JP2001272566A - Method for manufacturing photonic crystal - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing photonic crystals which makes it possible easily to obtain the photonic crystals varying in optical characteristics by areas. SOLUTION: A base body 21 is formed by laminating plural media 6 and 7 having different etching characteristics and refractive indices on a substrate 3 and plural hole parts 6a and 6b periodically arrayed on the surface of the base body 21 are formed by etching or anodic oxidation, etc. The diameters of the hole parts 6a and 7a are thereafter enlarged by etching. As a result, the spurious three-dimensional photonic crystals which are periodically arrayed with the media 6 and the media 7 in a thickness direction at a section G-G and are periodically arrayed with the media 6 and air in a thickness direction at a section H-H are obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for manufacturing a photonic crystal in which a plurality of media having different refractive indexes are periodically arranged.

[0002]

2. Description of the Related Art A photonic crystal in which a plurality of media having different refractive indexes are periodically arranged has a structure as shown in FIG. In the photonic crystal 1, media 2 a and 2 b having different refractive indexes are periodically arranged on a substrate 3. Medium 2
By making the refractive index of the optical waveguide layer 2 composed of a and 2b larger than the refractive index of the substrate 3, the optical waveguide layer 2 is sandwiched between the upper air layer having a small refractive index and the substrate 3. The light incident on the optical waveguide 2 is confined in the optical waveguide layer 2 and guided.

The photonic crystal 1 has a property that anisotropy of refractive index dispersion occurs. The refractive indices of the media 2a and 2b, the shapes of the media 2a and 2b such as cylinders and prisms, and the media 2
By appropriately selecting the sizes of a and 2b, the type of lattice such as a triangular lattice or a square lattice, or the period of arrangement, different optical characteristics can be obtained for light having a desired wavelength or polarization direction.

Thus, as shown in FIG. 1, for example, light having wavelengths λ1 and λ2 incident from the same direction can be emitted in different directions. Conversely, light having different wavelengths incident from different directions can be emitted in the same direction. It is also possible to reflect light of a specific wavelength. By utilizing such a property, it can be used as a splitter, a multiplexer or a filter of an optical signal.

The above photonic crystal 1 is manufactured by the manufacturing method shown in FIG. First, as shown in FIG. 13A, a resist 11 is applied to the surface of the medium 4 in a resist application step. The medium 4 is a substrate 3 (see FIG. 12).
It may be formed by film formation thereon. Next, as shown in FIG. 13B, in a patterning step, the resist 11 is patterned into a periodic shape by a photolithography technique.

Next, as shown in FIG. 13C, in the etching step, the medium 4 is etched by RIE (Reactive Ion Etching) or the like to form a hole 4a. Then, as shown in FIG. 13D, the resist 11 is removed in a resist removing step. FIG. 14 shows a cross-sectional view at this time, where the holes 4a are periodically arranged. Therefore,
The resist coating step of FIG. 13A to the resist removing step of FIG. 13D constitute a hole forming step of forming a periodic hole 4a. Then, a photonic crystal having a periodic structure made of a medium having a different refractive index is obtained by the medium 4 and the air in the hole 4a.

There is also known a method of forming holes arranged periodically by anodizing or anodizing. FIG. 15 is a diagram showing a hole forming step by anodization or anodization. The medium 4 made of a metal such as aluminum or titanium, or a semiconductor such as silicon, gallium arsenide, or indium arsenide is immersed in an appropriate electrolytic solution, and is oxidized or formed when a voltage is applied to the anode. As a result, as shown in the figure, the holes 4a that are regularly arranged can be obtained.

For example, when an aluminum thin film formed on a substrate or a medium 4 composed of an aluminum substrate is anodized in an acidic electrolytic solution such as oxalic acid, the diameter of the medium is several nm to several tens.
The pores 4a made of 00 nm pores are several nm to several hundreds n.
Porous alumina layers 5 regularly arranged in a triangular lattice at intervals of m are formed. The hole 4a has a very good verticality,
A hole having an extremely high aspect ratio can be easily obtained by anodizing or anodizing.

