JP4878259B2 - Optical components - Google Patents

Description

  The present invention relates to an optical component including an optical fiber.

  As an optical amplifier or a laser oscillator, an amplification optical fiber to which a rare earth element such as Er element or Yb element is added is used, and excitation light is supplied to the amplification optical fiber to excite the rare earth element. A laser that oscillates is known. Further, as optical components for outputting light in such an optical amplifier or laser oscillator, those disclosed in Patent Documents 1 and 2 are known.

  The optical component disclosed in Patent Document 1 is intended for light input according to the description of the document, but can also be used for light output. In this optical component, a glass rod having the same outer diameter as that of an optical fiber is fusion-bonded to the end face of the optical fiber.

  In the optical component disclosed in Patent Document 2, a glass rod having the same outer diameter as that of an optical fiber is fusion-bonded to the end face of the optical fiber, and a coating material having a higher refractive index than the glass rod is used for the glass rod. It is provided around. Examples of the covering material include ultraviolet curable resins and thermosetting resins.

If the optical components disclosed in Patent Documents 1 and 2 are used as optical components for outputting light in an optical amplifier or a laser oscillator, high-power light after being amplified in the optical fiber for amplification is optical After being guided by the core of the fiber, it is output to the outside through a glass rod. Since the light incident on the glass rod from the core of the optical fiber is diverged, the beam diameter of the light when being output from the glass rod to the outside is enlarged. Therefore, damage at the light output end is suppressed, which is advantageous in outputting high-power light.
Japanese Patent No. 3224106 JP 2005-303166 A

  However, the optical parts disclosed in Patent Documents 1 and 2 are output from the glass rod to the outside because the glass rod having the same outer diameter as the optical fiber is fusion-bonded to the end face of the optical fiber. The beam diameter of the light at this time is limited by the outer diameter of the glass rod (that is, the outer diameter of the optical fiber). That is, the power of light that can be output without damage at the light output end is limited by the diameter of the optical fiber.

  If a glass rod having an outer diameter larger than the outer diameter of the optical fiber is fused and connected to the end face of the optical fiber to form an optical component, the beam diameter of light when output from the glass rod to the outside is It is not limited by the outer diameter of the optical fiber. In this case, the larger the outer diameter of the glass rod, the greater the power of light that can be output without damage at the light output end. However, the greater the difference between the outer diameter of the optical fiber and the outer diameter of the glass rod, the more difficult the fusion splicing of the optical fiber and the glass rod, and the manufacture of such an optical component is not easy.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide an optical component that can increase the power of light that can be output without damage at the light output end and can be easily manufactured. And

An optical component according to the present invention includes: (1) an optical fiber having a core and a clad provided around the core and having a lower refractive index than the core; and (2) fused between end faces of the optical fiber. And (3) a glass tube having a through hole between the first end and the second end, and an optical fiber and a glass rod inserted into the through hole. And Furthermore, both the glass rod and the glass tube have a refractive index substantially equal to the refractive index of the core of the optical fiber or a refractive index substantially equal to the refractive index of the cladding of the optical fiber , At the position of the first end, the end surfaces of the glass rod and the glass tube are on the same plane, and in the first range along the longitudinal direction including the first end of the glass tube, the outer surface of the glass rod and the inside of the glass tube The wall surfaces are fusion-bonded to each other, and a gap is provided between the optical fiber and the glass tube in a second range along the longitudinal direction including the second end of the glass tube .

  In the first range, it is preferable that the outer peripheral surfaces of the optical fiber and the glass rod and the inner wall surface of the glass tube are fusion-bonded to each other. The outer diameter of the glass rod is preferably substantially equal to the outer diameter of the clad of the optical fiber. However, if the outer diameter of the clad of the optical fiber is not more than twice the outer diameter, the fusion bonding with the optical fiber is possible. The glass rod is preferably substantially cylindrical, but may be polygonal.

  This optical component is used in, for example, an optical amplifier, a MOPA type laser device, a high average output laser, or the like. In that case, the optical fiber included in the optical component may be connected to the amplifying optical fiber, or may itself be an amplifying optical fiber. The light amplified in the optical fiber for amplification is guided by the core of the optical fiber included in the optical component, is incident on the glass rod, and is emitted from the end face of the glass rod. The light can also be emitted from the end face of the glass tube. Therefore, the beam diameter of light emitted from the end surfaces of the glass rod and the glass tube is not limited by the outer diameter of the glass rod (that is, the outer diameter of the optical fiber), and the glass tube at the first end. It can be expanded to the outer diameter. As a result, the power of light that can be output without damage at the light output end can be increased. Further, since the outer diameters of the glass rod and the optical fiber are equal to each other, both of them can be easily fusion-connected at the end faces.

