JP2005326596A - Optical element and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical element having a plurality of periodic structures which include sections having different optical periods, and to provide a manufacturing method of the optical element. <P>SOLUTION: Three kinds of periodic structures 2, 3 and 4 are formed on a substrate 1, in that order. A periodic structure 2 is formed right above the substrate 1, made of silica particles having a particle diameter of 340nm and has approximately twenty layers. On top of the periodic structure 2, a periodic structure 3 is formed, made of silica particles having a particle diameter of 320nm and has approximately twenty layers. On top of the periodic structure 3, a periodic structure 4 is formed, made of silica particles having a particle diameter of 300nm and has approximately twenty layers. In all periodic structures 2 to 4, regions 5 (equivalent to approximately 2μm thickness, and approximately ten layers of fine particles), in which photo-setting resin is filled between silica particles, exists. Such optical element has a function of trapping light beams, having wavelengths corresponding to the particle diameters with resonators made of photosetting resin. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an optical element and a method for manufacturing the same, and more particularly, a waveguide using a periodic structure of fine particles in which fine particles are periodically arranged, a photonic crystal optical device such as an optical resonator, a laser, and an optical switch, The present invention relates to an inverse opal structure, an optical element such as an optical device in which a functional material is filled in the gap, and a manufacturing method thereof.

  A photonic crystal capable of confining light in a crystal by a photonic band gap is expected as a material that can be used for an optical device, and research and development have been actively conducted.

  As a photonic crystal formation technique, there is a method using self-organization of an optical medium (fine particles). Particulate films (periodic structures, photonic crystals) arranged by utilizing self-organization are particularly expected to enable high quality and a large surface area.

  Nagayama et al., In Japanese Patent Application Laid-Open No. 7-116502 (Patent Document 1) and Japanese Patent No. 2828386 (Patent Document 2) corresponding thereto, report a “method for producing a fine particle thin film” using a colloidal solution.

  This is intended to improve the quality of the accumulated crystals by utilizing the capillary force of the liquid and controlling the evaporation rate of the solvent and the volume fraction of the fine particles. A method for growing a colloidal crystal in a narrow gap between two substantially parallel planes has also been reported, including Puige, Peter Nicarus et al. (Patent No. 2669844, “Suspension Colloid Sphere” (Patent Document 3)). Has been.

  At this time, a technique has been proposed by Younan Xia et al. In which a mold is applied to the lower substrate of the two substrates and the shape formed by the fine particles is controlled using this mold (BT Mayers, et al., Advanded Materials, 12, No.21, pp.1629-1632, 2000. (Non-Patent Document 1), SH Park, et al., Advanded Materials, 11, No.6, pp. 462- 466, 1999. (see Non-Patent Document 2)).

  As fine particles to be used, monodisperse silica or polystyrene is generally used. However, these materials do not have a sufficiently high refractive index as a device material, and a device having desired characteristics cannot be obtained.

  In order to produce a fine particle film having a higher refractive index, a further improved method utilizing the fine particle film produced by the above method has been reported. In this method, a monomer such as a photocurable resin is poured into the gaps between the fine particles of the fine particle film to solidify the fine particles, and then the fine particles are removed by etching to form a periodic structure (inverted structure, inverted opal structure, inverse structure). Or an inverse opal method to obtain a template).

  The inverse opal method has been energetically reported by VL Colvin et al. (P. Jiang, et al., J. Am. Chem. Soc., 121, pp. 11630-11637, 1999. (Non-patent Document 3) ), KM Kulinowski, et al., Advanded Materials, 12, No. 11, pp. 833-838, 2000. (Non-patent Document 4), Japanese Patent Laid-Open No. 2003-2687 (Patent Document 4)).

  In addition, improved methods have been proposed. In the inverse opal method, a material having a higher refractive index is filled in the voids in which fine particles were initially present, and a portion (inverse opal structure) obtained by the inverse opal method is removed. As a result, a periodic structure substantially equivalent to the periodic structure obtained initially by self-organization can be obtained with the material changed.

  Examples of such hollow fine particle structures include P. Jiang, et al., Science, Vol.291, pp. 453-457, 2001. (Non-patent Document 5) by David Norris et al. There is Japanese Patent No. 3183344 (Patent Document 5).

  It is also possible to fill liquid crystal molecules in the voids in which the fine particles existed. Even in such a periodic structure, the fine particle film produced first becomes a template, so it is important to improve the technique for arranging the fine particles without defects.

  When used as an optical element, for example, in a waveguide, a portion that becomes an optical path is required, for example, a space in which fine particles do not exist continuously in a periodic structure.

  A method for producing a portion that becomes an optical path has been proposed by Lee, et al. (Adv. Mater. 14, 271-274, 2003; see Non-Patent Document 6).

  In the method proposed in this document, a monomer is poured into a gap between periodic structures of silica spheres, and a monomer is selectively cured using a laser, and an uncured monomer is removed to remove silicon. In this method, the silica sphere and the polymer are selectively removed, and the portion where the polymer was present is used as a waveguide.

  In addition, it is necessary to securely open the photonic band gap and confine light of a specific wavelength. For this purpose, it is considered that the photonic band gap becomes larger when the volume fraction of the high refractive index portion is lower.

