JP2009265461A - Optical device and its assembly method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical device capable of adjusting the position of an optical fiber and the position of a lens while retaining a lens holder and an optical fiber holder to each other without using joint by means of laser welding, adhesive, soldering or the like. <P>SOLUTION: The optical device 1, which condenses incident light to an optical fiber 18 via the lens 7 or turns the light from the optical fiber 18 into parallel light to emit the parallel light, is composed of the lens holder 11 that retains the lens 7 and the optical fiber holder 13 that retains the optical fiber 18. One side of the lens holder 11 and the optical fiber holder 13 comprises a ferromagnetic material in which spontaneous magnetization is induced and the other side comprises a ferromagnetic material or a paramagnetic material with high permeability. The lens holder 11 and the optical fiber holder 13 are adhered to each other by magnetic force and further are mechanically fixed to each other with a fixing member. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an optical device that converts light emitted from an optical fiber into parallel light, or collects parallel light and enters the optical fiber, and an assembling method thereof.

  In optical communications, laser processing, optical measurement / control, etc., using light emitted from a light source such as a semiconductor laser or fiber laser, the light propagates through the optical fiber as much as possible to emit parallel light into the air, or light from the outside. Is required to be condensed. Light collimator or condensing is necessary when light emitted from a light source is propagated in an optical fiber and emitted as parallel light (collimated light) into the air, or when light propagating in the air is incident on an optical fiber. An optical device such as an apparatus.

  Various optical devices have been developed (for example, Patent Document 1), and will be described with reference to FIG. The optical device 6 has a configuration in which a lens holder 11 that holds a lens 17 and an optical fiber holder 13 that holds an optical fiber 18 are joined.

The relative position of both optical elements in the plane perpendicular to the optical axis is determined by the mechanical accuracy when assembling the lens holder 11 that holds the lens 17 and the optical fiber holder 13 that holds the optical fiber 18, and the parallelism of the beam is accurate. To achieve this well, the relative position between the optical fiber 18 and the lens 17 can be adjusted by fitting the split sleeve 20 and the ferrule 19 that holds the optical fiber 18 in the direction along the optical axis.
Japanese Patent Laying-Open No. 2005-157108

  In the structure disclosed in Patent Document 1, in order to perform collimation and condensing with high accuracy, the distance between the end of the optical fiber 18 and the lens in the direction along the optical axis is kept at the focal length of the lens 17 as shown in FIG. Thus, the lens holder 11 and the optical fiber holder 13 are slid and moved in a plane perpendicular to the optical axis, and the center position of the core portion of the optical fiber 18 and the center position of the lens 17 are about the mode field diameter (6 to 10 μm) of the optical fiber 18. It is necessary to match with accuracy.

  After the positions of the lens holder 11 and the optical fiber holder 13 are determined, joining is performed by laser welding, adhesive bonding, or soldering. In the process of melting / solidifying the member, adhesive, or solder, An abrupt shape change and local expansion and contraction of the volume occur, and the adjusted optimum position is shifted. As a result, the parallelism of the emitted light cannot be achieved with high accuracy.

  In addition, when the position is adjusted using a highly accurate and highly accurate positioning XYZ stage jig, it takes a long time to adjust the gap between the lens holder joint surface and the optical fiber holder joint surface to 0.1 μm or less. is there.

  Further, even if the adjustment can be made so that there is no gap, the rigidity of the adjustment stage jig is high. Therefore, the lens holder 11 and the optical fiber holder are caused by a slight angular deviation of the holding member joint surface with the sliding movement plane of the stage jig. Local stress is generated in the joint surface. As shown in FIG. 7, even if the optimum position is adjusted with the stage jig and then fixed with an adhesive or the like due to this stress, a slight deviation occurs when the stage jig is released.