  Ideally, the refractive indexes of the glass rod and the glass tube are preferably substantially equal to the refractive index of the core of the optical fiber. In this case, no light reflection or refractive index occurs at the boundary between the core of the optical fiber and the glass rod or at the boundary between the glass rod and the glass tube. However, in practice, the refractive indexes of the glass rod and the glass tube may be substantially equal to the refractive index of the clad of the optical fiber. In this case, it is easy to obtain each of the glass rod and the glass tube.

In the optical component according to the present invention, it is preferable that the resin is filled between the optical fiber and the glass tube in the second range.

  In the optical component according to the present invention, it is preferable that the end surfaces of the glass rod and the glass tube are inclined with respect to the surface perpendicular to the axis of the glass rod at the position of the first end of the glass tube. It is preferable that a reflection reducing film is formed on each end face of the glass rod and the glass tube at the position of the first end of the glass tube. Further, it is preferable that a reflection reducing film is formed on the end surface of the glass tube at the position of the second end of the glass tube.

  An optical amplifier according to the present invention includes (1) the optical component according to the present invention described above and a pumping light source unit that outputs pumping light, and (2) an optical fiber included in the optical component or connected thereto. The other optical fiber is an amplifying optical fiber, (3) the pumping light output from the pumping light source section is introduced into the amplifying optical fiber, and (4) the light to be amplified is amplified by the amplifying optical fiber. The amplified light is propagated and amplified in an amplification optical fiber, and the amplified light is output through an optical fiber and a glass rod included in an optical component. The optical amplifier according to the present invention preferably further includes a photodetector for detecting light emitted from the second end of the glass tube included in the optical component, and the first of the glass tubes included in the optical component. It is also preferable to further include a light source that outputs light to be incident on the two ends.

  The optical component according to the present invention is used in an optical amplifier or the like, can increase the power of light that can be output without being damaged at the light output end, and can be easily manufactured. It is also possible to reduce the return light to the optical fiber.

  The best mode for carrying out the present invention will be described below in detail with reference to the accompanying drawings. In the description of the drawings, the same or equivalent elements are denoted by the same reference numerals, and redundant description is omitted.

  FIG. 1 is a configuration diagram of a MOPA light source device 1 including an optical amplifier 10 according to the present embodiment. A MOPA (Master Oscillator Power Amplifier) light source device 1 shown in this figure includes an optical amplifier 10, a seed light source 20, and an optical isolator 30, and the seed light output from the seed light source 20 and passed through the optical isolator 30 is supplied to the optical amplifier 10. It amplifies light and outputs the light amplified light.

The optical amplifier 10 includes six pumping light sources 11 _{1 to} 11 ₆ , six optical fibers 12 _{1 to} 12 ₆ , an optical fiber 13, an optical combiner 14, an amplification optical fiber 15, and an optical component 16. One end of the optical fiber 12 _n is connected to the light emitting end of the excitation light source 11 _n , and the other end of the optical fiber 12 _n is connected to the light incident end of the optical combiner 14. One end of the optical fiber 13 is connected to the light emitting end of the optical isolator 30, and the other end of the optical fiber 13 is connected to the light incident end of the optical combiner 14. One end of the amplification optical fiber 15 is connected to the light emitting end of the optical combiner 14, and the other end of the amplification optical fiber 15 is connected to the light incident end of the optical component 16. The light emitting end of the optical component 16 is the light emitting end of the optical amplifier 10.

  The amplification optical fiber 15 is an optical fiber made of quartz glass to which a rare earth element such as Er element or Yb element is added, and is supplied with excitation light having a wavelength capable of exciting the added rare earth element. It is possible to optically amplify light to be amplified having a wavelength included in a wavelength band having gain. The amplification optical fiber 15 has a so-called double clad structure, and has a core, an inner clad and an outer clad, and can condense and amplify the light to be amplified in the core, It can be guided by being confined in the inner cladding.