As a result, a photonic crystal having a periodic structure composed of a medium having a different refractive index depending on the medium 4 and the air in the hole 4a is obtained. In addition, since the distance between the holes 4a is substantially proportional to the applied voltage at the time of anodic oxidation, the distance between the holes 4a can be controlled by controlling the applied voltage, and desired optical characteristics can be obtained.

[0010]

However, according to the above-described conventional method for manufacturing a photonic crystal, in the thickness direction of the medium 4, the refractive index of the medium 4 and the air, the hole 4a,
Have the same shape, lattice type and arrangement period. For this reason, for example, in order to obtain a so-called three-dimensional photonic crystal having a periodic structure with a medium having a different refractive index also in the thickness direction, a two-dimensional photonic crystal is created by the above-described manufacturing process, and a similar It is necessary to create two-dimensional photonic crystals having different refractive indexes, hole diameters, hole periods, etc. depending on the manufacturing process.

[0011] In addition to the three-dimensional photonic crystal,
The two-dimensional photonic crystal having different optical characteristics in the thickness direction of the medium 4 can cause an action such as emitting incident light entering the different position in the thickness direction from the same direction in different directions. In the case of producing such a photonic crystal, it is necessary to perform the same steps a plurality of times as in the case of the three-dimensional photonic crystal.

In the method of manufacturing a photonic crystal in which the holes 4a are formed by anodic oxidation or anodization, the holes 4a having a higher aspect ratio can be formed in fewer steps than in the case of using etching. There are advantages that can be done. However, the diameter of the hole and the period of the hole cannot be varied in the plane direction of the medium 4, and it is difficult to arrange photonic crystals having different optical characteristics side by side.

Therefore, the photonic crystal which can obtain a plurality of optical characteristics by changing the refractive index, the shape of the hole 4a, the size of the hole 4a, the kind of lattice or the arrangement period in the thickness direction or the plane direction. However, there is a problem that the number of steps is large and the cost is high.

An object of the present invention is to provide a method for manufacturing a photonic crystal that can easily obtain a photonic crystal having different optical characteristics in a thickness direction and a plane direction.

[0015]

In order to achieve the above object, according to the present invention, there is provided a first step of forming a substrate made of a substance having at least one of a crystal axis direction and an etching characteristic different in a thickness direction. And a second step of forming a plurality of holes periodically arranged in the base.

According to this structure, for example, a substrate is formed by laminating a plurality of media having different crystal axis directions on the substrate, and the surface of the substrate is subjected to anodization, anodization, etching by photolithography, and electron beam. A plurality of holes arranged periodically are formed by a method such as beam processing. Thereby, the hole is formed in a different direction,
A photonic crystal in which the period of the medium and the air differs in the thickness direction depending on the cross section is obtained.

According to a second aspect of the present invention, there is provided a method for manufacturing a photonic crystal according to the first aspect.
It is characterized in that substances having different refractive indexes in the thickness direction are formed by the first step. According to this configuration, a two-dimensional photonic crystal in which one medium and air in the hole are periodically arranged in the plane direction, and a two-dimensional photonic crystal in which the other medium and air are periodically arranged in the plane direction. Nick crystals are periodically laminated in the thickness direction to obtain a photonic crystal having a plurality of optical characteristics.

According to a third aspect of the present invention, there is provided a method for manufacturing a photonic crystal according to the second aspect.
It is characterized in that the refractive index gradually changes in the thickness direction.

According to a fourth aspect of the present invention, in the method for manufacturing a photonic crystal according to any one of the first to third aspects, the cross-sectional area of the hole is etched by etching after the second step. A third step of enlarging is provided.

According to this structure, for example, a substrate is formed by laminating a plurality of media having different etching characteristics on the substrate, and a plurality of holes periodically arranged on the surface of the substrate in the second step are formed. Is done. Further, when the hole is enlarged by etching in the third step, the diameter of the hole of one medium differs from that of the other medium due to the difference in etching rate.

According to a fifth aspect of the present invention, a first step of forming a base made of a substance having different physical properties in a thickness direction, and a plurality of holes arranged periodically by applying a voltage to the base are provided. And a step of forming, wherein the applied voltage is varied according to the portion of the base.

