JP2001296442A - Method for manufacturing structure with refractive index period having photonic structure, and optical functional element using it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a structure with refractive index period capable of being used as a photonic structural body without or with a defect having a period equal to that of an optical wavelength, its applied functional element and a simple method for manufacturing those. SOLUTION: Structure with two-dimensional refractive index period equal to the optical wavelength which is composed with such a size as being used as the photonic structural body is obtained by using rugged structure having two-dimensional periodicity equal to the optical wavelength as a master disk 2 and by forming a die 6 having inversion structure of rugged structure by piling up and peeling stamper material.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a microstructure usable as a photonic structure, an optical functional device using the same, and more particularly, to a multidimensional element having a period of about the wavelength of light. The present invention relates to a method for manufacturing a periodic refractive index structure, that is, a photonic structure, and an optical device and the like using the same.

[0002]

2. Description of the Related Art It is known that a dielectric multilayer film having a refractive index cycle of about the wavelength of light has excellent characteristics as a mirror. Such a structure is regarded as a one-dimensional photonic structure. On the other hand, a structure having a refractive index period of about the light wavelength in the biaxial or triaxial directions is called a two-dimensional or three-dimensional photonic structure. Since the propagation of light waves of a specific wavelength determined by the refractive index and the period is prohibited inside these structures, application to optical functional devices such as waveguides and filters is expected. This forbidden band is called a photonic band gap.

[0003] As an actual method of manufacturing a two-dimensional or three-dimensional photonic structure, a semiconductor or a dielectric thin film is formed on a semiconductor or dielectric thin film by using a two-dimensional period of about the light wavelength in a two-dimensional plane using an etching technique or a photolithography technique. The main method is to manufacture a three-dimensional periodic structure by manufacturing an uneven structure or by laminating a two-dimensional periodic structure by sputtering or precise alignment (Shawn Yu Lin, Nature, vol. 16, p. .
251, 1998).

In addition, spherical particles (such as polystyrene and SiO ₂ ) having a size about the wavelength of light produced by chemical synthesis are used.
A method of manufacturing a three-dimensional periodic structure by regularly arranging the colloidal suspension according to the conditions such as the surface tension of the colloidal suspension and the ambient temperature has been proposed (NDDenkov, Langmuir, vol.
8, p. 3183, 1992; N. Yamamoto, Jpn. J. Appl. Phys.,
vol.37, p.L1052, 1998).

In recent years, a two-dimensional circular hole photonic structure having a band gap in a visible light region formed by anodizing carbon or alumina has also been manufactured.
(H. Masuda, Appl. Phys. Lett., Vol. 71 (19), p. 27
70, 10 November, 1997).

[0006]

However, when a wide range of periodic structures is manufactured on a dielectric or semiconductor material by a film forming method and an etching method and further laminated, a precise alignment of about a light wavelength must be repeatedly performed. .

Further, the periodic structure of the spherical particles in the size of about the wavelength of light produced by chemical synthesis, mainly produced in a self-organizing manner by polystyrene and SiO ₂ of capillarity and evaporation phenomena using spherical particles-suspension liquid However, it is actually affected by the conditions such as the concentration of the suspension, the ambient temperature and the humidity, and it is a reality that a defect-free periodic structure cannot be realized in a wide range, and a multilayer complete periodic structure cannot be expected. The periodic structure of the spherical particles can be laminated after being fixed with an adhesive such as a resin, but a decrease in the photonic band width due to the collapse of the periodic structure can be considered. In addition, these structures are manufactured on a substrate, and light waves propagate to the substrate to reduce the light confinement efficiency and hinder application to an optical functional element.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems of the prior art, and an object of the present invention is to provide a photonic structure having a period of about a light wavelength and which can be used as a defect-free or defective photonic structure. An object of the present invention is to provide a structure, an applied functional element thereof, and a simple manufacturing method thereof.

[0009]

According to the present invention, there is provided a method for manufacturing a photonic structure, comprising:
A light having a size that can be used as a photonic structure by forming a mold having an inverted structure of the concave-convex structure by depositing and peeling a stamper material with a concave-convex structure having dimensional periodicity as a master, It is characterized in that a two-dimensional refractive index periodic structure having a wavelength of about a wavelength is obtained. In this specification, 2
Dimensions include one dimension, and three dimensions include one or two dimensions. The light wavelength means the wavelength of ultraviolet light, visible light, and infrared light, and indicates a wavelength range from about 0.1 μm to about 10 μm from an excimer laser to a carbon dioxide laser.

Based on the above basic configuration, the following more specific modes are possible. The master is manufactured by patterning a structure having a period of about the light wavelength on the substrate, or is a periodic structure in which particles of a size about the light wavelength manufactured by chemical synthesis are arranged, or a V groove is formed on the substrate. The V-groove formed may be a periodic structure.

The deposition of the stamper material is performed by electroplating or electroless plating a metal, by electrodepositing an electrodeposition material, or by a molding method.

After forming the mold, the mold may be filled with an optical functional material and cured. If the mold is made of an optical functional material, it can be used as it is as a photonic structure. After the mold is filled with the optical functional material and cured, the mold may be removed. Of course, in this case as well, the mold need not be removed if the mold is made of an optical functional material.