The six pumping light sources 11 _{1 to} 11 ₆ output pumping light having a wavelength capable of pumping the rare earth element added to the amplification optical fiber 15, and preferably include a laser diode. The optical fiber 12 _n inputs the pumping light output from the pumping light source 11 _n to one end, and guides the pumping light toward the optical combiner 14. The optical fiber 13 inputs the seed light output from the seed light source 20 and passed through the optical isolator 30 to one end, and guides the seed light toward the optical combiner 14.

The optical combiner 14 inputs pumping light that is guided by the _six optical fibers 12 _{1 to} 12 ₆ and inputs seed light that is guided by the optical fiber 13, and these pumping light. The seed light is output to the amplification optical fiber 15. The amplification optical fiber 15 receives pumping light and seed light (amplified light), is excited by the pumping light, optically amplifies the seed light, and outputs the light amplified light.

  The optical component 16 inputs light output after being amplified in the amplification optical fiber 15 and uses the light as an output of the optical amplifier 10.

In the MOPA light source device 1, the seed light output from the seed light source 20 is input to the optical amplifier 10 via the optical isolator 30. In the optical amplifier 10, the pumping light output from the pumping light source 11 _n is propagated from the optical fiber 12 _n and is input to the amplifying optical fiber 15 through the optical combiner 14. The seed light output from the optical isolator 30 and input to the optical amplifier 10 is propagated by the optical fiber 13 and input to the amplification optical fiber 15 through the optical combiner 14. Then, the seed light is optically amplified in the amplification optical fiber 15, and the light after the optical amplification is output to the outside through the optical component 16.

  FIG. 2 is a longitudinal sectional view of the optical component 16 according to the present embodiment. The optical component 16 shown in this figure includes a glass tube 61, an optical fiber 62, a glass rod 63, a resin 64, a resin 65, a resin 66, a protective tube 67, and a glass 68.

  One end of the optical fiber 62 is disposed in the protective tube 67, and the coating layer is removed within a certain range from the one end to expose the glass. At one end of the protective tube 67, the optical fiber 62 is left in a state where the coating layer remains, and a resin 65 is filled between the optical fiber 62 and the protective tube 67. A glass window 68 made of, for example, quartz glass is attached to the other end of the protective tube 67.

  The optical fiber 62 includes a core 62a and a clad 62b that is provided around the core 62a and has a lower refractive index than the core 62a. One end of the optical fiber 62 is fused and connected at one end and the end surfaces of the glass rod 63 in the internal space of the protective tube 67. The glass rod 62 has an outer diameter substantially equal to the outer diameter of the optical fiber 62 and has a refractive index substantially equal to the refractive index of the clad 62 b of the optical fiber 62.

  The glass tube 61 has a refractive index substantially equal to the refractive index of the clad 62b of the optical fiber 62, and has a through hole. The optical fiber 62 and the glass rod 63 are inserted into the through hole. At the position of one end of the glass tube 61, the end surfaces of the glass rod 63 and the glass tube 61 are on the same plane. In a predetermined range along the longitudinal direction including one end of the glass tube 61, the inner wall surface of the glass tube 61 is fusion-bonded to the outer peripheral surface of the glass rod 63, and more preferably, the outer peripheral surface of the optical fiber 62 is also connected. It is fusion spliced.

  A resin 64 is inserted between the optical fiber 62 and the glass tube 61. The protective tube 67 and the glass tube 61 are fixed to each other by a resin 66, and a hole for injecting the resin is provided in the protective tube 67. Although the internal space of the protective tube 61 may be filled with resin, even in that case, it is preferable that no resin exists between the glass rod 63 and the end surfaces of the glass tube 61 and the glass window 68. The other end of the optical fiber 62 is connected to the amplification optical fiber 15. The optical fiber 62 and the amplification optical fiber 15 may be a series of optical fibers.

  By using the optical component 16 configured in this manner in the optical amplifier 10, the light amplified in the amplification optical fiber 15 passes through the optical fiber 62, the glass rod 63, and the glass window 68 included in the optical component 16. After being output. Further, in this optical component 16, the light incident on the glass rod 63 from the core 62 a of the optical fiber 62 can be emitted not only from the end face of the glass rod 63 but also from the end face of the glass tube 61. .