  Therefore, it is necessary to form a structure that lowers the volume fraction of the high refractive index portion more than the inverse structure. One is a halo structure in which hollow particles are regularly arranged (see, for example, P. Jiang, et al., Science, Vol.291, pp. 453-457, 2001. (Non-patent Document 5) described above). .

  When producing a periodic structure with fine particles, once a few layers of film are produced, the substrate is immersed again in a colloidal solution, so that a new periodic structure is further formed on the produced periodic structure. Can be produced. At this time, the photonic band gap wavelength of the periodic structure produced first and the periodic structure produced thereon can be changed by changing the material and particle size of the fine particles of the colloidal liquid.

  Attempts have been made to change the photonic band gap wavelength by introducing a conductive polymer, a photochromic dye, or the like into a photonic crystal or a void of an inverse opal structure.

  In addition, in photonic crystals using microfabrication, it has been reported that light of a specific wavelength is demultiplexed by defects of different sizes by defect engineering using a line defect waveguide (S. Noda, et al. al., Nature 407, pp 608, 2000 (Non-patent Document 7)). In manufacturing by microfabrication, processing accuracy is required for the apparatus, and since much energy is required for manufacturing, it is necessary to propose an alternative simple manufacturing method. Regarding photonic crystals, K. Yoshino, et al., Jpn. J. Appl. Phys., Vol.38, ppL786-788, 1999 (Non-patent Document 8), Y. Shimoda, et al., Appl. See also Phys. Lett., Vol. 79, pp. 3627-3629, 2001 (Non-patent Document 9).

JP-A-7-116502 Japanese Patent No. 2828386 Japanese Patent No. 2,693,844 JP 2003-2687 A Japanese Patent No. 3183344 B. T. Mayers, et al., Advanded Materials, 12, No. 21, pp. 1629-1632, 2000. S. H. Park, et al., Advanded Materials, 11, No. 6, pp. 462-466, 1999. P. Jiang, et al., J. Am. Chem. Soc., 121, pp. 11630-11637, 1999. K. M. Kulinowski, et al., Advanded Materials, 12, No. 11, pp.833-838, 2000. P. Jiang, et al., Science, Vol.291, pp. 453-457, 2001. Lee, et al. Adv. Mater. 14, 271-274, 2003 S. Noda, et al., Nature 407, pp 608, 2000. K. Yoshino, et al., Jpn. J. Appl. Phys., Vol.38, ppL786-788, 1999. Y. Shimoda, et al., Appl. Phys. Lett., Vol. 79, pp. 3627-3629, 2001.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an optical element having a plurality of periodic structures including portions having different optical periods and a method for manufacturing the optical element. An object is to provide an optical element including a plurality of resonators and a simple manufacturing method thereof. The purpose of each claim is described below.

a) Object of Claim 1 An object of the present invention according to Claims 1 to 4 is to provide an optical element including a plurality of resonators for light of a plurality of wavelengths.

b) Object of Claim 5 An object of the present invention according to Claim 5 is to provide a simple method for producing an optical element having a resonator for light of a plurality of wavelengths using a periodic structure of fine particles. It is.

c) The object of claim 6 The object of the present invention according to claim 6 is the same as the object of claim 5.

d) Object of Claim 7 An object of the present invention according to Claim 7 is to provide a simple method for producing an optical element having a resonator for light of a plurality of wavelengths, using a fine particle inversion structure. .

e) The object of claim 8 The object of the present invention according to claim 8 is the same as the object of claim 7.

f) The object of claim 9 The object of the present invention according to claim 9 is the same as the object of claim 7.

g) The object of claim 10 An object of the present invention according to claim 10 is to reduce the number of defects of the periodic structure by using fine particles having good monodispersibility.

h) Object of Claim 11 An object of the present invention according to Claim 11 is to easily obtain an inverted structure using a polymer.

i) Object of Claim 12 An object of the present invention according to Claim 12 is to easily obtain an inverted structure using nanoscale particles.

j) Object of Claim 13 An object of the present invention according to Claim 13 is to produce an inverted structure by removing by heat when polymer particles are used as the particles.

k) The object of claim 14 The object of the present invention according to claim 14 is to easily produce an inversion structure.

The present invention employs the following configuration in order to achieve the above object.
a) The invention according to claim 1 is an optical element using a photonic crystal that forms a photonic band gap by a periodic structure of a spherical substance or an inverted structure thereof, and a periodic structure having a different period length is used as a substrate. A plurality of the periodic structures each include a region in which the periodicity is broken, and the region in which the periodicity is broken is characterized in that: It is a region having a periodic structure different from the void or surrounding periodic structure. In the third and fourth aspects of the present invention, an optical waveguide and an optical laser element are realized by using such an optical element.

b) The invention according to claim 5 is a step (A) in which a periodic structure is prepared by periodically arranging fine particles on the surface of a substrate using a colloidal solution, and the period prepared in step (A). Step (B) of periodically arranging fine particles having a material or particle diameter different from the fine particles used in the step (A) on the surface of the structural structure, and the same as the steps (A) and (B). And (C) repeating the step of periodically arranging fine particles having different materials or particle diameters from the fine particles used for the arrangement on the surface of the newly produced periodic structure one or more times, It is characterized by having a step (D) of partially filling and fixing a material to each periodic structure manufactured in steps (A) to (C) to form a region in which the periodicity is lost. This is a method for manufacturing an optical element.