According to this structure, for example, in the first step, a plurality of media having different physical properties are laminated on the substrate to form a base, and in the second step, a voltage is applied to the base to perform anodic oxidation or anodization. Thereby, a hole is formed. Then, by varying the applied voltage according to the portion of the base, the period of the hole is formed differently.

According to a sixth aspect of the present invention, there is provided a first step of forming a base made of substances having different physical properties in a thickness direction, and a plurality of holes periodically arranged by applying a magnetic field to the base from outside. A second step of forming a portion, wherein the direction of the magnetic field is changed so that the hole is inclined with respect to the thickness direction of the base.

According to this structure, for example, in the first step, a plurality of media having different physical properties are laminated on the substrate to form a base, and in the second step, a voltage is applied to the base to perform anodic oxidation or anodization. To form a hole. The traveling direction of the ions accelerated by the electric field is inclined with respect to the direction of the electric field according to the direction of the magnetic field. Thereby, a hole inclined according to the direction of the magnetic field is formed.

According to a seventh aspect of the present invention, in the method for manufacturing a photonic crystal according to the fifth or sixth aspect, the physical property value is at least one of a refractive index, a crystal axis direction, and an etching characteristic. It is characterized by being.

According to an eighth aspect of the present invention, there is provided a method for manufacturing a photonic crystal according to the fifth or sixth aspect, wherein the materials having different refractive indexes in the thickness direction are formed in the first step. Features.

According to a ninth aspect of the present invention, in a method of manufacturing a photonic crystal according to the eighth aspect,
It is characterized in that the refractive index gradually changes in the thickness direction.

According to a tenth aspect of the present invention, a first step of forming a base made of a material having different physical properties in a plane direction and a second step of forming a plurality of holes periodically arranged in the base are provided. And a process.

According to this structure, a plurality of media having different physical property values in the plane direction are arranged in parallel to form the base, so that a plurality of holes periodically arranged by anodic oxidation, etching, or the like are formed. It is formed. Thus, a two-dimensional photonic crystal in which one medium and air in the hole are periodically arranged in the plane direction, and a two-dimensional photonic crystal in which the other medium and air are periodically arranged in the plane direction. Can be obtained in parallel with each other in a plane direction.

According to an eleventh aspect of the present invention, in the method for manufacturing a photonic crystal according to the tenth aspect, the physical property value is at least one of a refractive index, a crystal axis direction, and an etching characteristic. Features.

The invention according to claim 12 has a hole forming step of applying a magnetic field to the medium from the outside to recess a plurality of holes periodically arranged on the surface of the medium. And According to this configuration, for example, a voltage is applied to the medium to form a hole by anodization or anodization. The traveling direction of the ions accelerated by the electric field is inclined with respect to the direction of the electric field according to the direction of the magnetic field. Thereby, a hole inclined according to the direction of the magnetic field is formed.

Further, the invention according to claim 13 has a hole forming step of applying a different voltage depending on a portion of the medium and recessing a plurality of holes periodically arranged on the surface of the medium. It is characterized by: According to this configuration, the substrate on which the medium is formed is immersed in a predetermined solution, and the substrate is placed on the anode and a voltage is applied to perform anodization or anodization. As a result, the substrate is oxidized or converted from the surface, and periodically arranged holes are formed in the substrate. At this time, a different voltage is applied depending on the portion of the medium, and the period of the hole is varied.

According to a fourteenth aspect of the present invention, in the method of manufacturing a photonic crystal according to the thirteenth aspect, the medium is formed on a substrate made of a resistive material. According to this configuration, the voltage drops due to the resistance of the substrate according to the distance from the voltage application point, and the voltage applied to the medium is varied.

According to a fifteenth aspect of the present invention, in the method for manufacturing a photonic crystal according to the thirteenth aspect, the medium is formed on a base having a different resistance value for each region. And According to this configuration, the voltage applied to the substrate drops due to the resistance of the base, and the voltage applied to the medium varies for each region.

According to a sixteenth aspect of the present invention, in the method of manufacturing a photonic crystal according to any one of the twelfth to thirteenth aspects, the hole forming step is performed by anodization or anodization. It is characterized by.