  Therefore, the beam diameter of the light emitted from the end surfaces of the glass rod 63 and the glass tube 61 is not limited by the outer diameter of the glass rod 63 (that is, the outer diameter of the optical fiber 62). It is possible to increase the power of light that can be output without damage at the light output end. Further, since the outer diameters of the glass rod 63 and the optical fiber 62 are equal to each other, both can be easily fusion-connected at the end faces.

  In this optical component 16, the coating removal portion of the optical fiber 62 is put in the protective tube 67 and sealed with the resin 65, so that it is protected from external force and moisture. The protective tube 67 is preferably made of a material having a thermal expansion coefficient substantially equal to that of the optical fiber 62, and is preferably made of the same quartz glass as the material of the optical fiber 62.

  In addition, the coating removal portion of the optical fiber 62 is also protected from vibration and moisture by filling the protective tube 67 with the resin 66. The resin 66 preferably has a refractive index lower than that of the clad 62b of the optical fiber 62, and is preferably a resin that is cured by ultraviolet irradiation. In this case, the protective tube 67 is preferably made of transparent glass. That is, after injecting resin into the internal space of the protective tube 67 through the hole of the protective tube 67, ultraviolet light from the outside passes through the protective tube 67 and is irradiated to the resin, whereby the resin can be cured. Instead of the glass window 68, a collimating lens may be attached and output as substantially parallel light. Moreover, it is also possible to use as an optical connector part without attaching a glass window or a lens.

  Next, the principal part of the optical component 16 according to the present embodiment will be described in more detail including modifications. In the description of the optical components 16A and 16B in the following embodiments, a portion including those corresponding to the glass tube 61, the optical fiber 62, the glass rod 63, and the resin 64 in FIG. Descriptions of those corresponding to the resins 65 and 66, the protective tube 67, and the glass window 68 are omitted.

  FIG. 3 is a longitudinal sectional view showing an optical component 16A as a first configuration example of the optical component 16 according to the present embodiment. As shown in this figure, the optical component 16A includes a glass tube 61, an optical fiber 62, a glass rod 63, and a resin 64.

The optical fiber 62 includes a core 62a and a clad 63b that is provided around the core 62a and has a lower refractive index than the core 62a. The optical fiber 62a is made of quartz glass, and GeO ₂ is added to the core 62a, so that the core 62a has a higher refractive index than the clad 62b. Further, the coating of the optical fiber 62 is removed in a certain range including the end face fused and connected to the glass rod 63. Specifically, the outer diameter of the core 62a is about 25 μm, and the outer diameter of the clad 62b is about 250 μm.

  The glass rod 63 has a cylindrical shape made of quartz glass, has an outer diameter equal to the outer diameter of the clad 62 b of the optical fiber 62, and has a refractive index substantially equal to the refractive index of the clad 62 b of the optical fiber 62. . The glass rod 63 is fused and connected to the optical fiber 62 at the end faces. Specifically, the outer diameter of the glass rod 63 is about 250 μm.

  The glass tube 61 is made of quartz glass, has a refractive index substantially equal to the refractive index of the clad 62b of the optical fiber 62, has a through hole between the first end 61a and the second end 61b, and the through hole. An optical fiber 62 and a glass rod 63 are inserted into the optical fiber 62. At the position of the first end 61a of the glass tube 61, the end surfaces of the glass rod 63 and the glass tube 61 are on the same plane. In the first range 61c along the longitudinal direction including the first end 61a of the glass tube 61, the inner wall surface of the glass tube 61 is fusion-bonded to the outer peripheral surface of the glass rod 63, and more preferably an optical fiber. The outer peripheral surface 62 is also fusion-connected. Specifically, the glass tube 61 has an outer diameter of about 600 μm, an inner diameter of about 500 μm, and a length of about 8 mm at the second end 61b.

  In the second range 61 d along the longitudinal direction including the second end 61 b of the glass tube 61, a gap is provided between the optical fiber 62 and the glass tube 61. The gap may be a vacuum, but may be provided with another medium. For example, the resin 64 is preferably a gas such as an inert gas or air. Or a liquid such as

  It is preferable that a reflection reducing film is formed on each end face of the glass rod 63 and the glass tube 61 at the position of the first end 61 a of the glass tube 61. Further, it is preferable that a reflection reducing film is formed on the end surface of the glass tube 61 at the position of the second end 61 b of the glass tube 61. This reflection reducing film is made of a dielectric multilayer film and reduces the reflectance at the wavelength of light to be emitted. For example, when a Yb-doped fiber is used as a laser fiber, it is preferable that the reflection reducing film reduce the reflectance at least in the wavelength range of 1.0 μm to 1.1 μm.

