrode 5a, and a core layer 2 is provided below it. This upper core layer 2' has a refractive index sufficiently higher than that of the low refractive index interference layer 6, and has a refractive index higher than that of the first cladding layer 3'' and a thickness of the second cladding layer 4', so that resonance reflection conditions can be achieved. The first cladding layers 3', 3 located above and below the lower core layer 2 have a refractive index lower than that of the core layer 2, and the second cladding layers 4', 4 have a lower refractive index than the core layer 2.
A resonant reflection condition is established, and the light is confined within the core layer 2 below. There is an electrode 5b further below, and an electrode 5b above.
By applying a voltage between the leading waveguide and the waveguide a, waveguide in the leading waveguide can be controlled. Note that 13 is a flattening layer.

[Examples] Example 1 Ai) having a thickness of 3000 Å was vapor-deposited on a glass substrate l to form an electrode 6b, and 2 #L layers of 5iOz were further vapor-deposited. Furthermore, a benzene solution of 5% by weight of 4-amino-4'-nitrobiphenyl dissolved in polymethyl methacrylate resin was spin-coated onto the material on which 100 OA of lithium fluoride had been vapor-deposited to give a thickness of 4 diabases. A piece of aluminum foil is attached to this element to form an electrode 8a, and a
While applying a DC voltage of 0.00 mm, the film was cooled from 120° C. to room temperature to achieve orientation for the nonlinear optical effect.

A laser beam was applied to the thin film waveguide device thus obtained as shown in FIG.

A Nd:YAG laser (wavelength: 1.084B) was used as the laser light source 7, and was introduced into the core layer 2 having a nonlinear optical effect through a condensing lens 8. At this time, the light emitted from the second cladding layer 4 had a symmetrical shape, and when it was analyzed using a spectrometer, a second harmonic of 532 ns was detected.

In FIG. 1, 9 is a modulation device, and 10 is a modulation signal generator.

Example 2 AI with a thickness of 3000A on a glass substrate l! was vapor-deposited to form the electrode 5b, and 5i023μ porcelain was further vapor-deposited. Further L
A cyclohexanone solution of a polymer liquid crystal represented by the following formula (I) was spin-coated onto the material on which iF was deposited at 500 OA, and after drying, the thickness was made to be 4 final layers. Core layer 2 of this device
When the semiconductor laser of the 830B layer was incident on the laser as shown in FIG. 3, it was guided and emitted from the output end face.

At this time, there was almost no light leaking from other than the output end face of the element.

Next, an aluminum foil was closely attached to the device to form an electrode 5a, and while applying a DC voltage of 150 V between the electrode 5b of the 11 layers deposited, the device was heated to 120° C. and cooled. When an 830B layer semiconductor laser was incident on this element in the same manner as described above, most of the light was emitted as leakage light from other than the output end face.

In FIG. 3, 8 is a condensing lens, 11 is a switching region, and 12 is a voltage application control device.

(I) Example 3 5i023 p, m was deposited on a glass substrate 1, and LiF was further deposited at 5000A. A cyclohexane solution of the same polymer liquid crystal as in Example 2 was spin-coded onto this substrate 1, and after drying, a core layer 2 having a thickness of 4 μm was obtained.

After depositing 5i021p and m on that E, 5i021p and m
0OA vapor deposition was performed. As shown in FIG. 5, when a He-Me laser is focused from the end face of this element by a condensing lens 8 and is incident on the core layer 2, it is guided through the core layer 2 and most of the light is emitted. After the emitted zero order, this element was installed so that a 1oxc magnetic field was applied to the waveguide at any time, and a semiconductor laser of 830 nm and 10 layers was irradiated while the magnetic field was applied. When the He-Me laser beam was again incident on the end face, most of it was emitted from the second cladding layer 4 as branched light.

In FIG. 5, 3 is a first cladding layer, 6 is a low refractive index interference layer, 11 is a switching region, and 14 is an IR absorption layer.

[Effects of the Invention] The present invention is as described above, and has the following effects.

(1) The thin film waveguide element of the present invention is of a resonant reflection type, and
Since there are few restrictions on the substrate and it is easy to form a guiding waveguide, high performance can be obtained at low cost.

(2) In particular, according to the invention of claim 1, by using a nonlinear optical effect, harmonic phase matching in a thin film waveguide element is facilitated, and characteristics that are sufficiently stable against temperature changes, etc. can be achieved. Obtainable. Also, the obtained harmonics are
The beam shape and phase state are good, and it is extremely effective when used after further shaping.

(3) When polymeric materials are used as in the inventions of claims 2 to 5, multilayering and clustering are easy, and optical integrated circuits and three-dimensional waveguide devices are made smaller and more efficient. can. Also,
Active waveguide elements that perform demultiplexing, radiation, coupling, switching, etc. can be easily obtained. In particular, according to the invention of claim 4 or 5, the control of this active function becomes reliable.

[Brief explanation of drawings]

Fig. 1 is an explanatory diagram of Example 1, Fig. 2 is a sectional view showing an example of multilayering, Fig. 3 is an explanatory diagram of Embodiment 2, and Fig. 4 is a sectional view showing another example of multilayering. , w45 is an explanatory diagram of the third embodiment. 2 substrates 2.2': Core layer 3.3', 3": First cladding layer 4.4': Second cladding layer

Claims (1)

[Claims] 1) A core layer that performs wavelength conversion using a nonlinear optical effect, a first cladding layer with a lower refractive index than the core layer, and a second cladding layer with a higher refractive index than the first cladding layer, on a substrate. 1. A thin film waveguide element characterized by having a layered structure. 2) The thin film waveguide device according to claim 1, wherein a polymer material is used for at least one of the core layer, the first cladding layer, and the second cladding layer. 3) A core layer for optical waveguide, a first cladding layer having a lower refractive index than the core layer, and a second cladding layer having a higher refractive index than the first cladding layer are laminated on the substrate, and the core layer, A thin film waveguide device characterized in that a polymer material is used for at least one of the first cladding layer and the second cladding layer. 4) The thin film waveguide element according to claim 2 or 3, wherein the polymer material has an electro-optic effect. 5) The thin film waveguide device according to claim 4, wherein the polymer material is a polymer liquid crystal.