JP2007232957A - Optical coupling component - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To facilitate adjustment of optical characteristics of an optical coupling component while increasing resistance of the component to vibrations and shocks, and further to reduce the costs of the component. <P>SOLUTION: The optical coupling component 1 is equipped with an optical fiber 2, a sphere lens 3, and a cylindrical ferrule 4 in which a through-hole 41 for fixing the optical fiber 2 therein is coaxially arranged. On one end side of the ferrule 4, a hollow counterbore part 43 which is a trapezoidal body of rotation is formed coaxially with the through-hole. The ferrule 4 therefore becomes a rotation symmetry form with the through-hole 41 as an axis, and the ferrule 4 can be manufactured easily and inexpensively. The sphere lens 3 is fixed to the counterbore part 43 with an adhesive 5, and the resistance to vibrations or the like can be increased as a result. The sphere lens position in the direction perpendicular to the optical axis is determined by the counterbore part 43 coaxial with the through-hole 41. The optical characteristics therefore can be adjusted only by shifting the optical fiber 2 in the direction of the optical axis. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an optical coupling component that optically couples light propagating in space and an optical fiber.

  In recent years, with the spread of optical communication, optical components are used in various environments. For this reason, there is a need for an optical component such as an optical coupling component that can stably maintain performance in an environment with impact, vibration, and the like. The optical coupling component includes an optical fiber that transmits an optical signal, a lens that converges or diverges the optical signal between the space and the optical fiber, and a ferrule that fixes the optical fiber and the lens, and propagates through the space. The light and the optical fiber are optically coupled via a lens.

  Among the above optical coupling components, an optical coupling system device in which a spherical lens is press-fitted into a housing and fixed so as to be used in an environment with vibration or the like is known (for example, see Patent Document 1). This optical coupling device will be described with reference to FIG. The apparatus 101 includes an optical fiber 102, a ferrule 103 that supports the optical fiber 102, a spherical lens 104 that focuses a light path transmitted from the optical fiber, and a housing 105 that aligns the ferrule 103 and the spherical lens 104. . The housing 105 has a through hole 106 coaxial with the housing 105 and a counterbore 107 on one end side, and is formed so that the ferrule 103 and the ball lens 104 can be supported and fixed simultaneously. The manufacturing method of this apparatus is as follows. First, the optical fiber 102 is inserted and fixed in the center of the ferrule 103. Thereafter, the cross section of the ferrule 103 is polished so as to be inclined from a plane perpendicular to the axis of the ferrule 103. Next, the ferrule 103 is inserted and fixed to the through hole from the opening formed on the end surface of the housing 105 opposite to the side on which the counterbore 107 is formed. After the ferrule 103 is fixed, the spherical lens 104 is press-fitted into the counterbore part 107. By moving the spherical lens 104 in the optical axis direction, the distance from the tip of the optical fiber 102 is adjusted. Thereafter, the spherical lens 104 is fixed. Since the spherical lens 104 is fixed by such a method, the present apparatus can be used in an environment with vibration or the like.

Further, an optical collimator in which a spherical lens is fixed in a lens fixing hole of a ferrule is known (for example, see Patent Document 2). This optical collimator includes a metal ferrule having a fiber holding hole for holding an optical fiber, a spherical lens attached to the opening on the distal end side of the ferrule so as to face the distal end surface of the optical fiber, Is provided. A lens fixing hole is recessed around the opening on the tip side of the ferrule. The front-view shape of the lens fixing hole is smaller than the diameter of the spherical lens. The spherical lens is fixed to the ferrule with the spherical surface in contact with the hole edge of the lens fixing hole.
JP-A-9-189826 JP 2005-221671 A

  However, in the conventional technique and the technique described in Patent Document 1, since the ball lens 104 is fixed only by press-fitting, the force with which the housing 105 holds the ball lens 104 is weak. Further, since the distance between the spherical lens 104 and the optical fiber 102 is adjusted by moving the spherical lens 104 when the spherical lens 104 is press-fitted, fine adjustment is difficult. Further, since the shape of the ferrule 103 is not rotationally symmetric, it is difficult to manufacture and the cost is high. In the technique described in Patent Document 2, the shape of the lens fixing hole in which the spherical lens is fixed is smaller than the diameter of the spherical lens, so that the force with which the ferrule fixes the spherical lens is weak and sufficient for vibration or impact. I couldn't have enough tolerance.

  The present invention has been made in order to solve the above-described conventional problems, and has improved resistance to vibration or impact, and can easily adjust optical characteristics, and can be manufactured at low cost. The purpose is to provide.