  In the optical component 16A configured as described above, the light that is guided by the core 62a of the optical fiber 62 and enters the glass rod 63 is not only emitted from the end face of the glass rod 63, but also partially glass. The light can also be emitted from the end face of the tube 61. Therefore, the beam diameter of the light emitted from the end surfaces of the glass rod 63 and the glass tube 61 is not limited by the outer diameter of the glass rod 63 (that is, the outer diameter of the optical fiber 62). It can be expanded to the outer diameter of the glass tube 61 at the end 61a. As a result, the power of light that can be output without damage at the light output end can be increased. Further, since the outer diameters of the glass rod 63 and the optical fiber 62 are equal to each other, both can be easily fusion-connected at the end faces.

  Further, by using the optical component 16A in the optical amplifier 10, the following effects can be obtained. That is, a part of the light is reflected at the emission end surfaces of the glass rod 63 and the glass tube 61, but a part of the reflected light is radiated to the outside from the end surface on the second end 61b side of the glass tube 61. The power of light returning to the amplification optical fiber 15 via the optical fiber 62 is reduced. In general, when the power of the return light to the amplification optical fiber is large, the threshold for parasitic oscillation is lowered, and the upper limit of the amplification factor is lowered. However, in this embodiment, since the optical component 16A is used in the optical amplifier 10, the power of the return light to the amplification optical fiber 15 is reduced. Lowering of the upper limit can be suppressed. In order to effectively exhibit such an effect, it is preferable that a reflection reducing film is formed on the end surface of the glass tube 61 at the position of the second end 61 b of the glass tube 61. It should be noted that when the glass tube 61 is fused to the optical fiber 62, the portion provided with the reflection reducing film has no fear of being adversely affected by heating because of the low thermal conductivity of the glass.

  Further, in the second range 61 d along the longitudinal direction including the second end 61 b of the glass tube 61, mechanical strength is obtained by filling the resin 64 between the optical fiber 62 and the glass tube 61. In addition, the following effects can be obtained. That is, when the refractive index of the resin 64 is equal to or higher than the refractive index of the glass rod 63, a part of the reflected light generated at the first end 61a also enters the resin 64 and the resin 64 at the position of the second end 61b. Is emitted from the outside. Therefore, since the power of the return light to the amplification optical fiber 15 is further reduced, the decrease in the parasitic oscillation threshold can be further suppressed, and the decrease in the upper limit of the amplification factor can be further suppressed.

  In order to effectively exhibit the effect of reducing the return light power by the resin 64, it is preferable that the resin 64 has a small absorption at the output light wavelength. However, this is effective when the average output power of the output light is relatively low, but when the average output power of the output light is high, there is a risk that the resin 64 will burn out because the light passes through the resin 64. . Therefore, when the average output power of the output light is high, it is desirable that the resin 64 having a lower refractive index than that of the glass rod 63 is filled.

  FIG. 4 is a diagram illustrating a manufacturing process of the optical component 16A. In this figure, the manufacturing process for the glass tube 61, the optical fiber 62, and the glass rod 63 is shown. First, as shown in FIG. 5A, an optical fiber 62 having a core 62a, a clad 62b, and a coating layer 62c is prepared, and is coated in a certain range (for example, a range of about 3 cm) from one end of the optical fiber 62. Layer 62b is removed to expose the glass.

  The exposed glass end face of the optical fiber 62 is finished to a clean end face that can be fused by a fiber cleaver so as to be perpendicular to the axial direction. Further, the end surface of the glass rod 63A having the same diameter (for example, about 3 cm in length) is also finished to a clean end surface that can be fused by the fiber cleaver so as to be perpendicular to the axial direction. The end faces of the optical fiber 62 and the glass rod 63A are fusion-connected to each other.

  Subsequently, as shown in FIG. 5B, the coating removal portion of the optical fiber 62 and the glass rod 63A, whose end faces are fusion-connected to each other, are inserted into the glass tube 61A. The glass tube 61A has an outer diameter and an inner diameter that are substantially uniform along the axial direction, and a reflection reducing film is formed on the end surface on the second end 61b side.

