JP2003194667A - Optical fiber end face inspection device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a device for inspecting the shape of an optical fiber end face to be connected, formed by polishing or the like. <P>SOLUTION: This device is equipped with an optical fiber holder 2 for holding plural optical fibers 1 mutually in parallel with optical fiber end faces 1a positioned in order, a laser beam source 3 for irradiating the optical fiber end faces 1a with laser beams, a lens 5 for converging the laser beams 4a into a light flux having the smaller diameter than the center interval between each optical fiber 1 on the optical fiber end face 1a, a screen 7 which is a measuring means for measuring inclination of the optical fiber end face 1a by receiving the laser beams 4b reflected by the optical fiber end face 1a, and a stage for moving the optical fiber holder 2 or the beam source 3 in order to change the optical fiber end face 1a to be irradiated with the laser beams. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical fiber connector for collectively connecting a plurality of optical fibers, or an optical waveguide / optical device for connecting a plurality of optical waveguides formed on a substrate and a plurality of optical fibers. The present invention relates to an apparatus for inspecting the shape of an end face of a connecting optical fiber formed by polishing or the like in a process of manufacturing a fiber connector.

[0002]

2. Description of the Related Art At present, with the rapid spread of the Internet, there is an increasing demand for a large-capacity network system capable of transmitting a large amount of information such as moving images and voice in a short time. Therefore, in the future, it is expected that the optical network based on the optical fiber communication will be expanded in order to realize such a high performance network. In order to popularize the optical network, it is necessary to make various optical components or various optical devices such as optical transmitting / receiving devices and optical switching devices functional and economical.

An optical fiber connector is an optical component having a function of optically connecting optical fibers to each other, that is, in a state in which light propagating in one optical fiber can propagate to the other optical fiber. . Hereinafter, the optical connection will be simply referred to as a connection. The optical fiber connector is an important and many optical component used in constructing an optical network system, and is used for connecting optical fibers to each other in an optical fiber transmission line or an optical device. So far, SC type, M type as single-core optical fiber connector
U type optical connector, MT as multi-fiber optical fiber connector
Type optical connectors have been developed and used. But,
It is expected that the number of optical fibers to be connected in the optical fiber transmission line and the optical device will greatly increase as the optical network system becomes more sophisticated and larger in the future. Along with this, it is required that a large number of small-sized optical fibers be collectively connected to the optical fiber connector, that is, high-density multi-core connection is possible and that the cost is low.

Therefore, as an optical fiber connector having a possibility of satisfying such requirements, Japanese Patent Laid-Open No. 9-1598 / 1997.
There is one disclosed in Japanese Patent Laid-Open No. 60. FIG. 7 shows an outline of this optical fiber connector. This optical connector is shown in FIG.
The coating has been removed, as shown in cross section in (a). That is, the first with the bare optical fiber 1-1 fixed
Plug 20-1, adapter 21, first plug 20-
2nd plug 2 which fixed optical fiber 1-2 like 1
It is composed of 0-2. Then, as shown in FIG. 7B, the first plug 20-1 and the second plug 20
-2 is connected to the adapter 21 from both ends, the optical fibers 1-1 and 2 fixed to the first and second plugs 20-1 and 20-2, respectively, are joined at their opposite end surfaces. , Both optical fibers 1-1 and 2 are connected.

More specifically, in the first plug 20-1, the optical fiber 1-1 is fixed in a state of forming a cantilever, and in the second plug 20-2, the optical fiber 1 is also fixed.
-2 is similarly fixed. Here, the first plug 20-
In No. 1, the tip of the optical fiber 1-1 projects from the tip of the plug by an appropriate length (ΔL). In the second plug 20-2, the tip of the optical fiber 1-2 is flush with the end surface of the plug 20-2. The end faces of the optical fibers 1-1 and 2 are processed to be smooth and perpendicular to the axial direction. On the other hand, the adapter 21 includes the first and second
Of the plugs 20-1 and 20-2 have alignment members 21a into which the optical fibers are inserted from both sides. , 2 outer diameter (about 125 μm).

