JP2013088720A - Light coupling device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical coupling device capable of, even if members generate heat, preventing the members from coming off.SOLUTION: An optical coupling device 10 includes: a light guiding one, e.g. an optical fiber 21; an optical element 41 functioning by irradiation with light guided through the optical fiber 21; and a holding member 51 for holding the optical fiber 21 and the optical element 41 inside so as to optically couple the optical fiber 21 to the optical element 41. Further, the optical coupling device 10 includes reducing portions 71 which are arranged on the holding member 51 so as to be positioned around the optical element 41 to reduce the rigidity of the holding member 51.

Description

  The present invention relates to an optical coupling device that optically couples an optical fiber and an optical element.

  For example, Patent Document 1 discloses a new optical component that can be attached to an end portion of an optical fiber holding member and a light-emitting device that uses this optical component. In this optical component, the cap has an inner hole into which the light conversion member and the optical fiber holding member can be inserted, and a locking portion that can lock the light conversion member and the optical fiber holding member. The light conversion member is disposed between the optical fiber holding member and the locking portion. When the optical fiber holding member is pressed toward the locking portion, the light converting member is prevented from coming off from the cap.

JP 2008-76798 A

  In Patent Document 1 described above, the light conversion member and the optical fiber holding member are fixed in close contact with the cap. Further, the optical conversion member, the optical fiber holding member, and the cap have different linear expansion coefficients, and the expansion / contraction amounts also differ accordingly.

  Therefore, for example, when each generates heat as lighting is turned on and off, each expands and contracts according to the respective linear expansion coefficient. At this time, it is difficult to adjust the amount of expansion / contraction due to the fact that the respective linear expansion coefficients are different from each other and that each is closely fixed. Thereby, when each expands and contracts, each rattles, the cap comes off from the light conversion member and the optical fiber holding member, and the light conversion member which is an optical element is removed.

  Therefore, the present invention has been made in view of these circumstances, and an object of the present invention is to provide an optical coupling device that can prevent a member from coming off even if the member generates heat.

  In order to achieve the object, the present invention provides a light guide member that guides light, an optical element that functions by being irradiated with the light guided by the light guide member, the light guide member, and the optical element. A holding member that holds the light guide member and the optical element inside so as to be optically coupled to the element, and a holding member that is positioned around the optical element, the rigidity of the holding member being increased. An optical coupling device comprising: a reduction unit that reduces the optical coupling device.

  ADVANTAGE OF THE INVENTION According to this invention, even if a member heat | fever-generates, the optical coupling device which can prevent that a member remove | deviates can be provided.

FIG. 1A is an exploded perspective view of the optical coupling device according to the first embodiment of the present invention. FIG. 1B is a perspective view of the optical coupling device assembled from the state shown in FIG. 1A. 1C is a cross-sectional view of the optical coupling device shown in FIG. 1B. FIG. 2A is an exploded perspective view of an optical coupling device according to a first modification of the first embodiment. FIG. 2B is a perspective view of the optical coupling device assembled from the state shown in FIG. 2A. 2C is a cross-sectional view of the optical coupling device shown in FIG. 2B. FIG. 3A is an exploded perspective view of an optical coupling device according to a second modification of the first embodiment. FIG. 3B is a perspective view of the optical coupling device assembled from the state shown in FIG. 3A. 3C is a cross-sectional view of the optical coupling device shown in FIG. 3B when the bottom surface of the slit portion is parallel to the outer peripheral surface of the optical element. 3D is a cross-sectional view of the optical coupling device shown in FIG. 3D when the bottom surface of the slit portion is parallel to the outer peripheral surface of the holding member. FIG. 4A is an exploded perspective view of an optical coupling device according to a third modification of the first embodiment. 4B is a perspective view of the optical coupling device assembled from the state shown in FIG. 4A. FIG. 5A is an exploded perspective view of the optical coupling device according to the second embodiment. FIG. 5B is a perspective view of the optical coupling device assembled from the state shown in FIG. 5A. FIG. 5C is a cross-sectional view of the optical coupling device shown in FIG. 5B. FIG. 6 is an exploded perspective view of the optical coupling device according to the first modification of the second embodiment. FIG. 7A is an exploded perspective view of an optical coupling device according to a second modification of the second embodiment. FIG. 7B is a perspective view of the optical coupling device assembled from the state shown in FIG. 7A. FIG. 7C is a cross-sectional view of the optical coupling device shown in FIG. 7B.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
The first embodiment will be described with reference to FIGS. 1A, 1B, and 1C.
In some drawings, illustration of a part of members is omitted for clarity of illustration.