[0036]

Embodiments of the present invention will be described below with reference to the drawings. For convenience of description, the same parts as those in FIGS. 12 to 15 of the conventional example are denoted by the same reference numerals.
FIG. 1 is a cross-sectional view illustrating a method for manufacturing a photonic crystal according to the first embodiment. As shown in FIG. 1A, media 6 and 7 having different etching characteristics are periodically laminated on a substrate 3 in a thickness direction, and a base 21 made of a multilayer film is formed.

The media 6 and 7 can be formed by sputtering, vapor deposition, CVD, or the like, and may be laminated using different materials, or by doping other materials during the formation of a desired material. Is also good. Next, as shown in FIG. 13, the resist 11 is patterned into a desired shape by photolithography in a hole forming step,
Etch with E or the like.

Thus, as shown in FIG. 1B, it is possible to obtain periodically arranged holes 6a and 7a which are recessed in the thickness direction of the base 21. As a result, the photonic crystal composed of the medium 6 and the air in the hole 6a,
And a photonic crystal composed of air in the hole 7a. Next, the diameter of the holes 6a and 7a can be increased by immersing the holes 6a and 7a in a predetermined etching solution in the hole expanding step. At this time, since the media 6 and 7 have different etching characteristics, the holes 6a and 7a can have different diameters as shown in FIG.

Accordingly, when the refractive indices of the media 6 and 7 are different, the media 6 and 7 are periodically arranged in the thickness direction in the section GG, and the medium 6 and the air are separated in the section HH. A photonic crystal having a pseudo three-dimensional periodic structure periodically arranged in the thickness direction can be obtained.

Further, even if the media 6 and 7 have the same refractive index, the holes 6a and 7a having different diameters are formed.
In (c), different optical characteristics are obtained depending on the incident position of the incident light as indicated by arrows X1 and X2.

Therefore, as shown in FIG.
2, a two-dimensional photonic crystal having different optical characteristics depending on the incident position of incident light, such as a multi-layered photonic crystal, or a three-dimensional photonic crystal can be formed at a low cost by a single hole forming step. Can be created with The same effect can be obtained by performing the hole forming step by anodic oxidation or anodization as shown in FIG.

Next, FIGS. 2A and 2B are a perspective view and a sectional view showing a method for manufacturing a photonic crystal according to the second embodiment. In the present embodiment, a hole is formed on a substrate 22 having a refractive index distribution in the thickness direction (vertical direction in the figure) by the etching shown in FIG. 13 or the hole forming step using anodic oxidation or anodization shown in FIG. 22a are formed.

The substrate 22 having a refractive index distribution can be formed by doping another substance during film formation of a desired material and gradually changing the doping amount. Further, a substance to be doped may be gradually changed, and a material to be formed may be gradually changed.

The photonic crystal 1 obtained in this manner is a photonic crystal having different optical characteristics depending on the incident position of incident light, as indicated by arrows X1 and X2, at low cost by a single hole forming step. Can be created. Further, as in the first embodiment, the diameter of the hole 22a can be increased by immersing the hole 22a in a predetermined etching solution in the hole enlarging step. At this time, if the base 22 has a distribution of etching characteristics in the thickness direction, the holes 22a can have different diameters in the thickness direction as shown in FIG.

Thus, it is possible to obtain a photonic crystal having further different optical characteristics depending on the incident position of the incident light in the thickness direction. Also, as in the first embodiment,
Even if the substrate 22 has the same refractive index in the thickness direction, if the etching characteristics are different, the hole diameter can be varied in the thickness direction by the hole enlarging step, and different optical characteristics can be obtained according to the incident position.

Next, FIG. 4 is a plan view showing a method for manufacturing a photonic crystal according to the third embodiment. This embodiment is shown in FIG.
As shown in (a), the substrate 23 is formed by arranging media 6 and 7 having different refractive indexes in a plane direction (a direction parallel to the paper surface). Then, as shown in FIG. 4B, the holes 6 are formed in the base 23 by the above-described etching shown in FIG. 13 or the hole forming step using anodic oxidation or anodization shown in FIG.
a and 7a are formed.

The substrate 23 having the media 6 and 7 having different refractive indices arranged in the plane direction can be prepared by the following method. First, the medium 6 is formed by sputtering or the like.
Next, the region of the medium 7 is patterned and etched by photolithography. Next, the medium 7 is formed into a film, and the region of the medium 6 is etched by the thickness of the medium 7.