Further, the periodic structure of the optical functional material formed by removing the mold may be filled with another optical functional element and cured.

A plurality of molds are opposed to each other to form a new mold,
The new mold may be filled with an optical functional material and cured. Also in this case, the mold may be left as it is or may be removed. Furthermore, another optical function element may be filled and cured in the periodic structure of the optical function material formed by removing the mold.

After at least a part of the mold is filled with an optical functional element and cured, an unfilled portion is filled with an optical functional material different from the optical functional material and cured to form an arbitrary part of the periodic refractive index structure of about the light wavelength. A defective portion may be formed at the site.

When the optical functional material is cured, a non-cured portion may be formed in a part, and a defective portion may be formed in an arbitrary portion of the refractive index periodic structure of about the light wavelength. When the optical functional material is photocurable, an uncured portion can be produced by covering a part with a mask.

The two-dimensional periodic refractive index structure is aligned and laminated so as to form a three-dimensional periodic refractive index structure, and is fixed with a curable material to produce a three-dimensional photonic structure. it can.

The optical functional device of the present invention that achieves the above object has a three-dimensional periodic structure of a refractive index of about a light wavelength, which is made of an optical functional material having a size usable as a three-dimensional photonic structure. And has a continuous defective portion.

The defect portion may be a portion made of an optical functional material different from the surroundings, or a portion from which the optical functional material has escaped.

The three-dimensional periodic refractive index structure is formed by stacking a plurality of two-dimensional periodic refractive index structures including a two-dimensional periodic refractive index structure having a defect so as to form a three-dimensional periodic structure. Can be configured.

The defect portion can be typically configured as an optical waveguide for confining a light wave by a photonic effect. Further, the defect portion constitutes a branch waveguide, and a configuration in which a defect-free photonic structure is disposed around the branch waveguide, or the defect portion forms a bent waveguide, and a defect-free peripheral portion forms a bent waveguide. Can be adopted in which the photonic structures are arranged.

The optical waveguide structure of the present invention for achieving the above object is an optical waveguide having a branch waveguide section, wherein a three-dimensional refraction made of an optical functional material of about the light wavelength is provided around the branch waveguide section. A photonic structure having a periodic structure is arranged. Alternatively, an optical waveguide having a bent waveguide portion, at least in contact with an outer corner portion of the bent waveguide portion (a mirror surface may be formed as shown in FIG. 14), A photonic structure, which is a three-dimensional periodic refractive index structure made of an optical functional material having a light wavelength or so, is disposed.

Further, in the duplexer according to the present invention, which achieves the above object, a photonic structure having a defect-free two-dimensional refractive index periodic structure made of an optical functional material having a light wavelength or the like is arranged on an end face of an optical waveguide. In addition, the present invention is characterized in that guided light is wavelength-demultiplexed in different directions depending on the wavelength using the Bragg diffraction phenomenon. Alternatively, a photonic structure, which is a defect-free two-dimensional periodic refractive index structure made of an optical functional material of about the light wavelength, is disposed at the end face of the optical waveguide, and the guided light is divided into different directions using the Bragg diffraction phenomenon. It is characterized by waving.

According to the optical wiring apparatus of the present invention, which achieves the above object, a concave portion is provided in an electric wiring board, and a light emitting element and a light receiving element are arranged on the wall surface of the concave portion. An optical wiring path is formed by inserting at least one of the optical waveguide structure and the duplexer, and light from the light emitting element is guided to the light receiving element via the optical wiring path. Alternatively, a concave portion is provided in the substrate, an optical waveguide is arranged on the wall surface of the concave portion, and at least one of the optical function element, the optical waveguide structure, and the duplexer is inserted into the concave portion to form an optical wiring path. And guiding the light to the optical waveguide through the optical wiring path.

In each of the above structures, the optical functional material comprises:
Examples of the material include a material having a non-linear optical polarizability, a light-emitting material, a magnetic material, a conductive material, an electro-optic material, and a light or thermosetting resin material mixed with a light amplification material.

[0026]

Embodiments of the present invention will be described below with reference to the drawings.

(First Embodiment) First, a two-dimensional photonic structure serving as a master will be described. A single-layer film made of metal, semiconductor, or insulator is formed on a substrate, and a light wavelength (0.1 μm) as shown in FIG.
The rectangular uneven structure 1 having a two-dimensional periodicity of about 10 to 10 μm) is manufactured in the substrate surface. A typical photonic structure is made of a dielectric or polymer material such as PMMA (polymethyl methacrylate) or SiO ₂ . However, in the present invention, since the material is used as a master, only a process may be considered as long as it is a material capable of forming a periodic structure on the order of a light wavelength. Unless the material is porous, any material such as metal can be used. It is possible to handle materials.

There is also a method in which a liquid in which spherical particles (such as polystyrene and SiO ₂ ) having a diameter of about the light wavelength produced by chemical synthesis are suspended is dropped on a substrate and arranged. When the substrate is inclined and the ambient temperature, humidity and angle of inclination are adjusted and left as it is, the surface tension of the suspension, the evaporation phenomenon and the force between particles cause the particles to move to the higher side of the inclined substrate. Is attracted. At this time, the spherical particles accumulate in a dense state in a self-organized manner as shown in FIG. This structure is a spherical particle uneven structure 2 having a periodic structure in a two-dimensional plane of the substrate.