c) The invention according to claim 6 was produced in steps (A) and (A) of producing a periodic structure by periodically arranging fine particles on the surface of a substrate using a colloid solution. A step (B) of periodically arranging fine particles having a material or particle diameter different from the fine particles used in the step (A) on the surface of the periodic structure; hereinafter, the steps (A) and (B); Similarly, a step (C) of repeating a step of periodically arranging fine particles having different materials or particle diameters from the fine particles used for the arrangement on the surface of the newly produced periodic structure one or more times, For each periodic structure produced in the steps (A) to (C), the method includes a step (D) of partially removing fine particles to form a region in which the periodicity is lost. It is a manufacturing method of an optical element.

d) According to the seventh aspect of the invention, in the steps (A) and (A), the periodic structure is prepared by periodically arranging fine particles on the surface of the substrate using a colloid solution. Step (B) in which fine particles having a particle diameter different from the fine particles used in the step (A) are periodically arranged on the surface of the structural structure, hereinafter, similarly to the steps (A) and (B), The step (C) of repeating the step of periodically arranging fine particles having a particle diameter different from the fine particles used in the arrangement on the surface of the newly produced periodic structure one or more times, the step (A) A step (D) of filling a material of a material different from the fine particles used in the arrangement between the fine particles of the periodic structure produced in (C), and solidifying or fixing the material, and a step of removing the fine particles (E), produced in steps (A) to (E). Further, each periodic structure has a step (F) of partially filling and fixing a material different from the material used in the step (D) to form a region in which the periodicity is lost. This is a method for manufacturing an optical element.

e) The invention according to claim 8 is the period prepared in steps (A) and (A) in which a periodic structure is prepared by periodically arranging fine particles on the surface of a substrate using a colloid solution. In the same manner as in the step (B), the steps (A) and (B), the fine particles having a particle diameter different from the fine particles used in the step (A) are periodically arranged on the surface of the structural structure. The step (C) of repeating the step of periodically arranging fine particles having a particle diameter different from the fine particles used for the arrangement on the surface of the produced periodic structure one or more times, the steps (A) to ( A step (D) of filling a material of a material different from the fine particles used in the arrangement between the fine particles of the periodic structure produced in C) and solidifying or fixing the material; and a step of removing the fine particles ( E), prepared in the steps (A) to (E) Each periodic structure has a step (F) of partially filling and fixing a material of the same quality as the material used in the step (D) to form a region in which the periodicity is lost. This is a method for manufacturing an optical element.

f) The invention according to claim 9 was produced in steps (A) and (A) of producing a periodic structure by periodically arranging fine particles on the surface of a substrate using a colloid solution. A step (B) in which fine particles having a particle diameter different from the fine particles used in the step (A) are periodically arranged on the surface of the periodic structure, as in the steps (A) and (B). Step (C) of repeating the step of periodically arranging fine particles having a particle diameter different from the fine particles used in the arrangement on the surface of the periodic structure produced in step (C), the steps (A) to The step (D) of removing a part of the fine particles of the periodic structure produced in (C) was used for arrangement between the fine particles of the periodic structure produced in the steps (A) to (D). Filling with a material different from fine particles and solidifying or fixing it (E), a method for manufacturing an optical element characterized by having a step (F) to remove the fine particles.

g) The invention according to claim 10 is the method for producing an optical element according to any one of claims 5 to 9, wherein the colloidal liquid in the steps (A) to (C) is silica fine particles, polystyrene fine particles or polymethacrylic acid. It contains methyl acid fine particles.

h) The invention according to claim 11 is the method for producing an optical element according to any one of claims 7 to 9, wherein a material of a material different from the fine particles used for the arrangement is provided between the fine particles of the periodic structure. The step of filling and solidifying or fixing it is characterized in that it is a step of fixing as a polymer using a monomer that is polymerized by light or heat as a filling material between fine particles.

i) The invention according to claim 12 is the method for producing an optical element according to any one of claims 7 to 9, wherein a material of a material different from the fine particles used for the arrangement is provided between the fine particles of the periodic structure. The process of filling and solidifying or immobilizing it uses a solution containing nanoscale silica particles or titania particles as a filling material between fine particles, and immobilizes nanoscale particles by drying and heating them. It is the process to perform.

j) The invention according to claim 13 is characterized in that, in the method of manufacturing an optical element according to any one of claims 7 to 9, the step of removing the fine particles is burning of the fine particles by heat.

k) The invention according to claim 14 is characterized in that, in the optical element manufacturing method according to any one of claims 7 to 9, the step of removing the fine particles is removal by a chemical reaction in a liquid phase. .

