Optical waveguide type device

Abstract

This optical waveguide type device comprises, for example: a first core that extends along a first direction and that guides light to an end portion in the first direction; cladding that has a lower refractive index than the first core and that surrounds the outer periphery of the first core; and a groove portion that extends along a second direction intersecting the first direction so as to include a region in which the end portion of the first core extends along the first direction, and that has a bottom surface which is located below a lower end of the first core. As a result, the present invention provides a novel improved optical waveguide type device that enables precise design of light emission characteristics, for example.

Description

Optical Waveguide Devices

[0001] The present invention relates to an optical waveguide device.

[0002] 2. Description of the Related Art Conventionally, optical devices are known that irradiate a fluid with light and measure its response characteristics to light, such as absorption (see, for example, Patent Document 1).

[0003] Special Publication No. 2009-516844

[0004] In this type of optical device, it would be beneficial if the light irradiation characteristics, such as the amount of light to be irradiated and the timing, could be designed with high precision according to the application, the object to be inspected, and the like.

[0005] Therefore, one object of the present invention is to provide a new and improved optical waveguide device that allows, for example, the light irradiation characteristics to be designed with high precision.

[0006] The optical waveguide device of the present invention comprises, for example, a first core extending along a first direction and guiding light to an end in the first direction, a cladding having a lower refractive index than the first core and surrounding the outer periphery of the first core, and a groove portion extending along a second direction intersecting the first direction to include a region where the end of the first core is extended along the first direction, and whose bottom surface is located below the lower end of the first core.

[0007] In the optical waveguide device, the groove may be a reaction layer in which a reaction progresses as a fluid flows along the second direction.

[0008] In the optical waveguide device, the angle between the first direction and the second direction may be equal to or greater than 0° and equal to or less than 90°.

[0009] In the optical waveguide device, the angle between the first direction and the second direction may be greater than 0° and smaller than 90°.

[0010] The optical waveguide device may include a lid formed on the cladding and covering an opening of the groove.

[0011] The optical waveguide device may include a light absorbing material disposed above or below the cladding, which absorbs the light.

[0012] The optical waveguide device may include a second core extending in the first direction on the opposite side of the groove from the end of the first core.

[0013] In the optical waveguide device, the groove portion may be a microfluidic channel through which fluids flow, and may have a mixing portion that mixes the fluids or a branching portion that branches the fluids.

[0014] The optical waveguide device may include a plurality of the first cores, and each of the first cores may guide light.

[0015] In the optical waveguide device, the plurality of first cores may guide the light of different wavelengths.

[0016] In the optical waveguide device, the first core may include an optical branching section that branches the light, or an optical multiplexing section that multiplexes the light.

[0017] In the optical waveguide device, the first core may be routed so as to be curved by 360 degrees or more in the horizontal direction.

[0018] The optical waveguide device may include a plurality of the grooves, and the grooves may be formed spaced apart from one another.

[0019] In the optical waveguide device, the groove may be formed so as to curve 360 ​​degrees or more in the horizontal direction.

[0020] The optical waveguide device may include a light absorbing material that is disposed on the opposite side of the groove from the end of the first core and that absorbs the light.

[0021] The optical waveguide device may include a light scattering section that is provided between an end of the first core and the groove section, or on the opposite side of the groove section from the first core, and that scatters the light.

[0022] In the optical waveguide device, the end of the first core may have a tapered shape in the height direction or horizontal direction that narrows toward the end, an inverse tapered shape that widens toward the end, or a curved end face, or multiple cores may extend along the first core near the end.

[0023] In the optical waveguide device, a side surface of the groove portion close to the end of the first core may be inclined or curved in a height direction or a horizontal direction.

[0024] According to the present invention, it is possible to obtain a new and improved optical waveguide device, which allows, for example, the light irradiation characteristics to be designed with high precision.