When the first and second plugs 20-1 and 20-2 are connected to the adapter 21, respectively, the optical fibers 1-1 and
The two end faces are joined together. At this time, based on the above ΔL,
The optical fiber 1-1 includes the plug 20 outside the alignment member 21a.
Buckling in the -1 cavity. Buckled optical fiber 1
Since -1 exerts an elastic force that tends to extend to the original length, the end faces of the optical fibers 1-1 and 2 are joined with an appropriate load. As a result, the end faces of the optical fibers 1-1 and 2 are brought into close contact with each other. This state is PC (Physical Con
tact). In this state, the optical fibers 1-1,
Since the interface between the air and the end face of the optical fiber, which causes the reflection of light, is eliminated between the two end faces, the power of the light propagating through the optical fiber in the direction opposite to the propagation direction at the above-mentioned joint surface is Noticeably smaller In other words, the return loss on the joint surface is large.

Compared with the conventional optical fiber connector, this optical fiber connector does not require the use of a ferrule, and the optical fibers 1-1 and 2 can be spatially arranged at a high density. Further, it is not necessary that the distance between the optical fibers 1-1 and 2 and the distance between the holes of the alignment member 21a be high, and if the optical fibers 1-1 and 2 can be inserted into the corresponding holes of the alignment member 21a, the opposing light beams will be The fibers can be aligned with high precision, and a low splice loss can be easily obtained.

On the other hand, optical modules such as an optical transmitter / receiver, an optical distributor, an optical exchanger, and a wavelength multiplexer / demultiplexer which are basically composed of a substrate type optical waveguide are important optical parts constituting various optical devices. is there. Hereinafter, the substrate type optical waveguide is simply referred to as an optical waveguide. An optical fiber is usually connected to these optical modules in order to input and output an optical signal to the outside. At present, the mainstream of the connection between the optical module and the optical fiber, in other words, the connection between the optical waveguide and the optical fiber, is a permanent connection using an adhesive or a fusion method, and the connection and the release cannot be repeated. Therefore, the module must be mounted on the printed circuit board with the optical fiber connected, which hinders the mounting of the optical module itself and other components, and causes a high mounting cost. .

Further, Japanese Patent Application No. 8-77282 discloses that
An optical waveguide / optical fiber connector capable of repeating the collective connection and disconnection of a plurality of optical fibers and an optical waveguide is described. By applying this connector to the above optical module and connecting the optical module and the optical fiber into a connector, the optical module can be mounted on the printed board without the optical fiber.
As a result, it becomes easy to mount the optical module and other optical components and electronic components on the printed board, and the mounting cost can be reduced.

FIG. 8 schematically shows the optical waveguide / optical fiber connector. In this optical connector, as shown in the sectional view of FIG. 8A, a jack 22 is mounted on the optical waveguide substrate 24, and a guide member 23 is mounted on the end face of the optical waveguide substrate 24. The optical fiber 1 is fixed to the plug 20 so as to form a cantilever. Here, the optical fiber 1 in the plug 20 is in a bare state, and its tip projects from the tip of the plug 20 by an appropriate length (ΔL). Further, the end surface of the optical fiber 1 is processed into a smooth surface which is perpendicular to the axial direction. The guide member 23 has an insertion hole 23a for aligning the optical axes of the optical waveguide 25 and the optical fiber 1. Then, as shown in FIG. 8B, when the plug 20 is inserted and fitted into the jack 22, the optical fiber 1 is inserted into the insertion hole 23a, the end face of the optical fiber 1 hits the end face of the optical waveguide 25, The optical waveguide 25 and the optical fiber 1 are connected. At this time, since the end face of the plug 20 and the end face of the optical fiber 1 abut against the end face of the optical waveguide substrate 24, the optical fiber 1 is projected from the end face of the plug 20 (ΔL), so that the optical fiber 1 in the cavity of the plug 20. Buckle and bend. Then, the end face of the optical fiber 1 is pressed against the end face of the optical waveguide 25 with an appropriate load due to the elastic force of the optical fiber 1 trying to extend to the original length. Thereby, the PC of the end face of the optical fiber 1 and the end face of the waveguide 25
Will be realized. Then, from the optical waveguide 25 to the optical fiber 1
When the light propagates to or from the optical fiber 1 to the optical waveguide 25, the power of the reflected return light at the contact portions of both end faces becomes very small. Since this connector also accommodates the bare optical fibers 1, the optical fibers 1 can be arranged at a high density, and a compact and high-density multi-core connection can be realized. After that, P based on the buckling of the optical fiber
The above-mentioned optical fiber connector and optical waveguide / optical fiber connector using C will be generically referred to as a connector.