  As shown in FIG. 1A, the optical coupling device 10 includes a light guide member such as an optical fiber 21 that guides light, and an optical element 41 that functions by being irradiated with light guided by the optical fiber 21. The optical fiber 21 and the optical element 41 have a holding member 51 that holds the optical fiber 21 and the optical element 41 therein so that the optical fiber 21 and the optical element 41 are optically coupled.

  As shown in FIG. 1C, the optical fiber 21 has a flat emission end face 23 a that emits light at one end of the optical fiber 21. This light is, for example, laser light. The other end of the optical fiber 21 is covered with a coating layer (not shown) made of, for example, resin that protects the optical fiber 21. The optical fiber 21 is formed of at least one of glass and plastic, for example.

  The optical element 41 as shown in FIG. 1A is formed of at least one of ceramic and glass, for example. The optical element 41 has a phosphor, for example. In the optical element 41, the outer peripheral surface 41c of the optical element 41 is covered with a reflective film (not shown). The optical element 41 has, for example, a truncated cone shape. The optical element 41 is not limited to having a truncated cone shape, and may have, for example, a cylindrical shape, a hemispherical shape, or a parabolic shape. The optical element 41 has, for example, a planar end face 41a. The one end face 41a is an incident end face on which light emitted from the outgoing end face 23a enters. The one end face 41a abuts on the emission end face 23a so that the optical fiber 21 and the optical element 41 are optically coupled. The one end face 41a is larger than the emission end face 23a.

  The holding member 51 as shown in FIG. 1A is a ferrule formed of, for example, at least one of zirconia, glass, and metal. This metal is made of, for example, at least one of nickel, SUS, and brass. The holding member 51 has, for example, a cylindrical shape. The outer diameter of the holding member 51 is, for example, 1 mm or less.

  As shown in FIGS. 1A and 1C, the holding member 51 has a through hole 51 c into which the optical fiber 21 is fitted or bonded and a housing portion 51 d that houses the optical element 41 inside the holding member 51. doing. As shown in FIG. 1C, the holding member 51 includes the optical fiber 21 and the optical element 41 through the through hole 51c and the accommodating portion 51d so that the optical fiber 21 and the optical element 41 are optically coupled inside the holding member 51. It is held directly inside the holding member 51. As shown in FIG. 1C, the optical fiber 21 fitted or bonded to the through hole 51 c and the optical element 41 accommodated in the accommodating portion 51 d are in direct contact with each other inside the holding member 51. More specifically, the emission end face 23a of the optical fiber 21 and the one end face 41a of the optical element 41 are in contact with each other.

  As shown in FIG. 1C, the through hole 51c and the accommodating portion 51d are arranged so that the light emitted from the optical fiber 21 (the emission end face 23a) enters the optical element 41 (the one end face 41a) in the axial direction. In FIG. The central axis of the through hole 51c and the central axis of the accommodating portion 51d are arranged coaxially so that light emitted from the optical fiber 21 (exit end face 23a) enters the optical element 41 (one end face 41a). ing. For this reason, the through-hole 51c and the accommodating part 51d are arrange | positioned on the central axis of the holding member 51, for example. The through hole 51 c is disposed on the one end surface 51 a side of the holding member 51, and the accommodating portion 51 d is disposed on the other end surface 51 b side of the holding member 51.

  As shown in FIG. 1C, the through hole 51c is provided for the holding member 51 to hold the optical fiber 21, and functions as a holding hole. The through hole 51 c functions as an insertion hole through which the optical fiber 21 is inserted into the holding member 51. The through hole 51c has, for example, a cylindrical shape, and is formed by, for example, cutting. The through hole 51 c penetrates the holding member 51 in the axial direction of the holding member 51. The through hole 51c is also a housing portion in which the optical fiber 21 is housed.