[0025] FIG. 1 is an exemplary and schematic plan view of an optical waveguide device according to a first embodiment. FIG. 2 is a cross-sectional view of the optical waveguide device according to FIG. 1 taken along line II-II. FIG. 3 is an exemplary and schematic plan view of an optical waveguide device according to a second embodiment. FIG. 4 is an exemplary and schematic plan view of an optical waveguide device according to a third embodiment. FIG. 5 is an exemplary and schematic cross-sectional view of an optical waveguide device according to a fourth embodiment. FIG. 6 is an exemplary and schematic cross-sectional view of an optical waveguide device according to a fifth embodiment. FIG. 7 is an exemplary and schematic plan view of an optical waveguide device according to a sixth embodiment. FIG. 8 is a cross-sectional view of the optical waveguide device according to FIG. 7 taken along line III-III. FIG. 9 is an exemplary and schematic plan view of an optical waveguide device according to a seventh embodiment. FIG. 10 is an exemplary and schematic plan view of an optical waveguide device according to an eighth embodiment. FIG. 11 is an exemplary and schematic plan view of an optical waveguide device according to a ninth embodiment. FIG. 12 is an exemplary and schematic plan view of an optical waveguide device according to a tenth embodiment. FIG. 13 is an exemplary and schematic cross-sectional view of an optical waveguide device according to an eleventh embodiment. FIG. 14 is an exemplary and schematic plan view of an optical waveguide device according to a twelfth embodiment. FIG. 15 is a cross-sectional view of the optical waveguide device of FIG. 14 taken along line IV-IV. FIG. 16 is an exemplary and schematic plan view of an optical waveguide device according to a thirteenth embodiment. FIG. 17 is a cross-sectional view of the optical waveguide device of FIG. 16 taken along line V-V. FIG. 18 is an exemplary and schematic plan view showing the shape of the tip of a core. FIG. 19 is an exemplary and schematic cross-sectional view showing the shape of the tip of a core. FIG. 20 is an exemplary and schematic cross-sectional view showing the shape of the tip of a core. FIG. 21 is an exemplary and schematic plan view showing the shape of a side surface of a groove. FIG. 22 is an exemplary and schematic cross-sectional view showing the shape of a side surface of a groove. FIG. 23 is an exemplary and schematic cross-sectional view showing the shape of a side surface of a groove.

[0026] Hereinafter, several exemplary embodiments of the present invention will be disclosed. The configurations of the embodiments shown below, as well as the actions and results (effects) brought about by these configurations, are merely examples. The present invention can also be realized by configurations other than those disclosed in the following embodiments. Furthermore, according to the present invention, it is possible to obtain at least one of the various effects (including derivative effects) obtained by the configurations.

[0027] The following embodiments have similar configurations. Therefore, according to the configurations of each embodiment, similar actions and effects based on the similar configurations can be obtained. Furthermore, in the following, similar configurations are given similar reference numerals, and duplicated descriptions may be omitted.

[0028] Furthermore, each drawing is a schematic diagram, and the dimensions in the drawing may differ from the actual dimensions. In each drawing, the X direction is represented by an arrow X, the Y direction is represented by an arrow Y, and the Z direction is represented by an arrow Z. The X direction, Y direction, and Z direction intersect with each other and are perpendicular to each other. In this specification, a plan view is a line of sight seen in the opposite direction to the Z direction, and a plan view is a drawing in that plan view.

[0029] 1 is a plan view of an optical waveguide device 10A (10) according to a first embodiment. The optical waveguide device 10 has, for example, a flat rectangular parallelepiped shape that is relatively thin in the Z direction. The optical waveguide device 10 can be used, for example, as a spectroscopic analysis element for inspecting an object to be inspected or an optical device for causing a reaction of a reaction object.

[0030] The optical waveguide device 10 can be configured as, for example, a known planar lightwave circuit (PLC). In this case, the optical waveguide device 10 integrally includes a substrate extending across the Z direction and a structure stacked on the substrate in the Z direction. The substrate is a glass substrate or a silicon substrate. The structure on the substrate includes a core 12 (first core) and a clad 11 surrounding the outer periphery of the core 12. The clad 11 and the core 12 are made of, for example, SiO ２The cladding 11 is made of a material containing any one of Si, SiN, InP, GaAs, and GaN. The cladding 11 has a refractive index lower than that of the core 12.

[0031] In the optical waveguide device 10, the core 12 extends along the first direction DA1 and guides light to an end in the first direction DA1. The relative refractive index difference between the core 12 and the cladding 11 is, for example, 0.2% to 15%. The light is guided through the core 12 in a single mode or multimode.

[0032] 1, the optical waveguide device 10 extends along an imaginary plane that intersects with the Z direction. Light input to the input end of the core 12 is transmitted along the core 12 and output from the end of the core 12.

[0033] Furthermore, the optical waveguide device 10 includes a groove 13 extending along a second direction DA2 intersecting the first direction DA1 so as to include an area where the end of the core 12 extends along the first direction DA1, with the bottom surface located below the lower end of the core 12. The groove 13 has reservoirs 13a located at both ends and is a microfluidic channel through which a fluid containing a test or reaction target flows. Specifically, the groove 13 is a reaction layer in which a reaction progresses as the fluid flows from one reservoir 13a to the other along the second direction DA2. The fluid may be, for example, a liquid or gas, but may also be a viscoelastic body, a flexible solid, or the like. In the first embodiment, the first direction DA1 and the second direction DA2 are orthogonal to each other. In other words, the angle θA1 between the first direction DA1 and the second direction DA2 is 90°.

