WO2011019164A2

WO2011019164A2 - Optical waveguide device

Info

Publication number: WO2011019164A2
Application number: PCT/KR2010/005160
Authority: WO
Inventors: 조기호; 안준원
Original assignee: 주식회사 엘엠에스
Priority date: 2009-08-10
Filing date: 2010-08-06
Publication date: 2011-02-17
Also published as: WO2011019164A3; KR100954834B1

Abstract

The present invention relates to an optical waveguide device, and particularly, to a planar optical waveguide device. The optical waveguide device of the present invention comprises: a substrate; a core formed on the substrate, consisting of a main optical path and a branch optical path; cladding made of a material having a refractive index smaller than that of the core, formed on the substrate such that the cladding covers at least both outer transverse sides of the core; and a splitter unit arranged at the branching point of the main optical path, having a refractive index different from that of the core. The splitter unit has a mirror angle for reflecting a portion of incident light from the main optical path in the direction of the branch optical path.

Description

Optical waveguide device

The present invention relates to an optical waveguide device, and more particularly, to a planar optical waveguide device.

Recently, a lot of researches have been made on a technique for fabricating an optical waveguide on a planar substrate using a planar waveguide technology for the purpose of optical signal processing such as optical signal branching, modulation, switching, and signal multiplexing. As a technique required for fabricating such an optical waveguide device, a waveguide design, fabrication, and packaging may be exemplified.

A typical optical waveguide is an optical transmission path that traps light waves and propagates low loss in the longitudinal direction. The optical waveguide is composed of a core having a high refractive index and a cladding having a low refractive index surrounding the core, and the internal reflection due to the difference in refractive index between the core and the cladding. It has a principle of transmitting the optical signal based on the basic principle.

In the planar optical waveguide as described above, when a single optical signal traveling along the optical waveguide is to be separated and transmitted through multiple channels, the receiving end is branched into a Y shape. In other words, the receiving end is branched into a Y-shape, and the branched branch of the receiving end is again branched into a Y-shape to branch until the desired number of channels is reached.

The Y-shaped branching system as described above has a problem that the area of the optical waveguide is enlarged. In particular, in view of the trend toward miniaturization of mobile digital devices employing touch screens, the problem of area enlargement is a fatal disadvantage.

An object of the present invention for solving the above problems is to provide an optical waveguide device in which the output of light is constant and the area is minimized even if the number of receiving channels increases.

The optical waveguide device of the present invention for achieving the above object is a substrate; A core formed on the substrate, the core including a main path and a branch path; A cladding formed on the substrate with a material having a refractive index smaller than that of the core, the cladding being disposed to surround at least two outer sides of the core; A splitter is disposed on the main optical path at a branching position of the split optical path, and includes a splitter having a refractive index difference from the core.

In addition, in the optical waveguide device of the present invention, the splitter portion has a directing angle to reflect a part of incident light from the main optical path in the direction of the branch optical path.

In addition, in the optical waveguide device of the present invention, a plurality of branch light paths may be formed along an extension direction of the main light path, and the splitter part may be formed in the same number as the number of the branch light paths.

In addition, in the optical waveguide device of the present invention, the splitter portion is formed of a material having the same refractive index as the cladding.

In addition, in the optical waveguide device of the present invention, the splitter is air.

In addition, in the optical waveguide device of the present invention, the plurality of splitters are formed to have a directing angle with respect to the incident light so as to reflect a part of the incident light from the main optical path in the direction of the branch optical path, and the directing angle increases along the main optical path. It is done.

In addition, in the optical waveguide device of the present invention, each splitter part is characterized in that the direction angle is in the range of 40 ° to 50 °.

In the optical waveguide device of the present invention, the branched light path is branched to be perpendicular to the main light path.

In the optical waveguide device of the present invention, the difference in refractive index between the core and the splitter portion is 0.1 or more and 0.3 or less.