The effects of the invention will be described below for each claim.
a) Effects of the Inventions of Claims 1 to 4 In the optical elements according to claims 1 and 2, light having a plurality of wavelengths is confined by an element having a plurality of periodic structures including portions having different optical periods. According to claim 3, a waveguide using a plurality of wavelengths can be realized, and according to claim 4, an optical resonator emitting a laser having a plurality of wavelengths can be realized.

b) Effect of the Invention According to Claim 5 The method for manufacturing an optical element according to claim 5 has an effect of providing a simple method for manufacturing the optical element according to claim 1.

c) Effect of the Invention According to Claim 6 The method for manufacturing an optical element according to claim 6 has an effect of providing a simple method for manufacturing the optical element according to claim 1.

d) Advantageous Effects of the Invention According to the seventh aspect of the invention, the optical element manufacturing method according to the seventh aspect has an effect of providing a simple manufacturing method of the inversion periodic structure by the air gap.

e) Effect of Invention of Claim 8 The method for producing an optical element according to claim 8 has an effect of providing a simple method for producing an inverted periodic structure by a gap.

f) Effect of Invention of Claim 9 The method for producing an optical element according to claim 9 has an effect of providing a simple method for producing an inversion periodic structure by a gap.

g) Effect of the Invention of Claim 10 The method for producing an optical element according to claim 10 has the effect of improving the regularity of the periodic structure using fine particles having good monodispersity.

h) Effect of Invention of Claim 11 The method for producing an optical element according to claim 11 has an effect of easily producing an inverted structure by using polymerization.

i) Effect of Invention of Claim 12 The method for producing an optical element according to claim 12 has an effect of easily producing an inverted structure by using nanoscale particles.

j) Effect of Invention of Claim 13 The method for producing an optical element according to claim 13 has an effect of easily producing an inverted structure by utilizing thermal burning of polymer fine particles.

k) Effect of Invention of Claim 14 The method for manufacturing an optical element according to claim 14 has an effect of easily obtaining an inverted structure by utilizing a chemical reaction in a liquid phase.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the description of each embodiment, the case where the configuration is similar will be described with reference to a common drawing. However, the substrate material, the particle material, the particle diameter and the like are different in each embodiment.

  First, the correspondence between each embodiment of the present application and the claims will be described. In the first embodiment, the invention according to claims 1 to 4, 5, and 10 will be described. In the second embodiment, the invention according to claims 1 to 4, 7, 10, 12, and 13 will be described. In the third embodiment, the invention according to claims 1 to 4, 8, 11, and 14 will be described. In the fourth embodiment, the invention according to claims 1 to 4, 9 and 10 will be described. In the fifth embodiment, the invention according to claims 1 to 4, 6, and 10 will be described.

<Example 1>
1 and 2 are schematic views of an optical element manufactured according to Example 1. FIG.
FIG. 2 is a partially enlarged view of FIG. In the figure, the particle diameter, the number of layers, and the like are different from those of the actually manufactured structure, but are simply schematically shown.

  In the optical element shown in FIGS. 1 and 2, three types of periodic structures 2, 3, and 4 are formed on a substrate 1 in order.

  The periodic structure 2 formed of silica particles having a particle diameter of 340 nm and having approximately 20 layers is formed immediately above the substrate 1.

  Furthermore, a periodic structure 3 made of silica particles having a particle size of 320 nm and having about 20 layers is formed thereon.

  Further, a periodic structure 4 made of silica particles having a particle size of 300 nm and having about 20 layers is formed thereon.

  In any of the periodic structures 2 to 4, as shown in FIG. 2, there is a region 5 (corresponding to a thickness of about 2 μm and about 10 layers of fine particles) filled with a photocurable resin between silica particles. Such an element fulfills the function of confining light of a wavelength corresponding to the particle diameter with a resonator part made of a photo-curing resin.

A method for manufacturing the optical element shown in FIGS. 1 and 2 will be described below with reference to FIGS.
First, a quartz substrate 6 of several cm square and a silica fine particle dispersed aqueous solution (0.5 wt%, 100 ml) 7 having a diameter of 340 nm and a standard deviation of particle size distribution within 3% were prepared. One quartz substrate 6 was immersed in the solution so that the water surface was vertical as shown in FIG. 3, and the upper part of the quartz substrate 6 was fixed.

  The solution was left as it was for about one week to dry the solvent in the solution. Thereafter, the quartz substrate 6 was taken out and sufficiently dried. At this time, the periodic structure 8 made of silica fine particles was formed on the quartz substrate 6 by self-organization.

  In order to increase the hardness of the periodic structure (fine particle film) 8 on the quartz substrate 6 thus formed, heating was performed at 600 ° C. for 1 hour. This periodic structure 8 corresponds to the periodic structure 2 in FIGS.

  Thereafter, the quartz substrate 6 on which the periodic structure 2 is formed is again immersed in a silica fine particle dispersed aqueous solution (0.5 wt%, 100 ml) having a diameter of 320 nm and a standard deviation of the particle size distribution of 3% or less. By the method, the periodic structure 3 made of silica having a particle size of 320 nm was produced on the surface of the periodic structure 2 made of silica having a particle size of 340 nm. Similarly, a periodic structure 4 made of silica having a particle size of 300 nm was produced on the surface of the periodic structure 3 made of silica having a particle size of 320 nm.