  In order to achieve the above object, the invention of claim 1 includes an optical fiber, and a cylindrical ferrule in which a through hole having substantially the same diameter as the optical fiber is provided coaxially, and the optical fiber is fixed to the through hole. An optical coupling component that optically couples light propagating in space and the optical fiber, further comprising a spherical lens for making light emitted from the optical fiber into parallel light, and one end side of the ferrule A trapezoidal rotator-shaped hollow counterbore part having an enlarged opening end is formed coaxially with the through-hole, and the spherical lens is smaller than the maximum diameter of the counterbore part, and The optical fiber has a diameter larger than the minimum diameter, is inserted into the counterbore part, and is bonded and fixed by an adhesive so as to face the tip of the optical fiber, and the optical fiber is located at a position where the tip protrudes into the counterbore part. It, for the light emitted from the bulb lens into parallel light, in which the distance between the tip and the ball lens is fixed to the adjusted position.

  A second aspect of the present invention is the optical coupling component according to the first aspect, wherein the groove-shaped adhesive is provided on the opening end side from the portion of the counterbore portion that contacts the ball lens and toward the opening end. At least one reservoir is provided.

  A third aspect of the present invention is the optical coupling component according to the first aspect, wherein an adhesive reservoir is provided along the outer periphery of the spherical lens in the vicinity of a portion of the counterbore portion that contacts the spherical lens. Is.

  According to the first aspect of the present invention, the position of the spherical lens in the direction perpendicular to the optical axis is determined by the counterbore portion of the trapezoidal rotating body shape of the ferrule, and the counterbore portion and the through hole are formed coaxially. This eliminates the need to adjust the optical axis between the ball lens and the optical fiber fixed in the through-hole. By simply moving the optical fiber in the optical axis direction, the distance between the ball lens and the optical fiber can be adjusted to adjust the optical characteristics. Can be planned. Therefore, the adjustment of optical characteristics can be simplified. In addition, since the spherical lens is inserted into the counterbore part and bonded and fixed with an adhesive, the force with which the ferrule holds the spherical lens can be increased, and resistance to vibration or impact can be improved. Furthermore, the ferrule is cylindrical, and the shape of the counterbore part of the ferrule is a trapezoidal rotary body shape, and the opening end is enlarged in diameter, and the axis of the ferrule and the counterbore part is coaxial with the through hole. The ferrule has a rotationally symmetric shape with the through hole as an axis, so that the ferrule can be easily manufactured, the production efficiency is improved, the ferrule yield is improved, and the cost of the optical coupling component can be reduced.

  According to the invention of claim 2 or claim 3, when the ball lens and the counterbore part are bonded and fixed by the adhesive, the adhesive flows into the adhesive pool, so that the adhesive emits an optical signal of the ball lens or It is possible to prevent the light path from being interrupted by entering the incident site.

  An optical coupling component according to a first embodiment of the present invention will be described with reference to FIG. FIG. 1 shows the configuration of the optical coupling component. The optical coupling component 1 fixes an optical fiber 2 for transmitting an optical signal, a spherical lens 3 for making light emitted from the optical fiber 2 (indicated by broken arrows) into parallel light, and the optical fiber 2 and the spherical lens 3. A cylindrical ferrule 4 for optically coupling the light propagating through the space and the optical fiber 2. The optical fiber 2 and the spherical lens 3 are bonded and fixed to the ferrule 4 with an adhesive 5. A portion of the optical fiber 2 outside the ferrule 4 is covered with a coating 6.

  The ferrule 4 is made of, for example, ceramic, resin, or metal. The ferrule 4 is formed with a through-hole 41 having substantially the same diameter as the optical fiber 2 and coaxial with the ferrule 4. When the ferrule 4 is made of metal, the optical coupling component 1 can be fixed to another component by soldering or welding, so that the force with which the other component holds the optical coupling component 1 can be improved. .

  The end portion 42 on one end side of the ferrule 4 is formed with a hollow counterbore portion 43 having a trapezoidal rotator shape and having an open end whose diameter is increased. The counterbore part 43 is provided coaxially with the through hole 41. The maximum diameter of the counterbore part 43, that is, the diameter of the opening is smaller than the outer diameter of the ferrule 4. The ball lens 3 is inserted and fixed in the counterbore part 43. The diameter expansion degree of the counterbore part 43 is adjusted so that a part of the ball lens 3 to be fixed protrudes from the ferrule 4. For this reason, it is possible to accurately grasp the position of the ball lens 2 from the outside, and when the optical coupling component 1 and other optical components are optically connected, it is possible to accurately adjust these positions. .