[0034] Fig. 2 is a cross-sectional view taken along line II-II of the optical waveguide device 10A in Fig. 1. As shown in Fig. 2, the clad 11 includes a lower clad 11a laminated on a substrate 14 and an upper clad 11b laminated on the lower clad 11a. The lower clad 11a is located below the core 12, and a step (not shown) is formed between the lower clad 11a and the upper clad 11b. The lower clad 11a and the upper clad 11b are made of, for example, the same material and have the same refractive index, but may be made of different materials or may have different refractive indices.

[0035] The groove 13 is provided, for example, in an area of ​​±100 μm from the center in the height direction of the end of the core 12, but it may be provided in any position where light can be irradiated.

[0036] The distance LA1 between the end of the core 12 and the side surface of the groove 13 is, for example, 0 μm or more, but is not particularly limited as long as light can be irradiated from the end of the core 12 to the groove 13. The groove between the liquid pools 13 a extends, for example, over the entire section with the cross-sectional shape shown in FIG. 2, i.e., with a substantially constant width and a substantially constant depth.

[0037] When inspecting an object to be inspected using light, light irradiated from the end of the core 12 enters the fluid from the side of the groove 13 and is absorbed by the object to be inspected contained in the fluid. In this case, the intensity of the outgoing light decreases relative to the intensity of the incident light by the amount of light absorbed by the object to be inspected. The amount of decrease in the intensity of the outgoing light relative to the incident light (loss intensity), i.e., the amount of absorption, varies depending on the object to be inspected. Therefore, it is possible to identify the object to be inspected by measuring the loss intensity.

[0038] When reacting a reaction target using light, light irradiated from the end of the core 12 enters the fluid from the side of the groove portion 13, causing a light-induced chemical reaction (photoreaction) in the reaction target contained in the fluid.

[0039] Here, we will explain the manufacturing method of optical waveguide device 10. First, glass films that will become the lower cladding and core are formed in that order on substrate 14. Then, the core layer is processed into the shape of a waveguide by lithography and etching, and a glass film that will become the upper cladding is formed on top of that. After that, grooves 13 are formed by lithography and etching.

[0040] As described above, in the optical waveguide device 10A (10), the core 12 guides light to the end in the first direction DA1 and irradiates the light onto the groove 13 extending along the second direction DA2 intersecting the first direction DA1. As a result, in the optical waveguide device 10, the distance LA1 between the core 12 and the side surface of the groove 13, the angle between the first direction DA1 and the second direction DA2, and the like can be processed with lithographic precision, making it possible to design the light irradiation characteristics with high precision.

[0041] In the optical waveguide device 10 of this embodiment, the groove 13 is a reaction layer in which a reaction proceeds as a fluid flows from one liquid pool 13 a to the other liquid pool 13 a along the second direction DA2. As a result, by adjusting the position at which the end of the core 12 approaches the groove 13, it is possible to irradiate light at a targeted timing for the reaction proceeding from one liquid pool 13 a to the other liquid pool 13 a.

[0042] In addition, in this embodiment, the groove portion 13 is provided in an area of ​​±100 μm from the center in the height direction of the end of the core 12, so that a sufficient amount of light can be irradiated onto the test object or reaction object contained in the fluid flowing through the groove portion 13.

[0043] Furthermore, in this embodiment, the first direction DA1 and the second direction DA2 are perpendicular to each other, so that the light irradiation characteristics such as the amount of light and timing of irradiating the grooves 13 with light can be designed with high precision.

[0044] In this embodiment, the clad 11 and the core 12 are made of SiO ２ The optical waveguide device 10 is made of a material containing any of Si, SiN, InP, GaAs, and GaN, and can be configured as a PLC, which allows for a high degree of freedom in designing the routing of the core 12 and the groove portion 13.

[0045] Second Embodiment Fig. 3 is a plan view of an optical waveguide device 10B (10) according to a second embodiment. As shown in Fig. 3, in this embodiment, light is emitted from the core 12 along a second direction DB2 in which the groove 13 extends. In other words, the angle θB1 between the first direction DB1 in which the core 12 extends and the second direction DB2 in which the groove 13 extends is 0°. The distance between the end of the core 12 and the side surface of the groove 13 is a distance LB1.

[0046] As explained above, in the optical waveguide device 10B (10), light is irradiated from the core 12 along the second direction DB2 in which the groove portion 13 extends, thereby making it possible to increase the distance that the light irradiated from the core 12 passes through the groove portion 13, and therefore it is possible to irradiate sufficient light onto test objects with low absorbance or reaction objects with weak reactions.

[0047] 4 is a plan view of an optical waveguide device 10C (10) according to a third embodiment. As shown in FIG. 4, in this embodiment, the angle θC1 between the first direction DC1 in which the cores 12 extend and the second direction DC2 in which the grooves 13 extend is an arbitrary angle greater than 0° and less than 90° (0°<θC1<90°). The distance between the end of the core 12 and the side surface of the groove 13 is a distance LC1.