  Thereafter, a photocurable resin is poured between the silica fine particles of the produced periodic structures 2 to 4, and a confocal laser is used for each of the three types of periodic structures 2 to 4, as shown in FIG. The region 5 of 2 was selectively irradiated with light to cure the photocurable resin. Thereafter, the photo-curing resin other than the uncured region 5 was removed.

  The optical elements shown in FIGS. 1 and 2 are produced by producing three types of periodic structures (fine particle films) 2 to 4 having different optical distances by utilizing the capillary force of a colloidal solution and the self-organization of fine particles. It is possible to confine light having different wavelengths by having different periods in the three types of periodic structures 2 to 4.

  Such a three-dimensional periodic structure is difficult to manufacture by microfabrication, and has a high light confinement effect. As in this example, the bottom-up method using the phenomenon in which fine particles are arranged in a self-organized manner has no waste of materials and is a process compared to the top-down method of processing materials using an etching apparatus or the like. It is also easy to save resources and energy, and is excellent in terms of the environment.

  Conventionally, a photonic crystal such as a waveguide can be produced only by a method of performing microfabrication, which has a problem in terms of environment. However, the present invention has made it possible to produce a photonic crystal that is environmentally friendly and has a somewhat complicated structure.

<Example 2>
4 and 5 are schematic views of an optical element manufactured according to Example 2. FIG.
FIG. 5 is a partially enlarged view of FIG. In the figure, the particle diameter, the number of layers, and the like are different from those of the actually manufactured structure, but are simply schematically shown.

  In the optical element shown in FIG. 4, three types of periodic structures 10, 11, and 12 are formed on a substrate 9. What is formed immediately above the substrate 9 is a periodic structure 10 made of a spherical gap having a size of 500 nm and comprising about 10 layers.

  Furthermore, a periodic structure 11 made of a spherical void having a size of 400 nm and having about 10 layers is formed thereon. Further, a periodic structure 12 made of a spherical void having a size of 300 nm and having about 10 layers is formed thereon.

  In any of the periodic structures 10 to 12, voids are formed by silica nanoparticle solids, but there is a region 13 partially filled with a photocurable resin as shown in FIG. 5.

  The particle size of the photocurable resin filling the voids is 500 nm, 400 nm, and 300 nm in order from the periodic structure close to the substrate 9. The region 13 where the photocurable resin is present instead of being a void has an optical distance different from the periodic structure due to the void. Therefore, such an element functions to confine light having a wavelength corresponding to the particle diameter in a resonator part made of a solid material of silica nanoparticles in which a photocurable resin is present.

Hereinafter, a method for manufacturing the optical element shown in FIGS. 4 and 5 will be described with reference to FIGS.
First, a quartz substrate 6 of several centimeters square and a polystyrene fine particle dispersion aqueous solution (0.5 wt%, 100 ml) having a diameter of 500 nm and a standard deviation of particle size distribution within 3% were prepared.

  One quartz substrate 6 was immersed in the solution so that the water surface was vertical as shown in FIG. 3, and the upper part of the quartz substrate 6 was fixed. The solution was left as it was for about one week to dry the solvent in the solution. Thereafter, the quartz substrate 6 was taken out and sufficiently dried. At this time, the periodic structure 8 made of polystyrene fine particles was formed on the quartz substrate 6 by self-organization. This periodic structure 8 corresponds to the periodic structure 2 in FIGS.

  Thereafter, the quartz substrate 6 on which the periodic structure 2 is formed is immersed in an aqueous polystyrene fine particle dispersion (0.5 wt%, 100 ml) having a diameter of 400 nm and a standard deviation of the particle size distribution of 3% or less, and the same method as above. Thus, a periodic structure made of polystyrene having a particle size of 400 nm was prepared on the surface of the periodic structure made of polystyrene having a particle size of 500 nm, and sufficiently dried. Similarly, a periodic structure made of polystyrene having a particle size of 300 nm was prepared on the surface of the periodic structure made of polystyrene having a particle size of 400 nm.

  Thereafter, an aqueous solution containing silica nanoparticles having a particle size of about 3 to 6 nm was poured between the fine particles of the produced periodic structure and dried. Thereafter, heating was performed at 500 ° C. for 5 hours to burn off the polystyrene by heat, and the silica nanoparticles were fixed to prepare a periodic structure with voids.

  Thereafter, a photocurable resin is poured into the gap, and each of the three types of periodic structures 10 to 12 is selectively irradiated with light to the region 13 using a confocal laser. Cured. Then, the photocurable resin of parts other than the area | region 13 which is not hardened | cured was removed.

  The optical elements shown in FIGS. 4 and 5 are produced by producing three types of periodic structures (fine particle films) 10 to 12 having different optical distances by utilizing the capillary force of a colloidal solution and self-organization of fine particles. It is possible to confine light having different wavelengths by having different periods in the three types of periodic structures 10 to 12.

  It is a three-dimensional periodic structure that is difficult to manufacture by microfabrication, and has a high light confinement effect. The bottom-up method using the phenomenon in which fine particles are arranged in a self-organized manner is less wasteful and easier as a process than the top-down method of processing a material using an etching apparatus. It is resource and energy saving and is excellent in terms of environment. Conventionally, a photonic crystal such as a waveguide can be produced only by a method of performing microfabrication, which has a problem in terms of environment. However, the present invention has made it possible to produce a photonic crystal that is environmentally friendly and has a somewhat complicated structure.

