Fiber-type light transporting medium having in-situ formed lens, and manufacturing method thereof

Abstract

Disclosed are a light transporting medium and a manufacturing method thereof. A method of manufacturing a fiber-type light transporting medium comprises the steps of: forming one or more light-transmitting windows penetrating a clad on the outer peripheral surface of an optical fiber; supplying a liquid resin droplet to the light-transmitting window of the optical fiber to form a liquid lens in-situ on the light-transmitting window; and curing the liquid lens to form a cured resin lens on the light-transmitting window.

Description

Fiber-like optical transport medium having an in-situ forming lens and method for manufacturing the same

[0001] The present disclosure relates to a fiber-shaped optical transport medium for transporting optical energy and a method for manufacturing the same, and relates to an optical transport medium in which a solid lens is formed in situ in a light-passing window on the side of an optical fiber to increase light transmission efficiency and a method for manufacturing the same.

[0002] Optical fiber is an optical transmission medium used for various purposes such as optical communications, solar power generation, and plant cultivation.

[0003] These optical fibers include a core through which light propagates and a thin film-like cladding covering the core, which may be used in single strands or bundles depending on the application.

[0004] Optical fibers can be used for a variety of purposes, including optical communications, solar power generation, decorative lighting, and artificial lighting for plant cultivation.

[0005] These optical fibers comprise a core through which light propagates and a membrane-like cladding covering the core. Depending on the application, a single optical fiber may be used, or in plant cultivation systems such as solar power generation or smart farms, optical fibers may be bundled to transmit large amounts of light energy.

[0006] Among the optical fibers used for solar power generation, information display, decorative lighting, or artificial lighting, there are so-called side-emitting optical fibers, or more precisely side-emitting optical fibers, that emit light from the side of the optical fiber.

[0007] This optical fiber has light-passing windows formed in the cladding surrounding the core, through which light traveling through the core escapes. These light-passing windows are openings through which some of the light traveling through the core of the optical fiber escapes. Research is needed on structures that enable light to escape from the core with low loss and high efficiency.

[0008] As a result of this research, the inventors have proposed an optical transport medium with a structure in which a lens is implanted in an optical fiber. However, this optical transport medium has a structure in which the lens is attached using an adhesive. The process of bonding the lens to the optical fiber using an adhesive is extremely difficult and requires a considerable amount of time. In particular, the adhesive used to bond the lens is located along the light propagation path, making it impossible to avoid light transmission loss due to light blocking, absorption, or scattering.

[0009] The present disclosure proposes a side-emitting fiber-shaped optical transport medium capable of effective light output and a method for manufacturing the same.

[0010] The present disclosure proposes a side-emitting fiber-shaped optical transport medium capable of high brightness light output through a light passing window and a method for manufacturing the same.

[0011] According to this disclosure,

[0012] An optical fiber comprising a core through which light propagates and a clad surrounding the core, and having one or more light-transmitting windows on one side of the outer periphery, the light penetrating through the clad and exposing the surface of the core therebelow;

[0013] A fiber-type optical transport medium is provided, which comprises a coated solid lens formed within the optical passage window of the optical fiber and directly coupled to the optical passage window and the lower portion of the optical passage window.

[0014] According to one or more embodiments, the solid lens is attached to the surface of the light-transmitting window and the core thereunder by physical bonding and / or chemical bonding.

[0015] According to one or more embodiments, the coated solid lens has a head portion positioned above the aperture plane of the light-transmitting window and a stem in the form of a short leg or column positioned below the head portion, the perimeter of the head portion overlapping a cladding of the periphery of the light-transmitting window by an arbitrary width, and the entire surface of the stem is bonded to the inner periphery of the light-transmitting window and the surface of the core.

[0016] According to one or more embodiments, a solid lens can be formed by the curable resin.

[0017] According to one or more embodiments, the resin may be a crystal resin in which the base resin and the curing agent (or hardener) are separated, or a high-viscosity or low-viscosity UV resin that is cured by UV as a single material.

[0018] According to one or more embodiments, the coated solid lens may be a colored lens of a specific color.

[0019] According to one or more embodiments, a coating film may be formed on the surface of the coated solid lens.

[0020] According to one or more embodiments, the coating film may be a protective coating or a color coating film.

[0021] According to one or more embodiments, the colored lens may contain at least one of a transparent dye, a pigment, and a pigment dispersion.