[0048] As explained above, in the optical waveguide device 10C (10), the angle θC1 between the core 12 and the groove portion 13 is any angle greater than 0° and less than 90° (0°<θC1<90°), so that the angle can be set arbitrarily depending on the object to be inspected or the object to be reacted, and the amount of light absorption or the amount of photoreaction, etc. can be adjusted arbitrarily.

[0049] [Fourth Embodiment] Fig. 5 is a cross-sectional view of an optical waveguide device 10D (10) according to a fourth embodiment. As shown in Fig. 5, in this embodiment, the groove 13 is provided so as to contact the end of the core 12. In other words, the distance between the end of the core 12 and the side surface of the groove 13 is 0 µm.

[0050] The optical waveguide device 10D also includes a lid 20 formed on the clad 11 and covering the opening of the groove 13. The lid 20 may be provided at a position corresponding to the liquid reservoir 13a and may have a hole formed therein for injecting a fluid from the liquid reservoir 13a. The lid 20 is made of a resin such as COP (cycloolefin polymer), PC (polycarbonate), PET, PS (polystyrene), PDMS, or SU-8, or a Si wafer, glass, or the like. The lid 20 is fixed onto the clad 11 by direct bonding using plasma surface treatment or by curing an adhesive.

[0051] The optical waveguide device 10D also includes light absorbing materials 21 that absorb light and are disposed above and below the clad 11. The light absorbing materials 21 are made of, for example, a material in which a pigment that absorbs the wavelength of light that is guided through the core 12 is mixed with a resin.

[0052] As described above, in the optical waveguide device 10D (10), the end of the core 12 is in contact with the side surface of the groove 13, so that light can be irradiated onto the groove 13 without loss.

[0053] As explained in the first to third embodiments above, the angle between the first direction in which the core 12 extends and the second direction in which the groove portion 13 extends can be selected from the range of 0° to 90° depending on the object to be inspected or the object to be reacted, thereby adjusting the amount of light absorption or the amount of photoreaction, etc.

[0054] In this embodiment, the optical waveguide device 10D includes the lid 20, which allows the fluid to be transported and handled by a fluid transport mechanism using a pump, etc. The lid 20 also prevents foreign matter from being mixed into the test object or reaction object during testing, and prevents the fluid injected into the groove 13 from spilling.

[0055] In this embodiment, the optical waveguide device 10D includes the light absorbing material 21, which prevents external light from entering the groove 13 and also prevents the light from being reflected and affecting the measurement results. The lid 20 may also have a light absorbing function.

[0056] 6 is a cross-sectional view of an optical waveguide device 10E (10) according to a fifth embodiment. As shown in FIG. 6, the lid 20 of the optical waveguide device 10E of this embodiment regulates the height of a fluid injected into the groove 13.

[0057] As described above, in the optical waveguide device 10E (10), the lid 20 regulates the height of the fluid poured into the groove 13, making it possible, for example, to irradiate the entire fluid with light. By adjusting the height of the fluid with the lid 20, it becomes possible to design the light irradiation characteristics for the test object and the reaction object with even greater precision.

[0058] In addition, in the first to third embodiments described above and the sixth to thirteenth embodiments described later, a lid may be provided as in the fourth or fifth embodiment. In other embodiments, the lid also allows for the transfer and handling of fluid, thereby controlling the transfer rate and reaction time and enabling any chemical reaction to be performed. Furthermore, the lid can prevent foreign matter from being mixed into the test object or reaction object during testing and can prevent the fluid injected into the groove from spilling.

[0059] Sixth Embodiment Fig. 7 is a plan view of an optical waveguide device 10F (10) according to a sixth embodiment. Fig. 8 is a cross-sectional view of the optical waveguide device of Fig. 7 taken along the line III-III. In the optical waveguide device 10F of this embodiment, the angle θF1 between the first direction DF1 in which the cores 12 extend and the second direction DF2 in which the grooves 13 extend is 90°. The optical waveguide device 10F also includes a core 12Fb (second core) extending along the first direction DF1 on the opposite side of the groove 13 from the end of the core 12Fa (first core). The ends of the cores 12Fa and 12Fb are in contact with the groove 13. Furthermore, the core 12Fb is connected to the detector 16 via an optical fiber.

[0060] As described above, the optical waveguide device 10F (10) has a core 12Fb that faces the core 12Fa across the groove portion 13, so that light that has passed through the groove portion 13 can be detected by the detector 16.

[0061] Furthermore, in this embodiment, the ends of the cores 12Fa and 12Fb are in contact with the grooves 13, so that light transmitted through the grooves 13 can be efficiently introduced into the detector 16.