  As shown in FIG. 1C, the holding member 51 has a guide port 51e that guides one end of the optical fiber 21 to the through hole 51c so that the optical fiber 21 is inserted into the through hole 51c. 51a. The guide port 51e communicates with the through hole 51c. The guide port 51e has a truncated cone shape that is reduced in diameter from one end surface 51a of the holding member 51 toward the other end surface 51b of the holding member 51, and has a tapered taper. Note that the above-described coating layer is disposed only on the one end surface 51a side of the holding member 51, specifically, near the guide port 51e, and is not inserted into the through hole 51c. For this reason, one end of the optical fiber 21 is exposed from the coating layer.

  The accommodating portion 51d is disposed for the holding member 51 to hold the optical element 41, and functions as a holding hole. The accommodating portion 51d functions as an insertion hole into which the optical element 41 is inserted into the holding member 51. As shown in FIG. 1C, the accommodating portion 51d has the same shape as the optical element 41, for example, a truncated cone shape. Therefore, the accommodating part 51d is diameter-reduced toward the one end surface 51a from the other end surface 51b. The accommodating part 51d has substantially the same size as the optical element 41 and a size with which the optical element 41 adheres to the accommodating part 51d. In addition, the accommodating part 51d may have a magnitude | size which the optical element 41 fits with the accommodating part 51d. The accommodating portion 51 d penetrates the other end surface 51 b of the holding member 51 in the axial direction of the holding member 51.

  As shown in FIG. 1C, an adhesive member 61 is disposed on one end surface 51a including the guide port 51e. The adhesive member 61 adheres the other end side of the optical fiber 21 including the coating layer to the holding member 51. Although not shown, the adhesive member 61 is also applied to at least one of the outer peripheral surface 41 c of the optical element 41 and the inner peripheral surface of the holding member 51 in the housing portion 51 d to bond the optical element 41 to the holding member 51. .

  Such an adhesive member 61 is, for example, an optical adhesive or an adhesive such as silicon or epoxy. The adhesive member 61 is a resin that is cured by heat or a resin that is cured by being irradiated with ultraviolet rays. The adhesive member 61 fixes the optical fiber 21 and the optical element 41 to the holding member 51 by curing.

  As shown in FIGS. 1A, 1B, and 1C, the optical coupling device 10 further includes a reduction unit 71 disposed on the holding member 51 so as to be positioned around the optical element 41. The reduction part 71 is arrange | positioned at the holding member 51 so that it may be located around the accommodating part 51d, for example. In detail, the reduction part 71 should just be arrange | positioned at the side of the optical element 41 at least. In other words, the reduction part 71 is disposed on the same straight line as the optical element 41 (the accommodating part 51d) in the radial direction of the holding member. In the present embodiment, the reduction unit 71 includes, for example, a slit portion 71 a that is cut from the other end surface 51 b of the holding member 51 toward the one end surface 51 a of the holding member 51 along the axial direction of the holding member 51. ing. The slit portion 71a opens on the other end surface 51b side, and penetrates the holding member 51 on the other end surface 51b side. The slit portion 71 a does not necessarily have to penetrate the one end surface 51 a side in the axial direction of the holding member 51. 1A, FIG. 1B, and FIG. 1C, the slit portion 71a penetrates the holding member 51 in the radial direction of the holding member 51. For example, four reduction portions 71 are arranged, and are spaced apart from each other at equal intervals in the circumferential direction of the holding member 51.

  The reduction part 71 (slit part 71a) is disposed in order to reduce the rigidity of the holding member 51. Accordingly, the reducing unit 71 (slit unit 71a) buffers stress generated by heat around the optical element 41 (accommodating unit 51d).

  The optical fiber 21, the optical element 41, and the holding member 51 have different linear expansion coefficients, and each expands and contracts in accordance with the respective linear expansion coefficient. Therefore, for example, when each generates heat as light emission is turned on and off, each expands and contracts according to the respective linear expansion coefficient. At this time, each expansion / contraction amount differs according to each linear expansion coefficient.