  A groove-like adhesive reservoir 46 is provided on the opening end side from the portion of the counterbore 43 that contacts the ball lens 3. This adhesive reservoir 46 is formed from the portion of the counterbore 43 that contacts the spherical lens 3 toward the opening end. Further, the adhesive reservoir 46 is disposed at an angle of approximately 90 degrees with respect to the axis of the through hole 41 on a plane perpendicular to the axis of the through hole 41. The number of adhesive reservoirs 46 is four. The depth of the adhesive reservoir 46 is deeper toward the opening end. The cross-sectional shape of the adhesive reservoir 46 is, for example, a rectangle.

  An optical fiber insertion port 45 for inserting the optical fiber 2 is formed at the end 44 on the other end side of the ferrule 4. The diameter of the optical fiber insertion port 45 extends in an arc shape toward the opening end. The shape of the optical fiber insertion port 45 is a tapered shape with the opening end having an enlarged diameter, and is, for example, the same shape as a rounded chamfer, and is a rotationally symmetric shape about the axis. The through hole 41, the counterbore part 43, and the optical fiber insertion port 45 are provided coaxially connected.

  As described above, the ferrule 4 is cylindrical, the shape of the counterbore part 43 is a trapezoidal rotator, and the shape of the optical fiber insertion port 45 is a rotationally symmetric shape. The axes of the ferrule 4, the counterbore part 43, and the optical fiber insertion port 45 are coaxial with the through hole 41. Therefore, the ferrule 4 has a rotationally symmetric shape with the through hole 41 as an axis, and the ferrule 4 can be easily manufactured. Accordingly, the production efficiency can be improved, the yield of the ferrule 4 can be improved, and the cost of the optical coupling component 1 can be reduced.

  The optical fiber 2 is inserted into the through hole 41 from the optical fiber insertion port 45 of the ferrule 4, and the tip thereof is fixed at a position protruding from the bottom surface 47 of the counterbore part 43. The front end surface of the optical fiber 2 is cut obliquely with respect to the direction perpendicular to the optical axis, and the inclination angle is, for example, about 8 degrees. The front end surface has an antireflection coating for reducing reflection loss. Is given. The optical fiber 2 is fixed by the adhesive 5 poured from the optical fiber insertion port 45 after the tip of the optical fiber 2 is cut obliquely and the optical fiber 2 is positioned. The direction perpendicular to the optical axis means a direction perpendicular to the optical axis.

  The spherical lens 3 is made of a spherical optical material having a diameter of approximately 1 mm to 2 mm, and has a diameter smaller than the maximum diameter of the counterbore part 43 and larger than the minimum diameter of the counterbore part 43. The spherical lens 3 is inserted into the counterbore part 43 and positioned so as to face the tip of the optical fiber 2. The adhesive 5 is applied to the contact portion between the ball lens 3 and the counterbore part 43, and the ball lens 3 is bonded and fixed to the counterbore part 43. For this reason, the force with which the ferrule 4 holds the ball lens 3 can be increased, and resistance to vibration or impact can be improved. Further, since the adhesive 5 applied to the spherical lens 3 and spread by the surface tension flows into the adhesive reservoir 46, the adhesive 5 wraps around the portion of the spherical lens 3 where the optical signal is emitted and blocks the optical path. Can be prevented. The adhesive 5 includes, for example, an instantaneous adhesive, a two-component adhesive, an ultraviolet curable adhesive, or the like. The surface of the spherical lens 3 that is in contact with the air is provided with an antireflection coating, which makes it possible to reduce reflection loss.

  Next, a procedure for fixing the optical fiber 2 and the spherical lens 3 will be described. First, the spherical lens 3 is inserted into the counterbore part 43 of the ferrule 4. The position of the spherical lens 3 in the direction perpendicular to the optical axis is determined by a counterbore portion 43 having a trapezoidal rotating body shape. After the positioning of the ball lens 3, the ball lens 3 is bonded and fixed to the counterbore part 43 with the adhesive 5. After the ball lens 3 is fixed, the optical fiber 2 is inserted into the through hole 41, and the position of the optical fiber 2 in the direction perpendicular to the optical axis is determined. Since the counterbore part 43 and the through hole 41 are formed coaxially, it is not necessary to adjust the optical axis between the spherical lens 3 and the optical fiber 2 fixed to the through hole 41. For this reason, the optical characteristic can be adjusted by adjusting the distance between the ball lens 3 and the optical fiber 2 only by moving the optical fiber 2 in the optical axis direction. Therefore, the adjustment of optical characteristics can be simplified.