[0062] Seventh Embodiment Fig. 9 is a plan view of an optical waveguide device 10G (10) according to a seventh embodiment. As shown in Fig. 9, the optical waveguide device 10G of this embodiment includes cores 12Ga, 12Gb, 12Gc, 12Gd, and 12Ge. Light input from the fiber array 15 to the core 12Ga is output from the fiber array 15, and this light can be used as reference light that is not absorbed by the test object or the reaction object. The core 12Ga is routed so as to be curved by 360 degrees or more in the horizontal direction.

[0063] The groove 13 is a microfluidic channel through which fluids flow, and has a mixing section that mixes the fluids and a branching section that branches the fluids. When liquids are delivered from the two liquid reservoirs 13a on the left side of Fig. 9, the branching section of the groove 13 functions as a mixing section that mixes the liquids. On the other hand, when liquids are delivered from the liquid reservoir 13a on the right side of Fig. 9, the branching section of the groove 13 functions as a branching section that branches the liquid.

[0064] As described above, in the optical waveguide device 10G (10), the distances LG1, LG2, LG3, LG4 between the ends of the cores 12Gb, 12Gc, 12Gd, 12Ge and the side of the groove 13, the angles θG1, θG2, θG3, θG4 between the cores 12Gb, 12Gc, 12Gd, 12Ge and the groove 13, the thickness of each core, the shape of the end, etc. are set according to the application and the object to be inspected or the object to be reacted, and by guiding light of different wavelengths to the cores 12Gb, 12Gc, 12Gd, 12Ge, respectively, it is possible to measure the response of the object to be inspected or the object to be reacted under various conditions.

[0065] In addition, in this embodiment, the cores 12Gb, 12Gc, 12Gd, and 12Ge irradiate light at different positions in the groove portion 13, so that the fluid reacting as it travels through the groove portion 13 can be irradiated with light at the desired timing.

[0066] Furthermore, in this embodiment, the optical waveguide device 10G can be configured as a PLC, which allows for a highly flexible design, such as allowing the core 12Ga to bend 360 degrees or more in the horizontal direction.

[0067] 10 is a plan view of an optical waveguide device 10H (10) according to an eighth embodiment. As shown in Fig. 10, in the optical waveguide device 10H of this embodiment, the core 12Ha includes an optical branching portion 12Hb that branches light, and the branched light is guided through the cores 12Hc, 12Hd, and 12He, respectively.

[0068] The optical branching unit 12Hb may be any configuration capable of branching light, such as a power splitter, a WDM (wavelength division multiplexing) splitter, a polarization beam splitter, or a variable splitter.

[0069] When the optical branching unit 12Hb is a power splitter, the splitter distributes the light to the cores 12Hc, 12Hd, and 12He at a set intensity ratio (for example, 1:1).

[0070] When the optical branching unit 12Hb is a WDM splitter, the WDM splitter distributes light to the cores 12Hc, 12Hd, and 12He for each different wavelength band. In this case, the absorption characteristics of the test object for each wavelength band can be inspected based on the loss intensity in the cores 12Hc, 12Hd, and 12He. In addition, in this case, the cores 12Hc, 12Hd, and 12He can induce photoreactions of the test object for each different wavelength band.

[0071] When the optical branching unit 12Hb is a polarizing beam splitter, the polarizing beam splitter splits the light into a TE polarized component and a TM polarized component. In this case, the absorption characteristics of each polarized component of the test object can be inspected based on the loss intensity in the cores 12Hc, 12Hd, and 12He. In addition, in this case, the cores 12Hc, 12Hd, and 12He can induce a photoreaction of each polarized component of the reaction object.

[0072] When the optical branching unit 12Hb is a variable beam splitter, the variable beam splitter can variably set the intensity ratio of the light distributed to the cores 12Hc, 12Hd, and 12He.

[0073] The optical branching unit 12Hb may be configured as, for example, an optical switch. In this case, the optical branching unit 12Hb can selectively input light to any of the cores 12Hc, 12Hd, and 12He in a time-division manner. The optical switch is an example of an optical branching unit.

[0074] In either case, the optical waveguide device 10H (10) has the optical branching unit 12Hb, which allows the number of light sources to be reduced compared to a case where the optical branching unit 12Hb is not provided. Also, various inspections can be performed with a relatively simple configuration.

[0075] Furthermore, the light input from the fiber array 15a to the cores 12Hf and 12Hg is multiplexed by the optical multiplexer 12Hh, irradiated onto the groove 13, and input to the detector 16 via the fiber array 15b.

[0076] Furthermore, the cores 12Hi, 12Hj, and 12Hk each guide light to the same position in the groove 13. As a result, the light from the cores 12Hi, 12Hj, and 12Hk is irradiated so as to be concentrated at one point in the groove 13, and high-intensity light can be irradiated at one point in the groove 13.