In addition, the core material in the optical waveguide device of the present invention comprises a nano-dispersion component, characterized in that any one or two or more of alumina, tin oxide, antimony oxide, silica, zirconia, titania is a mixed metal oxide.

In the optical waveguide device of the present invention, the core and / or the splitter portion and / or the cladding are formed of a Sol-Gel material.

Further, in the optical waveguide device of the present invention, the uniformity of the light reflected from the splitter portion is 3 dB or less.

On the other hand, the optical waveguide device of the present invention as described above can be used in the optical splitter for optical communication.

On the other hand, there is provided an optical waveguide device according to another embodiment, comprising: a substrate; A core in the form of a lattice grid formed on the substrate; A cladding formed on the substrate with a material having a refractive index smaller than that of the core on the substrate, the cladding being disposed to surround at least both outer sides of the core; And a splitter part disposed at each branch point of two adjacent optical paths among the outermost optical paths of the grid and having a material having a refractive index difference from the core.

In addition, in the optical waveguide device of the present invention, the splitter portion is formed to have a directing angle to reflect a part of the incident light in the branching direction at the branching point of the outermost optical path of the grid.

In addition, in the optical waveguide device of the present invention, the splitter portion is formed of the same material as the cladding.

In addition, in the optical waveguide device of the present invention, each of the splitters is formed such that the directing angle increases as the distance from the intersection of the outermost optical path of the grid increases.

In addition, in the optical waveguide device of the present invention, the splitter is characterized in that the direction angle is in the range of 40 ° to 50 °.

Further, in the optical waveguide device of the present invention, the grid-like grid of the core is characterized in that the crossing angle is vertical.

In addition, in the optical waveguide device of the present invention, the core material includes a nanodispersion component, wherein the nanodispersion component is a metal mixed with any one or two or more of alumina, tin oxide, antimony oxide, silica, zirconia, and titania. It is characterized by being an oxide.

In the optical waveguide device of the present invention, the core and / or splitter and / or cladding may be formed of a Sol-Gel material.

On the other hand, the optical waveguide device of the present invention as described above can be used in the touch screen device.

The optical waveguide device of the present invention as described above has an advantage of receiving a uniform light output even with a large number of receiving channels. In particular, even if the number of channels is increased, the optical waveguide can be realized with a minimum area, thereby reducing the size of the product having the optical waveguide device.

1 is a view schematically illustrating a touch key pad to which an optical waveguide device according to an exemplary embodiment of the present invention is applied.

2 is a view for explaining a core and a splitter according to an embodiment of the present invention;

3 is a view for explaining in detail the splitter shown in FIG.

FIG. 4 is a light output distribution chart for each channel when the splitter shown in FIG. 3 is formed at the same angle.

5 is a light output distribution chart for each channel when the splitters shown in FIG. 3 are formed at set angles, respectively.

6 is a view for explaining the operation of the optical waveguide device according to an embodiment of the present invention;

Hereinafter, with reference to the accompanying drawings 1 to 6 will be described in detail a preferred embodiment according to the present invention with reference to the accompanying drawings. Note that the same components in the drawings are represented by the same reference numerals and symbols as much as possible even if shown in different drawings. In addition, in describing the embodiments of the present invention, if it is determined that the detailed description of the related known function or configuration may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted.

First, referring to FIG. 1, a brief description will be given of a touch key pad to which an optical waveguide device according to an exemplary embodiment of the present invention is applied.

The optical waveguide device of the present embodiment is arranged to surround the substrate 10, the core 20 formed of a core material on the upper surface of the substrate 10, and the periphery of the core 20, that is, at least in both transverse directions. It includes a cladding (30). The cladding 30 will be described as an example of being disposed on both sides in both transverse directions, but is not limited thereto. In the optical waveguide device as described above, the pattern of the core 20 is pressed onto the substrate 10 by using a silicon stamper (not shown) in which the waveguide pattern is formed. Accordingly, the core 20 formed by the pattern is formed on the substrate 10, and a material for forming the cladding 30 is injected around the core 20 to be completed.