<Example 3>
4 and 5 are schematic views of an optical element manufactured according to this example. FIG. 5 is a partially enlarged view of FIG. In the figure, the particle diameter, the number of layers, and the like are different from those of the actually manufactured structure, but are simply schematically shown. In the optical element shown in FIG. 4, three types of periodic structures 10, 11, and 12 are sequentially formed on a substrate 9.

  What is formed immediately above the substrate 9 is a periodic structure 1 made of a spherical gap of 340 nm and comprising about 20 layers. Furthermore, a periodic structure 2 made of a spherical void having a size of 320 nm and having about 20 layers is formed thereon. Further, a periodic structure 3 made of a spherical void having a size of 300 nm and having about 20 layers is formed thereon.

  In any periodic structure, a void is formed by a photocurable resin, not a void, and there is a portion filled with the photocurable resin inside. The particle size of the photocurable resin filling the voids is 340 nm, 320 nm, and 300 nm in order from the periodic structure close to the substrate 9.

  The portion where the photocurable resin is filled to the inside instead of being a void has an optical distance different from the periodic structure due to the void. Therefore, such an element fulfills a function of confining light having a wavelength corresponding to the particle diameter in a resonator portion including a portion filled with a photo-curable resin to the inside of the gap.

Hereinafter, a method for manufacturing the optical element shown in FIGS. 4 and 5 will be described with reference to FIGS.
First, a quartz substrate 6 of several cm square and a silica fine particle dispersed aqueous solution (0.5 wt%, 100 ml) 7 having a diameter of 340 nm and a standard deviation of particle size distribution within 3% were prepared.

  One quartz substrate 6 was immersed in the solution so that the water surface was vertical as shown in FIG. 3, and the upper part of the quartz substrate 6 was fixed. The solution was left as it was for about one week to dry the solvent in the solution. Thereafter, the quartz substrate 6 was taken out and sufficiently dried. At this time, a periodic structure 8 made of silica fine particles was formed between the quartz substrates by self-organization.

  In order to increase the hardness of the periodic structure (fine particle film) 8 on the quartz substrate 6 thus formed, heating was performed at 600 ° C. for 1 hour. This periodic structure 8 corresponds to the periodic structure 10 in FIGS.

  Thereafter, the quartz substrate 9 on which the periodic structure 10 is formed is again immersed in a silica fine particle dispersed aqueous solution (0.5 wt%, 100 ml) having a diameter of 320 nm and a standard deviation of the particle size distribution of 3% or less, and the same as above. By the method, the periodic structure 11 made of silica having a particle size of 320 nm was produced on the surface of the periodic structure 10 made of silica having a particle size of 340 nm. Similarly, a periodic structure 12 made of silica having a particle size of 300 nm was produced on the surface of the periodic structure 11 made of silica having a particle size of 320 nm.

  Thereafter, a photocurable resin was poured between the fine particles of the produced periodic structures 10 to 12 and cured with ultraviolet rays. Thereafter, the silica was removed by etching using hydrofluoric acid.

  After obtaining a periodic structure consisting of voids, it was placed on the substrate 9 again, the inside of the voids was filled again with a photocurable resin, and the region 13 was selectively photocured using a confocal laser. After that, the photocurable resin in the voids other than the uncured region 13 was removed.

<Example 4>
FIG. 6 is a schematic diagram of an optical element manufactured according to this example.
In the figure, the particle diameter, the number of layers, and the like are different from those of the actually manufactured structure, but are simply schematically shown. In the figure, the particle diameter, the number of layers, and the like are different from those of the actually manufactured structure, but are simply schematically shown.

  In the optical element shown in FIG. 6, two types of periodic structures 14 and 15 are formed on a substrate 9. What is formed immediately above the substrate 9 is a first periodic structure 14 made of a spherical void having a size of 320 nm and having about 20 layers.

  Furthermore, a second periodic structure 15 having a spherical gap of 300 nm and having about 20 layers is formed thereon. In any periodic structure, the inverted structure is made of a solid material of nanoscale silica particles.

  The particle size of the photocurable resin filling the voids is 320 nm and 300 nm in order from the periodic structure close to the substrate 9. In addition, a region 16 where no periodic structure exists is partially present above the first periodic structure 14 and the second periodic structure 15. Since such a region does not have a periodic structure, light of a specific wavelength is confined.

Hereinafter, a method for manufacturing the optical element in FIG. 6 will be described with reference to FIGS.
First, a quartz substrate 6 of several centimeters square and a polystyrene fine particle dispersion aqueous solution (0.5 wt%, 100 ml) 7 having a diameter of 320 nm and a standard deviation of particle size distribution within 3% were prepared.

  One quartz substrate 6 was immersed in the solution so that the water surface was vertical as shown in FIG. 3, and the upper part of the quartz substrate 6 was fixed. The solution was left as it was for about one week to dry the solvent in the solution. Thereafter, the quartz substrate 6 was taken out and sufficiently dried. At this time, a periodic structure 8 made of polystyrene fine particles was formed between the quartz substrates by self-organization. This periodic structure 8 corresponds to the periodic structure 14 in FIG.