  Further, in order to avoid the occurrence of this local stress, when a slight gap is made between the joint surface of the lens holder 11 and the joint surface of the optical fiber holder 13 and the periphery is fixed with an adhesive or the like, as shown in FIG. Due to variations in the amount of adhesive applied during the curing process of the adhesive 27, the adhesive 27 locally expands and contracts, resulting in misalignment. As a result, the state adjusted to the optimum position is lost. End up.

  The present invention has been made in view of the above circumstances, and provides an optical device that can be adjusted while holding a lens holder and an optical fiber holder without using laser welding, an adhesive, or soldering. For the purpose.

  In order to achieve the above object, an optical device according to a first aspect of the present invention is an optical device that condenses incident light on an optical fiber or emits light from the optical fiber as parallel light via a lens. A lens holder for holding the lens and an optical fiber holder for holding the optical fiber, and one of the lens holder and the optical fiber holder is made of a ferromagnetic material in which spontaneous magnetization is induced, and the other is made of a ferromagnetic material or a high The lens holder and the optical fiber holder are made of magnetic permeability paramagnetic material, and are attracted by magnetic force and mechanically fixed by a fixing member.

  Preferably, both the lens holder and the optical fiber holder are made of a ferromagnetic material in which spontaneous magnetization is induced.

  An optical device according to a second aspect of the present invention is an optical device that collects incident light on an optical fiber or emits light from the optical fiber as parallel light through a lens, and holds the lens. And both the lens holder and the optical fiber holder are made of a ferromagnetic material or a high permeability paramagnetic material in which spontaneous magnetization is not induced, and the lens holder and the optical fiber. Magnetic holder mounting grooves are provided in at least one of the holders, and the lens holder and the optical fiber holder are mechanically fixed by a fixing member.

  Preferably, one of the lens holder and the optical fiber holder is provided with a screw hole, the other is provided with a through hole corresponding to the screw hole, and a screw inserted from the through hole is screwed into the screw hole, and the lens The holder and the optical fiber holder are pressed against each other and mechanically fixed.

  More preferably, a sphere having a through hole for holding the optical fiber is rotatably installed in the optical fiber holder.

  An optical device assembling method according to a third aspect of the present invention is an optical device assembling method for condensing incident light on an optical fiber or emitting light from the optical fiber as parallel light via a lens, A lens holder for holding a lens, which is composed of a ferromagnetic material in which spontaneous magnetization is induced and the other is composed of a ferromagnetic material or a high permeability paramagnetic material, and an optical fiber holder for holding an optical fiber are prepared. A step, a step of providing a screw hole in one of the lens holder and the optical fiber holder, and a through hole in the other, a step of attracting the lens holder and the optical fiber holder by a magnetic force, and inserting a screw from the through hole to form the screw hole And a step of mechanically fixing the screw.

  An optical device assembling method according to a fourth aspect of the present invention is an optical device assembling method for condensing incident light on an optical fiber or emitting light from the optical fiber as parallel light via a lens, A step of preparing a lens holder for holding a lens provided with a magnetic force source mounting groove on one side and an optical fiber holder for holding an optical fiber, and a step of providing a screw hole in one of the lens holder and the optical fiber holder and a through hole in the other A step of attaching a magnet to the magnetic force source mounting groove to attract the lens holder and the optical fiber holder by magnetic force, and inserting a screw through the through hole and screwing the screw into the screw hole, and the lens holder and the optical fiber holder And a step of removing the magnet from the magnetic source mounting groove. And butterflies.

  According to the optical device of the present invention, the lens holder and the optical fiber holder are attracted to each other by an attraction force by the magnetic force. And after adjusting the optimal position of a lens holder and an optical fiber holder, it can fix mechanically with fixing members, such as a screw, maintaining the adsorption state by this magnetic force. Optimal position adjustment is possible without using welding by laser welding, adhesive, or soldering, and the position adjusted at the time of fixing does not shift, so in addition to reducing the cost of adjustment auxiliary devices, etc. An optical device with high parallelism is realized.

