JP2022116640A - Light connection structure and illumination system - Google Patents

Abstract

To provide a technique allowing light emitted from a wavelength conversion unit efficiently incident on an optical fiber.SOLUTION: In response to irradiation with a first laser beam transmitted by a first optical fiber, a wavelength conversion unit emits first light having a wavelength spectrum different from a wavelength spectrum of the first laser beam. A surface of the wavelength conversion unit has a first area that is directly irradiated with the laser beam from the first optical fiber, a second area that is located on a first member that reflects the first light, and a third area that is not opposite to the first area. A second optical fiber has an incident surface directed to the third area. The first light includes a first component that is directly emitted from the wavelength conversion unit, the component emitted from the third area and incident on the incident surface, and a second component that is emitted from the second area, reflected on the first member, and incident on the incident surface.SELECTED DRAWING: Figure 1

Description

The present disclosure relates to an optical connection structure.

Patent Literature 1 describes a wavelength conversion section that emits light in response to irradiation with laser light.

Japanese Unexamined Patent Application Publication No. 2012-15001

When transmitting the light emitted from the wavelength converter through an optical fiber, it is desired that the light emitted from the wavelength converter efficiently enters the optical fiber.

An optical connection structure and lighting system are disclosed. In one embodiment, an optical connection structure includes a first optical fiber, a wavelength conversion section, a second optical fiber, and a first member. A first optical fiber transmits a first laser beam. The wavelength conversion section is irradiated with the first laser light and emits the first light having a wavelength spectrum different from the wavelength spectrum of the first laser light in response to the irradiation of the first laser light. The second optical fiber receives the first light and transmits the first light. The first member reflects the first light. The surface of the wavelength converting portion has a first region directly irradiated with laser light from the first optical fiber, a second region located on the first member, and a third region not facing the first region. The second optical fiber has a face of incidence facing the third region. The first light is a component that is directly emitted from the wavelength conversion unit, and includes a first component that is emitted from the third region and is incident on the incident surface, and a first component that is emitted from the second region and is reflected by the first member and is incident. and a second component incident on the surface.

In one embodiment, an illumination system includes the optical connection structure described above, and emits the first light emitted by the wavelength conversion section of the optical connection structure as illumination light.

The light emitted by the wavelength conversion section can be efficiently incident on the optical fiber.

It is a schematic diagram showing an example of an optical connection structure. It is a schematic diagram showing an example of an optical connection structure. It is a schematic diagram showing an example of an optical connection structure. It is a schematic diagram showing an example of an optical connection structure. It is a schematic diagram showing an example of an optical connection structure. It is a schematic diagram showing an example of an optical connection structure. It is a schematic diagram showing an example of an optical connection structure. It is a schematic diagram showing an example of an optical connection structure. It is a schematic diagram showing an example of an optical connection structure. It is a schematic diagram showing an example of an optical connection structure. It is a schematic diagram showing an example of an optical connection structure. It is a schematic diagram showing an example of an optical connection structure. It is a schematic diagram showing an example of an optical connection structure. It is a schematic diagram showing an example of an optical connection structure. It is a schematic diagram showing an example of an optical connection structure. It is a schematic diagram showing an example of an optical connection structure. It is a schematic diagram showing an example of an optical connection structure. It is a schematic diagram showing an example of an optical connection structure. It is a schematic diagram showing an example of an optical connection structure. 1 is a schematic diagram showing an example of a system with an optical connection structure; FIG. 1 is a schematic diagram showing an example of a system with an optical connection structure; FIG. 1 is a schematic diagram showing an example of a system with an optical connection structure; FIG.

FIG. 1 is a schematic diagram showing an example of an optical connection structure 1. As shown in FIG. The optical connection structure 1 will be described below using the XYZ orthogonal coordinate system shown in FIG. In the following description, the −Z side is the lower side and the +Z side is the upper side.

As shown in FIG. 1, the optical connection structure 1 includes, for example, an optical fiber 2 (also referred to as a first optical fiber), an optical fiber 3 (also referred to as a second optical fiber), a wavelength converter 4, and a substrate 5. and a heat radiating member 6. The optical connection structure 1 irradiates the wavelength conversion unit 4 with the laser light L1 emitted from the optical fiber 2 , and the light L2 emitted from the wavelength conversion unit 4 in response to the irradiation of the laser light L1 enters the optical fiber 3 . FIG. 1 shows a cross section along the axial direction (also referred to as the optical axis direction) of the optical fibers 2 and 3 .

The optical fiber 2 receives the laser beam L1 and transmits the incident laser beam L1. The laser light L1 is directly irradiated from the optical fiber 2 to the wavelength converting section 4 . A cross section in a direction perpendicular to the axial direction of the optical fiber 2 is circular, for example. The optical fiber 2 is positioned, for example, on the +X side of the wavelength converting section 4 . The optical fiber 2 extends, for example, along the X-axis direction.

The optical fiber 2 includes, for example, a core 20 that transmits laser light L1 and a clad 21 that surrounds the core 20 . The optical fiber 2 may be, for example, a quartz fiber made of quartz glass, a plastic fiber made of plastic, or an optical fiber made of other materials. The optical fiber 2 may be a single mode fiber or a multimode fiber.

The optical fiber 2 has an emission surface 20a from which the laser beam L1 is emitted. For example, the core 20 has an exit surface 20a. The output surface 20a is, for example, a circular plane, and can be called an output end surface. The exit surface 20a is positioned near the wavelength conversion section 4 . The exit surface 20a faces the wavelength converting section 4 . The wavelength conversion section 4 is directly irradiated with the laser light L1 emitted from the emission surface 20a. The laser beam L1 is emitted from the emission surface 20a, for example, along the -X direction.

As the laser light L1, for example, a short wavelength laser light with a wavelength of 460 nm or less is adopted. The laser light L1 may be a short wavelength laser light of 440 nm or less. In this case, the laser beam L1 may be, for example, a purple laser beam of 405 nm.

The optical fiber 2 may include a member that covers the clad 21 . The member covering the cladding 21 may be composed of one layer, or may be composed of multiple layers. A member covering the clad 21 may include a protective layer.

The wavelength conversion unit 4 can emit light L2 (also referred to as first light) having a wavelength spectrum different from the wavelength spectrum of the laser light L1 in response to irradiation of the laser light L1 from the optical fiber 2. . The light L2 is, for example, visible light. The shape of the wavelength converting portion 4 is, for example, a rectangular parallelepiped.

The surface 40 of the wavelength converting portion 4 includes, for example, a flat upper surface 45 and a lower surface 46 facing each other. Each of the upper surface 45 and the lower surface 46 extends, for example, along the XY plane. Each of the upper surface 45 and the lower surface 46 is parallel to the XY plane, for example. Moreover, the surface 40 of the wavelength converting portion 4 includes, for example, a first flat side surface 41 and a flat second side surface 42 that face each other. Each of the first side surface 41 and the second side surface 42 extends, for example, along the YZ plane. Each of the first side surface 41 and the second side surface 42 is parallel to the YZ plane, for example. Further, the surface 40 of the wavelength converting portion 4 includes, for example, flat third and fourth side surfaces 43 and 44 facing each other. Each of the third side surface 43 and the fourth side surface 44 extends, for example, along the XZ plane. Each of the third side surface 43 and the fourth side surface 44 is parallel to the XZ plane, for example. The first side surface 41 , the second side surface 42 , the third side surface 43 and the fourth side surface 44 constitute a peripheral side surface 48 connecting the upper surface 45 and the lower surface 46 . The term "parallel" as used in the present disclosure may be substantially parallel, or slightly deviated from parallel due to an error, for example, inclined by several degrees with respect to the parallel position.

The surface 40 of the wavelength converting portion 4 has an irradiated region 140 (also referred to as a first region) irradiated with the laser beam L1. In the example of FIG. 1, the irradiated region 140 is included in the first side surface 41 of the wavelength conversion section 4, for example. The first side surface 41 is directly irradiated with the laser beam L1. The irradiated region 140 can be identified by acquiring an image using a light irradiation/light receiving measuring device or the like. The first side surface 41 may be irradiated with all of the laser light L1, or may be irradiated with only a portion of the laser light L1.

The surface 40 of the wavelength converting portion 4 has a second region on which a member that reflects the light L2 is located. It can also be said that the second region included in the surface 40 is positioned on a member that reflects the light L2. Hereinafter, a member that is positioned on the surface 40 of the wavelength conversion section 4 and that reflects the light L2 may be referred to as a high reflectance member (also referred to as a first member or a second member). Also, the light L2 may be referred to as the converted light L2. In this example, the substrate 5 is employed as the high reflectance member. The high reflectance member may be able to reflect not only the converted light L2 but also the laser light L1.

A second region located on the high reflectance member includes, for example, lower surface 46 . In the example of FIG. 1, since the substrate 5 is positioned only on the lower surface 46 of the surface 40 of the wavelength converting portion 4, the second region is composed only of the lower surface 46. As shown in FIG.

As the wavelength conversion section 4, for example, a phosphor portion 400 containing a phosphor is employed. The phosphor included in the phosphor portion 400 can emit fluorescence in response to irradiation with the laser beam L1. A wavelength (also referred to as a peak wavelength) indicating a peak in the wavelength spectrum of fluorescence emitted by the phosphor may be larger or smaller than the peak wavelength of the wavelength spectrum of the laser light L1.

Phosphor portion 400 includes, for example, multiple phosphors. Multiple phosphors include, for example, one or more phosphors. Phosphor portion 400 may include a plurality of types of phosphors having different peak wavelengths. In this case, the phosphor portion 400 includes, for example, a phosphor that emits red (R) fluorescence in response to irradiation with the laser light L1 (also referred to as a red phosphor) and a green (G) phosphor in response to irradiation with the laser light L1. ) (also referred to as green phosphor) and a phosphor that emits blue (B) fluorescence in response to irradiation with laser light L1 (also referred to as blue phosphor). For the red phosphor, for example, a phosphor having a peak wavelength in the wavelength spectrum of fluorescence emitted in response to irradiation with the laser light L1 is in the range of about 620 nm to 750 nm is applied. For the green phosphor, for example, a phosphor having a peak wavelength in the wavelength spectrum of fluorescence emitted in response to irradiation with the laser light L1 is in the range of about 495 nm to 570 nm is applied. As the blue phosphor, for example, a phosphor having a peak wavelength in the wavelength spectrum of fluorescence emitted in response to irradiation with the laser light L1 is in the range of about 450 nm to 495 nm is applied.

When the phosphor portion 400 contains multiple types of phosphors, the fluorescence emitted by the multiple types of phosphors constitutes the converted light L2 emitted by the phosphor portion 400 . That is, the converted light L2 is composed of multiple types of color components. When the phosphor portion 400 contains a red phosphor, a green phosphor, and a blue phosphor, the fluorescence emitted by the red phosphor, the green phosphor, and the blue phosphor constitutes the converted light L2.

When the phosphor portion 400 contains multiple types of phosphors, the wavelength spectrum of the converted light L2 has multiple wavelength peaks different from each other. For example, if the phosphor portion 400 contains three or more types of phosphors, the wavelength spectrum of the converted light L2 has three or more different wavelength peaks. When the phosphor portion 400 contains a red phosphor, a green phosphor, and a blue phosphor, the wavelength spectrum of the converted light L2 is the wavelength peak of the fluorescence emitted by the red phosphor and the wavelength spectrum of the fluorescence emitted by the green phosphor. A wavelength peak and a wavelength peak of the fluorescence emitted by the blue phosphor are included. The converted light L2 may be pseudo-white light or visible light of another color temperature.