[0022] Method for manufacturing a fiber-type optical transport medium according to the present disclosure:

[0023] A step of forming one or more light-transmitting windows penetrating a clad covering a core on an outer surface of an optical fiber;

[0024] A step of supplying a liquid lens material in the form of droplets to one or more of the above light-passing windows to form a liquid lens on the light-passing windows; and

[0025] A step of curing the liquid lens to form a cured solid lens in the light-transmitting window is included.

[0026] According to one or more embodiments, the method: fills the opening of the light-passing window and the cavity thereunder when supplying the liquid lens material in the form of the droplet, so that the liquid lens forms a head portion positioned above the opening plane of the light-passing window and a stem positioned thereunder, and the periphery of the head portion overlaps a clad of the periphery of the light-passing window by an arbitrary width.

[0027] According to one or more embodiments, the method may utilize a curable resin as the liquid lens material.

[0028] According to one or more embodiments, the resin used in the method may be a crystal resin in which the subject matter and the hardener are separated, or a high-viscosity or low-viscosity UV resin that is UV-cured as a single material.

[0029] The above resin lens may be a colored lens of a specific color. To achieve this, a colorant may be included in the liquid resin, or a colored coating film may be formed on the surface of the lens.

[0030] Figure 1 illustrates an optical transport medium according to one or more embodiments of the present disclosure.

[0031] FIG. 2 illustrates an optical transport medium in which a coated solid lens is formed and fixed in-situ on the side of an optical fiber in the form of a thread or wire according to one or more embodiments of the present disclosure.

[0032] FIG. 3 is a front view of a solid lens according to an embodiment of the present disclosure.

[0033] FIG. 4 is a cross-sectional view of an optical transport medium having a lens fixed to a light passage window according to an embodiment of the present disclosure.

[0034] Figures 5a to 5e show an optical transport medium structure and its manufacturing process according to one embodiment of the present disclosure.

[0035] Figures 6a and 6b are enlarged photographs showing a solid lens portion of an optical transport medium manufactured according to the present disclosure.

[0036] Figure 7 is an enlarged photograph of a solid lens of an optical transport medium manufactured according to the present disclosure.

[0037] FIGS. 8 and 9 show the output of light through solid lenses of a plurality of light-passing windows provided on the side of an optical fiber when light is injected from one end of an optical fiber of an optical transport medium manufactured according to the present disclosure.

[0038] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings. However, the embodiments of the present invention may be modified in various different forms, and the scope of the present invention should not be construed as being limited by the embodiments described below. It is preferable to interpret that the embodiments of the present invention are provided to more completely explain the present invention to a person having average knowledge in the art. Like reference numerals denote like elements throughout. Furthermore, various elements and areas in the drawings are schematically drawn. Therefore, the present invention is not limited by the relative sizes or intervals drawn in the attached drawings.

[0039] While terms like "first" and "second" may be used to describe various components, these components are not limited by these terms. These terms are used solely to distinguish one component from another. For example, a first component could be referred to as a "second component," and vice versa, without departing from the scope of the present invention.

[0040] The terminology used in this application is only used to describe specific embodiments and is not intended to limit the concept of the present invention. The singular expression includes the plural expression unless the context clearly indicates otherwise. In this application, it should be understood that the expressions "comprises" or "has" indicate the presence of a feature, number, step, operation, component, part, or combination thereof described in the specification, but do not exclude in advance the possibility of the presence or addition of one or more other features, numbers, operations, components, parts, or combinations thereof.

[0041] Unless otherwise defined, all terms used herein, including technical and scientific terms, have the same meaning as commonly understood by those of ordinary skill in the art to which the present invention pertains. Furthermore, it is to be understood that commonly used terms, such as those defined in dictionaries, should be interpreted to have a meaning consistent with their meaning within the relevant technical context, and should not be interpreted in an overly formal sense unless explicitly defined herein.

[0042] In some embodiments, where the implementation is otherwise feasible, a particular process sequence may be performed in a different order than described. For example, two processes described in succession may be performed substantially simultaneously, or in a reverse order from the described order.

[0043] In the accompanying drawings, variations in the shapes depicted may be expected, for example, depending on manufacturing techniques and / or tolerances. Therefore, embodiments of the present invention should not be construed as being limited to the specific shapes of the regions depicted herein, but should include, for example, changes in shapes resulting from the manufacturing process. All terms "and / or" used herein include each and every combination of one or more of the mentioned components. In addition, the term "substrate" used herein may mean the substrate itself, or a laminated structure including the substrate and a predetermined layer or film formed on the surface thereof. In addition, the "surface of the substrate" used herein may mean the exposed surface of the substrate itself, or the outer surface of a predetermined layer or film formed on the substrate. In addition, the terms "upper" or "on" may include not only what is directly over it in contact with it, but also what is over it in a non-contact manner.

