JPS6221106A - Aligning device for optical fiber - Google Patents

Abstract

PURPOSE:To adjust the relative position of an optical fiber or optical system by fitting plural tension springs in different directions on a plane nearly perpendicular to the optical axis of the optical fiber or optical system on a holder, and adjusting the tensile force of each spring. CONSTITUTION:The 1st and the 2nd tension springs 23 and 25 are fitted almost at right angles to each other in the plane nearly perpendicular to the optical axis of a fiber end 7a. Their positions are adjustable independently in directions V1 and V2 and position adjusting operation is performed while the detected light power of a photodetector 33 is referred to; and linear actuators 27 and 29 are only moved so that the photodetector 33 detects maximum light power, thereby aligning the optical axes of the 1st and the 2nd fibers 7 and 21 with each other. The Young's modulus and size of a rod member 3, the size of the holder 5, the spring constants of the 1st and the 2nd tension springs 23 and 25, etc., are determined properly and the displacement of the fiber end 7a is adjusted finely for the displacement of the linear actuators 27 and 29.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to an optical fiber alignment device, and more specifically, for aligning the optical axis between an optical fiber and an optical system to be optically connected to the optical fiber. This invention relates to an alignment device using a stress-strain method.

(Prior art) Conventionally, in optical fiber characteristic measurement tests, configuration of optical fiber communication systems, etc., connections between optical fibers and optical fibers or between optical fibers and other optical equipment have been used. It is well known to use a so-called stress-strain type alignment device to achieve highly accurate alignment between the optical axes of these optical fibers and optical equipment. As shown in FIG. 2, the conventional stress-strain type alignment device has one side which is connected to a holder 5 supported in a cantilever manner by a fixed part 1 via an elastically deformable member 3. The tip of the optical fiber 7, which is a member of
By applying a force in the direction v2 orthogonal to vl via a rotary lever 15 pivoted about the holder 5, t #) adjusts the optical axis position of the optical fiber 7 fixed on the holder, and aligns it with the optical axis of the other member to be connected fixedly arranged opposite to the optical fiber 7, for example, the optical fiber 21. The optical axis position is adjusted by referring to the amount of light emitted from the other optical fiber 21 so that the amount of light incident on the other optical fiber 21 to be connected from the optical fiber 7 is maximized. It is carried out while

(Problems to be Solved by the Invention) However, the conventional alignment device described above has difficulty in performing stable and highly accurate positioning for the following reasons.

1) When a displacement is applied to the holder 5 in the v2 direction via the compression spring 11 and the rotary lever 15, the tip of the compression spring 9 is dragged in the v2 direction due to friction with the holder 5. When a force in the v1 direction is applied to the spring 9, buckling occurs in the compression spring 9, so that the proportional relationship between the compression force of the spring 9 in the v1 direction and the displacement of the holder 5 no longer holds true. Note that buckling of a spring means that the proportional relationship between the load in the axial direction and the displacement breaks down as a result of the axial center of the spring being bent.

++) Frictional force acts between the holder 5 and the rotary lever 15, and this frictional force fluctuates due to the compression force of the spring 11. Therefore, this also causes the difference between the compression force of the spring 9 in one direction and the displacement of the holder 5. The proportional relationship between them breaks down.

111) Similarly, a frictional force acts between the spring 9 and the holder 5, and this frictional force varies depending on the compressive force of the spring 9, so
v2 applied to spring 11 via rotary lever 15
The force in the direction and the displacement of the holder 5 in the v2 direction are not proportional.

1 Even when the holder 5 is not displaced in the v2 direction, if the spring 9 is buckled, the holder 5 is displaced in the v2 direction.

Furthermore, even if the spring 9 does not buckle, when the holder 5 is displaced in the Vi direction, the friction between the holder 5 and the rotary lever 15 causes the rotary lever to rotate, so that the holder 5 has v2 A displacement in the direction occurs.

In other words, in conventional alignment devices, the compressive force of one spring or the displacement of the holder always causes friction or buckling on the end face of the other spring, making it difficult to achieve stable and accurate positioning. . In response to this, attempts have been made to eliminate the effects of friction by smoothing the end faces of the springs and the abutting surfaces between the rotary lever and the holder, but this is not a sufficient countermeasure. Moreover, if the rigidity of the spring is increased to prevent buckling, the frictional force will be increased, and no fundamental solution could be obtained due to the contradictory nature of the two.

(Means for Solving the Problems) The present invention has been made to eliminate the above-mentioned drawbacks of the conventional art. The optical fiber and the optical system facing each other are fixed in position, and the other is supported on a holder in a cantilever manner via a member that can be elastically deformed from the fixing part. A plurality of tension springs are directly attached to the holder in different directions in a plane substantially perpendicular to the optical axis of the optical fiber or optical system on the holder, and the tension of each spring is adjusted. The present invention is characterized in that a means is provided so that the relative position of the optical fiber or optical system fixed on the holder can be adjusted by adjusting the tensile force of each spring applied to the holder.

(Function) The optical axis of the optical fiber or optical system fixed on the holder and the holder can be adjusted in position by adjusting the tensile force of each tension spring directly attached to the holder. can. In this case, as mentioned above, the buckling of the spring and the friction between the holder and the spring system have a large effect on the accurate positioning of the holder, but since the present invention uses a tension spring, one spring Even if the holder connecting end of the holder is displaced during the action of another spring, the spring axis will not bend, so there is no risk of buckling. In addition, since each spring is directly pulling the holder, there is no room for friction between the holder and the spring, and since there is no inclusion between the holder and the spring, such as the above-mentioned rotating lever, there is no interference between the holder and the spring. There is no effect of friction caused by objects. Therefore, the position of the holder can be adjusted stably and precisely using only the tensile force of the spring.