The cladding 30 is formed of a material having a refractive index difference from a material forming the core 20, and internal reflection is generated by the difference in refractive index between the two materials to transmit an optical signal. In the present embodiment, the cladding 30 has a smaller refractive index than the core material as an example, but is not limited thereto.

2 is a plan view of a part of the optical waveguide device 100 manufactured as described above, wherein the core 20 has a light source (not shown) installed on the left side and a main light path extending in a horizontal direction ( 21, and a branched light path 22 branched from the main light path 21 in a vertical direction, wherein the core material and the branched light path 22 branch on the main light path 21. Further, a splitter 40 is formed of a material having a difference in refractive index and reflects a part of the incident light of the main optical path 21 toward the branch optical path 22. In the present exemplary embodiment, the branched light 22 is vertically branched from the main light path 21, but is not limited thereto. In addition, the splitter 40 has a smaller refractive index than the core 20 as an example, but is not limited thereto.

The core 20, the cladding 30, and the splitter 40 are acrylic, cellulose, polyester, polyamide, polyether, vinyl, urethane, urea, alkyd, silicone, fluorine, olefin, petroleum, rosin, Selected from epoxy resin, unsaturated polyester, diaryl phthalate resin, phenol, oxetane, oxazine, bismaleimide, sol-gel process silicone resin, melamine, acrylic resin, rubber, natural polymer, glass resin and glass frit One or more compounds may be used. In the present invention, a silicone resin made of Sol-Gel will be described as an example. This thermal property is superior to conventional polymer materials, which is advantageous for securing product reliability. Especially, in the field of display apparatuses in which a lot of heat is generated during use, thermal durability is of paramount importance. Therefore, when the optical waveguide according to the present embodiment is applied to a display device-related field, that is, a touch screen, it is preferable to manufacture by Sol-Gel. In addition, the sol-gel (Sol-Gel) is preferable as a material for optical foam that requires a really rough processing because the shrinkage characteristics generated during the curing process is very superior to other materials. Since the core 20, the cladding 30, and the splitter portion 40 must satisfy the refractive index conditions described above and described below, the core 20, the cladding 30, and the splitter portion 40 are identically formed of any one material. The core 20, the cladding 30, and the splitter 40 may be formed of the same material formed differently.

The branch optical path 22 is formed in plural along the extension direction of the main optical path 21, and the splitter portion 40 is formed at each branch point of the branch optical path 22. The splitter portion 40 should have a refractive index smaller than that of the core material. The splitter portion 40 may be formed of the same material as the cladding 30. At this time, when the difference in refractive index between the core 20 and the splitter portion 40 is too large, most of the incident light is reflected by the splitter portion 40 located at the front end of the optical path, so that the amount of light is not sufficiently supplied to the branch light path at the rear stage. On the contrary, when the difference in refractive index is too small, the light supply to the branched optical path is too small. Therefore, the difference in refractive index between the core material constituting the core 20 and the splitter 40 is most preferably 0.1 or more and 0.3 or less. In view of the above refractive index difference range, the splitter 40 is kept in the state of injecting air, that is, nothing is injected, and the material of the core 20 is appropriately selected to exist in the refractive index difference range. It is also possible to form the core 20 from the material. When selecting the material constituting the core 20 in consideration of only the refractive index may not be easy to form during the production process, so even if the refractive index is relatively low, select a material that is easy to mold, in order to increase the refractive index nano It is also possible to satisfy the conditions of the difference in refractive index by producing a dispersion component. The nano-dispersion component as described above may be used by mixing one or more components such as alumina, tin oxide, antimony oxide, silica, zirconia, titania.