According to this embodiment, the two-dimensional photonic crystal in which the air and the medium 6 in the hole 6a are periodically arranged, and the air and the medium 7 in the hole 7a are periodically arranged. Two-dimensional photonic crystals are arranged at different positions in the same plane. Thus, a photonic crystal having different optical characteristics depending on the incident position of incident light incident on different positions in the same plane can be formed at a low cost by one hole forming step.

Also, the photonic crystal of FIG.
The diameter of the holes 6a and 7a can be increased by immersing the holes 6a and 7a in a predetermined etching solution in the hole expanding step.
At this time, if the media 6 and 7 have different etching characteristics, the holes 6a and 7a can have different diameters as shown in FIG.

Thus, when the hole forming step is performed by etching, the diameter of the holes 6a and 7a can be changed by patterning. However, when the hole forming step is performed by anodic oxidation or anodization, the hole 6a, 7a
Can be varied. Therefore, it is possible to obtain a photonic crystal having further different optical characteristics depending on the incident position of the incident light in the plane direction.

Further, similarly to the first and second embodiments, the media 6 and 7 of the substrate 23 may have the same refractive index. If the etching characteristics are different, the hole forming step may be performed by anodizing or anodizing. Even in the case of the above, the hole diameter can be varied in the same plane by the hole enlarging step, and different optical characteristics can be obtained with respect to incident light incident on different incident positions in the plane direction.

Further, as shown in FIG. 11, a waveguide made of the medium 7 can be formed by arranging the medium 7 in an L-shape to form the base 25. Accordingly, it is possible to produce a waveguide without a loss bent at an acute angle at a low cost, which is impossible with the conventional technique.

Next, a fourth embodiment will be described. When a desired medium is formed on a substrate by sputtering, vapor deposition, CVD, or the like, the substrate 3 is inclined as shown in FIG. Is formed such that the direction of the crystal axis 8 b is inclined with respect to the substrate 3. When a hole is formed in the medium 8 by etching, anodic oxidation, or the like, as shown in FIG. 5B, the hole 8a is formed along the crystal axis 8b, and the hole 8a is inclined with respect to the substrate 3. .

A fourth embodiment utilizing this property is shown in FIG.
As shown in FIG. FIGS. 6A, 6B, and 6C are cross-sectional views parallel to planes A, B, and C of FIG. 7, respectively. In the present embodiment, the media 9p, 9q, and 9p in which the directions of the crystal axes 9b are different.
The base 24 is formed by laminating r and 9s.

The media 9p, 9q, 9r, 9s are shown in FIG.
In the state where the points p, q, r, and s in (c) are inclined upward away from the plane of the paper, film formation is performed from above the plane away from the plane of the paper, so that different crystal axes 9 are formed.
It is formed in the direction of b.

A hole 9a is formed in the base 24 by the above-described etching shown in FIG. 13 or the hole forming step using anodic oxidation or anodization shown in FIG. At this time, since the holes 9a are formed according to the crystal axes 9b, the holes 9a have a spiral shape as shown in FIG.

Each layer composed of the stacked media 9p to 9s forms a periodic structure in the plane direction in which the refractive index of the medium, the diameter of the hole, the period of the hole, and the like are the same. In the thickness direction of the base 24, a periodic structure is formed in which the air in the holes 9a and the media 9p to 9s are periodically arranged every four layers. Therefore, a three-dimensional photonic crystal can be formed at low cost by one hole forming step. The hole 9a can be formed in a smoother spiral by forming the film while changing the inclination direction of the base 24 more finely or continuously.

Further, the first to third elements shown in FIGS.
A photonic crystal having more complicated optical characteristics can be obtained by stacking and forming media having different crystal axis directions as the substrates 21 to 23 of the embodiment.

Next, a fifth embodiment will be described. FIG. 8A shows a state in which the medium 10 such as aluminum is formed on the substrate 3 by film formation or the like, and the hole 10a is formed by the hole forming step using anodic oxidation or anodization shown in FIG. FIG. At this time, a magnetic field is applied to the medium 10 from the outside.