  In this embodiment, since the reduction part 71 is arrange | positioned, the rigidity of the holding member 51 falls in the circumference | surroundings of the optical element 41, ie, the other end surface 51b side of the holding member 51. Therefore, even if the respective linear expansion coefficients are different, the reduction unit 71 suppresses the difference between the expansion amount and the contraction amount.

Next, an assembling method of the optical coupling device 10 in this embodiment will be described with reference to FIGS. 1A, 1B, and 1C.
The optical fiber 21 is guided to the through hole 51c by the guide port 51e and is fitted into the through hole 51c. The adhesive member 61 is applied to one end surface 51a including the guide port 51e and the inner peripheral surface of the holding member 51 in the housing portion 51d. The optical element 41 is accommodated in the accommodating portion 51d so that the optical element 41 is adhered to the inner peripheral surface of the holding member 51 in the accommodating portion 51d by the adhesive member 61, and the emission end surface 23a abuts on the one end surface 41a.

  The adhesive member 61 is cured by heat or by being irradiated with ultraviolet rays. Thereby, the optical fiber 21 and the optical element 41 are fixed to the holding member 51 by the adhesive member 61.

  Then, as shown in FIGS. 1B and 1C, the optical coupling device 10 is assembled.

  The adhesive member 61 may be poured between the optical element 41 and the inner peripheral surface of the holding member 51. Further, matching oil or the like may be applied to the one end face 41a in order to prevent air from being interposed between the emission end face 23a and the one end face 41a.

  When a light source device (not shown) emits light, the optical fiber 21 guides this light. The emission end face 23a emits light toward the one end face 41a. Thereby, the optical fiber 21 generates heat, and the heat is transmitted from the optical fiber 21 to the optical element 41 and the holding member 51. The optical fiber 21, the optical element 41, and the holding member 51 are expanded and contracted by heat.

  The optical fiber 21, the optical element 41, and the holding member 51 have different linear expansion coefficients, and each expands and contracts in accordance with the respective linear expansion coefficient. At this time, each expansion / contraction amount differs according to each linear expansion coefficient.

  In this embodiment, the rigidity of the holding member 51 is reduced around the optical element 41, that is, on the other end surface 51 b side of the holding member 51 by providing the reduction unit 71. Therefore, even if the respective linear expansion coefficients are different, the difference between the expansion amount and the contraction amount is suppressed by the reduction unit 71. Thereby, even if the optical fiber 21 and the optical element 41 generate heat, the optical fiber 21 and the optical element 41 are prevented from being detached from the holding member 51 and are fixed to the holding member 51 and maintained in a state.

  Further, the reduction unit 71 reduces the rigidity of the holding member 51, thereby preventing thermal stress from accumulating in the optical fiber 21, the optical element 41, and the holding member 51, and the optical fiber 21, the optical element 41, the holding member 51, and the like. Improves resistance to heat stress. Thereby, the reduction part 71 prevents that the optical fiber 21, the optical element 41, and the holding member 51 are damaged by heat, and prevents that a desired optical characteristic is not acquired by heat.

  Thus, in this embodiment, the reduction | restoration part 71 is arrange | positioned and the rigidity of the holding member 51 can be reduced. Thereby, in this embodiment, even if each linear expansion coefficient is different, the difference between the expansion amount and the contraction amount can be suppressed by the reduction unit 71. Therefore, in this embodiment, even if the optical fiber 21 and the optical element 41 generate heat, the optical fiber 21 and the optical element 41 can be prevented from being detached from the holding member 51.

  In the present embodiment, thermal stress can be prevented from accumulating in the optical fiber 21, the optical element 41, and the holding member 51, and resistance to thermal stress on the optical fiber 21, the optical element 41, and the holding member 51 can be improved. In the present embodiment, the optical fiber 21, the optical element 41, and the holding member 51 can be prevented from being damaged by heat, and desired optical characteristics can be obtained even if heat is generated.