(Embodiments) Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings.

Figure 1 shows 7742~ according to the present invention using a two-axis movement mechanism.
7747, in which 1 is a fixed part of the device, 3 is an elastically deformable rod-like member whose one end is fixed in a cantilever manner to the fixed part, and 5 is the rod-like member 3. A holder is fixed at the other end, 7 is a first fiber whose tip 7cL is fixed on the holder, and 21 is a second fiber to be optically connected to the first fiber. Although not shown, the distal end portion is fixed in position to a device fixing portion. Reference numerals 23 and 25 denote first and second tension springs, 27 and 25, which are directly attached to the holder 5 and are oriented in directions vl and v2 that are perpendicular to each other in a plane perpendicular to the optical axis of the fiber end 7α. first and second linear actuators 29 are respectively supported on the device fixing part and connected to the first and second tension springs 23.25 to adjust the tension of the first and second tension springs; 31 is the first
A light source is connected to the rear end of the second fiber 7, and 33 is a light receiver connected to the rear end of the second fiber 21.

In this embodiment, the first and second tension springs 23
．． 25 are attached in a plane perpendicular to the optical axis of the fiber end 7a and at right angles to each other, so that the position adjustment by one tension spring does not affect the position adjustment by the other tension spring. The positions can be adjusted independently in the Vl and V2 directions. The position adjustment is performed while referring to the optical power detected by the optical receiver 33. By moving the linear actuators 27 and 29 so that the optical receiver 33 detects the maximum optical power, the optical axes of the first and second fibers 7 and 21 can be adjusted. Can be matched. In this case, the elastic modulus and dimensions of the rod-shaped member 3, the dimensions of the holder 50, and the first and second tension springs 2
By appropriately determining the spring constant of 3.25, etc., the fiber end 7
The displacement of a can be finely adjusted. For example, the elastic modulus of the spring system consisting of the rod-shaped member 3 and the holder 5 is V,
Both direction and ■2 are equal L < k t = 40Kf
, /1m, and the spring constants of spring 23.25 are both IK9/mm, then the linear actuator is 27°2
When the fiber end 7a is displaced by one distance, the amount of displacement of the fiber end 7a in the v1 direction and the V2 direction is both 0.025 mm. In addition, by performing positioning with reference to the optical power of the light receiver 33 as described above, quick and accurate positioning is possible.

Although the above embodiment describes alignment between 7747 and 7747, the present invention is not limited to this, and one fiber is an optical system such as a pinhole, a lens system, a glass rod, an aperture, etc., and the fiber and this are aligned. It can also be applied to alignment with an optical system. In this case, either the fiber or the optical system may be fixed on the holder and its position adjusted. Furthermore, in the above embodiment, two tension springs are mounted on the holder so as to be orthogonal to each other in a plane perpendicular to the optical axis of the fiber fixed on the holder. It can be changed at any time within a plane perpendicular to the axis.

(Effects of the Invention) As described above, according to the present invention, when aligning the optical axes of an optical fiber and an optical system using a stress-strain alignment device, the positioning of an optical fiber or an optical system can be performed with high accuracy, speed, and accuracy. It can be done stably.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a main part showing an embodiment of an alignment device according to the present invention, and FIG. 2 is a perspective view of a main part of a conventional alignment device. Patent applicant: Sumitomo Electric Industries, Ltd. (5 others)

Claims (6)

[Claims] (1) An alignment device between an optical fiber and an optical system to be optically connected to the optical fiber, which fixes the position of either the optical fiber or the optical system facing each other, and fixes the other one to a fixing part. It is fixed on a holder supported in a cantilever manner via a more elastically deformable member, and a plurality of tension springs are directly attached to the holder approximately perpendicular to the optical axis of the optical fiber or optical system on the holder. The optical fiber or the optical system fixed on the holder can be fixed to the holder by adjusting the tension of each spring. Optical fiber alignment device with adjustable position. (2) The alignment device according to item 1, wherein the tension spring is oriented in two directions that are substantially perpendicular to each other in a plane that is substantially perpendicular to the optical axis of the optical fiber or optical system fixed on the holder. (3) The alignment device according to item 1 or 2, wherein the optical system is any one of an optical fiber, a pinhole, a lens system, a glass rod, and an aperture. (4) An alignment device between an optical fiber and an optical system to be optically connected to the optical fiber, which fixes the position of either the optical fiber or the optical system facing each other, and fixes the other one in a fixed position. It is fixed on a holder supported in a cantilever manner via a more elastically deformable member, and a plurality of tension springs are directly attached to the holder approximately perpendicular to the optical axis of the optical fiber or optical system on the holder. The optical fiber or the optical system fixed on the holder can be fixed to the holder by adjusting the tension of each spring. The optical system is characterized in that the position is adjustable, a light source is connected to one of the optical fiber and the optical system, and a light receiver is connected to the other, and alignment is performed while referring to the amount of light received by the light receiver. Optical fiber alignment device. (5) The alignment device according to item 4, wherein the tension spring is oriented in two substantially perpendicular directions within a plane substantially perpendicular to the optical axis of the optical fiber or optical system fixed on the holder. (6) The alignment device according to item 4 or 5, wherein the optical system is any one of an optical fiber, a pinhole, a lens system, a glass rod, and an aperture.