[0077] Ninth Embodiment Fig. 11 is a plan view of an optical waveguide device 10I (10) according to a ninth embodiment. As shown in Fig. 11, the optical waveguide device 10I of this embodiment includes grooves 131 and 132. The grooves 131 and 132 each have two liquid reservoirs 131a and 132a at both ends. Since the grooves 131 and 132 are spaced apart from each other, different fluids can be injected into the grooves 131 and 132. Furthermore, the groove 132 is curved 360 degrees or more in the horizontal direction.

[0078] Furthermore, by irradiating the grooves 131 and 132 with light from multiple cores under various conditions, such as the cores 12Ia to 12Ii, it becomes possible to measure responses of test objects or reaction objects under various conditions. For example, like the cores 12Ih and 12Ii, light may be irradiated so as to pass through multiple grooves 131 and 132. In this case, it becomes possible to irradiate light onto two different test objects or reaction objects at the same time.

[0079] 12 is a plan view of an optical waveguide device 10J (10) according to a tenth embodiment. As shown in Fig. 12, in the optical waveguide device 10J of this embodiment, the core 12Ja includes an optical branching section 12Jb that branches light input from the light source 17 via the fiber array 15, and the branched light is guided through the cores 12Jc, 12Jd, and 12Je, respectively.

[0080] The cores 12Jc and 12Jd irradiate the groove 131 with light at different angles. The core 12Je irradiates the light along the direction in which the groove 132 extends. The light that has passed through the groove 132 is input to the detector 16 via the fiber array 15. As a result, it becomes possible to measure the response of the test object or reaction object under various conditions.

[0081] 13 is a cross-sectional view of an optical waveguide device 10K (10) according to an eleventh embodiment. As shown in FIG. 13, the optical waveguide device 10K of this embodiment includes light absorbers 21Ka that absorb light and are disposed above and below the cladding 11. The light absorbers 21Ka prevent external light from entering the grooves 13 and also prevent the light from being reflected and affecting the measurement results.

[0082] The optical waveguide device 10K also includes a light absorbing material 21Kb that absorbs light and is disposed on the opposite side of the groove 13 from the end of the core 12. The light absorbing material 21Kb absorbs light that has passed through the groove 13. The light absorbing material 21Ka and the light absorbing material 21Kb may be made of the same material or different materials. The material to be filled as the light absorbing material 21Kb can be arbitrarily selected depending on the test object or reaction object and the purpose of the test or reaction, and can be filled or replaced.

[0083] As described above, in the optical waveguide device 10K (10), the light absorbing materials 21Ka and 21Kb absorb unnecessary light, thereby improving the accuracy of measurement.

[0084] [Twelfth Embodiment] Fig. 14 is a plan view of an optical waveguide device 10L (10) according to a twelfth embodiment. Fig. 15 is a cross-sectional view of the optical waveguide device 10L of Fig. 14 taken along the line IV-IV. In the optical waveguide device 10L of this embodiment, the core 12La is curved by 90° from the end toward the base end. As a result, it is possible to prevent light that is not guided through the core 12La from being irradiated onto the groove portion 13.

[0085] The optical waveguide device 10L of this embodiment also includes a plurality of cores 12Lb located on the opposite side of the groove 13 from the end of the core 12La. The optical waveguide device 10L further includes light absorbers 21La and 21Lb that absorb light. The light absorbers 21La and 21Lb may be made of the same material or different materials.

[0086] The light absorbing material 21La is disposed on the opposite side of the groove portion 13 from the core 12La. The light absorbing material 21La absorbs light that has passed through the groove portion 13.

[0087] The light absorbing material 21Lb is disposed closer to the core 12La than the groove portion 13. The light absorbing material 21Lb absorbs light scattered by the side surface of the groove portion 13 on the core 12La side and light scattered by the side surface of the groove portion 13 opposite to the core 12La.

[0088] As described above, in the optical waveguide device 10L (10), the light absorbing materials 21La and 21Lb absorb unnecessary light, thereby improving the accuracy of measurement.

[0089] 16 is a plan view of an optical waveguide device 10M (10) according to a thirteenth embodiment. As shown in FIG. 16, optical waveguide device 10M according to this embodiment includes light scattering sections 18 that scatter light and are provided between the ends of cores 12 and grooves 13 and on the opposite side of grooves 13 from cores 12. Light scattering sections 18 may be linear, or may be inclined or curved relative to the direction in which cores 12 extend. The material to be filled into light scattering sections 18 can be selected as desired depending on the test or reaction target and the purpose of the test or reaction, and can be filled or replaced.