FIG. 8B shows an enlarged view of the hole 10a. For example, when performing anodic oxidation, a voltage is applied to the substrate 3 and an electric field E acts on the oxygen ions 16 in the electrolyte. . As a result, the oxygen ions 16 dig down the hole 10a in the direction of the electric field E, and form an oxide 10b such as porous alumina.
To form Further, by applying a magnetic field in a direction perpendicular to the paper surface, an electromagnetic force F acts on the oxygen ions 16 in the left-right direction in the figure. As a result, the oxygen ions 16 travel obliquely with respect to the surface of the medium 10, and the holes 10a are formed obliquely.

Accordingly, by changing the direction of the magnetic field applied to the medium 10 during the anodization or the anodization, a spiral hole can be formed as in the fourth embodiment shown in FIG. Can be. As a result, a three-dimensional photonic crystal can be formed at low cost by a single hole forming step.

Further, the first to fourth data shown in FIGS.
By applying a magnetic field to the substrates 21 to 24 when forming the holes in the substrates 21 to 24 of the embodiment by anodizing or anodizing, a photonic crystal having more complicated optical characteristics can be obtained.

Next, FIG. 9 is a view showing a sixth embodiment. A medium 10 such as aluminum is formed on the substrate 3 by film formation or the like, and a power supply 13 for applying a voltage of the substrate 3 during anodization or anodization is connected to an end of the substrate 3. The substrate 3 is made of a resistance material such as carbon or an iron-nickel alloy, and has a different resistance value according to a distance from a voltage application point Q by the power supply 13.

For this reason, when a voltage is applied to the substrate 3 and the anodic oxidation or anodization shown in FIG. 15 is performed, a high voltage is applied to the medium 10 with a small voltage drop near the application point Q. At a position far from the application point Q, a large voltage drop is applied to the medium 10.

Since the period P of the hole 10a is substantially proportional to the applied voltage, the period P of the hole 10a decreases in the direction of the arrow D2, and the period P of the hole 10a increases in the direction of the arrow D1. Therefore, by forming the substrate 3 with a resistance material having a desired resistance value, it is possible to obtain a desired period in which the period P of the hole 10a is gradually changed,
A photonic crystal having complicated optical characteristics can be obtained.

Also, the first to fourth data shown in FIGS.
When the holes are formed by anodizing or anodizing the substrates 21 to 24 of the embodiment, the substrate 3 is formed from a resistive material having a predetermined resistance value, so that a photonic crystal having more complicated optical characteristics is obtained. Can be obtained.

Next, FIGS. 10A and 10B are a side view and a plan view showing a seventh embodiment. The upper surface of the conductive substrate 3 is divided into regions R1 to R5 by an insulator 14 such as SiO ₂ . In each of the regions R1 to R5, an underlayer 12 made of a resistance material is formed on the substrate 3, and a medium 10 such as aluminum is formed on the underlayer 12 by film formation or the like. A power supply 13 is connected to the substrate 3, and by applying a voltage to the medium 10, the above-described anodization or anodization shown in FIG. 15 is performed.

The underlayers 12 in the regions R1 to R5 are formed so as to have different resistance values, and different voltages are applied to the medium 10 in the regions R1 to R5 by the voltage drop due to the underlayer 12. Since the period P of the holes 10a is substantially proportional to the applied voltage, the holes 10a having different periods are formed in each of the regions R1 to R5. Underlayer 12 of each region R1 to R5
The resistance value may be varied depending on the thickness of the resistance material as shown in the figure, or a different resistance material may be formed.

Thus, in the sixth embodiment shown in FIG. 9 described above, the period P of the holes is changed concentrically from the application point Q, whereas the period of the holes 10a is changed for each region of a desired shape. Can be variable. Therefore, it is possible to obtain a photonic crystal having different optical characteristics according to different incident positions in a plane direction of a plurality of incident lights.

Also, the first to fourth data shown in FIGS.
When the holes are formed by anodizing or anodizing the substrates 21 to 24 of the embodiment, an underlayer having a predetermined resistance value is formed in each of the divided regions between the substrate 3 and the substrates 21 to 24. By doing so, a photonic crystal having more complicated optical characteristics can be obtained.