  After insertion of the optical fiber 2, the optical fiber 2 is moved in the optical axis direction, and the light emitted from the optical fiber 2 becomes parallel light through the spherical lens 3. The distance is adjusted. The optical fiber 2 is bonded and fixed by an adhesive 5 at a position where the light emitted from the spherical lens 3 becomes parallel light.

  In addition, when the inside of the ferrule 4 is filled with the adhesive 5 and the tip of the optical fiber 2 and the ball lens 3 are bonded and fixed to the ferrule 4, the optical fiber 2 is fixed after the ball lens 3 is fixed and before the optical fiber 2 is inserted. The adhesive 5 is poured from the fiber insertion port 45. Thereafter, the optical fiber 2 is inserted into the optical fiber insertion port 45. In this case, the adhesive 5 is an optical adhesive made of a translucent resin. When this optical adhesive is made of an ultraviolet curable resin, the ferrule 4 is formed of a transparent material that is capable of transmitting ultraviolet rays, so that the optical adhesive is cured by irradiating ultraviolet rays from the outside, and the optical fiber 2 is attached to the ferrule 4. It becomes possible to bond and fix.

  Next, an optical coupling component according to a second embodiment of the present invention will be described with reference to FIG. FIG. 2 shows the optical coupling component of this embodiment. The optical coupling component of this embodiment is different from that of the above embodiment in that the shape of the adhesive reservoir 46 is different. In the present embodiment, the same members as those in the first embodiment are denoted by the same reference numerals.

  The adhesive reservoir 46 is provided along the outer periphery of the spherical lens 3 in the vicinity of the portion of the counterbore 43 of the ferrule 4 that contacts the spherical lens 3. The adhesive reservoir 46 is formed by further increasing the diameter of the counterbore part 43 from the contact portion with the ball lens 3 toward the opening end. Also in the optical coupling component of this embodiment, the same effect as the said embodiment is obtained.

  The present invention is not limited to the configuration of the embodiment as described above, and various modifications can be made according to the purpose of use. For example, the cross-sectional shape of the adhesive reservoir 46 is not limited to a rectangle, and may be a semicircle, a semi-ellipse, a part thereof, or a trapezoid. The number of groove-like adhesive reservoirs 46 is not limited to four, and may be any number. Further, the propagation path of the optical signal is not limited to the above-described propagation path, the optical signal is incident on the spherical lens 3 from the outside, converged by the spherical lens 3, and the converged optical signal is incident on the optical fiber 2. It doesn't matter.

(A) is sectional drawing of the optical coupling component which concerns on the 1st Embodiment of this invention, (b) is sectional drawing of the component, (c) BB 'sectional view taken on the line, (c) is the same It is a longitudinal cross-sectional view of components, and the enlarged view of the broken-line A part of (a). (A) is sectional drawing of the optical coupling component which concerns on the 2nd Embodiment of this invention, (b) is sectional drawing of the component, (c) DD 'line sectional drawing, (c) is the same It is a longitudinal cross-sectional view of components, and the enlarged view of the broken-line C part of (a). Sectional drawing of the conventional optical coupling system apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Optical coupling component 2 Optical fiber 3 Ball lens 4 Ferrule 5 Adhesive 41 Through-hole 43 Counterbore part 45 Optical fiber insertion port 46 Adhesive reservoir

Claims (3)

An optical fiber, and a cylindrical ferrule in which a through-hole having substantially the same diameter as the optical fiber is provided coaxially, and the optical fiber is fixed to the through-hole, and the light propagating through space and the optical fiber In an optical coupling component that optically couples
A spherical lens for making the light emitted from the optical fiber parallel light;
On the one end side of the ferrule, a hollow counterbore part having a trapezoidal rotary body shape and having an enlarged opening end is formed coaxially with the through hole,
The spherical lens has a diameter smaller than the maximum diameter of the counterbore part and larger than the minimum diameter of the counterbore part, is inserted into the counterbore part, and is bonded and fixed by an adhesive so as to face the tip of the optical fiber. ,
The optical fiber is fixed at a position where the tip of the optical fiber protrudes into the counterbore, and the distance between the tip of the ball lens and the ball lens is adjusted in order to make the light emitted from the ball lens parallel light. An optical coupling component characterized by that.   2. The groove-like adhesive reservoir is provided at the opening end side of the counterbore part with respect to the ball lens from the part toward the opening end. Optical coupling component.   2. The optical coupling component according to claim 1, wherein an adhesive reservoir is provided along an outer periphery of the spherical lens in a vicinity of a portion of the counterbore portion that contacts the spherical lens.

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