Note that the phosphor portion 400 may contain phosphors other than the red phosphor, the green phosphor, and the blue phosphor. The phosphor portion 400 may include, for example, a phosphor that emits blue-green fluorescence in response to irradiation with the laser light L1 (also referred to as a blue-green phosphor). Further, the phosphor portion 400 may include, for example, a phosphor that emits yellow fluorescence in response to irradiation with the laser beam L1 (also referred to as a yellow phosphor). Phosphor portion 400 may include at least one phosphor of a red phosphor, a green phosphor, a blue phosphor, a blue-green phosphor, and a yellow phosphor.

As the blue-green phosphor, for example, a phosphor having a peak wavelength of about 495 nm in the wavelength spectrum of fluorescence emitted in response to irradiation with the laser light L1 is applied. For the yellow phosphor, for example, a phosphor having a peak wavelength in the wavelength spectrum of fluorescence emitted in response to irradiation with the laser light L1 is in the range of about 570 nm to 590 nm is applied.

The concentration of the phosphor in the wavelength converting portion 4 (in other words, the phosphor portion 400) is such that the laser light L1 irradiated to the first side surface 41 reaches the second side surface 42 opposite to the first side surface 41. may be set. Since the laser light L1 reaches the second side surface 42, the light emission area of the converted light L2 can be enlarged. When the concentration of the phosphor in the wavelength conversion section 4 is relatively low, the laser light L1 easily reaches the second side surface 42. When the concentration of the phosphor in the wavelength conversion section 4 is relatively high, the laser light L1 reaches the second side surface 42. It becomes difficult to reach the side surface 42 .

Phosphor portion 400 may be composed of, for example, a low-melting glass containing multiple phosphors. Alternatively, phosphor portion 400 may be composed of crystallized glass containing multiple phosphors. Alternatively, phosphor portion 400 may be composed of a ceramic containing multiple phosphors. Alternatively, phosphor portion 400 may be composed of a bulk ceramic that is fluorescent. In this case, it can be said that the phosphor portion 400 is composed only of the phosphor.

The substrate 5 supports the wavelength converting portion 4 (in other words, the phosphor portion 400). The substrate 5 is bonded to the lower surface 46 of the wavelength conversion section 4, for example. The substrate 5 is, for example, a rectangular parallelepiped. The surface 50 of the substrate 5 includes a flat upper surface 51 and a lower surface 52 facing each other, and a peripheral side surface 53 connecting the upper surface 51 and the lower surface 52 . The wavelength conversion part 4 is bonded to the upper surface 51 of the substrate 5, for example. The upper surface 51 and the lower surface 52 are parallel to the XY plane, for example.

The substrate 5 as a high reflectance member can reflect the converted light L2 emitted by the wavelength conversion section 4 . Further, the substrate 5 can reflect the laser beam L1, for example. The substrate 5 functions as a member that reflects the converted light L2 and the laser light L1.

The substrate 5 is made of metal, for example. The substrate 5 may be made of, for example, an aluminum alloy containing aluminum as a main component, may be made of aluminum, or may be made of another material.

The wavelength conversion unit 4 may be directly bonded to the substrate 5 or may be bonded using a bonding material. For example, when the wavelength conversion section 4 is composed of low-melting glass containing many phosphors, the wavelength conversion section 4 may be directly bonded to the substrate 5 by oxygen bonding. In other words, the wavelength conversion unit 4 is formed on the substrate 5 by oxidation bonding between the oxygen in the oxide film formed on the upper surface 51 of the substrate 5 by heating and the oxygen in the low-melting-point glass (in other words, oxide glass) of the wavelength conversion unit 4 . 5 may be directly joined. Alternatively, the upper surface 51 of the substrate 5 may be provided with minute unevenness of, for example, several μm, and the wavelength conversion section 4 may be directly bonded to the substrate 5 by the anchor effect using the unevenness. That is, the low-melting-point glass of the wavelength conversion section 4 may flow, enter the unevenness of the upper surface 51 of the substrate 5 and harden, so that the wavelength conversion section 4 may be directly bonded to the substrate 5 . Also, the wavelength conversion unit 4 may be bonded to the substrate 5 using, for example, a bonding material made of a transparent resin through which the laser light L1 and the converted light L2 are transmitted.

The optical fiber 3 transmits the incident converted light L2. A cross section of the optical fiber 3 in a direction perpendicular to the axial direction is circular, for example. The optical fiber 3 is located, for example, on the +Z side with respect to the wavelength converting section 4 and the optical fiber 2 . The optical fiber 3 extends, for example, along the Z-axis direction. The optical fibers 2 and 3 are arranged, for example, so as not to cross each other.

The optical fiber 3 includes, for example, a core 30 and a clad 31 surrounding the core 30 . The core 30 receives the converted light L2 and transmits the converted light L2. The optical fiber 3 may be, for example, a quartz fiber made of quartz glass, a plastic fiber made of plastic, or an optical fiber made of other materials. The optical fiber 3 may be, for example, a single mode fiber or a multimode fiber.

The optical fiber 3 has an incident surface 30a on which the converted light L2 is incident. For example, the core 30 has an incident surface 30a. The incident surface 30a is, for example, a circular plane, and can also be called an incident end surface. The incident surface 30a is positioned near the wavelength converting section 4 .

The incident surface 30a faces the wavelength converting section 4 . The incident surface 30a faces a region of the surface 40 of the wavelength conversion unit 4 other than the irradiated region 140 irradiated with the laser beam L1 and the lower surface 46 located on the substrate 5, for example. The incident surface 30a faces, of the surface 40 of the wavelength conversion unit 4, a third region that does not face the irradiated region 140 (in other words, the first region), that is, does not face the irradiated region 140, for example. . In this example, the third region is the upper surface 45, for example. The incident surface 30a faces the upper surface 45 of the wavelength converting section 4, for example. The area of the third region (upper surface 45 in this example) facing the incident surface 30a is larger than the area of the irradiated region 140 irradiated with the laser beam L1, for example. In addition, when the incident surface 30a of the second optical fiber 3 faces the third area, for example, the third area and the incident surface 30a are parallel to each other, and the angle formed by the third area and the incident surface 30a is 0 degrees. Then, the angle formed by the third region and the incident surface 30a may be about 0 to 60 degrees. In addition, it may be said that the ratio of the light that enters the incident surface 30a out of the light emitted from the third region is higher than the ratio that enters other locations.

The incident surface 30a is positioned directly above the upper surface 45 of the wavelength converting section 4, for example. The incident surface 30a faces the upper surface 45, for example. The incident surface 30a is parallel to the upper surface 45, for example. The incident surface 30a is parallel to the XY plane, for example. The optical fiber 3 extends, for example, along a direction perpendicular to the upper surface 45 of the wavelength converting section 4 .

The incident surface 30 a is non-parallel to the exit surface 20 a of the optical fiber 2 . That is, the entrance surface 30a of the optical fiber 3 is not parallel to the exit surface 20a of the optical fiber 2. As shown in FIG. In the example of FIG. 1, the plane including the entrance surface 30a and the plane including the exit surface 20a are, for example, orthogonal.

The incident surface 30a does not face, for example, the emission direction of the laser light L1 from the optical fiber 2 (-X direction in the example of FIG. 1). The direction perpendicular to the incident surface 30a (the Z-axis direction in the example of FIG. 1) is, for example, non-parallel to the emission direction of the laser light L1 from the optical fiber 2 (the −X direction in the example of FIG. 1). The incident surface 30a is arranged, for example, at a position where the laser beam L1 from the optical fiber 2 does not directly enter. The incident surface 30a is arranged, for example, at a position where the laser light L1 that has passed through the wavelength conversion section 4 does not directly enter.

The optical fiber 3 may have a member that covers the clad 31 . The member covering the cladding 31 may be composed of a single layer, or may be composed of multiple layers. A member covering the clad 31 may include a protective layer.

The optical fiber 3 is positioned, for example, on the side opposite to the substrate 5 with respect to the wavelength converting section 4 . The optical fiber 3 is positioned, for example, on the upper surface 45 side with respect to the wavelength converting section 4 . The substrate 5 is positioned, for example, on the side opposite to the optical fiber 3 with respect to the wavelength converting section 4 . The substrate 5 is positioned on the lower surface 46 side with respect to the wavelength conversion section 4 . The optical fiber 2 is located on the first side surface 41 side with respect to the wavelength converting section 4 .

In this example, the substrate 5 is positioned on the lower surface 46 of the surface 40 of the wavelength converting section 4 that faces the upper surface 45 facing the incident surface 30a of the optical fiber 3 . It can be said that the high reflectance member is positioned on the first facing region on the surface 40 of the wavelength converting portion 4 that faces the third region facing the incident surface 30a.

The converted light L2 emitted by the wavelength converter 4 includes, for example, the first component L2a. The first component L2a is a component that is directly emitted from the wavelength converting portion 4, and is emitted from the third region, which is included in the surface 40 of the wavelength converting portion 4 and faces the incident surface 30a of the optical fiber 3, and is emitted from the optical fiber 3. is the component incident on As mentioned above, in this example the third region is, for example, the top surface 45 . The first component L2a can be said to be a component of the converted light L2 that is emitted from the upper surface 45 of the wavelength conversion section 4 without being reflected by the substrate 5 and directly enters the optical fiber 3 .

Further, the converted light L2 includes a second component L2b that is emitted from a second region located on the substrate 5 included in the surface 40 of the wavelength conversion unit 4, reflected by the substrate 5, and incident on the optical fiber 3. In this example, of the converted light L2, the component that is emitted from the lower surface 46 of the wavelength conversion unit 4, reflected by the substrate 5, and incident on the optical fiber 3 is the second component L2b. The second component L2b is reflected by the upper surface 51 of the substrate 5 and then transmitted through the wavelength conversion section 4 to enter the optical fiber 3 . The second component L2b includes a component that passes through the wavelength conversion section 4, is emitted from the upper surface 45, and is directly incident on the optical fiber 3. FIG. The surface 50 of the substrate 5 has an irradiated region 150 (also referred to as a fifth region) irradiated with the second component L2b. In the example of FIG. 1, the illuminated area 150 is included in the top surface 51 of the substrate 5 . The converted light L2 includes components that do not enter the optical fiber 3 in addition to the first component L2a and the second component L2b. The converted light L2 may include components incident on the optical fiber 3 other than the first component L2a and the second component L2b.

The reflectance of the converted light L2 on the surface 50 of the substrate 5 is higher than the reflectance of the converted light L2 on the surface 40 of the wavelength conversion unit 4, for example. Since the irradiated region 150 is included in the surface 50 and the second region (lower surface 46 in this example) located on the substrate 5 is included in the surface 40, the reflectance of the converted light L2 in the irradiated region 150 is the wavelength It can be said that it is higher than the reflectance of the converted light L2 in the second region of the conversion unit 4 . The reflectance of the converted light L2 on the surface 40 of the wavelength conversion unit 4 is, for example, several percent. The reflectance of the converted light L2 on the surface 50 of the substrate 5 is, for example, 35% or more. The reflectance of the laser beam L1 on the surface 50 of the substrate 5 is not limited to this, and may be, for example, 40% or more, 50% or more, or 60% or more. However, it may be 70% or more, or 80% or more.

Note that the reflectance of light on an object also depends on the wavelength of the light, and if the wavelength of the light changes, the reflectance also changes. Also, the reflectance can be specified from the material of the object, or can be measured with a colorimeter or the like.