  Thereafter, the quartz substrate 6 on which the periodic structure 14 is formed is again immersed in a polystyrene fine particle dispersion aqueous solution (0.5 wt%, 100 ml) having a diameter of 300 nm and a standard deviation of the particle size distribution of 3% or less. The periodic structure 15 made of polystyrene having a particle size of 300 nm was produced on the surface of the periodic structure 14 made of polystyrene having a particle size of 320 nm by the above method.

  Thereafter, a part of the few fine particle layers located on the first periodic structure 14 and the second periodic structure 15 thus produced are removed using a femtosecond laser to form a defective region 16. did.

  Thereafter, nanoscale silica particles were poured between the fine particles, and heating was performed at 500 ° C. for 5 hours. A periodic structure composed of voids was obtained by burning out polystyrene. Since the region 16 from which the fine particles have been removed using the femtosecond laser becomes a defect, light having a specific wavelength can be confined.

<Example 5>
FIG. 7 is a schematic view of an optical element manufactured according to this example.
In the figure, the particle diameter, the number of layers, and the like are different from those of the actually manufactured structure, but are simply schematically shown.

  In the optical element of this example, the first and second periodic structures 2 and 3 composed of polystyrene fine particles having different particle diameters are formed in the same manner as in the above-described example, and the defect in which the polystyrene fine particles do not exist on the upper surface thereof. The region 17 is formed by a femtosecond laser or the like.

  As mentioned above, although Example 1-5 has been demonstrated in order to demonstrate this invention, it cannot be overemphasized that a various application is possible for this invention not only in these Examples.

  For example, as the kind of fine particles in the present invention, for example, zirconium oxide may be used in addition to silica and polyethylene shown in the examples.

  Moreover, although the fine particle diameter is usually from several nanometers to several hundred nanometers, it is not limited to these.

  Further, the wavelength of light to be confined can be selected by changing the diameter of the fine particles used for producing the periodic structure.

  In addition, the periodic structure may be manufactured by, for example, a periodic structure by another manufacturing method such as (b) placing the substrate horizontally or (b) processing the substrate.

  Further, the periodic structure may be formed between two substrates, and one of the substrates may be removed, or either one of the methods of manufacturing a single substrate surface from the beginning as shown in FIG. .

  Further, the size of the periodic structure to be manufactured, the substrate to be used, and the like are not limited, and the material is not limited as long as it satisfies the claims.

  Furthermore, the solution concentration, temperature, etc. at the time of producing the periodic structure are not limited to the values in the examples.

  In addition, as in the present invention, the bottom-up method using the phenomenon in which fine particles are arranged in a self-organized manner is less wasteful of the material than the top-down method of processing a material using an etching apparatus or the like, and the process Because it is easy, it saves resources and energy and is very excellent in terms of environment.

  In the top-down method, the vacuum device also uses a vacuum pump, a heater, etc., so that a large amount of power is used for a long time and material is wasted. However, according to the bottom-up method as in the present invention, the substrate is dispersed in fine particles. By soaking in the liquid, fine particles accumulate and a periodic structure is formed, so that the energy required for production is remarkably small, and the process itself is also energy saving. In addition, the solvent used in the manufacturing process can be easily recovered, saving resources and being environmentally friendly.

  In the above embodiment, it is possible to confine light of a specific wavelength in the periodic structure by providing a region where the periodicity is lost in the periodic structure. If it is confined inside the periodic structure, it functions as an optical resonator for an optical laser, etc., and if the region where the periodicity is broken is connected from one end to the other end of the periodic structure, it serves as an optical waveguide. Needless to say, it works.

1 is a front view of an optical element manufactured in Example 1. FIG. 3 is an enlarged front view of an optical element manufactured in Example 1. FIG. It is a manufacturing method schematic diagram of a periodic structure by fine particles. 6 is a front view produced in Example 2 and Example 3. FIG. 6 is an enlarged front view of an optical element manufactured in Example 2 and Example 3. FIG. 6 is a front view of an optical element manufactured in Example 4. FIG. 10 is a front view of an optical element manufactured in Example 5. FIG.

Explanation of symbols

1: Substrate 2: First periodic structure 3: Second periodic structure 4: Third periodic structure 5: Region where fine particles are filled with other materials,
6: Substrate 7: Colloid liquid containing fine particles 8: Periodic structure by fine particles formed on substrate 9: Substrate 10: First periodic structure by voids 11: Second periodic structure by voids 12 : Third periodic structure with voids 13: region filled with other materials in the voids 14: first periodic structure with voids 15: second periodic structure with voids 16: defect region 17: Void defect area

Claims (14)