[0090] The optical waveguide device 10M also includes light absorbing materials 21Ma and 21Mb that absorb light. The light absorbing material 21Ma is arranged on the opposite side of the groove 13 from the core 12. The light absorbing material 21Mb is arranged on the core 12 side of the groove 13. As a result, light scattered by the light scattering portion 18 is prevented from affecting the measurement.

[0091] 17 is a cross-sectional view taken along the line VV of optical waveguide device 10M in FIG. 16. As shown in FIG. 17, light scattering portion 18 is formed by removing lower cladding 11a and upper cladding 11b by etching, similar to groove portion 13, and then filling the space with a light-scattering substance. Light scattering portion 18 is filled with, for example, a gas such as air, a liquid, or a solid. Furthermore, an optical element such as an optical filter may be disposed in light scattering portion 18.

[0092] As described above, in the optical waveguide device 10M (10), light is scattered by the light scattering portion 18, so that, for example, the amount of light irradiated onto the groove portion 13 can be averaged regardless of the position.

[0093] The light input to core 12 may be light of a single wavelength, or may be broadband light having a wide band of wavelengths. When the light is broadband light, the light scattering characteristics of light scattering section 18 may have wavelength dependency.

[0094] When light is scattered by light scattering section 18, the number of interfaces with different refractive indices can be increased compared to when the end face of the waveguide is curved to scatter light. Therefore, by arbitrarily designing the distance between light scattering section 18 and the end of core 12 or groove section 13, the refractive index or shape of light scattering section 18, it is possible to precisely control the area of ​​groove section 13 onto which light is irradiated.

[0095] Furthermore, if a light scattering section 18 is provided on the opposite side of the core 12 of the groove section 13, the reflected light by the light scattering section 18 can be efficiently irradiated onto the object to be inspected or the object to be reacted within the groove section 13, thereby promoting the progress of light absorption and photoreaction.

[0096] [Modifications of Core Tip Shape] Figure 18 is a plan view showing modifications of the shape of the core tip. Core 12A has a width expanded by a predetermined length from the end in the horizontal direction. Core 12B has multiple cores extending horizontally along a central core (first core) near the end. Core 12C has a width expanded horizontally near the end, and gaps are formed between the cores. These structures may control the confinement of light in the cores and control the characteristics of light irradiated onto groove portion 13.

[0097] The end of core 12D has an inverse tapered shape that becomes wider toward the end in the horizontal direction. The end of core 12E has a tapered shape that becomes thinner toward the end in the horizontal direction. The end of core 12F has an end surface that is convexly curved in the horizontal direction. The end of core 12G has an end surface that is concavely curved in the horizontal direction. These structures may be used to focus or diffuse light irradiating groove portion 13.

[0098] The shape of the core in the horizontal direction can be designed as desired depending on the shape of the photomask.

[0099] FIG. 19 is a cross-sectional view showing a modified example of the shape of the core tip. The core 12H shown in FIG. 19 has multiple cores extending in the height direction along the central core (first core) near the end. This structure may control the confinement of light in the cores and the characteristics of the light irradiated into the groove 13. The core 12H is realized by first providing a clad 11c with the same refractive index as the clad 11 on the lower core and lower clad 11a, and then forming a core and upper clad 11b above it. In this way, stacking two or more waveguide layers can achieve a configuration in which multiple cores extend in the height direction. A configuration like the core 12H can uniformly irradiate the solution flowing in the groove 13 with light.

[0100] Figure 20 is a cross-sectional view showing a modified example of the shape of the tip of the core. The end of the core 12I shown in Figure 20 has an inverse tapered shape that becomes thicker toward the end in the height direction. This structure may be used to focus or diffuse the light irradiated onto the groove portion 13. The shape of the core in the height direction can be realized by a halftone (graytone) photomask or a tapered structure of the resist in photolithography. By using a configuration like core 12I, the light irradiation intensity on the solution flowing in the groove portion 13 can be made uniform.

[0101] [Modification of the Shape of the Side of the Groove] Figure 21 is a plan view showing a modification of the shape of the side of the groove. The side of the groove 13A near the end of the core 12 is inclined or curved in the horizontal direction. As a result, light is refracted at the side of the groove 13A, making it possible to control the light irradiated onto the test object or reaction object. When light is detected using a second core as in the sixth embodiment, a side shape like that of the groove 13A can reduce stray light entering the second core.

[0102] FIG. 22 is a cross-sectional view showing a modified example of the shape of the side surface of the groove. The side surface of the groove 13B shown in FIG. 22 is inclined in the height direction so that the width of the groove narrows downward. As a result, light is refracted at the side surface of the groove 13B, making it possible to control the light irradiated onto the test object or reaction object. The groove 13B can be realized by etching using the Bosch process. When light is detected using a second core as in the sixth embodiment, a side surface shape like that of the groove 13B can reduce stray light entering the second core.