  Subsequently, as shown in FIG. 5C, the central region of the glass tube 61A is heated, and the heated central region contracts due to surface tension. For the heating at this time, for example, laser light having a wavelength of 10.6 μm output from a carbon dioxide laser light source, discharge, a micro burner, or the like is used. The glass tube 61B thus contracted is connected to the outer peripheral surfaces of the glass rod 63A and the optical fiber 62 in a part of the contracted range.

  And it is cut | disconnected in any position of the shrinkage | contraction range of the glass tube 61B, as the figure (d) shows. Further, the cut surface is polished to form a reflection reducing film on the polished surface, and the resin 64 is filled between the glass tube 61 and the optical fiber 62, whereby the optical component 16A is manufactured. In this cutting, the laser beam output from the carbon dioxide laser light source was collected and used. Further, the distance between the fusion position of the glass rod 63 and the cutting position can be based on the distance from the coated end of the optical fiber 62.

  Instead of fusing the glass rod 63 to the tip of the optical fiber 62, a multimode optical fiber having a core-clad structure is fused to the tip of the optical fiber 62, and the clad of the multimode optical fiber is etched. After the removal, the glass tube 61 may be fused.

  FIG. 5 is a longitudinal sectional view showing an optical component 16B as a second configuration example of the optical component 16 according to the present embodiment. As shown in this figure, the optical component 16B includes a glass tube 61, an optical fiber 62, a glass rod 63, and a resin 64.

  Compared with the optical component 16A of the first configuration example shown in FIG. 3 before, the optical component 16B of the second configuration example shown in FIG. 5 has a glass rod 63 on the first end 61a side of the glass tube 61 and The difference is that the end face of each glass tube 61 is inclined. That is, at the position of the first end 61 a of the glass tube 61, the end surfaces of the glass rod 63 and the glass tube 61 are inclined with respect to a plane perpendicular to the axis of the glass rod 63. The inclination angle is, for example, 8 degrees.

  In order to manufacture such an optical component 16B, the cut surface may be inclined during the cutting step (FIG. 4D) among the manufacturing steps shown in FIG. Since the light exit end face is inclined in this manner, the power of the return light to the amplification optical fiber 15 is further reduced, so that the reduction of the threshold of the parasitic oscillation is further suppressed, and the upper limit of the amplification factor is reduced. It can be further suppressed.

  Next, a modification of the optical amplifier according to the present embodiment will be described with reference to FIGS. 6 and 7. FIG. 6 is a configuration diagram of a MOPA light source device 1A including an optical amplifier 10A according to a modification. Compared with the configuration shown in FIG. 1, the MOPA light source device 1 </ b> A shown in FIG. 6 is different in that an optical amplifier 10 </ b> A is provided instead of the optical amplifier 10. The optical amplifier 10 </ b> A further includes an optical fiber 17 and a photodetector 18 in addition to the configuration of the optical amplifier 10. One end of the optical fiber 17 is connected to the second end of the glass tube 61 included in the optical component 16, and the other end of the optical fiber 17 is connected to the photodetector 18. The light detector 18 detects light radiated from the second end of the glass tube 61 and reached through the optical fiber 17. Thereby, with a simple configuration, the fluorescence intensity and laser output when the amplification optical fiber 15 is excited can be measured by the photodetector 18, and parasitic oscillation can be detected. Moreover, it is also possible to measure the reflected light from the object irradiated with the laser light by the photodetector 18. The optical fiber 17 may be fusion-bonded, bonded, or butt-connected to the second end of the glass tube 61, or the tip of the optical fiber 17 may be embedded in the resin in the glass tube 61. The measured or detected signal can be used according to the purpose, such as stabilizing the operation of the optical amplifier 10A, preventing damage, or grasping the state of the apparatus.

  FIG. 7 is a configuration diagram of a MOPA light source device 1B including an optical amplifier 10B according to another modification. Compared with the configuration shown in FIG. 1, the MOPA light source device 1 </ b> B shown in FIG. 7 is different in that an optical amplifier 10 </ b> B is provided instead of the optical amplifier 10. The optical amplifier 10B further includes an optical fiber 17 and a light source 19 in addition to the configuration of the optical amplifier 10. One end of the optical fiber 17 is connected to the second end of the glass tube 61 included in the optical component 16, and the other end of the optical fiber 17 is connected to the light source 19. The light source 19 outputs light to be incident on the second end of the glass tube included in the optical component. The light output from the light source 19 is incident on the second end of the glass tube 61 through the optical fiber 17, is emitted to the outside through the optical component 16, and can illuminate the workpiece. Thereby, it becomes easy to observe a processing state, for example in the case of laser processing. Since the illumination light is emitted so as to surround the laser light emitted from the optical component, the laser light collimating lens and the processing condensing lens can be shared. The light source 19 may be supplied to the second end of the glass tube 61 via the optical fiber 17, or the illumination light may be directly supplied by placing a light source near the second end of the glass tube 61. The optical fiber 17 may be fusion-bonded, bonded, or butt-connected to the second end of the glass tube 61, or the tip of the optical fiber 17 may be embedded in the resin in the glass tube 61.