[0044] FIGS. 1 and 2 illustrate an optical transport medium (110) in which a coated solid lens (20) is formed and fixed in-situ on the side of an optical fiber (11) in the form of a thread or wire, according to one or more embodiments of the present disclosure.

[0045] The above solid lens (20) is manufactured in the form of a coating body to have a specific shape on the side or surface of the optical fiber (11), and is manufactured, for example, through a process of supplying and curing a liquid material such as a resin to the surface of the optical fiber (11).

[0046] In Fig. 1, "A" represents a light injection region (Ri) of an optical fiber (11) to which a lens (20) is directly fixed. The optical fiber (11) includes a core (11a) at the center and a clad (11b) covering it. The optical fiber (11) guides light incident through the lens (20) of the light injection region (Ri) in the opposite direction through the core (11a). The lens (20) is directly fixed to the periphery or end portion, or both the periphery and end portion, of the optical fiber (11) in the light penetration injection region (Ri).

[0047] FIG. 2 illustrates an optical transmission medium having a lens (20) fixed to an optical fiber having a light injection region (Ri) and a light emission region (Ro), according to one or more embodiments.

[0048] Referring to Fig. 2, an optical fiber (11) including a core (11a) and a clad (11b) is provided with a light injection area (Ri) on the side of which a plurality of lenses (20) are fixed, through which light (1) is incident, and a light emission area (Ro) is provided on the other side. The light injection area (Ri) and the light emission area (Ro) may be adjacent or spaced apart from each other by a predetermined distance.

[0049] In the embodiments illustrated in FIGS. 1 and 2 above, the lens (20) is described as being installed in the light injection area (Ri). However, according to another embodiment of the present invention, the lens (20) may be installed in the light emission area (Ro), and may not be installed in the light injection area (Ri). When the lens (20) is installed in the light emission area (Ro), the installation of the lens in the light injection area may be excluded, and further, a light passage window may be excluded in the light injection area, in which case light injection may be performed from an end of the light injection area (Ri).

[0050] Fig. 3 is a front view illustrating a lens (20) manufactured directly on the side of an optical fiber (11) using liquid resin, and Fig. 4 is a longitudinal cross-sectional view of the optical fiber (11) to which the lens (20) is fixed.

[0051] Referring to FIGS. 3 and 4, the lens (20) has a dome-shaped head (20a) with a rounded upper surface protruding above the opening plane of the light-passing window (11c) and a stem (20b) in the shape of a short leg below it. In addition, a skirt (20c) is formed around the lower side of the head (20a). The stem (20b) is a portion that is fixed by contacting the core (11b) of the optical fiber (11) below the opening plane of the light-passing window (11c) and has a shape that matches the inner profile of the cavity above the core (11b) below the light-passing window (11c). This is because the stem (20b) portion is formed by a liquid resin injected into the cavity below the light-passing window (11c).

[0052] Accordingly, the stem (20b) is fixed to the core (11b) while filling the cavity, and the dome-shaped head (20a) thereon is positioned to protrude above the light-passing window (11c), and the skirt (20c) is overlapped on the clad (11c) at the edge of the light-passing window (11c).

[0053] The above-described light-transmitting window (11c) is formed by mechanical processing such as drilling so that the surface of the core (11a) is exposed to the outside at the lower bottom by penetrating the outer skin, i.e., the clad (11b), of the optical fiber (11). According to this mechanical processing, processing is also performed on a part of the surface of the core, and according to this processing, the surface of the core that is cut off due to the limitations of the mechanical processing is not as clean as a mirror but is rough. This rough surface to be processed causes light transmission loss by absorbing and scattering the passing light. However, according to the present invention, since the lens (20) is directly formed on the surface of the optical fiber by a material such as a liquid resin, the above-described problem is greatly improved.

[0054] Below, a process for manufacturing a fiber-type optical transport medium that forms a lens in situ on the optical fiber itself without an adhesive and can suppress light scattering and absorption at the interface in particular is described.

[0055] As shown in Fig. 5a, an optical fiber (11) having a core (11a) and a clad (11b) covering the core (11a) is prepared.