[0103] Fig. 23 is a cross-sectional view showing a modified example of the shape of the side surface of the groove. The side surface of the groove 13C shown in Fig. 23 is curved in the height direction. As a result, light is refracted at the side surface of the groove 13C, making it possible to control the light irradiated onto the inspection target or reaction target. The groove 13C can be realized by etching using the Bosch process.

[0104] While the above describes exemplary embodiments of the present invention, the above embodiments are merely examples and are not intended to limit the scope of the invention. The above embodiments can be implemented in various other forms, and various omissions, substitutions, combinations, and modifications can be made without departing from the spirit of the invention. Furthermore, the specifications of each configuration, shape, and the like (structure, type, direction, model, size, length, width, thickness, height, number, arrangement, position, material, etc.) can be appropriately modified and implemented.

[0105] For example, the number of cores or grooves may be three or more. When an optical waveguide device has multiple cores, one of the cores may be used as a reference waveguide for referencing the loss intensity of a test object whose characteristics are known. Similarly, when an optical waveguide device has multiple cores, one of the cores may be used as a reference waveguide for referencing the reaction amount of a reaction object whose characteristics are known.

[0106] 10, 10A to 10M... Optical waveguide device 11... Cladding 11a... Lower cladding 11b... Upper cladding 11c... Cladding 12, 12A to 12I, 12Fa, 12Fb, 12Ga to 12Ge, 12Ha, 12Hc to 12Hg, 12Hi to 12Hk, 12Ia to 12Id, 12If to 12Ii, 12Ja, 12Jc to 12Je... Core 12Hb, 12Ie, 12Jb, 12La, 12Lb Optical branching section 12Hh Optical multiplexing section 13, 13A to 13C, 131, 132... Groove section 13a, 131a, 132a... Liquid reservoir 14... Substrate 15, 15a, 15b... Fiber array 16... Detector 17... Light source 18... Light scattering portion 20... Lid portion 21, 21Ka, 21Kb, 21La, 21Lb, 21Ma, 21Mb... Light absorbing material X... direction Y... direction Z... direction

Claims

1. An optical waveguide device comprising: a first core extending along a first direction and guiding light to an end in the first direction; a cladding having a lower refractive index than the first core and surrounding the outer periphery of the first core; and a groove portion extending along a second direction intersecting the first direction to include a region where the end of the first core is extended along the first direction, and whose bottom surface is located below the lower end of the first core.

2. The optical waveguide device according to claim 1, wherein the groove is a reaction layer in which a reaction progresses as a fluid flows in the second direction.

3. The optical waveguide device according to claim 1, wherein the angle between the first direction and the second direction is between 0° and 90°.

4. The optical waveguide device according to claim 1, wherein the angle between the first direction and the second direction is greater than 0° and smaller than 90°.

5. The optical waveguide device according to claim 1, further comprising a lid formed on said cladding and covering an opening of said groove.

6. The optical waveguide device according to claim 1, further comprising a light absorbing material disposed above or below said cladding, said light absorbing material absorbing said light.

7. The optical waveguide device according to claim 1, further comprising a second core extending along the first direction on the opposite side of the groove from the end of the first core.

8. The optical waveguide device according to claim 1, wherein the groove portion is a microfluidic channel through which fluids flow, and has a mixing portion that mixes the fluids or a branching portion that branches the fluids.

9. The optical waveguide device according to claim 1, comprising a plurality of said first cores, each of said first cores guiding light.

10. The optical waveguide device according to claim 8, wherein the plurality of first cores guide the light of different wavelengths.

11. The optical waveguide device according to claim 1, wherein the first core comprises an optical branching section that branches the light or an optical multiplexing section that multiplexes the light.

12. The optical waveguide device according to claim 1, wherein the first core is routed so as to be curved 360 degrees or more in the horizontal direction.

13. The optical waveguide device according to claim 12, comprising a plurality of said grooves, said grooves being formed at intervals from one another.

14. The optical waveguide device according to claim 1, wherein the groove is formed so as to curve 360 ​​degrees or more in the horizontal direction.

15. The optical waveguide device according to claim 1, further comprising a light absorbing material that absorbs the light and is disposed on the opposite side of the groove from the end of the first core.

16. The optical waveguide device according to claim 1, further comprising a light scattering section that scatters the light, the light scattering section being provided between the end of the first core and the groove section, or on the opposite side of the groove section from the first core.

17. The optical waveguide device according to claim 1, wherein the end of the first core has a tapered shape in the height direction or horizontal direction that narrows toward the end, an inverse tapered shape that widens toward the end, a curved end face, or a plurality of cores extending along the first core near the end.

18. The optical waveguide device according to claim 1, wherein the side surface of the groove portion adjacent to the end of the first core is inclined or curved in the height direction or horizontal direction.

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