An optical element using a photonic crystal that forms a photonic band gap by a periodic structure of a spherical substance or an inverted structure thereof,
An optical element comprising a plurality of periodic structures having different periodic lengths in parallel to the substrate, each of the periodic structures including a region in which periodicity is lost. The optical element according to claim 1, wherein
The optical element according to claim 1, wherein the region in which the periodicity is broken is a region having a periodic structure different from a gap or a surrounding periodic structure.   An optical waveguide using the optical element according to claim 1.   An optical laser element using the optical element according to claim 1. Step (A) of producing a periodic structure by periodically arranging fine particles on the surface of a substrate using a colloid solution
Step (B) of periodically arranging fine particles having a different material or particle diameter from the fine particles used in Step (A) on the surface of the periodic structure produced in Step (A).
Thereafter, similarly to the steps (A) and (B), fine particles having a different material or particle diameter from the fine particles used in the arrangement are periodically arranged on the surface of the newly produced periodic structure. Step (C) of repeating the step to be repeated at least once
Step (D) of partially filling and fixing a material to each periodic structure manufactured in the steps (A) to (C) to form a region in which the periodicity is lost.
A method for manufacturing an optical element, comprising: Step (A) of producing a periodic structure by periodically arranging fine particles on the surface of a substrate using a colloid solution
Step (B) of periodically arranging fine particles having a different material or particle diameter from the fine particles used in Step (A) on the surface of the periodic structure produced in Step (A).
Thereafter, similarly to the steps (A) and (B), fine particles having a different material or particle diameter from the fine particles used in the arrangement are periodically arranged on the surface of the newly produced periodic structure. Step (C) of repeating the step to be repeated at least once
Step (D) in which fine particles are partially removed from each periodic structure produced in steps (A) to (C) to form a region in which the periodicity is lost.
For manufacturing an optical element characterized by comprising Step (A) of producing a periodic structure by periodically arranging fine particles on the surface of a substrate using a colloid solution
Step (B) of periodically arranging fine particles having a particle diameter different from the fine particles used in Step (A) on the surface of the periodic structure produced in Step (A).
Hereinafter, similarly to the steps (A) and (B), a step of periodically arranging fine particles having a particle diameter different from the fine particles used for the arrangement on the surface of the newly produced periodic structure. Step (C) to repeat at least once
Step (D) of filling the material of the material different from the fine particles used for the arrangement between the fine particles of the periodic structure produced in the steps (A) to (C) and solidifying or immobilizing it.
Step (E) for removing the fine particles
A region in which the periodicity is destroyed by partially filling and fixing a material different from the material used in the step (D) for each periodic structure manufactured in the steps (A) to (E). Forming step (F)
For manufacturing an optical element characterized by comprising Step (A) of producing a periodic structure by periodically arranging fine particles on the surface of a substrate using a colloid solution
Step (B) of periodically arranging fine particles having a particle diameter different from the fine particles used in Step (A) on the surface of the periodic structure produced in Step (A).
Similarly to the steps (A) and (B), the step of periodically arranging fine particles having a particle diameter different from the fine particles used for the arrangement on the surface of the newly produced periodic structure 1 Step (C) to repeat more than once
Step (D) of filling a material of a material different from the fine particles used in the arrangement between the fine particles of the periodic structure produced in the steps (A) to (C) and solidifying or immobilizing it.
Step (E) for removing the fine particles
A region in which the periodicity is destroyed by partially filling and fixing the same material as that used in the step (D) for each periodic structure manufactured in the steps (A) to (E). Forming step (F)
For manufacturing an optical element characterized by comprising Step (A) of producing a periodic structure by periodically arranging fine particles on the surface of a substrate using a colloid solution
Step (B) of periodically arranging fine particles having a particle diameter different from the fine particles used in Step (A) on the surface of the periodic structure produced in Step (A).
Similarly to the steps (A) and (B), the step of periodically arranging fine particles having a particle diameter different from the fine particles used for the arrangement on the surface of the newly produced periodic structure 1 Step (C) to repeat more than once
A step (D) of removing a part of the fine particles of the periodic structure produced in the steps (A) to (C).
Step (E) of filling the material of the material different from the fine particles used for the arrangement between the fine particles of the periodic structure produced in the steps (A) to (D) and solidifying or immobilizing it.
Step (F) for removing the fine particles
For manufacturing an optical element characterized by comprising In the manufacturing method of the optical element in any one of Claims 5-9,
The method for producing an optical element, wherein the colloidal liquid in the steps (A) to (C) contains silica fine particles, polystyrene fine particles, or polymethyl methacrylate fine particles. In the manufacturing method of the optical element in any one of Claims 7-9,
A step of filling a material of a material different from the fine particles used for the arrangement between the fine particles of the periodic structure and solidifying or fixing the material is a monomer that is polymerized by light or heat as a filling material between the fine particles. A method for producing an optical element, which is a step of immobilizing as a polymer. In the manufacturing method of the optical element in any one of Claims 7-9,
The step of filling the material of the periodic structure with a material different from the fine particles used for the arrangement and solidifying or fixing the material is a nanoscale silica particle or titania as a filling material between the fine particles. A method for producing an optical element, which is a step of immobilizing nanoscale particles by drying and heating a solution containing particles and the like. In the manufacturing method of the optical element in any one of Claims 7-9,
The method for producing an optical element, wherein the step of removing the fine particles is burning of the fine particles by heat. In the manufacturing method of the optical element in any one of Claims 7-9,
The method for producing an optical element, wherein the step of removing the fine particles is removal by a chemical reaction in a liquid phase.

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