(Embodiment 1)
An embodiment of an optical device and an assembly method thereof according to the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view showing a configuration of an optical device 1 according to Embodiment 1 of the present invention. The optical device 1 according to Embodiment 1 mainly includes a lens 17, a lens holder 11, an optical fiber 18, an optical fiber holder 13, and screws 16a and 16b.

  The lens holder 11 has a cylindrical shape with an outer diameter of 26 mm, and has a through hole having a two-stage diameter with the same central axis. The diameter of the through hole closer to the optical fiber holder 13 is 4.6 mm, and the diameter of the through hole farther from the optical fiber holder 13 is 6.52 mm. A lens holding member 12 made of an annular rubber or the like is assembled on the inner periphery of the through hole far from the optical fiber holder 13. A lens 17 is fitted on the lens holding member 12. The lens holding member 12 is processed so that the central axis of the outer diameter thereof coincides with the central axis of the lens 17. The outer diameter of the lens holding member 12 is slightly smaller than 6.52 mm so as to fit in the through hole of the lens holder 11 without any gap.

  The lens holder 11 is provided with two screw holes 14a and 14b for fastening M2 screws at a position 11.5 mm away from the central axis. The two screw holes 14a and 14b are respectively provided at positions to be sandwiched by the central axis of the lens holder 11. The focal length of the lens 17 is 15.29 mm.

  The optical fiber holder 13 has a cylindrical shape with an outer diameter of 26 mm, similar to the lens holder 11, and is provided with through holes having two different diameters with the same central axis. The diameter of the through hole closer to the lens holder 11 is 8 mm, and the diameter of the through hole farther from the lens holder 11 is 3.23 mm.

A pipe-shaped split sleeve 20 having a split groove penetrating along the axial direction is inserted into a through hole far from the lens holder 11 and bonded with a two-component mixed polymer adhesive. The split sleeve 20 is made of zirconia (zirconium dioxide: ZrO ₂ ), and the outer diameter is 3.20 mm in accordance with the diameter of the through hole. A ferrule 19 is fitted inside the split sleeve 20.

  The inner diameter of the split sleeve 20 is slightly smaller than the outer diameter of 2.49 mm of the ferrule 19, and is bonded in a state of being expanded so as to be fitted to the ferrule 19 when bonded to the optical fiber holder 13.

  The ferrule 19 is made of metal whose main raw material is nickel, and has a through hole having an inner diameter of 270 μm, and the optical fiber 18 is passed through the through hole. The optical fiber 18 uses a multimode fiber having a core diameter of 30 μm and a cladding diameter of 250 μm, but may be a single mode fiber.

  Then, through holes 5 a and 5 b having a diameter of 2.5 mm are provided at positions corresponding to the screw holes 14 a and 14 b of the lens holder 11, that is, at a position 11.4 mm away from the central axis of the optical fiber holder 13.

  The lens holder 11 and the optical fiber holder 13 are mainly made of a ferromagnetic material. And spontaneous magnetization is induced in at least one, and the lens holder 11 and the optical fiber holder 13 are attracted by magnetic force. For example, an alnico magnet, a ferrite magnet, a neodymium magnet, a samarium cobalt magnet, a KS steel, an MK steel, an Fe—Cr—Co magnet, a praseodymium magnet, or a manganese aluminum magnet can be used.

  Further, both the lens holder 11 and the optical fiber holder 13 may be made of a ferromagnetic material in which spontaneous magnetization is induced.

When the lens holder 11 and the optical fiber holder 13 are attracted to each other, the magnetic force does not shift when an external force such as weak vibration is applied, and the magnetic force is such that the suction position can be adjusted by sliding with a finger. Is preferred. For example, if the surface area of each of the lens holder 11 and the optical fiber holder 13 is 5.1 × 10 ⁻⁴ m ² and the surface accuracy Rz (ten-point average roughness) is 6.3, the lens holder 11 and the optical fiber holder If the pressure between the 13 joining surfaces is 1.6 to 8.5 Pa, the lens holder 11 or the optical fiber holder 13 can be slid and adjusted by applying a force of 2.0 to 10.6 N, and There is no slippage when tightening the screws. This force is a force that humans can apply with their fingers. When one of the lens holder 11 and the optical fiber holder 13 is made of SUS430, the other can be made of a material capable of exhibiting an attractive force of 8.2 to 43.3 N by magnetic force, thereby satisfying the above condition.