[0071]

According to the first aspect of the present invention, the crystal axis direction in the thickness direction or the surface of the substrate having different etching characteristics is
By recessing a plurality of holes arranged periodically, the holes are formed with different diameters and directions. Thus, a photonic crystal having different optical characteristics depending on the incident position of the incident light can be formed at a low cost by one hole forming step.

According to the second and third aspects of the present invention,
Since a substance having a different refractive index is formed in the thickness direction, a two-dimensional photonic crystal in which one medium and the air in the hole are periodically arranged in the plane direction, and the other medium and the air are in the plane direction. A two-dimensional photonic crystal periodically arranged in a matrix is periodically stacked in the thickness direction, and a photonic crystal having a plurality of optical characteristics can be formed at a low cost by a single hole forming step. .

According to the fourth aspect of the present invention, since the cross-sectional area of the hole is enlarged by etching, if the holes formed in a plurality of media having different etching characteristics are enlarged by etching, one hole is formed due to a difference in etching rate. The diameter of the hole of the medium is different from the diameter of the hole of the other medium. Therefore, it is possible to easily obtain a photonic crystal such as a three-dimensional photonic crystal having different optical characteristics in the thickness direction.

According to the fifth aspect of the present invention, the period of the holes is changed by forming the holes by changing the applied voltage according to the position of the base. Therefore, a desired period in which the period of the hole gradually changes is obtained, and a photonic crystal having complicated optical characteristics can be produced at a low cost by a single hole forming process.

According to the sixth aspect of the present invention, by forming a hole by applying a magnetic field from the outside, an inclined hole is formed because an electromagnetic force acts on oxygen ions and the like. Therefore,
By changing the direction of the magnetic field, a helical hole can be formed. As a result, a three-dimensional photonic crystal can be formed at low cost by a single hole forming step.

According to the invention of claims 7 to 9,
Since the substrate has different refractive indexes, crystal axis directions, and etching characteristics in the thickness direction, a more complicated photonic crystal can be formed.

According to the tenth and eleventh aspects of the present invention, the surface of a substrate having different physical properties such as a refractive index in the plane direction is provided on the surface of the substrate.
By recessing a plurality of holes arranged periodically, the holes are formed with different diameters and directions. Thus, photonic crystals having different optical characteristics according to incident light incident on different positions in the same plane can be formed at a low cost by one hole forming step.

According to the twelfth aspect of the present invention, by forming a hole by applying a magnetic field from the outside, an inclined hole is formed because an electromagnetic force acts on oxygen ions and the like. Therefore, a spiral hole can be formed by changing the direction of the magnetic field. As a result, a three-dimensional photonic crystal can be formed at low cost by a single hole forming step.

According to the thirteenth aspect of the present invention, the period of the holes is varied by forming the holes by varying the applied voltage according to the position of the base. Therefore, a desired period in which the period of the hole gradually changes is obtained, and a photonic crystal having complicated optical characteristics can be produced at a low cost by a single hole forming process.

According to the fourteenth aspect of the present invention, by performing anodic oxidation or anodization using a resistive material on the substrate, it is possible to change the voltage applied to the medium and easily change the period of the hole. it can.

According to the fifteenth aspect of the present invention, the period of the hole can be easily varied by providing an underlayer having resistance in the medium for each region and performing anodic oxidation or anodization. Further, a hole having a desired period can be formed for each region.

According to the sixteenth aspect of the present invention, the direction and period of the hole can be easily changed by forming the hole by performing anodic oxidation or anodization.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a method for manufacturing a photonic crystal according to a first embodiment of the present invention.

FIG. 2 is a view illustrating a step of forming a hole in a photonic crystal according to a second embodiment of the present invention.

FIG. 3 is a cross-sectional view illustrating a step of enlarging a hole in a photonic crystal according to a second embodiment of the present invention.

FIG. 4 is a cross-sectional view illustrating a method for manufacturing a photonic crystal according to a third embodiment of the present invention.

FIG. 5 is a sectional view illustrating a method for manufacturing a photonic crystal according to a fourth embodiment of the present invention.

FIG. 6 is a sectional view illustrating a method for manufacturing a photonic crystal according to a fourth embodiment of the present invention.