The reflectance of the laser light L1 on the surface 50 of the substrate 5 is higher than the reflectance of the laser light L1 on the surface 40 of the wavelength conversion unit 4, for example. Since the irradiated region 150 is included in the surface 50 and the second region (lower surface 46 in this example) located on the substrate 5 is included in the surface 40, the reflectance of the laser light L1 in the irradiated region 150 is It can be said that it is higher than the reflectance of the laser beam L1 in the second region of the conversion unit 4 . The reflectance of the laser beam L1 on the surface 40 of the wavelength converting portion 4 is, for example, several percent. The reflectance of the laser beam L1 on the surface 50 of the substrate 5 is, for example, 35% or more. The reflectance of the laser beam L1 on the surface 50 of the substrate 5 is not limited to this, and may be, for example, 40% or more, 50% or more, or 60% or more. However, it may be 70% or more, or 80% or more.

Note that the reflectance of the converted light L2 on the surface 50 of the substrate 5 may be equal to or less than the reflectance of the converted light L2 on the surface 40 of the wavelength conversion unit 4 . Further, the reflectance of the laser light L1 on the surface 50 of the substrate 5 may be equal to or lower than the reflectance of the laser light L1 on the surface 40 of the wavelength conversion section 4 .

The heat radiating member 6 can radiate the heat generated in the wavelength converting section 4 . The heat dissipation member 6 is composed of, for example, a member that does not require a power source. For example, the heat dissipation member 6 is composed of a metal heat sink having heat dissipation fins. The heat radiating member 6 may be composed of, for example, an aluminum alloy containing aluminum as a main component, may be composed of aluminum, or may be composed of another material. The heat dissipation member 6 may be made of the same material as the substrate 5 or may be made of a material different from that of the substrate 5 . The thermal conductivity of the heat radiating member 6 is, for example, higher than the thermal conductivity of the wavelength converting section 4 . Moreover, the thermal conductivity of the substrate 5 is higher than that of the wavelength conversion section 4, for example. In this example, not only the heat radiation member 6 but also the substrate 5 can radiate the heat generated in the wavelength conversion section 4 . The thermal conductivity of the heat dissipating member 6 may be greater than, less than or equal to that of the substrate 5 . Thermal conductivity can be measured by two methods, for example, a steady method and a non-steady method. Non-stationary methods include the laser flash method, ASTM E1530 (compliant) disk heat flow meter method, JIS R 2616 (compliant), ASTM D5930 (compliant) hot wire (probe) method, and ISO 22007-6 AC steady state There are laws, etc.

A substrate 5 is fixed to the heat radiating member 6 . The heat generated by the wavelength conversion section 4 is transferred to the heat dissipation member 6 through the substrate 5 and released from the heat dissipation member 6 into the space. Various methods are conceivable for fixing the substrate 5 to the heat dissipation member 6 . For example, the substrate 5 may be screwed to the heat radiating member 6 with heat radiating grease interposed between the substrate 5 and the heat radiating member 6 . Alternatively, the substrate 5 may be fixed to the heat radiating member 6 with an adhesive containing a high thermal conductivity filler. Alternatively, the substrate 5 may be fixed to the heat dissipation member 6 with sintering paste.

Note that the heat dissipation member 6 may be composed of other members that do not require a power supply. For example, the heat dissipation member 6 may be composed of a heat pipe, which is a type of heat sink. In a heat pipe, for example, the working fluid evaporates in the heating portion to generate steam, which moves at high speed to the low temperature portion of the heat pipe and condenses in the low temperature portion. Reflux to the heating part by phenomenon. In the heat pipe, the heat dissipation function is realized by continuously performing these phase changes. Moreover, the heat dissipation member 6 may be configured by a member that requires a power source. For example, the heat dissipation member 6 may be composed of a Peltier element or a fan.

As described above, in the optical connection structure 1 of this example, the laser light L1 from the optical fiber 2 is directly irradiated to the wavelength conversion section 4 . As a result, for example, an optical system including an optical mirror (also referred to as an irradiation optical system) for irradiating the wavelength conversion unit 4 with the laser light L1 becomes unnecessary. Unlike this example, when the optical connection structure 1 is provided with an irradiation optical system, it is necessary to adjust the position of each part of the irradiation optical system when assembling the optical connection structure 1, and the work of assembling the optical connection structure 1 becomes complicated. Become. In this example, the assembling work of the optical connection structure 1 can be simplified because the irradiation optical system can be eliminated. Also, the configuration of the optical connection structure 1 can be simplified.

In addition, in the optical connection structure 1 of this example, the converted light L2 emitted by the wavelength converter 4 is directly incident on the optical fiber 3 . As a result, for example, an optical system including an optical mirror (also referred to as a fiber-injection optical system) for injecting the converted light L2 into the optical fiber 3 becomes unnecessary. Unlike this example, when the optical connection structure 1 has a fiber injection optical system, it is necessary to adjust the position of each component of the fiber injection optical system when assembling the optical connection structure 1. complicated. In this example, since the optical system for fiber injection can be made unnecessary, the assembly work of the optical connection structure 1 can be simplified. Also, the configuration of the optical connection structure 1 can be simplified.

The optical connection structure 1 may include an optical system for re-irradiating the wavelength conversion section 4 with the component of the laser light L1 that is reflected by the surface 40 of the wavelength conversion section 4 . The optical connection structure 1 may also include an optical system for condensing a component of the converted light L2 that does not travel toward the incident surface 30 a of the optical fiber 3 and making the component incident on the optical fiber 3 .

Further, in this example, the incident surface 30a of the optical fiber 3 faces a region (upper surface 45 in the example of FIG. 1) different from the irradiated region 140 irradiated with the laser light L1 on the surface 40 of the wavelength conversion unit 4. there is On the other hand, for example, when the optical fiber 3 is positioned on the first side surface 41 side with respect to the wavelength conversion unit 4 and the incident surface 30a of the optical fiber 3 faces the irradiated region 140, unlike this example, , there is a possibility that the optical fiber 3 will be an obstacle when the incident surface 30a is brought close to the wavelength conversion unit 4 . In this example, since the incident surface 30 a faces a region different from the irradiated region 140 , interference from the optical fiber 3 is less likely to occur when the incident surface 30 a is brought closer to the wavelength converting section 4 . Therefore, the incident surface 30a can be easily brought closer to the wavelength converting section 4. As shown in FIG. This makes it easier for the converted light L2 emitted from the wavelength conversion unit 4 to enter the optical fiber 3, and as a result, the converted light L2 can enter the optical fiber 3 efficiently.

Further, in this example, the third area (upper surface 45 in the example of FIG. 1) facing the incident surface 30a of the optical fiber 3 is not opposed to the irradiated area 140 irradiated with the laser beam L1. On the other hand, for example, unlike this example, the optical fiber 3 is located on the second side surface 42 side with respect to the wavelength conversion unit 4, and the incident surface 30a of the optical fiber 3 faces the irradiated region 140. When facing the second side surface 42, the component of the laser light L1 that has passed through the wavelength conversion unit 4 is likely to enter the incident surface 30a. In this example, since the incident surface 30a faces the region not facing the irradiated region 140 on the surface 40 of the wavelength conversion unit 4, the laser light L1 is less likely to enter the incident surface 30a. Therefore, the possibility of the laser light L1 being unintentionally transmitted through the optical fiber 3 that transmits the converted light L2 is reduced.

In addition, in this example, since the incident surface 30a of the optical fiber 3 is located on the side opposite to the substrate 5 with respect to the wavelength converting section 4, when the incident surface 30a of the optical fiber 3 is brought closer to the wavelength converting section 4, the substrate 5 becomes less susceptible to interference. This makes it easier to bring the incident surface 30 a of the optical fiber 3 closer to the wavelength converting section 4 .

Further, in this example, the second region located on the high reflectance member (the substrate 5 in the example of FIG. 1) included in the surface 40 of the wavelength conversion unit 4 is the third region to which the incident surface 30a of the optical fiber 3 faces. A first opposing region (lower surface 46 in the example of FIG. 1) facing the region (upper surface 45 in the example of FIG. 1) is included. As a result, on the surface 40 of the wavelength converting portion 4, the high reflectance member is positioned on the first opposing region facing the third region facing the incident surface 30a. Of the converted light L2, the component emitted from the first opposing region and reflected by the high reflectance member is likely to be emitted from the third region opposing the first opposing region and enter the incident surface 30a. The amount of light of the second component L2b incident on 30a can be increased. As a result, the converted light L2 emitted by the wavelength conversion unit 4 can be efficiently incident on the optical fiber 3. FIG.

Further, in this example, on the surface 40 of the wavelength conversion section 4, the area of the third region (upper surface 45 in the example of FIG. 1) facing the incident surface 30a of the optical fiber 3 is larger than the area of the irradiated region 140. ing. Thus, when the area of the third region is large, the converted light L2 emitted by the wavelength conversion section 4 is likely to enter the optical fiber 3 . This allows the converted light L2 to enter the optical fiber 3 efficiently. The area of the third region may be the same as the area of the irradiated region 140 or may be smaller than the area of the irradiated region 140 .

In addition, in the optical connection structure 1 of this example, the reflectance of the converted light L2 at the irradiated region 150 of the substrate 5 as the high reflectance member is higher than the reflectance of the converted light L2 at the lower surface 46 of the wavelength conversion unit 4. is also getting bigger. Therefore, of the converted light L2, the light amount of the second component L2b that is emitted from the lower surface 46 of the wavelength conversion unit 4, reflected by the irradiated region 150 of the substrate 5, and incident on the optical fiber 3 can be increased. As a result, the converted light L2 emitted by the wavelength converter 4 can enter the optical fiber 3 efficiently. As a result, the optical connection structure 1 with little connection loss can be realized.

In addition, since the optical connection structure 1 of this example includes the substrate 5 and the heat dissipation member 6 having thermal conductivity greater than that of the wavelength conversion section 4, the possibility of deterioration in performance due to heat generation of the wavelength conversion section 4 is reduced. be able to.

At least one of the exit surface 20 a of the optical fiber 2 and the entrance surface 30 a of the optical fiber 3 may be in contact with the surface 40 of the wavelength conversion section 4 . FIG. 2 is a schematic diagram showing an example of how both the exit surface 20a and the entrance surface 30a are in contact with the surface 40 of the wavelength conversion section 4. As shown in FIG. Only one of the exit surface 20a and the entrance surface 30a may be in contact with the surface 40 of the wavelength converting section 4 . At this time, the exit surface 20a of the optical fiber 2 and the entrance surface 30a of the optical fiber 3 may be partially in contact with the surface 40 of the wavelength converting section 4, or may be entirely in contact with the surface 40 of the wavelength converting section 4. may

In the example of FIG. 2, the output surface 20a of the optical fiber 2 is in contact with the first side surface 41 of the wavelength converting section 4, for example. When the emission surface 20a is in contact with the surface 40 of the wavelength conversion section 4, the irradiated area 140 on the surface 40 can be reduced. Therefore, the wavelength conversion part 4 can be made small.

In the example of FIG. 2, the incident surface 30a of the optical fiber 3 is in contact with the upper surface 45 of the wavelength converting section 4, for example. When the incident surface 30a contacts the surface 40 of the wavelength converting section 4, the converted light L2 emitted by the wavelength converting section 4 is likely to enter the incident surface 30a. As a result, the converted light L2 emitted by the wavelength converter 4 can enter the optical fiber 3 efficiently.