A method for assembling the optical device 1 configured as described above will be described. First, a lens holder 11 and an optical fiber holder 13 made of the above materials are prepared. The lens holder 11 and the optical fiber holder 13 are provided with through holes 15a and 15b on one side and screw holes 14a and 14b on the other side at positions corresponding to the through holes 15a and 15b. In this description, a configuration in which screw holes 14a and 14b are provided in the lens holder 11 and through holes 15a and 15b are provided in the optical fiber holder 13 will be described.
Then, the lens holder 11 and the optical fiber holder 13 are adsorbed with the lens 17 and the end of the optical fiber 18 facing each other. Since at least one of the holders is made of a ferromagnetic material in which spontaneous magnetization is induced, it naturally attracts the other holder.

  Then, the lens holder 11 or the optical fiber holder 13 is slid while being pressed with a finger, and the mutual positions are adjusted so that the central axis of the lens 17 and the central axis of the optical fiber 18 are linear. In this state, the optical fiber holder 13 and the lens holder 11 are attracted by magnetic force and can maintain this state, so that the determined position can be shifted and changed without using an adjustment auxiliary device such as a jig for applying an external force. Absent.

  After determining the position, screws 16a and 16b are inserted into the through holes 15a and 15b, respectively, and screwed into the screw holes 14a and 14b. Then, by tightening the screws 16a and 16b, the heads of the screws 16a and 16b press the optical fiber holder 13 toward the lens holder 11 side. Thereby, the force which mutually presses acts on the joint surface of the optical fiber holder 13 and the lens holder 11, and it is mechanically fixed.

  The screws 16a and 16b are screwed into the screw holes 14a and 14b, and the optical fiber holder 13 or the lens holder 11 is slid and positioned in a lightly tightened state, and then the screws 16a and 16b are tightened and fixed. May be. Since the through holes 15a and 15b are formed slightly larger than the diameters of the screws 16a and 16b, the fixing position can be adjusted within the range of the gap between the through holes 15a and 15b and the screws 16a and 16b.

  Since the optical fiber holder 13 and the lens holder 11 are attracted to each other by magnetic force, the position adjusted during fixing with the screws 16a and 16b does not shift and change. Therefore, in the optical device 1 according to the present invention, the central axis of the lens 17 and the central axis of the optical fiber 18 are linear, and the parallelism of incident light can be achieved with high accuracy.

  The distance between the lens 17 and the tip of the optical fiber 18 is adjusted by pushing or pulling the ferrule 19 fitted to the split sleeve 20. Thereby, the tip of the optical fiber 18 can be disposed at the focal position of the lens 17.

  As described above, since the lens holder 11 and the optical fiber holder 13 have a self-acting suction force, there is no need for joining by laser welding, adhesive, soldering, or the like, and the position of the lens holder 11 and the optical fiber holder 13 can be easily determined. Can be adjusted. Thereby, the cost concerning an adjustment auxiliary device etc. can be reduced.

  When the positions of the lens holder 11 and the optical fiber holder 13 are adjusted, the joint surface between the lens holder 11 and the optical fiber holder 13 is always kept in a state of being attracted by a magnetic force. Only sliding movement. For this reason, the working time and the number of processes are greatly reduced, resulting in cost reduction.