As shown in FIG. 3, the splitter unit 40 has a direction angle α ° to reflect a part of incident light from the main optical path 21 toward the branch optical path 22. The portion 40 is formed to increase the direction angle so as to be far from the light source. In the present invention, the direction angle is defined as an angle in which the direction of the optical path forms the normal of the splitter reflecting surface as shown in FIG. 3.

Looking at the angle of the splitter 40 in detail with reference to the experimental result graph of Figure 4 and 5 as follows. 4 and 5 have a refractive index of 1.555 of the core 20, a refractive index of 1.422 of the cladding 30 and the

splitter

40, and 50 split optical paths 22 to form the splitter 40. Is fixed or changed, and the ratio of the output light to the input light at the output side of the branched light path 22 is measured.

As shown in FIG. 4, when the angles of the 50 splitter parts 40 are fixed at 45 °, the output light ratio of the split light path 22 located on the side closest to the light source is 1.41%, while it is farthest from the light source. It can be seen that the output light ratio in the branch light path 22 located therein is 0.437%, and the light passing through the splitter unit 40 is gradually weakened. Therefore, in the case of detecting the light using the output light of each branch light path 22 as the same detector, the light output is not uniform as described above and the light output becomes weak as the light source moves away from the light source. . On the other hand, starting at an angle of 41.35 ° as shown in FIG. 5 and forming 50 splitters 40 so as to increase the directivity angle by 0.15 ° each, in the branch light path 22 located on the side closest to the light source. It can be seen that the output light ratio is 0.92% and the output light ratio in the branch light path 22 located farthest from the light source is 0.907%, which is substantially the same light output. As can be seen from the experimental data, the orientation angle of the splitter portion 40 is most preferably formed to belong to 40 ° or more and 50 ° or less. Using such a result, it can be applied to an optical communication optical splitter that supplies a uniform amount of light to a plurality of channels using only one light source.

6 illustrates an example in which the core 20 of the present embodiment is formed in the form of a lattice grid. In the drawing, the main light path and the branch light path are formed in the horizontal direction, and the main light path and the branch light path are also formed in the vertical direction, so that each of the horizontal and vertical direction light beams may be intersected to form a grid-like grid. . At this time, a plurality of splitters 40 are formed at each branch point except for the intersection point in two adjacent outermost grids, that is, the main light paths in the horizontal and vertical directions. Light is supplied to the horizontal and vertical main light paths by light sources L1 and L2 respectively. The amount of light may be measured by arranging a plurality of optical sensors along branch points of the outermost grid that face the outermost grid. If a contact is generated by a finger or the like on the grid, total reflection is broken on the upper surface, so that a change in the amount of light is detected by the optical sensor of the corresponding channel, thereby determining the contact position of the finger. In the present exemplary embodiment, the optical sensors are arranged along branch points, but the present invention is not limited thereto. It is also possible to achieve with only one sensor having a switching means along each branching point and for sensing the switching of said switching means. Using this principle, the present invention can be applied to a position detection device or a touch screen using only two light sources. In the above, the use of two light sources has been described as an example, but is not limited thereto. For example, it is also possible to arrange one light source and to supply light as shown in FIG. 6 using an appropriate light distribution means.

The uniformity of the light reflected from the splitter unit 40 as described above is preferably 3 dB or less. The uniformity of the light means a difference between the maximum output and the minimum output, which means that the difference is less than 3 dB. This is to prevent the case in which the optical sensor does not detect the output light, because when the uniformity of the light exceeds 3dB, the absorption and loss of light occurs to lower the functionality as a product.

One embodiment of the present invention described above should not be construed as limiting the technical spirit of the present invention. The protection scope of the present invention is limited only by the matters described in the claims, and those skilled in the art can change and change the technical idea of the present invention in various forms. Therefore, such improvements and modifications will fall within the protection scope of the present invention as long as it will be apparent to those skilled in the art.