  As described above, in this embodiment, the resistance to thermal stress can be improved without being affected by the linear expansion coefficient of each member and the fixing of the member, and desired optical characteristics can be obtained even when heat is generated.

  In the present embodiment, the adhesive member 61 can be prevented from being peeled off as described above, and the optical fiber 21 and the optical element 41 can be fixed to the holding member 51 by the adhesive member 61 even if a thermal shock occurs.

  Moreover, in this embodiment, the slit part 71a is arrange | positioned along the axial direction of the holding member 51, and can suppress the difference between the expansion amount and the contraction amount in the axial direction.

  Further, in the present embodiment, the slit portions 71 a are arranged at equal intervals in the circumferential direction of the holding member 51, whereby the stress when expanding and contracting can be uniformly transmitted to the holding member 51 in the circumferential direction. . Therefore, in this embodiment, it can prevent that stress concentrates on the site | part which desires, can reduce the local destruction of the holding member 51, and can reduce distortion of stress.

Next, a first modification of the present embodiment will be described with reference to FIGS. 2A, 2B, and 2C.
In this modification, the reduction part 71 has an opening 71b that is a long hole. The opening 71b is disposed away from the other end surface 51b. The opening 71 b penetrates the holding member 51 in the radial direction of the holding member 51. For example, four openings 71 b are provided, and are spaced apart from each other at equal intervals in the circumferential direction of the holding member 51. The shape, size, and number of the opening 71b are not particularly limited. Further, the plurality of openings 71b may be disposed along the axial direction of the holding member 51 as shown in FIG. 2A, or are arranged along the circumferential direction of the holding member 51 although not shown. Also good.

  Thereby, in this modification, the effort which processes the other end surface 51b can be saved, the shape of the other end surface 51b can be maintained, and the other end surface 51b can be easily disposed on another member.

  This modification can also be combined with the first embodiment. Therefore, the reduction part 71 should just have at least 1 of the slit part 71a and the opening part 71b. For this reason, the slit portion 71 a and the opening portion 71 b may be disposed along at least one of the axial direction of the holding member 51 and the circumferential direction of the holding member 51.

Next, a second modification of the present embodiment will be described with reference to FIGS. 3A, 3B, and 3C.
The slit portion 71 a is formed as a recess that is recessed from the outer peripheral surface of the holding member 51 toward the inner peripheral surface. That is, the slit portion 71 a does not penetrate the holding member 51 in the radial direction of the holding member 51.

  As shown in FIG. 3C, the slit portion 71 a is recessed, for example, such that the bottom surface 711 a of the slit portion 71 a is parallel to the outer peripheral surface 41 c of the optical element 41. Since the optical element 41 has a truncated cone shape, the outer peripheral surface 41 c of the optical element 41 is inclined with respect to the central axis of the holding member 51. Therefore, the bottom surface 711a of the slit portion 71a is inclined with respect to the central axis of the holding member 51 so as to be parallel to the outer peripheral surface 41c.

  Such a slit portion 71a has, for example, a quadrangular frustum shape or a quadrangular pyramid shape. For example, four slit portions 71 a are arranged and are spaced apart from each other at equal intervals in the circumferential direction of the holding member 51.

  In this modification, since the slit portion 71a does not penetrate the holding member 51, it is not necessary to process the inner peripheral surface of the holding member 51 in the accommodating portion 51d. Therefore, in the present embodiment, the reflective film can be easily disposed on the inner peripheral surface of the holding member 51 in the housing portion 51d. Moreover, in this embodiment, the adhesive member 61 can also be apply | coated to the whole internal peripheral surface of the holding member 51 in the accommodating part 51d, and the adhesive strength in the optical element 41 can be raised.

  The slit portion 71a may be recessed so that the bottom surface 711a of the slit portion 71a is parallel to the outer peripheral surface of the holding member 51 as shown in FIG. 3D. . Therefore, the slit portion 71a only needs to be recessed so that the bottom surface 711a of the slit portion 71a is parallel to at least one of the outer peripheral surface 41c of the optical element 41 and the outer peripheral surface of the holding member 51.

  In addition, in this modification, although the slit part 71a was demonstrated, it is not necessary to limit to this and it is applicable also to the opening part 71b.