  The lens holder 11 and the optical fiber holder 13 are fixed mechanically with screws or the like, and no adhesive is used. Since there is no deterioration over time when the adhesive is used and there is no shape change in the curing process of the adhesive, there is no displacement between the lens holder 11 and the optical fiber holder 13, and the optical coupling state between the lens 17 and the optical fiber 18 is deteriorated. Can be suppressed. Further, when an adhesive is used, the thermal expansion coefficient is significantly different between the adhesive layer and the holder. Therefore, the positional deviation occurs due to the environmental temperature change due to the difference in the thermal expansion coefficient. However, in the optical device 1 of the present invention, such a deviation is caused. Does not happen.

  Further, since the optical device 1 is mechanically firmly fastened, the lens holder 11 and the optical fiber holder 13 are not displaced even with respect to an external impact of 200 G or less, so that the durability is high and the reliability is high. The optical device 1 can be used with confidence in various environments.

  In the above description, the center axis of the lens is adjusted so that the center axis is linear, that is, the case where the end surface normal of the optical fiber is parallel to the optical axis of the incoming and outgoing light, but is not limited thereto. It is not a thing.

  FIG. 2 shows the direction of incoming and outgoing light when the end face of the optical fiber is inclined with respect to the central axis. The multimode fiber which consists of the core part 8a and the clad part 8b is used for the example. For example, when the angle formed by the normal of the end surface and the central axis of the optical fiber 8 is 4 °, the angle formed by the optical axis of the incident / exit light on the end surface of the optical fiber and the central axis of the optical fiber 8 is 1.8 °.

  In order to counteract this, as in the optical device 2 shown in FIG. 3, the through hole of the optical fiber holder 13 is 1.8 ° so that the principal axes of the ferrule 19 and the split sleeve 19 are inclined by 1.8 ° with respect to the ideal optical axis. You can respond by tilting.

  Further, as shown in FIG. 4, when the normal of the end face of the optical fiber is not parallel to the central axis of the optical fiber, the angles of the ferrule and the main axis of the split sleeve relative to the ideal optical axis may be arbitrarily adjusted.

  An optical fiber holder 13 of the optical device 3 includes a metal ball 21 having a diameter of 12.7 mm. The metal ball 21 has a through hole having a diameter of 3.23 mm. The metal sphere 21 is made of SUS304 stainless steel, and its center is substantially coincident with the focal position of the collimated light.

  Behind the metal sphere 21, an annular press ring 22 made of C3604 (brass), a wave washer 23 made of stainless steel, and a fixing ring 24 are provided in this order, and the metal sphere 21 is a lens holder by the elasticity of the wave washer 23. 11 is pressed down. There are corresponding thread grooves of outer diameter screws M14 on the inner side of the through hole of the optical fiber holder 13 and the outer peripheral surface of the fixing ring 24, and the fixing ring 24 has a structure for pressing the wave washer 23 while rotating the through hole.

  With such a configuration, the metal ball 21 can rotate smoothly while contacting the holding ring 22. Then, the rotation of the metal ball 21 can be fixed by inserting a grub screw into an M3 screw hole opened at a four-fold symmetrical position with respect to the central axis of the optical fiber holder 13 from the side surface of the optical fiber holder 13 toward the center, and tightening it. .

  In the optical device 3, the metal sphere 21 can be freely rotated. Therefore, by adjusting the positions of the lens holder 11 and the optical fiber holder 13 by assembling the center of the metal sphere 21 with the focal length of the lens 7, Regardless of the end face of the optical fiber 18, the incoming and outgoing light can be aligned with the ideal optical axis.

(Embodiment 2)
FIG. 5 is a cross-sectional view showing the configuration of the optical device 4 according to Embodiment 2 of the present invention. As with the optical device 1 according to the first embodiment, the optical device 4 according to the second embodiment mainly includes a lens 17, a lens holder 11, an optical fiber 18, an optical fiber holder 13, and screws 16a and 16b. Is done.