Further, the structure shown in FIG. 1C can be used. This is a one-dimensional structure in which V-shaped grooves 4 of the (111) plane, which can be formed by wet etching the Si substrate 3 with a potassium hydroxide solution, are formed at equal intervals. This structure can also not usually be a photonic structure,
It can be used as a master. The size of the photonic structure finally manufactured depends on the medium used as the stamper material to be sputter-deposited on the master and the light wavelength used. It is better if the periodic structure continues indefinitely, but 100
A photonic band gap is observed even at about the period.

Next, a description will be given of the fabrication of the concavo-convex inversion type by a molding technique or the like. In the case of the master shown in FIG.
A concave / convex inversion mold is manufactured by a molding method, and a curable liquid material is injected into each cell. In this regard, FIG.
Will be described in detail.

In the case of the master shown in FIG. 1B, the operation is performed as follows. FIG. 2A shows a structure 2 placed on a substrate 5 and having a period about the light wavelength. Fig. 2 (b) and (c)
As described above, the stamper material is sputter-deposited and then peeled off, thereby forming a mold 6 having an inverted structure of the master disk uneven structure. Since the master disk uneven structure is not necessarily defect-free, a master region having an arbitrary structure is selected and a stamper material is applied.

In the sputtering of a stamper material, there is a method of electroplating or electroless plating a metal having a small stress. In this case, for example, Ti, Au, MoO _x or Cr, Pt, MoO _x are sputtered on the master 2 in this order, and then a metal is plated. The first layer of Ti or Cr is composed of the master 2 and the second layer of Au or
It is applied to increase the adhesion between Pt. It no Au of the second layer is peeled off the base 2 and the mold 6 between MoO _x of Pt and third layer, MoO _x remaining in the mold side mold 6 is completed is removed by HF / H ₂ O.

Alternatively, instead of metal plating, a mold 6 may be formed by applying a thick coating of SiO ₂ or a resin and peeling it. In this method, a material that dissolves in HF / H ₂ O such as Ti or MoO _x is applied as an intermediate layer on the master 2 and then SiO ₂ or a resin is applied.
The intermediate layer is eroded in HF / H ₂ O to release the mold 6.

It is also possible to combine and bond a plurality of the produced dies 6 to use them as dies having a new uneven shape. As shown in the cross-sectional view of FIG. 2D, a mold having a new shape is manufactured by combining one or more of the molds 6 (the molds 6 can be arranged over a wide area). After the curable liquid material 7 is filled as shown in (d), it is cured by irradiating or heating with ultraviolet light to form a multidimensional photonic structure. The curable liquid material 7 contains, for example, a material having a non-linear optical polarizability, a light-emitting material, a magnetic material, a conductive material, an electro-optical material, a light amplification material, or the like according to the required physical characteristics. Light-curable material or thermosetting material.

When a plurality of molds are faced and combined as shown in the left part of FIG. 2D, these are bonded so as to form a slight gap between the concave periodic structures, and the mold 6 is inclined. Then, the curable liquid material 7 is injected from above. When the curable liquid material 7 has a high viscosity, it is preferable to open the air holes 17 as shown in FIG. 3 in order to prevent the gas inside the mold from being discharged and incomplete filling.

The curable liquid material 7 may be partially injected from the air holes 17. The smaller the gap between the concave periodic structures 6, the less the influence on the photonic bund phenomenon of the formed photonic structure. The photonic structure obtained by curing the curable liquid material 7 can be used as it is without removing the mold 6 or can be removed.
Kind can be considered. For example, if the stamper material is a SiO _2,
By immersing in HF / H ₂ O, the mold is transformed from the two-dimensional photonic structure
6 can be removed, and a photonic structure 8 having no influence on the photonic bund effect by the mold 6 can be obtained as shown in FIG. Also, if the stamper material that becomes mold 6 is also made of an optical functional material such as PMMA, it can be used as a clad to adjust the photonic band width and be used as a single-mode waveguide etc. It is.

In the case of FIG. 1B, a more specific example will be described. A suspension of polystyrene microspheres having a particle size of 0.5 μm and prepared by chemical synthesis is dropped on the inclined glass substrate. As described above, if the ambient temperature, humidity and tilt angle are adjusted and left, the particles are attracted to the higher side of the substrate by the action of the surface tension of the suspension, the evaporation phenomenon, and the force between the particles, and the spherical particles Accumulate in a dense state in a self-organizing manner as shown in FIG. In this manufacturing method, the hexagonal lattice is more stable than the square lattice, and thus is easier to manufacture. Using this structure as a master, a periodic structure portion having no defect is selected, and sputtering is performed in the order of Ti, Au, and MoO _x , and metal is further plated. The first layer of Ti is applied to increase the adhesion between the master and the second layer Au. The master and the mold are separated between the second layer Au and the third layer MoO _x , and MoO _x remaining on the mold is removed with HF / H ₂₀ to manufacture the mold. Two molds are opposed to each other as shown in FIG. 3 to form a spherical concave structure, and a UV curable resin having a refractive index of 1.6 is injected and UV cured. When the master is peeled off, a spherical particle hexagonal lattice two-dimensional photonic structure having a refractive index of 1.6 and a period of 0.5 μm is formed. Since this structure has a photonic band gap located in the visible light range, it can be applied to a mirror or the like for visible light.