The optical connection structure 1 may comprise a plurality of high reflectance members. FIG. 3 is a schematic diagram showing an example of how the optical connection structure 1 includes a high reflectance member 7 separately from the substrate 5 . The high reflectance member 7 is, for example, a metal film. The high reflectance member 7 is positioned, for example, on the second facing region 142 facing the irradiated region 140 on the surface 40 of the wavelength converting portion 4 . In the example of FIG. 3 , the second facing area 142 is included in the second side surface 42 . The second facing region 142 faces the irradiated region 140, for example, in the X-axis direction. The high reflectance member 7 is provided, for example, on the entire area of the second side surface 42 . The high reflectance member 7 is deposited, for example, on the second side surface 42 . The high reflectance member 7 may be composed of silver, aluminum, titanium or chromium, for example. Moreover, a dielectric multilayer film may be used instead of the metal film. When the high reflectance member 7 is a dielectric multilayer film, it may be made of, for example, silicon oxide, titanium oxide, hafnium oxide, magnesium fluoride, or the like. At this time, transparent films with a high refractive index (eg, TiO ₂ , HfO ₂ ) and transparent films with a low refractive index (eg, SiO ₂ , MgF ₂ ) are alternately laminated.

The reflectance of the converted light L2 on the surface of the high reflectance member 7 may be higher than the reflectance of the converted light L2 on the surface 40 of the wavelength converting section 4 . The reflectance of the converted light L2 on the surface of the high reflectance member 7 may be, for example, 35% or more, 40% or more, or 50% or more. Alternatively, the reflectance of the converted light L2 on the surface of the high reflectance member 7 may be 60% or more, 70% or more, or 80% or more.

As in the example of FIG. 3, the high reflectance member 7 is positioned on the second opposing region 142 facing the irradiated region 140 on the surface 40 of the wavelength conversion unit 4, so that the second opposing region of the converted light L2 is The component L2c emitted from the region 142 can be reflected by the high reflectance member 7 and enter the optical fiber 3 . As a result, the converted light L2 emitted by the wavelength converter 4 can enter the optical fiber 3 efficiently.

The high reflectance member 7 may function as a member that reflects the laser beam L1. In this case, the reflectance of the laser light L1 on the surface of the high reflectance member 7 may be higher than the reflectance of the laser light L1 on the surface 40 of the wavelength converting portion 4 . The reflectance of the laser beam L1 on the surface of the high reflectance member 7 may be, for example, 35% or more, 40% or more, or 50% or more. Alternatively, the reflectance of the laser beam L1 on the surface of the high reflectance member 7 may be 60% or more, 70% or more, or 80% or more.

When the high reflectance member 7 can reflect the laser light L1, the laser light L1 irradiated to the irradiated region 140 is transmitted through the wavelength conversion unit 4 and emitted from the second opposing region 142. The transmitted component can be reflected by the high reflectance member 7 and irradiated to the wavelength conversion section 4 again. As a result, the wavelength conversion section 4 emits light in accordance with the irradiation of the transmitted component, so that the luminous efficiency of the wavelength conversion section 4 is improved.

Note that the reflectance of the converted light L2 on the surface of the high reflectance member 7 may be equal to or lower than the reflectance of the converted light L2 on the surface 40 of the wavelength conversion unit 4 . Further, the reflectance of the laser light L1 on the surface of the high reflectance member 7 may be equal to or lower than the reflectance of the laser light L1 on the surface 40 of the wavelength converting portion 4 .

The high reflectance member 7 does not have to be provided in the area other than the second facing area 142 on the second side surface 42 . Also, the high reflectance member 7 may be provided in a region other than the second side surface 42 on the surface 40 of the wavelength converting portion 4 . For example, the high reflectance member 7 may be provided on at least part of the third side surface 43 or may be provided on at least part of the fourth side surface 44 . Also, the high reflectance member 7 may be partially provided on the upper surface 45 . Further, the high reflectance member 7 may be provided in a peripheral region 141 positioned around the irradiated region 140 on the surface 40 of the wavelength converting portion 4 . FIG. 4 is a schematic diagram showing an example of how the high reflectance member 7 is provided in the peripheral region 141. As shown in FIG. In FIG. 4, the high reflectance member 7 is indicated by hatching rising to the right, and the irradiated region 140 is indicated by hatching falling to the right. The peripheral region 141 is included in the first side surface 41, for example. The peripheral region 141 surrounds the irradiated region 140, for example. The peripheral region 141 does not have to surround the irradiated region 140 .

A plurality of high reflectance members 7 may be provided on the surface 40 of the wavelength conversion section 4 . For example, the high reflectance member 7 is provided in at least two regions of the second side surface 42, the third side surface 43, the fourth side surface 44, the peripheral region 141 included in the first side surface 41, and the upper surface 45. good too. The plurality of high reflectance members 7 provided on the surface 40 of the wavelength converting portion 4 may include a plurality of high reflectance members 7 made of the same material, or a plurality of high reflectance members 7 made of different materials. A rate member 7 may be included.

3, when the high reflectance member 7 is provided in the second opposing region 142 facing the irradiated region 140, the peripheral region 141 positioned around the irradiated region 140 as shown in FIG. A high reflectance member 7 may also be provided on the . In this case, the transmitted component of the laser light L1 that has passed through the wavelength conversion portion 4 and is emitted from the second opposing region 142 is reflected by the high reflectance member 7 on the second opposing region 142 and is transmitted to the wavelength conversion portion 4. be irradiated. Then, among the transmission components irradiated to the wavelength conversion section 4, the component transmitted through the wavelength conversion section 4 and emitted from the peripheral region 141 on the opposite side of the second opposing region 142 is highly reflected on the peripheral region 141. The light is reflected by the index member 7 and irradiated to the wavelength converting portion 4 . Thereby, the luminous efficiency of the wavelength conversion section 4 is improved.

The shape of the substrate 5 is not limited to the above examples. FIG. 5 is a schematic diagram showing an example of an optical connection structure 1 including a substrate 5 (also referred to as substrate 5A) having a shape different from the above example. In FIG. 5, cross-sections of the substrate 5A and the wavelength converting portion 4 are indicated by oblique lines. FIG. 6 is a schematic plan view showing an example of the substrate 5A, the wavelength converting section 4, and the optical fiber 2 viewed from the +Z side.

As shown in FIGS. 5 and 6, the substrate 5A surrounds the peripheral side surface 48 of the wavelength conversion section 4, for example. The substrate 5A faces, for example, the first side surface 41, the second side surface 42, the third side surface 43, and the fourth side surface 44 of the wavelength conversion section 4. As shown in FIG. The substrate 5A has a concave portion 55 that opens toward the upper surface 51. As shown in FIG. The wavelength converting portion 4 is accommodated within the recess 55 . The first side surface 41 , the second side surface 42 , the third side surface 43 , and the fourth side surface 44 of the wavelength conversion section 4 are joined to the inner surface (also referred to as inner wall) of the recess 55 , for example. The wavelength converting portion 4 may be directly bonded to the inner surface of the concave portion 55 in the same manner as described above, or may be bonded using a bonding material. The inner surface of the concave portion 55 has a shape corresponding to the shape of the peripheral side surface 48 of the wavelength converting portion 4 .

The upper surface 45 of the wavelength converting portion 4 is exposed from the upper surface 51 of the substrate 5 . The upper surface 45 of the wavelength conversion part 4 is located on the same plane as the upper surface 51 of the substrate 5, for example. The upper surface 45 of the wavelength conversion section 4 may be positioned above or below the upper surface 51 of the substrate 5 .

The substrate 5A has an insertion hole 56 into which the optical fiber 2 is inserted. The insertion hole 56 and the space inside the recess 55 are connected. The insertion hole 56 partially exposes the first side surface 41 of the wavelength conversion unit 4 from the substrate 5A, for example. At least the tip of the optical fiber 2 is held by the substrate 5A by being inserted into the insertion hole 56. As shown in FIG. The laser light L1 emitted from the emission surface 20a of the optical fiber 2 irradiates at least part of the exposed area 41a of the first side surface 41 exposed from the substrate 5A through the insertion hole 56. As shown in FIG. Therefore, the irradiated region 140 is included in the exposed region 41a.

In the examples of FIGS. 5 and 6, the second region, which is included in the surface 40 of the wavelength conversion unit 4 and where the substrate 5A as the high reflectance member is located, includes not only the lower surface 46 but also the second side surface 42 and the third A side surface 43 , a fourth side surface 44 and a peripheral region 141 included in the first side surface 41 are included.

Here, of the converted light L2, a component that is emitted from the lower surface 46, reflected by the substrate 5A, and incident on the optical fiber 3 is called a lower-surface reflected component, and is emitted from the second side surface 42 and reflected by the substrate 5A. The component incident on the fiber 3 is called the first side reflected component. A component of the converted light L2 that is emitted from the third side surface 43, reflected by the substrate 5A, and incident on the optical fiber 3 is called a third side reflection component, and is emitted from the fourth side surface 44 and reflected by the substrate 5A. A component that is incident on the optical fiber 3 as a result is called a fourth side reflection component. A component of the converted light L2 that is emitted from the peripheral region 141 included in the first side surface 41, reflected by the substrate 5A, and incident on the optical fiber 3 is called a first side reflection component. In this example, the second component L2b included in the converted light L2 includes a bottom reflection component, a first side reflection component, a second side reflection component, a third side reflection component, and a fourth side reflection component. Further, in this example, the inner surface of the concave portion 55 constitutes the irradiated region 150, which is included in the surface 50 of the substrate 5A and is irradiated with the second component L2b.

As in this example, the substrate 5A is positioned not only on the lower surface 46 but also on the peripheral side surface 48 of the surface 40 of the wavelength conversion unit 4, thereby increasing the light amount of the converted light L2 incident on the optical fiber 3. be able to. Therefore, the converted light L2 can enter the optical fiber 3 efficiently.

Further, since the substrate 5A is positioned not only on the lower surface 46 but also on the peripheral side surface 48 of the surface 40 of the wavelength conversion section 4, the heat radiation effect of the substrate 5A and the heat radiation member 6 can be improved. Therefore, it is possible to reduce the possibility that the performance of the wavelength conversion section 4 is deteriorated due to the heat generation of the wavelength conversion section 4 .

5 and 6, when the substrate 5A is positioned on the second opposing region 142 included in the second side surface 42, the laser light L1 is transmitted through the wavelength conversion unit 4 and is transmitted to the second wavelength. The transmission component emitted from the opposing region 142 can be reflected by the substrate 5A and irradiated to the wavelength conversion section 4 again. Thereby, the luminous efficiency of the wavelength conversion section 4 is improved.

Further, when the substrate 5A is positioned above the second opposing region 142 and the peripheral region 141, the transmission component of the laser light L1 that has passed through the wavelength conversion unit 4 and is emitted from the second opposing region 142 is the second The light is reflected by the substrate 5A on the 2-opposed region 142 and is irradiated to the wavelength conversion section 4 . Then, of the transmission component irradiated to the wavelength conversion section 4, the component transmitted through the wavelength conversion section 4 and emitted from the peripheral region 141 is reflected by the substrate 5A on the peripheral region 141 and irradiated to the wavelength conversion section 4. be done. Thereby, the luminous efficiency of the wavelength conversion section 4 is improved.

In addition, the substrate 5 may not be positioned on the second side surface 42 , the third side surface 43 , or the fourth side surface 44 . Also, the substrate 5 does not have to be located on the peripheral region 141 . Also, the substrate 5A may be partially located on the upper surface 45. FIG.

Further, the shape of the substrate 5A surrounding the peripheral side surface 48 of the wavelength converting portion 4 is not limited to the above example. For example, as shown in FIG. 7, the upper surface 51 of the substrate 5A may be formed in a convex shape, and a concave portion 55 for accommodating the wavelength conversion portion 4 may be provided in the convex portion 57 formed thereby. In the example of FIG. 7 , the convex portion 57 is provided with an exposure hole 58 that partially exposes the first side surface 41 of the wavelength converting portion 4 in the concave portion 55 . The first side surface 41 is irradiated with the laser beam L1 through the exposure hole 58 .