[0011]

In the connector, in order to achieve the PC of the connection surface by the force generated by the buckling of the optical fiber, the end surface of the optical fiber serving as the connection surface is a surface which is perpendicular to the axial direction and smooth. Must be In detail, the angular error of the actual end face relative to the ideal vertical plane (Δ
θ) needs to be equal to or less than an appropriate value (allowable value of angular error). If the angle error is large, the PC due to the buckling of the optical fiber cannot realize the PC of the connection surface, and a sufficient return loss cannot be achieved. Therefore, it is necessary to measure the angular error of the end surface of the optical fiber after forming the end surface of the optical fiber by polishing and inspect whether the angular error is within the allowable range. When the connector has a plurality of optical fibers, in other words, in the case of a multi-core type, when manufacturing the plurality of optical fibers, the plurality of optical fibers are arrayed (the plurality of optical fibers are aligned in parallel at regular intervals), and the end faces are polished and the end faces are polished. If it can be fixed to the plug through processing steps such as inspection and coating removal, the connector can be manufactured at a lower cost than in the case where the optical fibers are individually processed and then fixed to the plug.

In addition, in the SC type and MU type optical connectors, the ferrule end surface is polished to a convex spherical shape in order to achieve the PC of the connecting surface, but in the above-mentioned connector using the bare fiber, the optical fiber The diameter is as small as about 0.125 mm, and even if the end surface is flat, PC can be sufficiently achieved.

Up to now, the methods of measuring the angle error of the end face of the optical fiber include (1) observation of the end face of the optical fiber with a microscope, (2) a method utilizing light interference, and (3) utilizing a reflection angle of a light beam. There are ways to do it.

In the method (1), as shown in FIG. 9, the optical fiber end face 1a to be inspected is observed with a microscope from a direction perpendicular to the axial direction of the optical fiber. Although this method is simple, it has a problem in measurement accuracy of the angle error. Further, generally, the end surface of an optical fiber formed by polishing is not always inclined in a specific direction with respect to an ideal vertical surface. That is, the end surface of the optical fiber may tilt upward or laterally. Therefore, it is necessary to rotate the optical fiber 1 around the axis during observation and measure the tilt at the point where the tilt of the end face becomes the largest. When the optical fibers 1 are in the array state, it is impossible to individually rotate each optical fiber, and therefore it is not possible to perform measurement.

FIG. 10 shows an example of a configuration for carrying out the method (2). The light reflected from the optical fiber end face 1a and the light reflected from the half mirror 10 are caused to interfere with each other to generate interference fringes. Then, the interference fringes are subjected to image processing to obtain the inclination of the optical fiber end face 1a, that is, the angle error. However, with this method, focusing of the microscope 14 is troublesome, and the image processing described above also requires some time, so it is difficult to make the measurement time per optical fiber sufficiently short. Furthermore, in order to measure the inclination of the end face with sufficient accuracy, there is a problem that the device becomes expensive.