In the case of the master shown in FIG. 1C, a stamper material is sputter-deposited on the master 3 and then separated to form a one-dimensional periodic structure. This may be used by filling the groove with some material. They may be used alone or may be used in an appropriate combination by lamination.

(Second Embodiment) FIGS. 5A and 5B show an example of a master having a rectangular uneven structure. By using an etching technique or a photolithography technique on a metal, a semiconductor, or an insulator, a concavo-convex structure having a period of about a light wavelength in a two-dimensional plane is manufactured. For example, when the master 9 as shown in FIG.
A mold 9 having the shape shown in FIG. Further, when the master 9 as shown in FIG. 5B is manufactured and the concave / convex inversion mold is manufactured by the molding method, the mold 9 having the shape shown in FIG.

The mold shown in FIG. 5A has a curable liquid material 7 in each cell.
Is suitable for use in manufacturing defects as described in the third embodiment. A two-dimensional photonic structure is manufactured using the mold 9 shown in FIGS.
After the mold 9 is peeled off, the optical function material 12 different from the curable liquid material 11 injected and cured first is filled in the concave portion of the photonic structure. It is also possible to reduce the difference in the refractive index of the photonic structure (FIGS. 6A and 6B). Alternatively, the mold 9 may be manufactured in advance from an optical functional material such as PMMA, and used as the optical functional material 12 without peeling.

A more specific example will be described. PMMA on the substrate
(Polymethyl methacrylate), silicon-based photoresist (FHSP)
5 (b), a square rectangular pattern having a period of 0.5 μm is formed. Since FHSP has resistance to oxygen dry etching, it is suitable for etching using this pattern as a mask and oxygen as a reactive gas. Reactive ion etching
The master 9 having a rectangular uneven structure is completed by etching the PMMA by the (RIE method). When a UV-curable resin having a refractive index of 1.6 is injected into the concave portion, UV-cured, and the master is peeled off, a square rectangular two-dimensional photonic structure having a refractive index of 1.6 and a period of 0.5 μm is formed.

(Third Embodiment) A method of manufacturing a photonic structure having a defect in an arbitrary shape will be described. Fig. 7 (a)
As shown in FIG. 5, when the curable liquid material 7 placed in the mold 6 is cured, the non-cured portion 15 is manufactured by covering a part of the curable liquid material 7 with a mask 13 which is a light non-transmissive portion 14 (in this case, light was applied. Only the part cures). Then, by removing the non-cured portion 15 after removing the mold 6, a defect of an arbitrary shape can be formed in the photonic structure 8 as shown in FIG. 7B.

As shown in FIG. 8 (a), at least a part of the mold 6 is filled with the curable liquid material 7,
After being cured by, for example, the curable liquid material 18 different from the liquid material 7 is filled in the unfilled portion and cured,
A defect 15 can be formed in the photonic structure 8. As shown in FIG. 8 (b), when two molds 6 made of a master having a spherical concave-convex structure are combined, for example, a curable liquid material 7 is formed on a portion where a defect is formed before combining the molds 6.
After that, the mold 6 is combined and a curable liquid material 18 different from the curable liquid material 7 is injected and cured from the holes 17.

A more specific example will be described. Using the master 2 (see FIG. 1B) manufactured in the first embodiment, continuous defects are manufactured in a two-dimensional plane. The UV curable resin having a refractive index of 1.6 injected into the mold 6 of the master 2 is cured through a mask having a light non-transmissive portion of the second layer defect pattern in FIG. When the mold 6 is peeled off and the resin in the non-cured portion is removed, a two-dimensional hexagonal lattice sphere having a period of 0.5 μm and a refractive index of 1.6 having a defect used as the second-layer waveguide in FIG. A photonic structure is created.

(Fourth Embodiment) An example in which the manufactured two-dimensional photonic structures are stacked will be described. Fig. 9 (a), (b)
When a two-dimensional photonic structure 8 is laminated to form a three-dimensional periodic structure and fixed with a curable liquid material as shown in the cross-sectional view shown in FIG. 10 (a), (b), (c), and (d) show examples in which a spherical particle square lattice photonic structure 8 having a size about a light wavelength is stacked.
Assuming that the center of a certain sphere is the origin, FIG. 10A shows that the origin 19 of the first layer and the origin 20 of the second layer are on the same Z axis (perpendicular to the plane of the two-dimensional photonic structure). Where
FIG. 10B is a top view thereof. FIG. 10C shows a case where the origin 19 of the first layer and the origin 20 of the second layer are shifted by a half cycle in the XY plane, and FIG. 10D is a top view thereof. In the conventional method using evaporation of the suspension of the spherical particles, the sphere is stabilized in the middle of the sphere between the lower layer and the sphere, so that FIGS. 9 (a) and 9 (b)
And the lamination form of FIG. 10A is difficult to realize.