In the above example, the laser beam L1 is applied perpendicularly to the peripheral side surface 48 of the wavelength converting portion 4, but may be applied obliquely. 8 and 9 are schematic diagrams showing an example of how the laser light L1 is obliquely irradiated onto the peripheral side surface 48 of the wavelength converting portion 4. FIG. In the example of FIG. 8, the laser beam L1 is irradiated slightly obliquely from the +Z side (in other words, slightly from above) with respect to the first side surface 41 . In the example of FIG. 9, the laser beam L1 is irradiated slightly obliquely from the -Z side (in other words, from slightly below) with respect to the first side surface 41 . The first side surface 41 may be irradiated with the laser beam L1 obliquely from the +Y side or obliquely from the -Y side.

In the above example, the shape of the wavelength converting portion 4 is a rectangular parallelepiped, but it may be another shape. For example, the shape of the wavelength converting portion 4 may be a cube, a cylinder, a truncated pyramid, or a truncated cone. FIG. 10 is a schematic diagram showing an example of an optical connection structure 1 including a truncated cone-shaped wavelength converting portion 4 (also referred to as a wavelength converting portion 4A). In FIG. 10, cross-sections of the substrate 5A and the wavelength converting portion 4A are indicated by oblique lines.

A surface 40 (also referred to as a surface 40A) of the truncated cone-shaped wavelength converting portion 4A has a flat upper surface 145 and a lower surface 146 facing each other, and an annular peripheral side surface 148 connecting the upper surface 145 and the lower surface 146 . Each of the upper surface 145 and the lower surface 146 is parallel to the XY plane, for example. Upper surface 145 and lower surface 146 are circular. The radius of upper surface 145 is larger than the radius of lower surface 146, for example. Therefore, the area of upper surface 145 is larger than the area of lower surface 146 . The radius of upper surface 145 may be smaller than the radius of lower surface 146, for example. In addition, when the radius of the upper surface 145 and the lower surface 146 is the same, the wavelength conversion part 4A becomes cylindrical.

The wavelength conversion section 4A is housed in a recess 55 of the substrate 5A. The inner surface of the concave portion 55 has a shape corresponding to the shape of the surface 40A of the truncated cone-shaped wavelength conversion portion 4A. A peripheral side surface 148 of the wavelength conversion section 4A is joined to the inner surface of the recess 55, for example. The wavelength converting portion 4A may be directly bonded to the inner surface of the recess 55, or may be bonded using a bonding material.

A portion of the peripheral side surface 148 of the wavelength converting portion 4A is exposed through an insertion hole 56 provided in the substrate 5A. The laser beam L1 emitted from the optical fiber 2 inserted into the insertion hole 56 irradiates at least a part of the exposed area 148a of the peripheral side surface 148 exposed from the substrate 5A through the insertion hole 56 . Therefore, the irradiated area 140 is included in the exposed area 148a.

An upper surface 145 of the wavelength converting portion 4A is exposed from the substrate 5A. The upper surface 145 of the wavelength conversion part 4A is positioned, for example, on the same plane as the upper surface 51 of the substrate 5A. The upper surface 145 of the wavelength conversion section 4A may be positioned above or below the upper surface 51 of the substrate 5A.

The incident surface 30 a of the optical fiber 3 faces the upper surface 145 . The incident surface 30a faces the upper surface 145 and is parallel to the upper surface 145, for example. The irradiated region 140 does not face the upper surface 145 to which the incident surface 30a of the optical fiber 3 faces. In the example of FIG. 10, the second region, which is included in the surface 40A of the wavelength conversion unit 4A and where the substrate 5A as the high reflectance member is located, includes the lower surface 146 and the region of the peripheral side surface 148 other than the exposed region 148a. is included. A component of the converted light L2 emitted from the wavelength converter 4A, which is emitted from the second region, is reflected by the substrate 5A and enters the optical fiber 3. FIG.

In the example of FIG. 10, the area of the upper surface 145 is larger than the area of the lower surface 146 on the surface 40A of the wavelength converting portion 4A. In this manner, by increasing the area of the third region facing the incident surface 30a of the optical fiber 3 on the surface 40A of the wavelength conversion unit 4A, the converted light L2 emitted from the third region can easily enter the incident surface 30a. Become. Thereby, the light amount of the converted light L2 incident on the incident surface 30a can be increased.

In the example of FIG. 10, a second opposing region 142 facing the irradiated region 140 in the X-axis direction is included in the peripheral side surface 148 of the surface 40A of the wavelength converting portion 4A. A peripheral area 141 located around the irradiated area 140 is included in the peripheral side surface 148 . The substrate 5A is positioned on the second facing region 142, but does not have to be positioned on the second facing region 142. FIG. Further, the substrate 5A is located on the peripheral region 141, but it does not have to be located on the peripheral region 141. FIG. Also, the substrate 5A may be partially located on the top surface 145 . Further, similarly to FIG. 7 described above, the upper surface 51 of the substrate 5A may be formed in a convex shape, and the convex portion 57 formed thereby may be provided with the concave portion 55 for accommodating the wavelength conversion portion 4A.

In the above example, the third region (for example, the upper surface 45) included in the surface 40 of the wavelength conversion unit 4 and facing the incident surface 30a of the optical fiber 3 is flat, but it may be convex or concave. may be FIG. 11 is a schematic diagram showing an example of the optical connection structure 1 in which the third region is concave.

In the example of FIG. 11, the upper surface 45 of the wavelength converting portion 4 forms a concave surface. The upper surface 45 forms, for example, a concave partial spherical surface. By forming the upper surface 45 as a concave surface in this manner, the spread of the converted light L2 emitted from the upper surface 45 can be reduced compared to the case where the upper surface 45 is flat. Thereby, the light amount of the converted light L2 propagating through the optical fiber 3 can be increased. Therefore, the converted light L2 can enter the optical fiber 3 efficiently. In addition, the spread of the converted light L2 is confirmed by measuring the size of the output surface, the size of the incident light on the incident surface, the size of the spot diameter on the surface to be illuminated, etc. by visual observation, measurement of the ratio of the incident light, etc. can. At this time, reducing the spread refers to a state in which light is condensed from a state in which light is emitted in all directions, or a spot diameter is reduced, when compared with the case where there is no concave surface.

Note that the shape of the concave surface formed by the third region is not limited to the above example. For example, the concave surface formed by the third region may have the same shape as the side surface of a cone or pyramid, or may be a partial spheroidal surface. Further, the concave surface formed by the third region may be a flat surface bent in a U shape.

The optical connection structure 1 may include an optical member that reduces the spread of the converted light L2 emitted from the third region and enters the incident surface 30a of the optical fiber 3 . This optical member may be a lens or a mirror. 12 and 13 are schematic diagrams showing an example of the optical connection structure 1 in this case. In the example of FIG. 12, the lens 8 is provided between the upper surface 45 of the wavelength conversion section 4 and the incident surface 30a of the optical fiber 3. In the example of FIG. In the example of FIG. 13 , a mirror 9 is provided between the upper surface 45 of the wavelength conversion section 4 and the incident surface 30a of the optical fiber 3 . In FIG. 13, the cross section of the mirror 9 is shown hatched.

Converted light L2 emitted from the upper surface 45 of the wavelength conversion unit 4 is incident on the lens 8 . The lens 8 reduces the spread of the converted light L2 emitted from the upper surface 45 of the wavelength converter 4 and enters the incident surface 30a of the optical fiber 3 . The lens 8 has, for example, an incident surface 81 on which the converted light L2 is incident and an output surface 80 from which the converted light L2 is emitted. The entrance surface 81 faces the upper surface 45, and the exit surface 80 faces the entrance surface 30a. The incident surface 81 constitutes, for example, a flat surface, and the exit surface 80 constitutes, for example, a convex curved surface. The incident surface 81 may form a concave curved surface.

Similar to the lens 8 , the mirror 9 reduces the spread of the converted light L<b>2 emitted from the upper surface 45 of the wavelength conversion section 4 and enters the incident surface 30 a of the optical fiber 3 . The mirror 9 has a reflecting surface 90 that reflects the converted light L2 emitted from the upper surface 45 of the wavelength converting section 4 . The reflecting surface 90 has, for example, a shape along a virtual ellipsoid of revolution (also referred to as a virtual ellipsoid of revolution). Such a mirror 9 is also called an elliptical mirror. One focal point of the virtual spheroid is located on or near the top surface 45, for example. The other focal point of the virtual ellipsoid of revolution is located, for example, on or near the entrance surface 30a.

As in the examples of FIGS. 12 and 13, the optical connection structure 1 includes an optical member that reduces the spread of the converted light L2 emitted from the third region and enters the incident surface 30a. It is possible to increase the light amount of the converted light L2. Therefore, the converted light L2 can enter the optical fiber 3 efficiently.

Also, the optical connection structure 1 may include optical members such as the lens 8 and the mirror 9 . In this case, the amount of converted light L2 entering the optical fiber 3 can be increased by making the third region concave as shown in FIG.

In the wavelength conversion section 4, the concentration of the phosphor may be uniform or non-uniform. In the latter case, in the wavelength conversion section 4, the concentration of the phosphor may increase as the area 140 to be irradiated with the laser light L1 is directed toward the opposite side thereof. In other words, in the wavelength conversion section 4 , the concentration of the phosphor may increase from the irradiated region 140 toward the second opposing region 142 that faces the irradiated region 140 . FIG. 14 is a schematic diagram showing an example of this situation. In FIG. 14, the plurality of phosphors 401 included in the wavelength conversion section 4 are schematically shown as circles.

In the wavelength conversion section 4 shown in FIG. 14 , the concentration of the phosphor 401 increases from the irradiated region 140 toward the opposite second side surface 42 or away from the irradiated region 140 . In the wavelength converting portion 4, the concentration of the phosphor 401 is low on the irradiated region 140 side, and the concentration of the phosphor 401 is high on the second side surface 42 side. In the example of FIG. 14 , the concentration of the phosphor 401 in the wavelength conversion section 4 increases from the irradiated region 140 toward the inner side along the upper surface 45 . The concentration of the phosphor can be measured from a cross-sectional image using a scanning electron microscope or the like, or can be partially measured using a spectrofluorophotometer.

Such a wavelength conversion section 4 may be realized by joining a plurality of phosphor portions having different concentrations of the phosphor 401 in a row, or by joining the phosphor portions 401 in one phosphor portion. It may be realized by changing Various methods are conceivable as a method of joining a plurality of phosphor portions. For example, multiple phosphor portions may be joined by pressing under heat. Alternatively, the plurality of phosphor portions may be bonded by subjecting the bonding surfaces of the phosphor portions to corona discharge treatment and then pressing them together. Also, multiple phosphor portions may be joined using a transparent adhesive. Moreover, when the base material of the phosphor portion is glass, a plurality of phosphor portions may be melt-bonded. Moreover, when the base material of the phosphor portion is ceramic, a plurality of phosphor portions may be laminated and joined by firing.

In this way, in the wavelength conversion section 4, the concentration of the phosphor increases toward the opposite side from the irradiated region 140, so that the fluctuation of the emission intensity in the wavelength conversion section 4 can be reduced.

Here, for example, consider a case where the concentration of phosphor is substantially uniform in the wavelength conversion section 4 . Since the phosphor 401 emits light when excited by the laser light L1, the intensity of the laser light L1 within the wavelength conversion section 4 decreases as the laser light L1 travels deeper from the surface 40. FIG. In other words, the intensity of the laser light L1 within the wavelength converting portion 4 decreases as it goes from the irradiated region 140 to the opposite side. Therefore, when the concentration of the phosphor is substantially uniform in the wavelength conversion section 4, the emission intensity at the wavelength conversion section 4 decreases toward the opposite side from the irradiated region 140, and the emission intensity at the wavelength conversion section 4 decreases. variation occurs. As a result, the intensity of the converted light L2 emitted from the upper surface 45 of the wavelength conversion unit 4 may be uneven.