FIG. 7 is a perspective view illustrating a method for manufacturing a photonic crystal according to a fourth embodiment of the present invention.

FIG. 8 is a cross-sectional view illustrating a method for manufacturing a photonic crystal according to a fifth embodiment of the present invention.

FIG. 9 is a sectional view illustrating a method for manufacturing a photonic crystal according to a sixth embodiment of the present invention.

FIG. 10 is a view illustrating a method for manufacturing a photonic crystal according to a seventh embodiment of the present invention.

FIG. 11 is a view showing another photonic crystal formed by the method for manufacturing a photonic crystal according to the third embodiment of the present invention.

FIG. 12 is a perspective view showing a conventional photonic crystal.

FIG. 13 is a perspective view showing a conventional method for manufacturing a photonic crystal.

FIG. 14 is a cross-sectional view showing a conventional photonic crystal.

FIG. 15 is a perspective view showing another method for manufacturing a conventional photonic crystal.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Photonic crystal 2 Optical waveguide layer 3 Substrate 4, 6-10 Medium 5 Porous alumina layer 11 Resist 12 Underlayer 13 Power supply 14 Insulator 16 Oxygen ion 21-24 Substrate

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme Court ゛ (Reference) G02B 6/12 N (72) Inventor Miyuki 2-13-13 Azuchicho, Chuo-ku, Osaka City Osaka International Building Minolta Co., Ltd. F term (reference) 2H047 KA03 LA18 PA01 PA24 QA01 2H049 AA01 AA02 AA31 AA33 AA37 AA44 AA48 AA57 AA59 AA65 BA01 BA42 BB01 BB03 BB06 BB62 BC08 BC25

Claims (16)

[Claims] A first step of forming a base made of a substance having at least one of a crystal axis direction and an etching characteristic different in a thickness direction, and a second step of forming a plurality of holes periodically arranged in the base.
A method for producing a photonic crystal, comprising: 2. The method for producing a photonic crystal according to claim 1, wherein a substance having a different refractive index in a thickness direction is formed in the first step. 3. The method for producing a photonic crystal according to claim 2, wherein said refractive index is made to gradually differ in a thickness direction. 4. The photonic crystal according to claim 1, further comprising, after the second step, a third step of enlarging a sectional area of the hole by etching. Method. 5. A first step of forming a base made of substances having different physical properties in the thickness direction, and a second step of applying a voltage to the base to form a plurality of holes arranged periodically. And a method of manufacturing a photonic crystal, wherein an applied voltage is varied according to a portion of the substrate. 6. A first step of forming a base made of a substance having different physical properties in the thickness direction, a second step of applying a magnetic field to the base from the outside to form a plurality of holes arranged periodically. Wherein the direction of the magnetic field is varied so that the hole is inclined with respect to the thickness direction of the substrate. 7. The method according to claim 5, wherein the physical property value is at least one of a refractive index, a crystal axis direction, and an etching characteristic. 8. The method for producing a photonic crystal according to claim 5, wherein a substance having a different refractive index in a thickness direction is formed in the first step. 9. The method for manufacturing a photonic crystal according to claim 8, wherein said refractive index is made to gradually differ in a thickness direction. 10. A first step of forming a base made of a substance having different physical properties in a plane direction, and a second step of forming a plurality of holes periodically arranged in the base.
A method for producing a photonic crystal, comprising: 11. The method according to claim 10, wherein the physical property value is at least one of a refractive index, a crystal axis direction, and an etching characteristic. 12. A method for manufacturing a photonic crystal, comprising a step of forming a plurality of holes that are periodically arranged in the surface of the medium by applying a magnetic field to the medium from the outside. 13. A photonic crystal according to claim 1, further comprising a hole forming step of applying a different voltage depending on a portion of the medium to form a plurality of holes periodically arranged on the surface of the medium. Production method. 14. The method according to claim 13, wherein the medium is formed on a substrate made of a resistive material. 15. The medium according to claim 13, wherein the medium is formed on a base formed with a different resistance value for each region.
3. The method for producing a photonic crystal according to item 1. 16. The method for producing a photonic crystal according to claim 12, wherein the hole forming step is performed by anodic oxidation or anodization.