FIGS. 11A and 11B show an example in which the rectangular two-dimensional photonic structures shown in FIGS. 6A and 6B are stacked. If the center of the rectangular unit cell 11 or 12 made of the same medium is set as the origin, FIG. 11A shows a case where the origin of the first layer and the origin of the second layer are on the same Z axis, and FIG. ) Shows a case where the origin of the first layer and the origin of the second layer are shifted by half a cycle in the XY plane. By using this method, it is possible to stack the photonic structure on the upper layer of the photonic structure having an air defect without filling the defect.

A more specific example will be described. Spherical particle hexagonal lattice two-dimensional photonic structure with a refractive index of 1.6 and a period of 0.5 μm manufactured in the first embodiment (see FIG. 4)
Are laminated so as to have a three-dimensional period by precise alignment. In the stacking of the spherical array structure, FIG.
The lamination form as shown in (b) has poor stability and is difficult.
On the other hand, the lamination form in which the upper sphere enters the gap between the spheres as shown in FIGS. 10C and 10D is very stable, and the alignment need not be very precise. 2 produced in the first embodiment
On the upper surface of the three-dimensional photonic structure, a resin having the same type of refractive index as that of the resin forming the structure is applied thinly, and the second two-dimensional photonic structure is placed between the balls of the first layer. The two layers are stacked so that the sphere is positioned, and both are fixed by UV irradiation. At this time, when the thickness of the resin as the adhesive becomes large, the periodic structure is broken, and the photonic band gap becomes shallow. The third layer can be considered to have the same arrangement as the lattice axis of the first layer, or two arrangements in which the lattice axis is shifted by 30 degrees. Do. This procedure is repeated to manufacture a multi-dimensional photonic structure.

(Fifth Embodiment) In an optical waveguide such as a dielectric, the biggest problem is how to reduce a loss when a light wave is branched or bent.
For example, a hexagonal lattice multi-dimensional photonic structure has a band gap extending in all directions, and thus can be used as a low-loss mirror.

For example, the spherical particle square lattice 2 shown in FIG.
Like the two-dimensional photonic structure, a defect 15 is manufactured in the second layer of the two-dimensional photonic structure 8, and a light wave having a wavelength located inside the photonic band gap unique to the two-dimensional photonic structure 8 is formed. 35 enters from the end face of the defect portion 15 (the outgoing light is indicated by 36). Since light waves are prohibited from propagating inside the crystal, the structure in FIG. 12 is a structure having an optical waveguide through which light propagates through the defect 15.

Further, as shown in the top views of FIGS. 13 and 14, the branch portion or the bent waveguide 3 of the Y-shaped optical waveguide 34 is formed.
A structure in which the multidimensional photonic structure 8 is arranged only around the bent portion 3 can be configured. The multidimensional photonic structure 8 is designed to have a photonic band gap in the wavelength range of the light wave propagating inside the optical waveguides 33 and 34. Since the propagation of the light wave inside the photonic structure 8 is prohibited, the light wave is not radiated to the outside even in a branched or sharply bent waveguide, and is guided with low loss.

FIG. 14 is a top view of a bent waveguide 33 having a 45-degree cut surface and a mirror structure formed by an outside (air layer or the like) at a bent portion. A multidimensional photonic crystal 8 is arranged in this mirror portion. To have the function of an external mirror,
Lightwave propagation loss is reduced.

As described above, by disposing the photonic structure around a conventional dielectric optical waveguide manufactured by photolithography or the like and using it as a mirror, the propagation loss can be reduced. More specifically, as shown in FIG.
Outside the curved waveguide 33 having a mirror shape of 5 degrees,
Spherical particle hexagonal lattice three-dimensional photonic structure 8 having a refractive index of 1.6 and a period of 0.5 μm manufactured in the fourth embodiment 8
Place. Since the photonic band gap is located near 640 nm in this structure 8, the optical waveguide 33
Propagation loss in the bent portion of the light wave of this wavelength propagating in the inside can be reduced.

(Sixth Embodiment) Next, an example in which the multidimensional photonic structure is used as an optical wavelength demultiplexer or an optical intensity demultiplexer will be described. The defect-free multidimensional photonic structure 8 is disposed on the terminal section of the optical waveguide 21 as shown in FIG. The photonic structure 8 functions as a two-dimensional diffraction grating for a light wave having a wavelength outside the photonic band gap, and the light wave 22 propagating inside the optical waveguide 21 is emitted with a two-dimensional spatial spread. I do. If the light wave 22 is monochromatic laser light, a Bragg diffraction spot pattern as shown in FIG. 15B can be seen on a plane perpendicular to the propagation direction of the light wave 22 (the YZ plane in FIG. 15A). 23, 2
Reference numerals 4, 25, and 26 denote zero-order light, first-order light, second-order light, and third-order light, respectively. The shorter the wavelength of the light wave 22, the shorter the spot interval in the same plane, and the higher the order of the spot, the lower the light intensity. Therefore, if a plurality of optical waveguides 21 are arranged as shown in FIG. 16A and each optical waveguide 21 is coupled to each spot, it can be used as a light intensity demultiplexer.