On the other hand, in the example of FIG. 14, in the wavelength conversion section 4, the concentration of the phosphor 401 increases from the irradiated region 140 toward the opposite side. As a result, variations in emission intensity in the wavelength conversion section 4 can be reduced. As a result, unevenness in the intensity of the converted light L2 emitted from the upper surface 45 of the wavelength conversion section 4 can be reduced.

In addition, for example, when the concentration of the phosphor is substantially uniform in the wavelength conversion section 4, as shown in FIG. may be irradiated.

In the example of FIG. 15, the optical connection structure 1 is provided with an optical fiber 12 that emits a laser beam L3. The optical fiber 12 receives the laser beam L3 and transmits the incident laser beam L3. The wavelength of the laser beam L3 is, for example, the same as the wavelength of the laser beam L1. The optical fiber 12 is positioned, for example, on the -X side of the wavelength converting section 4 . The optical fiber 12 extends, for example, along the X-axis direction. The laser light L1 and the laser light L3 may be generated by dividing the laser light output from one laser light source into two. Alternatively, a laser light source that outputs the laser light L1 and a laser light source that outputs the laser light L3 may be provided separately.

The optical fiber 12 includes, for example, a core 120 that transmits laser light L3 and a clad 121 that surrounds the core 120 . The optical fiber 12 may be, for example, a quartz fiber made of quartz glass, a plastic fiber made of plastic, or an optical fiber made of other materials. The optical fiber 12 may be a single mode fiber or a multimode fiber.

The optical fiber 12 has an emission surface 120a from which the laser beam L3 is emitted. For example, core 120 has output surface 120a. The output surface 120a is, for example, a circular plane. The exit surface 120a faces the second side surface 42 of the wavelength conversion section 4, for example. The output surface 120a is parallel to the second side surface 42, for example. The second side surface 42 is directly irradiated with the laser light L3 emitted from the emission surface 120a. A laser beam L3 is emitted from the optical fiber 12 along, for example, the +X direction. The surface 40 of the wavelength converting portion 4 has an irradiated region 144 irradiated with the laser beam L3. The irradiated region 144 is included in the second side surface 42, for example.

The optical fiber 12 may have a member that covers the clad 121 . The member covering the periphery of the clad 121 may be composed of one layer, or may be composed of multiple layers. A member covering the clad 121 may include a protective layer.

As in the example of FIG. 15, by irradiating the surface 40 of the wavelength conversion section 4 with the laser light L3 from the side opposite to the irradiated region 140 irradiated with the laser light L1, for example, the wavelength conversion section 4 Even if the concentration of the phosphor is substantially uniform at , variations in the emission intensity at the wavelength conversion section 4 can be reduced. As a result, unevenness in the intensity of the converted light L2 emitted from the upper surface 45 of the wavelength conversion section 4 can be reduced.

The method of bonding the wavelength conversion unit 4 to the substrate 5 is not limited to the above example. For example, the wavelength conversion section 4 may be joined to the substrate 5 by providing the metal film 13 on the lower surface 46 of the wavelength conversion section 4 and soldering the substrate 5 to the metal film 13 . FIG. 16 is a schematic diagram showing an example of the optical connection structure 1 in this case.

The metal film 13 is deposited, for example, on the lower surface 46 of the wavelength conversion section 4 . Metal film 13 is located on lower surface 46 . A solder layer 14 is present between the metal film 13 and the substrate 5 and the metal film 13 is soldered to the substrate 5 . Metal film 13 may be composed of, for example, silver, aluminum, titanium, or chromium. The thermal conductivity of the metal film 13 is higher than the thermal conductivity of the wavelength conversion section 4, for example.

The metal film 13 may function as a high reflectance member. In this case, the reflectance of the converted light L2 on the surface of the metal film 13 may be higher than the reflectance of the converted light L2 on the surface 40 of the wavelength conversion section 4 . The reflectance of the converted light L2 on the surface of the metal film 13 may be, for example, 35% or more, 40% or more, or 50% or more. Alternatively, the reflectance of the converted light L2 on the surface of the metal film 13 may be 60% or more, 70% or more, or 80% or more.

Also, the metal film 13 may function as a member that reflects the laser beam L1. In this case, the reflectance of the laser light L1 on the surface of the metal film 13 may be higher than the reflectance of the laser light L1 on the surface 40 of the wavelength converting section 4 . The reflectance of the laser beam L1 on the surface of the metal film 13 may be, for example, 35% or more, 40% or more, or 50% or more. Alternatively, the reflectance of the laser beam L1 on the surface of the metal film 13 may be 60% or more, 70% or more, or 80% or more.

Note that the reflectance of the converted light L2 on the surface of the metal film 13 may be equal to or lower than the reflectance of the converted light L2 on the surface 40 of the wavelength conversion unit 4 . Also, the reflectance of the laser light L1 on the surface of the metal film 13 may be equal to or lower than the reflectance of the laser light L1 on the surface 40 of the wavelength conversion unit 4 .

Also, the metal film 13 may be a multilayer film. In this case, the metal film 13 may be, for example, a multilayer film in which a layer made of titanium, a layer made of platinum, and a layer made of gold are laminated in this order from the wavelength conversion section 4 side. Alternatively, the metal film 13 may be a multilayer film in which a layer made of chromium or silver, a layer made of platinum and a layer made of gold are laminated in this order. Alternatively, the metal film 13 may be a multilayer film in which a layer made of chromium or silver, a layer made of nickel and a layer made of gold are laminated in this order.

When the reflectance of the converted light L2 on the metal film 13 is higher than the reflectance of the converted light L2 on the surface 40 of the wavelength conversion unit 4, the reflectance of the converted light L2 on the substrate 5 is the same as that of the wavelength conversion unit 4. It may be less than or equal to the reflectance of the converted light L2 on the surface 40 . Further, when the reflectance of the laser light L1 on the metal film 13 is higher than the reflectance of the laser light L1 on the surface 40 of the wavelength conversion unit 4, the reflectance of the laser light L1 on the substrate 5 is higher than that of the wavelength conversion unit. It may be less than or equal to the reflectance of the converted light L2 on the surface 40 of 4.

The optical connection structure 1 may not have the substrate 5, as shown in FIG. In the example of FIG. 17 , the metal film 13 on the lower surface 46 of the wavelength conversion section 4 is soldered to the heat dissipation member 6 . A solder layer 14 exists between the metal film 13 and the heat dissipation member 6 .

When the optical connection structure 1 does not include the substrate 5, the wavelength conversion section 4 can be directly bonded to the heat dissipation member 6 without using a bonding material such as solder, as shown in FIG. good. In the example of FIG. 18 , the lower surface 46 of the wavelength conversion section 4 is directly bonded to the heat dissipation member 6 . The heat dissipation member 6 is positioned on the bottom surface 46 of the wavelength conversion section 4 . For example, like when the wavelength converting portion 4 is bonded to the substrate 5, the wavelength converting portion 4 may be directly bonded to the heat dissipation member 6 by oxygen bonding. Alternatively, the surface of the heat radiating member 6 may be provided with minute unevenness of several μm, for example, and the wavelength converting section 4 may be directly bonded to the heat radiating member 6 by the anchor effect using the unevenness.

When the wavelength conversion section 4 is directly bonded to the heat dissipation member 6, the heat dissipation member 6 may function as a high reflectance member. In this case, it can be said that the high reflectance member functions as a heat radiating member that radiates heat generated by the wavelength conversion section 4 . The reflectance of the converted light L<b>2 on the surface of the heat dissipation member 6 may be higher than the reflectance of the converted light L<b>2 on the surface 40 of the wavelength converter 4 . The reflectance of the converted light L2 on the surface of the heat dissipation member 6 may be, for example, 35% or more, 40% or more, or 50% or more. Alternatively, the reflectance of the converted light L2 on the surface of the heat dissipation member 6 may be 60% or more, 70% or more, or 80% or more.

Moreover, the heat dissipation member 6 to which the wavelength conversion part 4 is directly joined may function as a member that reflects the laser beam L1. In this case, the reflectance of the laser light L1 on the surface of the heat dissipation member 6 may be higher than the reflectance of the laser light L1 on the surface 40 of the wavelength converting section 4 . The reflectance of the laser beam L1 on the surface of the heat dissipation member 6 may be, for example, 35% or more, 40% or more, or 50% or more. Alternatively, the reflectance of the laser beam L1 on the surface of the heat dissipation member 6 may be 60% or more, 70% or more, or 80% or more.

Note that the wavelength conversion unit 4 is not directly bonded to the heat dissipation member 6, but may be bonded to the heat dissipation member 6 using, for example, a bonding material made of a transparent resin through which the laser beam L1 and the converted light L2 are transmitted. good.

The reflectance of the converted light L2 does not have to be higher than the reflectance of the converted light L2 on the surface 40 of the wavelength conversion unit 4 over the entire surface area of the high reflectance member. For example, on the surface of the high reflectance member, a region where the reflectance of the converted light L2 is higher than the reflectance of the converted light L2 on the surface 40 of the wavelength conversion unit 4 is irradiated with the second component L2b of the converted light L2. It may be only the area where

Moreover, the reflectance of the laser beam L1 does not have to be higher than the reflectance of the laser beam L1 on the surface 40 of the wavelength conversion unit 4 in the entire surface area of the high reflectance member. For example, on the surface of the high-reflectance member, a region where the reflectance of the laser light L1 is higher than the reflectance of the laser light L1 on the surface 40 of the wavelength conversion unit 4 allows the laser light L1 to pass through the wavelength conversion unit 4. It may be only the area irradiated with the transmitted component. For example, when the substrate 5 functions as a high reflectance member and is made of an aluminum alloy or aluminum as in the example of FIG. A black alumite treatment may be performed on a region other than the irradiated region 150 among them. The black anodized area becomes black and absorbs the converted light L2 and the laser light L1. As a result, the irradiated region 150 is the only region on the surface 50 of the substrate 5 in which the reflectance of the converted light L2 is higher than the reflectance of the converted light L2 on the surface 40 of the wavelength conversion unit 4 . In addition, on the surface 50 of the substrate 5 , the irradiated area 150 is the only area where the reflectance of the laser light L<b>1 is higher than the reflectance of the laser light L<b>1 on the surface 40 of the wavelength conversion unit 4 . A similar process may be performed on the high reflectance member 7, a similar process may be performed on the metal film 13 functioning as the high reflectance member, and a similar process may be performed on the metal film 13 as the high reflectance member. A similar process may be performed on the functioning heat dissipation member 6 as well.

Although the optical connection structure 1 includes the heat dissipation member 6 in each of the above examples, the optical connection structure 1 does not have to include the heat dissipation member 6 . Also, in the above example, the first side surface 41 is irradiated with the laser beam L1, but the area of the surface 40 of the wavelength conversion unit 4 irradiated with the laser beam L1 may be other than the first side surface 41. The laser beam L1 may be applied to the second side surface 42, the third side surface 43, or the fourth side surface 44, for example.

The wavelength converting portion 4 may be, for example, an annular member 4B, as shown in FIG. In the example of FIG. 19, the annular member 4B has, for example, a shape obtained by bending an elongated rectangular parallelepiped into an annular shape. The surface 40B of the annular member 4B has, for example, an annular outer peripheral surface 411 and an annular inner peripheral surface 412 facing each other, and flat annular side surfaces 413 and 414 facing each other. Annular sides 413 and 414 are, for example, parallel to each other.