  Unlike the optical device 1 described above, the lens holder 11 and the optical fiber holder 13 of the optical device 4 according to Embodiment 2 are both made of a ferromagnetic material or a high permeability paramagnetic material in which spontaneous magnetization is not induced. Yes. For example, SUS430 or the like, a ferritic ferromagnetic stainless material or the like can be used. In this case, the high magnetic permeability paramagnetic material may be a paramagnetic material having a relative magnetic permeability of 1.02 or more. When the relative permeability is 1.02 or more, one holder comes to attract the other holder.

  Magnetic source mounting grooves 25 a and 25 b are provided on the outer periphery of the lens holder 11. Two magnetic source mounting grooves 25 a and 25 b are provided at positions symmetrical to the optical axis of the lens holder 11. The magnetic source mounting grooves 25a and 25b have a pocket structure with dimensions of about 9 mm × 7 mm × 3.5 mm, and magnetic sources such as permanent magnets and electromagnets with dimensions of about 8 mm × 8 mm × 2 mm are inserted therein. I can do it.

  Although FIG. 5 shows the case where the magnetic force source mounting grooves 25a and 25b are provided in the lens holder 11, they may be provided on the optical fiber holder 13 side.

Next, a method for assembling the optical device 4 will be described. First, a lens holder 11 and an optical fiber holder 13 made of the above materials are prepared. The lens holder 11 and the optical fiber holder 13 are provided with through holes 15a and 15b on one side and screw holes 14a and 14b on the other side at positions corresponding to the through holes 15a and 15b. In addition, magnetic source mounting grooves 25 a and 25 b are provided in one of the lens holder 11 and the optical fiber holder 13. In this description, a configuration in which the lens holder 11 is provided with magnetic force source mounting grooves 25a and 25b and screw holes 14a and 14b, and the optical fiber holder 13 is provided with through holes 15a and 15b will be described.
And magnetic source 26a, 26b, such as a permanent magnet, is installed in the magnetic source mounting grooves 25a, 25b of the lens holder 11 in which the lens 17 is installed, and the optical fiber holder 13 in which the lens holder 11 and the optical fiber 18 are installed is adsorbed. The lens holder 11 and the optical fiber holder 13 are naturally attracted by the magnetic force of the magnetic force sources 26a and 26b.

  Then, the lens holder 11 or the optical fiber holder 13 is slid while being pressed with a finger to adjust the mutual position. In this state, since the optical fiber holder 13 and the lens holder 11 are attracted by the magnetic force of the magnetic force sources 26a and 26b, it is not necessary to use an adjustment assisting device such as a jig for applying an external force.

  After positioning, screws 16a and 16b are respectively inserted into the through holes 15a and 15b, screwed into the screw holes 14a and 14b, and tightened, so that the heads of the screws 16a and 16b attach the optical fiber holder 13 to the lens holder. Press to 11 side. As a result, the optical fiber holder 13 and the lens holder 11 are fixed by applying a pressing force to each other.

  After the fiber holder 3 and the lens holder 11 are fixed, the magnetic sources 26a and 26b may be removed from the magnetic source mounting grooves 25a and 25b.

  Since other matters are the same as those of the optical device 1 of the second embodiment, description thereof is omitted.

  According to the optical device 4 of the second embodiment, the magnetic force sources 26a and 26b can be removed after fixing the holder, so that a strong magnetic field cannot be generated from the optical device 4. For this reason, processing for the surrounding environment is unnecessary, and it is effective for an adjacent device that malfunctions due to the influence of a magnetic field.

  In addition, since the magnetic force can be adjusted using a permanent magnet of various strengths, or the strength of the magnetic force can be adjusted using an electromagnet, the lens holder 11 and the optical fiber holder 13 are attracted by an appropriate attractive force and smoothly slidably moved. It is possible to switch between the state where the position can be adjusted by the method and the state where the adsorption is maintained with a strong attractive force so that the position adjusted to the optimal state when it is fixed by the fixing member does not deviate. Assembly of optical devices can be realized.