When a plurality of light waves 22 having different wavelengths propagate in the optical waveguide 21, the light waves 22 are decomposed with different diffraction angles for each wavelength, so that a plurality of spot patterns can be obtained. As an example, when white light (visible light) propagates through the optical waveguide 21, a two-dimensional photonic structure 8 of a hexagonal lattice made of polystyrene spherical particles (refractive index 1.6, particle diameter 1 μm) manufactured by chemical synthesis. Is disposed at the end of the optical waveguide 21, each spot 27 has a wavelength distribution in which the origin O side of the axis has a short wavelength as shown in FIG. As shown in FIG. 16B, the optical fiber is coupled to the bundle fiber 32 and can be used as an optical wavelength demultiplexer. When diffraction spots are seen to higher orders, they are also used as light intensity demultiplexers.

A more specific example will be described. A spherical particle hexagonal lattice two-dimensional photonic structure 8 having a refractive index of 1.6 and a period of 1.0 μm manufactured by the method of the first embodiment is connected to an end face of a rectangular waveguide 21 as shown in FIG. Vertically. Since this structure 8 has no band gap in the visible light wavelength region, it only causes the Bragg diffraction phenomenon for the light wave in the visible light wavelength region emitted from the waveguide 21. When coherent light such as a He-Ne laser is directly incident on the structure 8, a three-symmetric Bragg diffraction spot shown in FIG. 15B is observed. As shown in FIG. 15A, in the He-Ne laser light passing through the optical waveguide 21, the light wave has a spread due to reflection in the waveguide 21, so that the spot shape has a spread. Further, when white light is incident on the structure 8, a primary spot 27 having a continuous wavelength distribution with a short wavelength on the origin O side of the axis as shown in FIG. 15C is observed. As shown in FIG. 16B, the optical fiber is coupled to the bundle fiber 32 and can be used as an optical wavelength demultiplexer.

(Seventh Embodiment) At least a part of defect 1
The multi-dimensional photonic structures 8 having the 5 are stacked so as to have three-dimensional periodicity by alignment. For example, FIG.
When a two-dimensional photonic structure 8 having a number of defects 15 as shown in FIG.
It becomes a three-dimensional optical waveguide for confining light in the optical waveguide. At this time, the photonic structure 8 needs to have a band gap in all directions, and the light wavelength at which confinement occurs in the defect portion 15 depends on the periodic structure and the medium dielectric characteristic of the photonic structure 8 used. Depends on the rate.

A more specific example will be described. The upper and lower sides of a spherical particle hexagonal lattice two-dimensional photonic structure 8 having a period of 1.0 μm having a refractive index of 1.6 and having a continuous defect 15 manufactured in the third embodiment are manufactured in the first embodiment. In order to obtain a two-dimensional photonic structure free from defects, ten layers are stacked as a three-dimensional close-packed hexagonal structure similar to the fourth embodiment. This structure becomes an optical waveguide that propagates a light wave having a wavelength of around 640 nm, and has a highly efficient confinement effect even if it is sharply bent or branched.

(Eighth Embodiment) A three-dimensional photonic structure 8 having a defect 15 is embedded in a part of a wiring board 31 including a light emitting element 28 and a light receiving element 29 and having an electric wiring as shown in FIG. An example is described. In FIG. 18, a concave portion 30 is provided in an electric wiring board 31, and a light emitting element 28 such as a semiconductor laser and a light receiving element 2
9 are arranged. On the other hand, the three-dimensional photonic structure 8 that is optically coupled to the light emitting element 28 and the light receiving element 29 on the wiring board 31 is manufactured and inserted into the wiring board recess 30.
In this configuration, the electric wiring board 31 and the optical wiring section, ie, 3
There is an advantage that the manufacturing process with the two-dimensional photonic structure 8 can be performed simultaneously. Further, similarly to the seventh embodiment, the bent portion of the waveguide does not need to be a circular arc, and the optical wiring path can be configured three-dimensionally. The element can be reduced in size.

A more specific example will be described. 1.0 μm with a refractive index of 1.6 with continuous defects 15 of the seventh embodiment
Is embedded in a part of a wiring board 31 including a semiconductor laser 28 having an emission wavelength of 650 nm and a photodiode 29 and having an electric wiring as shown in FIG. Electric wiring board 3
1 is provided with a concave portion 30 corresponding to the three-dimensional photonic structure, and a semiconductor laser 28 and a terminal end are provided on the wall surface of the continuous defect portion 15 when the three-dimensional photonic structure is inserted. The structure is such that the photodiode 29 is located on the side.

[0060]

As described above, according to the present invention, the problems of the prior art are solved, and a photonic structure having a defect-free or defective portion having a period of about an optical wavelength and its applied functional element are flexible and reliable. And a simple manufacturing method thereof is also realized.

[Brief description of the drawings]

1 (a), 1 (b) and 1 (c) are perspective views showing examples of a master used in the process of the present invention.

2 (a), 2 (b), 2 (c) and 2 (d) are cross-sectional views showing an example of a method for manufacturing a mold having a spherical uneven structure.

FIG. 3 is a sectional view showing a mold having an air hole in the structure of FIG. 2 (d).

FIG. 4 is a cross-sectional view of a method for manufacturing a defect-free multidimensional photonic structure.

FIGS. 5 (a) and 5 (b) are top views of a second embodiment of the present invention showing examples of a master or a mold having a rectangular uneven structure.