The annular member 4B includes, for example, a plurality of wavelength conversion portions 450 arranged in the circumferential direction (also referred to simply as the circumferential direction) of the annular member 4B. A plurality of wavelength conversion portions 450 are joined in an annular shape. Each wavelength conversion portion 450 emits converted light L2 in response to irradiation with laser light L1. The wavelength spectra of the converted light L2 emitted by the plurality of wavelength conversion portions 450 are different from each other, for example. The color temperatures of the converted light L2 emitted by the plurality of wavelength conversion portions 450 are different from each other, for example. The emission colors of the plurality of wavelength conversion portions 450 are different from each other, for example. Each wavelength converting portion 450 has, for example, a configuration similar to the phosphor portion 400 described above. The plurality of wavelength converting portions 450 can be, for example, annularly bonded in a manner similar to the bonding method described above for the plurality of phosphor portions. In the example of FIG. 19, the annular member 4B comprises, for example, three wavelength conversion portions 450a, 450b, 450c. When the annular member 4B is viewed from the side of the annular side surface 413, the wavelength conversion portions 450a, 450b, and 450c are arranged counterclockwise in this order.

The surface of each wavelength converting portion 450 has an outer surface 451 and an inner surface 452 facing each other and flat sides 453 and 454 facing each other. Sides 453 and 454 are, for example, parallel to each other. An outer surface 451 of the plurality of wavelength converting portions 450 constitutes an outer peripheral surface 411 of the annular member 4B. An inner surface 452 of the plurality of wavelength conversion portions 450 constitutes an inner peripheral surface 412 of the annular member 4B. A side surface 453 of the plurality of wavelength converting portions 450 constitutes an annular side surface 413 of the annular member 4B. A side surface 454 of the plurality of wavelength converting portions 450 constitutes an annular side surface 414 of the annular member 4B.

The exit surface 20a of the optical fiber 2 faces, for example, the annular side surface 413 . The laser light L1 emitted from the emission surface 20a is irradiated onto the annular side surface 413, for example. The incident surface 30a of the optical fiber 3 faces the outer peripheral surface 411, for example. The converted light L2 emitted from the outer peripheral surface 411 is incident on the incident surface 30a. The outer peripheral surface 411 facing the incident surface 30a is not opposed to the annular side surface 413 irradiated with the laser beam L1.

For example, a high reflectance member 18 is arranged in the inner space of the annular member 4B. The shape of the high reflectance member 18 is, for example, a circular plate. The high reflectance member 18 is made of, for example, the same material as the substrate 5 described above. The outer peripheral surface 180 of the high reflectance member 18 is, for example, joined to the inner peripheral surface 412 of the annular member 4B. The bonding method of the high reflectance member 18 to the annular member 4B is, for example, the same as the bonding method to the substrate 5 of the wavelength conversion section 4 described above.

The reflectance of the converted light L2 on the surface of the high reflectance member 18 may be higher than the reflectance of the converted light L2 on the surface 40B of the annular member 4B (in other words, the wavelength converter 4). The reflectance of the converted light L2 on the surface of the high reflectance member 18 may be, for example, 35% or more, 40% or more, or 50% or more. Alternatively, the reflectance of the converted light L2 on the surface of the high reflectance member 18 may be 60% or more, 70% or more, or 80% or more.

The high reflectance member 18 may function as a member that reflects the laser beam L1. In this case, the reflectance of the laser light L1 on the surface of the high reflectance member 18 may be higher than the reflectance of the laser light L1 on the surface 40B of the annular member 4B (in other words, the wavelength converting portion 4). The reflectance of the laser beam L1 on the surface of the high reflectance member 18 may be, for example, 35% or more, 40% or more, or 50% or more. Alternatively, the reflectance of the laser beam L1 on the surface of the high reflectance member 18 may be 60% or more, 70% or more, or 80% or more.

The annular member 4B is, for example, rotatable in the circumferential direction. The annular member 4B is rotated in the circumferential direction by a rotary drive mechanism 900, for example. The rotation drive mechanism 900 may include a motor or the like. The annular member 4B may rotate clockwise when viewed from the annular side surface 413 side, may rotate counterclockwise, or may rotate in both directions.

In this example, the relative positions and attitudes of the optical fibers 2 and 3 with respect to the annular member 4B are constant. The output surface 20a of the optical fiber 2 can face the side surface 453 of each wavelength converting portion 450 by rotating the annular member 4B. Also, the incident surface 30a of the optical fiber 3 can face the outer surface 451 of each wavelength conversion portion 450 by rotating the annular member 4B.

In the optical connection structure 1 having such a configuration, it is possible to irradiate the side surface 453 of each wavelength conversion portion 450 with the laser light L1 by rotating the annular member 4B. As a result, a plurality of types of converted light L2 having different wavelength spectra are emitted from the annular member 4B (in other words, the wavelength conversion section 4). Each of the multiple types of converted light L2 is incident on the optical fiber 3 .

For example, as shown in FIG. 19, when the emission surface 20a of the optical fiber 2 faces the side surface 453 of the wavelength conversion portion 450a, when the laser beam L1 is emitted from the emission surface 20a, the side surface of the wavelength conversion portion 450a 453 is irradiated with laser light L1, and wavelength conversion portion 450a emits converted light L2. The converted light L2 emitted from the outer surface 451 of the wavelength converting portion 450a enters the incident surface 30a of the optical fiber 3. As shown in FIG. Of the converted light L2 emitted by the wavelength converting portion 450a, the component emitted from the inner surface 452 of the wavelength converting portion 450a is reflected by the high reflectance member 18 and enters the incident surface 30a through the wavelength converting portion 450a.

When the annular member 4B rotates clockwise from the state of FIG. 19 as viewed from the annular side surface 413, the output surface 20a of the optical fiber 2 faces the side surface 453 of the wavelength conversion portion 450b. At this time, when the laser light L1 is emitted from the emission surface 20a, the side surface 453 of the wavelength converting portion 450b is irradiated with the laser light L1, and the wavelength converting portion 450a emits the converted light L2. The converted light L2 emitted from the outer surface 451 of the wavelength converting portion 450b enters the incident surface 30a of the optical fiber 3. As shown in FIG.

When the annular member 4B further rotates clockwise when viewed from the annular side surface 413 side, the output surface 20a of the optical fiber 2 comes to face the side surface 453 of the wavelength conversion portion 450c. At this time, when the laser light L1 is emitted from the emission surface 20a, the side surface 453 of the wavelength converting portion 450c is irradiated with the laser light L1, and the wavelength converting portion 450c emits the converted light L2. The converted light L2 emitted from the outer surface 451 of the wavelength converting portion 450c enters the incident surface 30a of the optical fiber 3. As shown in FIG.

When the annular member 4B further rotates clockwise when viewed from the annular side surface 413 side, the output surface 20a of the optical fiber 2 again faces the side surface 453 of the wavelength conversion portion 450a. At this time, when the laser light L1 is emitted from the emission surface 20a, the wavelength conversion portion 450a emits the converted light L2. The converted light L2 emitted from the outer surface 451 of the wavelength converting portion 450a is incident on the incident surface 30a of the optical fiber 3. As shown in FIG. Thereafter, the optical connection structure 1 functions similarly, and the wavelength spectrum (in other words, color temperature or emission color) of the converted light L2 incident on the incident surface 30a changes according to the rotation of the annular member 4B.

It should be noted that the high reflectance member 18 may be positioned on the side surface 454 of the wavelength converting portion 450 . Further, the high reflectance member 18 may be positioned on the peripheral area of the area irradiated with the laser light L1 on the side surface 453 of the wavelength converting portion 450 . Also, the high reflectance member 18 may be partially located on the outer surface 451 of the wavelength converting portion 450 . The reflectance of the converted light L2 on the surface of the high reflectance member 18 may be equal to or less than the reflectance of the converted light L2 on the surface 40B of the annular member 4B. Further, the reflectance of the laser beam L1 on the surface of the high reflectance member 18 may be equal to or less than the reflectance of the laser beam L1 on the surface 40B of the annular member 4B.

The optical connection structure 1 as described above can be used in various systems. A configuration example of a system including the optical connection structure 1 will be described below.

FIG. 20 is a schematic diagram showing an example of the configuration of a system 500A that includes the optical connection structure 1. As shown in FIG. A system 500A shown in FIG. 20 is, for example, an illumination system that radiates converted light L2 emitted by the wavelength conversion unit 4 of the optical connection structure 1 as illumination light L5. The illumination light L5 emitted by the system 500A may be used indoors or outdoors.

As shown in FIG. 20, the system 500A includes, for example, a laser device 510, a radiation section 520 that emits illumination light L5, and the optical fiber 2 described above. The radiation section 520 has components other than the optical fiber 2 in the optical connection structure 1 . The laser device 510 and the radiation section 520 are connected by the optical fiber 2 .

The laser device 510 can generate a laser beam L<b>1 and enter the optical fiber 2 . Laser device 510 comprises a light source 511 . The light source 511 can generate and output laser light L1. The light source 511 is, for example, a laser diode (LD). Laser diodes are also called semiconductor lasers. A laser beam L<b>1 output from the light source 511 is incident on the optical fiber 2 .

The output power of the laser light L1 of the laser device 510 is, for example, several W or more and 10 W or less. The output power of the laser beam L1 is not limited to this. When the laser device 510 includes a plurality of light sources 511, the output power of the laser light L1 of the laser device 510 may be 10 W or more, for example.

The optical fiber 2 can transmit the laser light L1 output from the light source 511 to the radiation section 520 . The optical fiber 2 transmits the laser light L1 output from the light source 511 and emits it from the emission surface 20a. One end of the optical fiber 2 is connected to the laser device 510 and the other end of the optical fiber 2 is connected to the radiation section 520 . The optical fiber 2 may be connectorized with the laser device 510 or otherwise connected. Also, the optical fiber 2 may be connector-connected to the radiating section 520, or may be connected by other methods.

The optical fiber 2 enters even inside the radiation section 520 . The exit surface 20a of the optical fiber 2 is positioned near the wavelength conversion section 4 in the radiation section 520, as shown in FIG. The laser light L1 emitted from the emission surface 20a of the optical fiber 2 is applied to the wavelength conversion section 4 in the emission section 520. As shown in FIG. The radiation section 520 is provided with, for example, a short optical fiber 3 . The converted light L2 emitted by the wavelength conversion section 4 inside the radiation section 520 enters the optical fiber 3 inside the radiation section 520 . The optical fiber 3 transmits the converted light L<b>2 incident on its incident surface 30 a within the radiation section 520 . The converted light L2 emitted from the optical fiber 3 is radiated to the outside of the radiating section 520 as illumination light L5. The radiation section 520 may include an optical system into which the converted light L2 emitted from the optical fiber 3 is incident. This optical system may include at least one of a lens, a diffuser and a reflector. When the radiation section 520 includes an optical system, the radiation section 520 may have a function of adjusting the light distribution of the illumination light L5.

As shown in FIG. 15, when the optical connection structure 1 includes the optical fiber 12, one end of the optical fiber 12 is connected to the laser device 510, and the other end of the optical fiber 12 is connected to the laser device 510 in the same manner as the optical fiber 2. is connected to the radiating portion 520 . A laser beam output from a light source 511 may enter the optical fiber 12 , or a laser beam emitted from a light source provided in a laser device 510 other than the light source 511 may enter the optical fiber 12 .