[0056] As illustrated in Fig. 5b, the clad (11b) is partially machined to form a light-transmitting window (11c) in the clad (11b). A high-speed drilling machine can be used to form the light-transmitting window (11c), and thus a concave machined surface (11a') is generated on the surface of the core (11a) below the light-transmitting window (11c). The depth of this machined surface (11a') can be adjusted according to design conditions, and can be formed to a very shallow depth as illustrated in Fig. 4b, or can be formed close to the center of the core in the shape of a well of a predetermined depth.

[0057] As illustrated in Fig. 5c, a lens-forming resin (21) is supplied in the form of drops to the light-passing window (11c) using a nozzle (22) of a liquid resin supply device. The liquid resin supply device may have a needle-shaped supply nozzle (22) and a resin supply unit that supplies liquid resin to the nozzle.

[0058] The above resin may be a naturally curing crystal resin that is used by mixing the main agent and the hardener, or a UV resin that is cured by ultraviolet rays as a single material.

[0059] The above liquid resin (21) contains a coloring agent of a specific color, so that a colored lens can be implemented using the liquid resin.

[0060] FIG. 5d shows a state in which a liquid lens (20') is formed in a light-transmitting window (11c) by a liquid resin (21). The liquid resin (21) supplied to the light-transmitting window (11c) has a dome-shaped head (20a) with a round upper surface due to surface tension, and the stem (20b) at the bottom thereof is in contact with the light-transmitting window (11c) and the processing surface (11a') of the core at the bottom thereof. In addition, the edge of the head (20a) overlaps the clad (11b) around the light-transmitting window (11). The liquid resin (21) is supplied from above the light-transmitting window (11c) to fill the cavity at the bottom thereof, thereby completely covering the surface of the core (11b) and the clad (11b) of the light-transmitting window (11c), thereby protecting the exposed portion of the core (11b) and its periphery from the air.

[0061] In this way, the liquid resin (21) supplied in the form of a droplet to the light passage window (11c) is formed into a liquid lens (20') that completely covers the light passage window (11c) and protrudes partially above it, and hardens over time.

[0062] Crystal resin is supplied in the form of droplets containing a hardener (or curing agent) in the base resin, so after being supplied to the light-transmitting window (11c), it gradually hardens naturally in a lens-shaped state. In the case of UV resin, ultraviolet light is required for curing.

[0063] Figure 5e shows a state in which a solid lens (20) is formed in-situ on an optical fiber (11) after the resin has been cured. The solid lens (20) may be formed of a colorless resin, and a coating film may be formed on its surface. The coating film may be formed not only on the solid lens but also on the entire surface of the optical fiber (11). Such a coating film may be obtained by applying a coating material to the entire optical fiber after the lens formation is completed.

[0064] According to one or more embodiments, the coating film may be a protective coating or a color coating film, and further, according to one or more embodiments, the lens may be a color lens containing at least one of a transparent dye, a pigment, and a pigment dispersion.

[0065] According to one or more embodiments of the present disclosure, by forming a lens in situ using a liquid material on an optical fiber, which is an element of an optical transport medium, the lens (20) is very strongly fixed to the optical fiber (11) by physical adhesion. The adhesion of the lens (20) is generated by molecular interactions, physical forces, chemical forces, etc., between the optical fiber and the surface and the lens surface.

[0066] By forming a solid lens (20) in the optical transmission window of an optical fiber through the above process, an adhesive that causes optical loss becomes unnecessary. In addition, the machined surface of the core, which has been roughened by mechanical processing, is densely filled with liquid resin, thereby integrating the core and the solid lens, thereby reducing optical loss due to optical scattering and reflection at the interface between the core and the lens.

[0067] FIGS. 6A and 6B are partial enlarged photographs of an optical fiber having a solid lens formed in situ on the surface thereof, according to an embodiment of the present disclosure. As shown, a liquid resin supplied in the form of droplets forms a round solid lens on the surface of the optical fiber.

[0068] Figure 7 is a planar magnified photograph of a solid lens formed in situ in a light-transmitting window. As shown in Figure 7, the contact area with the core of the optical fiber is shown to be very bright, and light scattering in the lens-forming region is greatly reduced, resulting in a very bright donut-shaped bright region in the center.

[0069] Figures 8 and 9 show the output of light through a solid lens of a plurality of light-passing windows provided on the side of the optical fiber when light is injected from one end of the optical fiber.

[0070] As illustrated in Figures 8 and 9, the intensity of light emitted from the side of the optical fiber is very high. This is because the solid lens is completely integrated into the core of the optical fiber, so that the boundary between the core and the lens is completely physically bonded, and thus very high intensity light can escape through the lens.