1 is a configuration diagram of a MOPA light source device 1 including an optical amplifier 10 according to the present embodiment. It is a longitudinal cross-sectional view of the optical component 16 which concerns on this embodiment. It is a longitudinal cross-sectional view which shows 16 A of optical components as a 1st structural example of the optical component 16 which concerns on this embodiment. It is a figure explaining the manufacturing process of 16 A of optical components. It is a longitudinal cross-sectional view which shows the optical component 16B as a 2nd structural example of the optical component 16 which concerns on this embodiment. It is a block diagram of MOPA light source device 1A including optical amplifier 10A which concerns on a modification. It is a block diagram of the MOPA light source device 1B including the optical amplifier 10B which concerns on another modification.

Explanation of symbols

1 ... MOPA light source device, 10 ... optical amplifier, ₁₁ 1 to 11 6 _... pumping light source, ₁₂ 1 to 12 6 _... optical fiber, 13 ... optical fiber, 14 ... optical combiner, 15 ... optical fiber amplifier, 16, 16A, 16B: Optical component, 20: Seed light source, 30 ... Optical isolator, 61 ... Glass tube, 62 ... Optical fiber, 63 ... Glass rod, 64-66 ... Resin, 67 ... Protective tube, 68 ... Glass window.

Claims (9)

An optical fiber having a core and a cladding provided around the core and having a lower refractive index than the core;
A glass rod which is fusion spliced with end faces to the front Symbol optical fiber,
A glass tube having a through hole between the first end and the second end, and the optical fiber and the glass rod inserted into the through hole;
With
Both the glass rod and the glass tube have a refractive index substantially equal to the refractive index of the core of the optical fiber, or have a refractive index substantially equal to the refractive index of the cladding of the optical fiber,
At the position of the first end of the glass tube, the end surfaces of the glass rod and the glass tube are on the same plane,
In the first range along the longitudinal direction including the first end of the glass tube, the outer peripheral surface of the glass rod and the inner wall surface of the glass tube are fusion-bonded to each other ,
In a second range along the longitudinal direction including the second end of the glass tube, a gap is provided between the optical fiber and the glass tube.
An optical component characterized by that.   2. The optical component according to claim 1, wherein in the first range, an outer peripheral surface of each of the optical fiber and the glass rod and an inner wall surface of the glass tube are fusion-bonded to each other. Wherein in the second range, an optical component according to claim 1, wherein the resin between the optical fiber and the glass tube is characterized in that, being filled.   2. The optical device according to claim 1, wherein, at the position of the first end of the glass tube, an end surface of each of the glass rod and the glass tube is inclined with respect to a surface perpendicular to the axis of the glass rod. parts.   The optical component according to claim 1, wherein a reflection reducing film is formed on each end face of the glass rod and the glass tube at a position of the first end of the glass tube.   The optical component according to claim 1, wherein a reflection reducing film is formed on an end surface of the glass tube at a position of the second end of the glass tube. The optical component according to any one of claims 1 to 6 and an excitation light source unit that outputs excitation light.
The optical fiber included in the optical component or another optical fiber connected to the optical fiber is an amplification optical fiber,
Introducing excitation light output from the excitation light source unit into the amplification optical fiber,
The amplified light to be amplified is propagated by the amplification optical fiber, the amplified light is optically amplified in the amplification optical fiber, and the light after the optical amplification is transmitted to the light included in the optical component Output through the fiber and the glass rod,
An optical amplifier characterized by that. The optical amplifier according to claim 7 , further comprising a photodetector for detecting light emitted from a second end of the glass tube included in the optical component. The optical amplifier according to claim 7 , further comprising a light source that outputs light to be incident on a second end of the glass tube included in the optical component.

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