FIG. 21 is a schematic diagram showing an example of the configuration of another system 500B that includes the optical connection structure 1. As shown in FIG. The system 500B, like the system 500A, is an illumination system that emits the converted light L2 emitted by the wavelength converter 4 of the optical connection structure 1 as the illumination light L5.

As shown in FIG. 21, the system 500B includes, for example, a conversion device 550 that generates laser light L1 and converts the generated laser light L1 into light L2, a radiation unit 560 that emits illumination light L5, and the above-described and an optical fiber 3 . The conversion device 550 has components other than the optical fiber 3 in the optical connection structure 1 . The conversion device 550 and the radiation section 560 are connected by the optical fiber 3 . One end of the optical fiber 3 is connected to the conversion device 550 and the other end of the optical fiber 3 is connected to the radiation section 560 . The optical fiber 3 may be connectorized with the conversion device 550 or otherwise connected. Also, the optical fiber 3 may be connector-connected to the radiating section 560, or may be connected by other methods.

The conversion device 550 comprises the light source 511 described above. The conversion device 550 is provided with, for example, a short optical fiber 2 . A laser beam L1 output from the light source 511 enters the optical fiber 2 in the conversion device 550 . The optical fiber 2 transmits the incident laser light L1 within the conversion device 550, and emits the laser light L1 from its emission surface 20a. The laser light L1 emitted from the optical fiber 2 is applied to the wavelength conversion section 4 in the conversion device 550 .

The optical fiber 3 enters even inside the conversion device 550 . The incident surface 30a of the optical fiber 3 is positioned near the wavelength conversion section 4 in the conversion device 550, as shown in FIG. The converted light L2 emitted by the wavelength converter 4 is incident on the incident surface 30a of the optical fiber 3. As shown in FIG. The optical fiber 3 transmits the incident converted light L2 to the radiation section 560 .

The radiating section 560 radiates the converted light L2 emitted from the optical fiber 3 to the outside as the illumination light L5. The radiation section 560 may include an optical system into which the converted light L2 is incident. This optical system may include at least one of a lens, a diffuser and a reflector. When the radiation section 560 includes an optical system, the radiation section 560 may have a function of adjusting the light distribution of the illumination light L5.

Note that when the optical connection structure 1 includes the optical fiber 12 , the optical fiber 12 is provided in the conversion device 550 in the same manner as the optical fiber 2 . In this case, laser light output from the light source 511 in the conversion device 550 may be incident on the optical fiber 12 , or laser light emitted from a light source provided in the conversion device 550 separately from the light source 511 may be incident on the optical fiber 12 . may

FIG. 22 is a schematic diagram showing an example of the configuration of another system 500C that includes the optical connection structure 1. As shown in FIG. The system 500C, like the systems 500A and 500B, is an illumination system that emits the converted light L2 emitted by the wavelength converter 4 of the optical connection structure 1 as the illumination light L5.

As shown in FIG. 22, system 500C includes, for example, laser device 510 and emitter 560, repeater 580, and optical fibers 2 and 3 described above. The repeater 580 has a configuration other than the optical fibers 2 and 3 in the optical connection structure 1 .

The laser device 510 and the repeater 580 are connected by the optical fiber 2 . One end of the optical fiber 2 is connected to the laser device 510 and the other end of the optical fiber 2 is connected to the repeater 580 . The optical fiber 2 may be connectorized with the laser device 510 or otherwise connected. Also, the optical fiber 2 may be connector-connected to the repeater 580, or may be connected by other methods.

The repeater 580 and the radiation section 560 are connected by the optical fiber 3 . One end of the optical fiber 3 is connected to the repeater 580 and the other end of the optical fiber 3 is connected to the radiation section 560 . The optical fiber 3 may be connectorized with the repeater 580 or otherwise connected. Also, the optical fiber 3 may be connector-connected to the radiating section 560, or may be connected by other methods.

The optical fiber 2 transmits the laser light L1 output from the light source 511 of the laser device 510 to the repeater 580 . The optical fiber 2 enters even inside the repeater 580 . The output surface 20a of the optical fiber 2 is positioned near the wavelength converting section 4 in the repeater 580, as shown in FIG. The laser light L1 emitted from the emission surface 20a of the optical fiber 2 is applied to the wavelength conversion section 4 in the repeater 580. As shown in FIG.

The optical fiber 3 enters even inside the repeater 580 . The incident surface 30a of the optical fiber 3 is positioned near the wavelength converting section 4 in the repeater 580, as shown in FIG. The converted light L2 emitted by the wavelength converter 4 is incident on the incident surface 30a of the optical fiber 3. As shown in FIG. The optical fiber 3 transmits the incident converted light L2 to the radiation section 560 . The radiating section 560 radiates the converted light L2 emitted from the optical fiber 3 to the outside as the illumination light L5.

When the optical connection structure 1 includes the optical fiber 12, one end of the optical fiber 12 is connected to the laser device 510, and the other end of the optical fiber 12 is connected to the repeater 580, similarly to the optical fiber 2. . In this case, the laser light output by the light source 511 may be incident on the optical fiber 12 , or the laser light emitted by a light source provided in the laser device 510 separately from the light source 511 may be incident on the optical fiber 12 .

A system including the optical connection structure 1 is not limited to the above example. For example, the optical connection structure 1 may be used in an endoscope system. In this case, the converted light L2 emitted by the wavelength conversion unit 4 is used as illumination light for illuminating the inside of the body such as the gastrointestinal tract. Also, the optical connection structure 1 may be used in a system other than the lighting system that emits the illumination light L5. For example, the optical connection structure 1 may be used in a projector. In this case, the converted light L2 emitted by the wavelength converter 4 may be used as the light of the light source of the projector.

As described above, the optical connection structure and the system including the same have been described in detail, but the above description is illustrative in all aspects, and the present disclosure is not limited thereto. Also, the various examples described above can be applied in combination as long as they do not contradict each other. And it is understood that countless examples not illustrated can be envisioned without departing from the scope of this disclosure.

1 optical connection structure 2, 3, 12 optical fiber (first optical fiber, second optical fiber, third optical fiber)
4, 4A wavelength converter 4B annular member 5, 5A substrate 6 heat dissipation member 7, 18 high reflectance member 13 metal film 20, 30 core 20a exit surface 30a entrance surface 140, 150 irradiated area
L1, L3 laser light L2 converted light L2a first component L2b second component

Claims (19)

a first optical fiber that transmits the first laser light;
a wavelength conversion unit that is irradiated with the first laser light and emits a first light having a wavelength spectrum different from the wavelength spectrum of the first laser light in response to the irradiation of the first laser light;
a second optical fiber into which the first light is incident and which transmits the incident first light;
A first member that reflects the first light,
The surface of the wavelength conversion part is
a first region directly irradiated with the first laser beam from the first optical fiber;
a second region located on the first member;
Having a third region not facing the first region,
the second optical fiber has an incident surface facing the third region;
The first light is
a first component, which is a component that is directly emitted from the wavelength conversion unit and that is emitted from the third region and is incident on the incident surface;
and a second component that is emitted from the second region, reflected by the first member, and incident on the incident surface. The optical connection structure according to claim 1,
The optical connection structure, wherein the incident surface of the second optical fiber is located on the side opposite to the first member with respect to the wavelength conversion section. The optical connection structure according to claim 1 or claim 2,
The optical connection structure, wherein the second region has a first opposing region facing the third region. The optical connection structure according to any one of claims 1 to 3,
The optical connection structure, wherein the first member has a portion that reflects the first laser beam. The optical connection structure according to claim 4,
The optical connection structure, wherein the second region has a second opposing region that faces the first region. The optical connection structure according to claim 5,
The optical connection structure, wherein the second region has a peripheral region located around the first region. The optical connection structure according to any one of claims 1 to 6,
further comprising a second member that reflects the first light,
The optical connection structure, wherein the surface of the wavelength converting portion has a fourth region located on the second member. The optical connection structure according to any one of claims 1 to 7,
The optical connection structure, wherein at least one of the exit surface of the first optical fiber and the entrance surface of the second optical fiber is in contact with the surface of the wavelength converting section. The optical connection structure according to any one of claims 1 to 8,
The optical connection structure, wherein the third region is concave. The optical connection structure according to any one of claims 1 to 9,
The optical connection structure further comprising an optical member that reduces the spread of the first light emitted from the third region and enters the incident surface. The optical connection structure according to any one of claims 1 to 10,
The wavelength conversion unit includes a plurality of phosphors that emit fluorescence constituting the first light in response to irradiation with the first laser light,
In the optical connection structure, in the wavelength conversion section, the concentration of the phosphor increases as the distance from the first region increases. The optical connection structure according to any one of claims 1 to 11,
further comprising a third optical fiber that transmits the second laser light,
The wavelength conversion unit emits the first light in response to irradiation with the second laser light,
The optical connection structure, wherein the third optical fiber irradiates the surface of the wavelength converting portion with the second laser light from a side opposite to the first region. The optical connection structure according to any one of claims 1 to 12,
The wavelength conversion part is an annular member,
The annular member includes a plurality of portions arranged in the circumferential direction of the annular member,
each of the plurality of portions emits the first light in response to irradiation with the first laser light;
The optical connection structure, wherein wavelength spectra of the first light emitted by the plurality of portions are different from each other. The optical connection structure according to any one of claims 1 to 13,
The surface of the first member has a fifth region irradiated with the second component,
The optical connection structure, wherein the reflectance of light in the fifth region of the first member is higher than the reflectance of light in the second region of the wavelength conversion section. The optical connection structure according to any one of claims 1 to 14,
The optical connection structure, wherein the thermal conductivity of the first member is higher than the thermal conductivity of the wavelength conversion section. The optical connection structure according to claim 15,
Further comprising a heat dissipation member to which the first member is fixed,
The optical connection structure, wherein the thermal conductivity of the heat dissipation member is higher than the thermal conductivity of the wavelength conversion section. a first optical fiber that transmits the first laser light;
a wavelength conversion unit that is irradiated with the first laser light and emits a first light having a wavelength spectrum different from the wavelength spectrum of the first laser light in response to the irradiation of the first laser light;
a second optical fiber into which the first light is incident and which transmits the incident first light;
A first member that reflects the first light,
The surface of the wavelength conversion part is
a first region directly irradiated with the first laser beam from the first optical fiber;
a second region located on the first member;
the second optical fiber has an incident surface facing a third region other than the first region and the second region on the surface of the wavelength conversion part;
The incident surface is non-parallel to the exit surface of the first optical fiber,
The first light is
a first component, which is a component that is directly emitted from the wavelength conversion unit and that is emitted from the wavelength conversion unit and is incident on the incident surface;
and a second component that is emitted from the second region, reflected by the first member, and incident on the incident surface. a first optical fiber that transmits the first laser light;
a wavelength conversion unit that is irradiated with the first laser light and emits a first light having a wavelength spectrum different from the wavelength spectrum of the first laser light in response to the irradiation of the first laser light;
a second optical fiber into which the first light is incident and which transmits the incident first light;
A first member that reflects the first light,
The surface of the wavelength conversion part is
a first region directly irradiated with the first laser beam from the first optical fiber;
a second region located on the first member;
the second optical fiber has an incident surface facing a third region other than the first region and the second region on the surface of the wavelength conversion part;
the incident surface is not located on the opposite side of the emission surface of the first optical fiber with respect to the wavelength converting section,
The first light is
a first component, which is a component that is directly emitted from the wavelength conversion unit and that is emitted from the wavelength conversion unit and is incident on the incident surface;
and a second component that is emitted from the second region, reflected by the first member, and incident on the incident surface. An illumination system comprising the optical connection structure according to any one of claims 1 to 18, wherein the first light emitted by the wavelength converting section of the optical connection structure is emitted as illumination light.

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