[0071] If only a light-transmitting window is processed on the side of an optical fiber, the light has limited directivity and angle, and since the unprocessed side does not scatter light, the optical fiber must be processed in three or five or more radial directions as shown in FIGS. 1 and 2. However, this process requires very difficult mass-production processing equipment. However, when a solid lens is formed using resin in only one direction around the optical fiber as in the present invention, light is scattered in all 360 degrees and the intensity of the light also increases significantly.

[0072] Although the present disclosure has been illustrated and described with respect to specific embodiments, it will be readily apparent to those skilled in the art that the present invention can be variously improved and modified without departing from the spirit or scope of the present invention as defined by the following claims.

Claims

1. An optical fiber comprising a core through which light propagates and a clad surrounding the core, and having one or more light-transmitting windows on the outer surface thereof penetrating the clad and exposing the surface of the core therebelow; A fiber-type optical transport medium having a coated solid lens formed within the optical passage window of the optical fiber and directly coupled to the optical passage window and the lower portion of the optical passage window.

2. In paragraph 1, A fiber-type light transport medium, wherein the solid lens is a resin lens attached to the surface of the light passage window and the core thereunder by physical bonding and / or chemical bonding.

3. In paragraph 1, A fiber-like optical transport medium, wherein the solid lens has a head portion positioned above the aperture plane of the light passage window and a stem positioned below the head portion, the periphery of the head portion overlapping a cladding of the periphery of the light passage window by an arbitrary width, and the surface of the stem is bonded to the inner periphery of the light passage window and the surface of the core.

4. In paragraph 1, A solid lens is a fiber-shaped light transport medium formed by the above-mentioned curable resin.

5. In paragraph 4, The above resin is a fiber-shaped light transport medium that is a crystal resin in which the base resin and the curing agent (or hardener) are separated.

6. In paragraph 4, The above resin is a fiber-shaped light transport medium, which is a high-viscosity or low-viscosity UV resin that is cured by UV as a single material.

7. In paragraph 1, The above solid lens is a fiber-shaped light transport medium that is a color lens of a specific color.

8. In paragraph 7, A fiber-shaped optical transport medium having a color coating film formed on the surface of the above-mentioned solid lens.

9. In paragraph 1, A fiber-shaped optical transport medium having a color coating film formed on the surface of the above-mentioned solid lens.

10. In paragraph 1, A fiber-shaped light transport medium containing at least one transparent dye, pigment, or pigment dispersion in the above solid lens.

11. A step of forming one or more optical passage windows penetrating a clad covering a core on an outer surface of an optical fiber by a processing device; A step of a liquid lens material supply device supplying a liquid lens material in the form of droplets to one or more light-passing windows to form a liquid lens on the light-passing windows; and A method for manufacturing a fiber-type optical transport medium, comprising the step of forming a hardened solid lens in the light-transmitting window by hardening the liquid lens by a hardener or over time.

12. In paragraph 11, A method for manufacturing a fiber-type optical transport medium, wherein when supplying the liquid lens material in the form of a droplet, the opening of the light passage window and the cavity underneath are filled, so that the liquid lens forms a head portion positioned above the opening plane of the light passage window and a stem positioned underneath.

13. In paragraph 12, A method for manufacturing a fiber-type optical hydrogen medium, wherein the circumference of the above head portion overlaps the cladding of the circumference of the above light-passing window by an arbitrary width.

14. In paragraph 12, A method for manufacturing a fiber-type optical transport medium using a curable resin as the above liquid lens material.

15. In paragraph 11, A method for manufacturing a fiber-type optical transport medium using a curable resin as the above liquid lens material.

16. In paragraph 12, A method for manufacturing a fiber-type optical transport medium, wherein a crystal resin in which a subject and a curing agent are separated is applied as the above liquid lens material.

17. In paragraph 11, A method for manufacturing a fiber-type optical transport medium, wherein a crystal resin in which a subject and a curing agent are separated is applied as the above liquid lens material.

18. In paragraph 12, A method for manufacturing a fiber-type optical transport medium, wherein a high-viscosity or low-viscosity UV resin that is cured by UV is applied as the above liquid lens material.

19. In paragraph 11, A method for manufacturing a fiber-type optical transport medium, wherein a high-viscosity or low-viscosity UV resin that is cured by UV is applied as the above liquid lens material.

20. In paragraph 11, A method for producing a fiber-shaped optical transport medium, wherein the liquid lens material contains at least one of a transparent dye, a pigment, and a pigment dispersion.

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