  For example, the opening 71 b is recessed from the outer peripheral surface of the holding member 51 toward the inner peripheral surface. That is, the opening 71 b does not penetrate the holding member 51 in the radial direction of the holding member 51. The opening 71b may be recessed so that the bottom surface of the opening 71b is parallel to at least one of the outer peripheral surface 41c of the optical element 41 and the outer peripheral surface of the holding member 51.

  Moreover, in this modification, the opening part 71b and the slit part 71a may be arrange | positioned and arrange | positioned. Therefore, in the recessed slit portion 71a and the opening portion 71b, the bottom surfaces of the slit portion 71a and the opening portion 71b are parallel to at least one of the outer peripheral surface 41c of the optical element 41 and the outer peripheral surface of the holding member 51, respectively. Good.

  Moreover, this modification can also be combined with the first embodiment and the first modification. Therefore, at least one of the slit portion 71 a and the opening portion 71 b penetrates the holding member 51 in the radial direction of the holding member 51, or is recessed from the outer peripheral surface of the holding member 51 toward the inner peripheral surface. Just do it.

Next, a third modification of the present embodiment will be described with reference to FIGS. 4A and 4B.
The reduction part 71 has a slit part 71 a disposed along the axial direction of the holding member 51 and a slit part 72 a disposed along the circumferential direction of the holding member 51. The slit portion 72a is disposed on the other end surface 51b side. The slit portion 72a communicates with the proximal end portion of the slit portion 71a disposed on the other end surface 51b side. These slit portions 71 a and 72 a penetrate the holding member 51 in the radial direction of the holding member 51.

  The optical element 41 has a locking portion 41e that locks with the slit portion 72a that penetrates the holding member 51 via the slit portion 71a. As shown in FIG. 4A, the optical element 41 is accommodated in the accommodating portion 51d, and when the locking portion 41e slides on the slit portion 71a, the optical element 41 rotates around the axis of the holding member 51. As shown in FIG. 4, the locking portion 41e engages with the slit portion 72a. The locking portion 41 e protrudes outward from the other end surface of the optical element 41 in the radial direction of the optical element 41. The locking portion 41e is formed when the optical element 41 is formed.

  In this modification, it is possible to reliably prevent the optical element 41 from being detached from the holding member 51 by engaging the locking portion 41e with the slit portion 72a.

Next, a second embodiment will be described with reference to FIGS. 5A, 5B, and 5C.
The reducing portion 71 has a recess 71 c that is recessed from the outer peripheral surface of the holding member 51 toward the inner peripheral surface and is disposed along the circumferential direction of the holding member 51. The recess 71c is a groove and a slit.

  Thereby, in this embodiment, the difference between the expansion amount and the contraction amount of the holding member 51 can be suppressed in the circumferential direction of the holding member 51.

  The shape, size, and number of the recess 71c are not particularly limited. Thus, for example, the recess 71c may be continuously arranged in the circumferential direction as shown in FIGS. 5A and 5B, or may be discontinuously arranged in the circumferential direction, although not shown. May be. For example, as shown in FIGS. 5A and 5B, a plurality of the recesses 71 c are arranged at equal intervals along the axial direction of the holding member 51. In this case, the depth of each recess 71c is uniform. Alternatively, the depth of the recess 71c may gradually increase from the recess 71c on the other end surface 51b side toward the recess 71c on the one end surface 51a side. The bottom surface of the recess 71c is a flat surface, for example. The bottom surface of the recess 71c may be inclined.

Next, a first modification of the present embodiment will be described with reference to FIG.
The recess 71 c is further disposed along the axial direction of the holding member 51. Thereby, in this modification, the difference between the expansion amount and the contraction amount of the holding member 51 in the circumferential direction of the holding member 51 and the axial direction of the holding member 51 can be suppressed. In addition, the recessed part 71c arrange | positioned along an axial direction may penetrate the holding member 51 in the radial direction of the holding member 51, as shown in FIG. In this case, the recess 71c has the same configuration as the slit portion 71a shown in FIG. 1A.