It is sectional drawing of the optical device which concerns on Embodiment 1 of this invention. It is sectional drawing of the optical fiber used for this invention. It is sectional drawing of the optical device which concerns on Embodiment 1 of this invention. It is sectional drawing of the optical device which concerns on Embodiment 1 of this invention. It is sectional drawing of the optical device which concerns on Embodiment 2 of this invention. It is sectional drawing of the conventional optical device. It is sectional drawing of the conventional optical device. It is sectional drawing of the conventional optical device.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Optical device 2 Optical device 3 Optical device 4 Optical device 11 Lens holder 12 Lens holding member 13 Optical fiber holder 14 Screw hole 15 Through hole 16 Screw 17 Lens 18 Optical fiber 18a Core part 18b Cladding part 19 Ferrule 20 Split sleeve 21 Metal ball 22 Holding Ring 23 Wave washer 24 Fixed ring 25 Magnetic source mounting groove 26 Magnet source 27 Adhesive

Claims (7)

An optical device that condenses incident light on an optical fiber or emits light from an optical fiber as parallel light through a lens,
A lens holder for holding the lens;
An optical fiber holder for holding the optical fiber,
One of the lens holder and the optical fiber holder is composed of a ferromagnetic material in which spontaneous magnetization is induced, and the other is composed of a ferromagnetic material or a high permeability paramagnetic material,
The lens holder and the optical fiber holder are adsorbed by magnetic force and mechanically fixed by a fixing member.
An optical device characterized by that.   2. The optical device according to claim 1, wherein both the lens holder and the optical fiber holder are made of a ferromagnetic material in which spontaneous magnetization is induced. An optical device that condenses incident light on an optical fiber or emits light from an optical fiber as parallel light through a lens,
A lens holder for holding the lens;
An optical fiber holder for holding an optical fiber,
Both the lens holder and the optical fiber holder are composed of a ferromagnetic material or a high permeability paramagnetic material in which spontaneous magnetization is not induced,
A magnetic source mounting groove is provided in at least one of the lens holder and the optical fiber holder,
The lens holder and the optical fiber holder are mechanically fixed by a fixing member,
An optical device characterized by that. One of the lens holder and the optical fiber holder is provided with a screw hole, and the other is provided with a through hole corresponding to the screw hole,
The screw inserted from the through hole is screwed into the screw hole, and the lens holder and the optical fiber holder are pressed against each other and mechanically fixed. The optical device according to Item.   The optical device according to any one of claims 1 to 4, wherein a sphere having a through hole for holding the optical fiber is rotatably installed in the optical fiber holder. An assembly method of an optical device that condenses incident light on an optical fiber or emits light from the optical fiber as parallel light through a lens,
A step of preparing a lens holder and an optical fiber holder, each of which is composed of a ferromagnetic material or a high permeability paramagnetic material, and at least one of which is induced by spontaneous magnetization;
Providing a screw hole in one of the lens holder and the optical fiber holder and providing a through hole in the other; and
Adjusting the fixing position by adsorbing the lens holder and the optical fiber holder by magnetic force;
Inserting a screw from the through hole and screwing into the screw hole to fix the lens holder and the optical fiber holder; and
A method of assembling an optical device. An assembly method of an optical device that condenses incident light on an optical fiber or emits light from the optical fiber as parallel light through a lens,
Preparing a lens holder and an optical fiber holder composed of a ferromagnetic material or a high permeability paramagnetic material in which spontaneous magnetization is not induced;
Providing a magnetic force source mounting groove in one of the lens holder and the optical fiber holder;
Providing a screw hole in one of the lens holder and the optical fiber holder, and providing a through hole in the other;
Attaching a magnet to the magnetic source mounting groove and adsorbing the lens holder and the optical fiber holder by magnetic force, and adjusting a fixing position;
Inserting a screw from the through hole and screwing into the screw hole to fix the lens holder and the optical fiber holder;
Removing the magnet from the magnetic force source mounting groove.
A method of assembling an optical device.

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