6 (a) and 6 (b) are a top view and a perspective view showing an example of a rectangular two-dimensional photonic structure manufactured using the master or the mold of FIG.

FIGS. 7A and 7B are cross-sectional views of a third embodiment of the present invention showing an example of a method of manufacturing a defect.

FIGS. 8A, 8B, and 8C are cross-sectional views of another example of a method for manufacturing a defect.

FIGS. 9A and 9B are cross-sectional views of a fourth embodiment of the present invention showing a three-dimensional photonic structure.

10A and 10B are a perspective view and a top view of a spherical particle square lattice three-dimensional photonic structure in which the origins of the first and second layers are on the same Z axis. (c) and (d) are a perspective view and a top view of a spherical particle square lattice three-dimensional photonic structure in which the origins of the first layer and the second layer are shifted by half a period in the XY plane.

11A and 11B are perspective views of a rectangular three-dimensional photonic structure in which the origins of the first and second layers are on the same Z-axis, and the first and second layers. FIG. 3 is a perspective view of a rectangular three-dimensional photonic structure in which the origin of the rectangular three-dimensional photonic structure is shifted by a half cycle within the XY plane.

FIGS. 12 (a) and 12 (b) are perspective views of a fifth embodiment of the present invention showing an optical waveguide using a two-dimensional photonic structure.

FIG. 13 is a top view of a Y-shaped branch where peripheral multi-dimensional photonic structures are arranged.

FIG. 14 is a top view of a bent waveguide in which a multidimensional photonic structure is arranged at a bent portion.

FIGS. 15 (a), (b), and (c) are perspective views of a sixth embodiment of the present invention showing an optical waveguide having a multidimensional photonic structure disposed at an end, and a photonic structure. FIG. 3 is a diagram of a Bragg diffraction pattern when monochromatic light is incident on the photonic structure, and a diagram of a Bragg diffraction pattern when white light is incident on the photonic structure.

FIGS. 16A and 16B are perspective views of an example of an optical coupling system when the photonic structure is used as an optical wavelength demultiplexer or an optical intensity demultiplexer.

FIG. 17 is a perspective view of a seventh embodiment of the present invention illustrating an example of stacking a multidimensional photonic structure having a defect.

FIG. 18 is a perspective view of an eighth embodiment of the present invention illustrating an example of inserting a multidimensional photonic structure into a substrate provided with electric wiring and the like.

[Explanation of symbols]

Reference Signs List 1 master having rectangular uneven structure 2 master having spherical uneven structure 3 Si substrate 4 V-groove 5 substrate 6 mold using stamper material 7 curable liquid material 8 two-dimensional photonic structure of cured liquid material 9 rectangular photonic Mold manufactured by the structure 10 Concave portion 11 Optical functional material 12 Optical functional material or air different from optical functional material 11 13 Mask 14 Light non-transmissive portion of mask 15 Non-cured portion (defect) 16 UV light 17 Air hole 18 Curable Curable liquid material different from liquid material 7 19 Origin of first layer 20 Origin of second layer 21 Optical waveguide 22 Light wave 23 0th order light 24 1st order light 25 2nd order light 26 3rd order light 27 First order diffraction of white light Spot 28 semiconductor laser 29 photodiode 30 recess 31 wiring substrate 32 bundle fiber 33 bent waveguide 34 Y-shaped optical waveguide 35 incident light 36 emission

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H01L 31/0232 G02B 6/12 F H01S 5/02 H01L 31/02 DF term (Reference) 2H047 KA03 KB08 LA11 LA18 PA00 RA08 TA05 TA43 TA44 2H079 AA02 AA12 DA02 DA12 2K002 BA01 BA06 BA11 DA03 HA02 HA09 HA13 5F073 FA30 5F088 AA01 BB10 JA14 LA01 LA03 LA05

Claims (31)