The optical waveguide device of the present invention has an advantage of receiving a uniform light output even if the number of receiving channels is increased. In particular, the optical waveguide can be implemented with a minimum area even if the number of channels is increased, thereby minimizing the size of a product having the optical waveguide device, which is an invention that can be usefully used in the technical field of the present invention.

Claims

Board;

A core formed on the substrate, the core including a main path and a branch path;

A cladding formed on the substrate with a material having a refractive index smaller than that of the core, the cladding being disposed to surround at least two outer sides of the core;

A splitter portion disposed on the main optical path at a branching position of the branch optical path and having a refractive index difference from the core;

A plurality of branch light paths are formed along the extension direction of the main light path,

A plurality of splitters are formed in the same number as the number of split light paths,

The plurality of splitters are formed to have a directing angle with respect to the incident light so as to reflect a part of the incident light in the direction of the branch light from the main light path, the optical waveguide device characterized in that the directing angle increases along the main light path
The method of claim 1,

And the splitter portion has a directing angle to reflect a part of the incident light from the main optical path toward the split optical path.
The method of claim 2,

And the splitter part is formed of a material having the same refractive index as that of the cladding.
The method of claim 1,

And the splitter portion is air.
The method of claim 2,

An optical waveguide device, wherein the direction angle of each splitter is in the range of 40 ° to 50 °.
The method of claim 1,

And the branched light path is branched to be perpendicular to the main light path.
The method of claim 1,

The optical waveguide device, characterized in that the difference in refractive index between the core and the splitter portion is 0.1 or more and 0.3 or less.
The method of claim 1,

The core material is an optical waveguide device comprising a nano-dispersion component.
The method of claim 1,

The core and / or splitter portion and / or cladding,

An optical waveguide device, characterized in that formed of a Sol-Gel material.
The method of claim 8,

The nanodispersion component,

An optical waveguide device, wherein any one or two or more of alumina, tin oxide, antimony oxide, silica, zirconia, and titania are mixed metal oxides.
The method according to any one of claims 1 or 2 or 3 or 4 or 5 to 10,

The optical waveguide device, characterized in that the uniformity of the light reflected by the splitter portion is 3dB or less.
An optical splitter for optical communications comprising the optical waveguide device of claim 11.
Board;

A core in the form of a lattice grid formed on the substrate;

A material having a refractive index smaller than the core on the substrate, formed on the substrate, wherein at least the transverse direction of the core

A cladding disposed to surround both outer sides;

An optical waveguide device disposed at each branch point of two adjacent optical paths of the outermost optical path of the grid and comprising a splitter part made of a material having a refractive index difference from the core.
The method of claim 13,

And the splitter part has a directing angle to reflect a part of the incident light in the branching direction at the branching point of the outermost optical path of the grid.
The method of claim 13,

And the splitter portion is made of the same material as the cladding.
The method of claim 13,

And the splitter portion is air.
The method of claim 14,

And wherein each splitter portion is formed such that a direction angle increases as it moves away from an intersection point of the outermost optical path of the grid.
The method of claim 16,

An optical waveguide device, wherein the direction angles of the splitters are in the range of 40 ° to 50 °.
The method of claim 13,

And the lattice grid of the core is perpendicular to the crossing angle.
The method of claim 13,

An optical waveguide device, wherein a difference in refractive index between the core and the splitter portion is 0.1 or more and 0.3 or less.
The method of claim 13,

The core material is an optical waveguide device comprising a nano-dispersion component.
The method of claim 13,

The core and / or splitter portion and / or cladding,

An optical waveguide device, characterized in that formed of a Sol-Gel material.
The method of claim 22,

The nanodispersion component,

An optical waveguide device comprising any one or two or more of alumina, tin oxide, antimony oxide, silica, zirconia, and titania are mixed metal oxides.
The method according to any one of claims 11 to 23,

The optical waveguide device, characterized in that the uniformity of the light reflected from the splitter portion is 3dB or less.
A touch screen device comprising the optical waveguide device of claim 24.