  The recess 71 c may be disposed along the spiral direction with respect to the axial direction of the holding member 51. In this case, the difference between the expansion amount and the contraction amount of the holding member 51 can be suppressed in the spiral direction. The concave portion 71c disposed along the spiral direction is disposed so as to wind the optical element 41 when the optical element 41 is accommodated in the accommodating portion 51d. The concave portion 71 c disposed along the spiral direction may penetrate the holding member 51 in the radial direction of the holding member 51.

  As described above, the recess 71 c only needs to be disposed along at least one of the axial direction of the holding member 51, the circumferential direction of the holding member 51, and the spiral direction with respect to the axial direction of the holding member 51. The recess 71 c disposed along at least one of the axial direction and the spiral direction may penetrate the holding member 51 in the radial direction of the holding member 51.

Next, a second modification of the present embodiment will be described with reference to FIGS. 7A, 7B, and 7C.
The optical coupling device 10 further includes a prevention unit 81 that locks the holding member 51 by locking with the concave portion 71c disposed along the spiral direction so as to prevent the optical element 41 from coming off from the holding member 51 Have.

  The prevention unit 81 has an opening 81a through which light passes so as not to block light emitted from the optical element 41.

  Thereby, in this embodiment, the removal of the optical element 41 from the holding member 51 can be reliably prevented. In the present embodiment, the recess 71 c can have both a function of reducing the rigidity of the holding member 51 and a function of engaging with the holding member 51.

  The prevention part 81 does not need to be engaged with the recess 71c, and may be engaged with the holding member 51. The prevention unit 81 may be bonded to the holding member 51.

  Further, the present invention is not limited to the above-described embodiment as it is, and can be embodied by modifying the components without departing from the scope of the invention in the implementation stage. Further, various inventions can be formed by appropriately combining a plurality of constituent elements disclosed in the embodiment.

  DESCRIPTION OF SYMBOLS 10 ... Optical coupling device, 21 ... Optical fiber, 41 ... Optical element, 51 ... Holding member, 51d ... Housing part, 61 ... Adhesive member, 71 ... Reduction part, 71a, 72a ... Slit part, 71b ... Opening part, 71c ... Recess.

Claims (8)

A light guide member for guiding light;
An optical element that functions by being irradiated with the light guided by the light guide member;
A holding member for internally holding the light guide member and the optical element so that the light guide member and the optical element are optically coupled;
A reduction unit disposed on the holding member so as to be positioned around the optical element, and reducing the rigidity of the holding member;
An optical coupling device comprising:   The said reduction | decrease part has at least one of the slit part cut | disconnected along the axial direction of the said holding member at least from the end surface of the said holding member, and an opening part. The optical coupling device as described.   At least one of the slit portion and the opening portion penetrates the holding member in the radial direction of the holding member, or is recessed from the outer peripheral surface of the holding member toward the inner peripheral surface. The optical coupling device according to claim 2.   In each of the slit portion and the opening portion that are recessed, each bottom surface is parallel to at least one of the outer peripheral surface of the optical element and the outer peripheral surface of the holding member. The optical coupling device according to claim 3. The slit portion penetrating the holding member penetrates the holding member, passes through the holding member and a first slit portion disposed along the axial direction of the holding member, and holds the holding member. A second slit portion disposed along the circumferential direction of the member and communicating with the first slit portion;
4. The optical coupling device according to claim 3, wherein the optical element has an engaging portion that engages with the second slit portion via the first slit portion.   The reduction portion is recessed from an outer peripheral surface of the holding member toward an inner peripheral surface, and includes an axial direction of the holding member, a circumferential direction of the holding member, and a spiral direction with respect to the axial direction of the holding member. The optical coupling device according to claim 1, further comprising a recess disposed along at least one side.   The said recessed part arrange | positioned along at least one of the said axial direction and the said spiral direction has penetrated the said holding member in the radial direction of the said holding member, The Claim 6 characterized by the above-mentioned. Optical coupling device.   In order to prevent the optical element from coming off from the holding member, it further includes a preventing portion that locks with the concave portion disposed along the spiral direction and caps the holding member. The optical coupling device according to claim 7.

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