[Claims] An uneven structure having a two-dimensional periodicity of about a light wavelength is used as a master, and a mold having an inverted structure of the uneven structure is formed by depositing and peeling a stamper material to form a photonic structure. A method for manufacturing a photonic structure, characterized in that a two-dimensional periodic refractive index structure having a size that can be used and having a wavelength of about the light wavelength is obtained. 2. The method for manufacturing a photonic structure according to claim 1, wherein said master is produced by patterning a structure having a period of about a light wavelength on a substrate. 3. The method for manufacturing a photonic structure according to claim 1, wherein said master is a periodic structure in which particles having a size about a light wavelength manufactured by chemical synthesis are arranged. 4. The method of manufacturing a photonic structure according to claim 1, wherein said master is a periodic structure formed by V-grooves formed in a substrate. 5. The method for manufacturing a photonic structure according to claim 1, wherein the deposition of the stamper material is performed by electroplating or electroless plating a metal. 6. The method for manufacturing a photonic structure according to claim 1, wherein the deposition and peeling of the stamper material are performed by a molding technique. 7. The method for manufacturing a photonic structure according to claim 1, wherein after forming the mold, the mold is filled with an optical functional material and cured. 8. After the mold is filled with an optical functional material and cured,
The method for manufacturing a photonic structure according to claim 7, wherein the mold is removed. 9. The method for manufacturing a photonic structure according to claim 8, wherein another optical function element is filled and cured in the periodic structure of the optical function material formed by removing the mold. 10. The method for manufacturing a photonic structure according to claim 7, wherein the plurality of molds are opposed to each other to form a new mold, and the new functional mold is filled with an optical functional material and cured. 11. An optical functional element is filled in at least a part of the mold and cured, and then an optical functional material different from the optical functional material is filled in an unfilled part and cured to form a refractive index periodic structure of about the light wavelength. The method for manufacturing a photonic structure according to claim 7, wherein the defective portion is formed. 12. The photonic according to claim 7, wherein, when the optical functional material is cured, an uncured portion is formed in a part, and a defective portion is formed in the refractive index periodic structure of about the light wavelength. The method of manufacturing the structure. 13. The photonic structure according to claim 12, wherein, when the optical functional material is cured, a non-cured portion is formed by covering a part with a mask, and a defective portion is formed in the refractive index periodic structure of about the light wavelength. How to make the body. 14. The structure according to claim 1, wherein said two-dimensional periodic refractive index structure is aligned and laminated so as to form a three-dimensional periodic refractive index structure, and fixed with a curable material. 3. The method for producing a photonic structure according to item 1. 15. The light or heat mixed with a material having a non-linear optical polarizability, a light-emitting material, a magnetic material, a conductive material, an electro-optic material, or a light amplification material. The method for producing a photonic structure according to claim 7, wherein the photonic structure is a curable resin material. 16. A three-dimensional periodic structure of a refractive index of a light wavelength, which is made of an optical functional material having a size usable as a three-dimensional photonic structure, and has a continuous defect portion. Optical functional element. 17. The optical function device according to claim 16, wherein the defect portion is a portion made of an optical function material different from the surroundings. 18. The optical functional device according to claim 16, wherein the defective portion is a portion from which the optical functional material has escaped. 19. The three-dimensional periodic refractive index structure includes a plurality of two-dimensional periodic refractive index structures including a two-dimensional periodic refractive index structure having a defect, so as to form a three-dimensional periodic structure. 19. The optical functional device according to claim 16, 17 or 18, wherein the optical functional device is formed by stacking. 20. The optical function device according to claim 16, wherein said defect portion is an optical waveguide for confining a light wave by a photonic effect. 21. The optical functional device according to claim 20, wherein the defect portion forms a branch waveguide, and a defect-free photonic structure is disposed around the branch waveguide. 22. The optical function device according to claim 20, wherein the defect portion forms a bent waveguide, and a defect-free photonic structure is disposed around the bent waveguide. 23. Light or heat mixed with a material having a non-linear optical polarizability, a luminescent material, a magnetic material, a conductive material, an electro-optic material, or a light amplification material. 23. The optical function device according to claim 16, which is a curable resin material. 24. An optical waveguide having a branching waveguide portion, wherein a photonic structure having a three-dimensional periodic refractive index structure made of an optical functional material having a light wavelength is arranged around the branching waveguide. An optical waveguide structure, characterized in that: 25. An optical waveguide having a bent waveguide portion, wherein at least a corner portion of the bent waveguide portion is in contact with an outer corner portion, and the photo waveguide has a three-dimensional periodic structure of a refractive index of about a light wavelength made of an optical functional material. An optical waveguide structure, wherein a nick structure is arranged. 26. A light or heat mixed with a material having a non-linear optical polarizability, a luminescent material, a magnetic material, a conductive material, an electro-optic material, or a light amplification material. 26. The optical waveguide structure according to claim 24, wherein the optical waveguide structure is a curable resin material. 27. A photonic structure, which is a defect-free two-dimensional periodic refractive index structure made of an optical functional material of about the light wavelength, is arranged on the end face of an optical waveguide, and the guided light is changed by wavelength using the Bragg diffraction phenomenon. A demultiplexer characterized in that wavelengths are demultiplexed in different directions. 28. A photonic structure, which is a defect-free two-dimensional periodic refractive index structure made of an optical functional material of about the wavelength of light, is disposed on an end face of an optical waveguide, and guides the guided light in different directions using the Bragg diffraction phenomenon. A splitter characterized by intensity splitting. 29. A light or heat mixed with a material having a non-linear optical polarizability, a light-emitting material, a magnetic material, a conductive material, an electro-optic material, or a light amplification material. 29. The duplexer according to claim 27, wherein the duplexer is a curable resin material. 30. A concave portion is provided in an electric wiring board, and a light emitting element and a light receiving element are arranged on a wall surface of the concave portion, and the concave portion is provided in the concave portion.
The optical functional device according to any one of claims 6 to 23 and claim 24,
27. An optical waveguide structure according to claim 25 or claim 26, wherein
30. An optical wiring path is formed by inserting at least one of the duplexers according to 8 or 29, and light from the light emitting element is guided to the light receiving element via the optical wiring path. Optical wiring device. 31. A concave portion is provided on a substrate, an optical waveguide is arranged on a wall surface of the concave portion, and the optical functional element according to claim 16 and the optical functional element according to claim 24, 25 or 26 are provided in the concave portion. 30. Inserting at least one of the optical waveguide structure and the duplexer according to claim 27, 28, or 29 to form an optical wiring path, and guiding light to the optical waveguide via the optical wiring path. An optical wiring device characterized by the above-mentioned.