The method (3) has been reported by Matsunaga et al. (1998 IEICE General Conference, C-3-5).
2, March 1998). As shown in FIG. 11, the end face 1a of the optical fiber to be measured is irradiated with the visible laser beam 4a, and the laser beam 4b reflected from the end face is applied to the screen 7.
Is a method of measuring the inclination of the end face by arriving at. More specifically, the optical fiber 1 is held by the optical fiber holder 2 that sucks the optical fiber 1 in a vacuum state by the vacuum suction groove 26. When the optical fiber 1 is rotated around the axis with the central axis kept constant, the position where the laser beam 4a reflected from the optical fiber end face 1a reaches the screen 7, that is, the spot 13 also rotates on a circular orbit. When the angle error of the optical fiber end face 1a is Δθ and the distance from the optical fiber end face 1a to the screen 7 is L, the diameter of this circular orbit 13a is approximately 2L tan (2Δθ). Therefore,
Δθ can be obtained by measuring the diameter of the circular orbit 13a. The apparatus for carrying out this method is simple, and the inclination of the optical fiber end face 1a can be easily measured in a short time. However, when the optical fibers 1 are arranged in an array and the distance between the optical fibers is narrow, it is difficult to apply this method.

Conventionally, techniques for polishing the end face of an optical fiber in an array state and removing the coating have been established.
As described above, it is difficult to easily measure the angle error of the optical fiber end face in the array state in a short time.
Therefore, when manufacturing a multi-core connector, after polishing a plurality of optical fibers in an array at once, release the array, inspect the optical fiber end faces individually, align them again in the array, and plug It was fixed to. Therefore, in order to manufacture a connector at low cost as described above, there has been a demand for an invention of an apparatus that can easily and quickly inspect end faces of a plurality of optical fibers in an array state.

The present invention has been made to solve such a problem, and its object is to easily inspect the end faces of a plurality of optical fibers arranged in an array state in a short time, and An object is to provide a low-cost optical fiber end face inspection device.

[0019]

In order to solve the above-mentioned problems, a first invention is an optical fiber holder for holding a plurality of optical fibers in parallel with each other by aligning the positions of the end faces of the optical fibers. A laser light source for irradiating the optical fiber end face with laser light, a lens for focusing the laser light into a light beam having a diameter smaller than the center interval between the optical fibers at the optical fiber end face, and the optical fiber end face The optical fiber holder or the light source is moved so that the measuring means for receiving the reflected laser light and measuring the inclination of the optical fiber end surface and the optical fiber end surface irradiated with the laser light are changed. And an optical fiber end face inspection device.

A second invention is the invention of the first optical fiber end face inspection apparatus, which receives the laser light reflected by the end face of the optical fiber, reflects it, and sends the laser light to the screen or the camera. The optical fiber end face inspection apparatus is characterized by including a mirror.

A third aspect of the present invention is the optical fiber end face inspection apparatus according to the first or second optical fiber end face inspection apparatus, wherein the measuring means is a screen or a camera.

That is, the present invention relates to an apparatus for inspecting the end face of an optical fiber in the process of manufacturing an optical connector, wherein the end face of the optical fiber is irradiated with laser light and the reflected light is received by a screen which is a measuring means. It is a thing. A reference position corresponding to the reflected light position is provided in advance on the screen from a perfect end face without inclination, and the inclination of the end face is determined by how far the reflected light is projected from the reference face on the screen. Can be determined.

According to the present invention, the inspection mechanism is moved to
Since one measurement can be performed, the inspection can be performed while the fibers are aligned in the array, and the inspection procedure is simplified. Further, since the fibers can be arranged in an array and proceed to the next step, the manufacturing process of the optical connector can be simplified and the manufacturing cost of the optical connector can be reduced.

[0024]

By using visible light as the laser light source, for example, the position of the spot on the screen, which is the measuring means, can be directly observed with the naked eye, and if the scale is drawn on the screen, the position of the spot The angle error of the end face of the optical fiber can be read immediately from. Therefore,
The angle error can be read in a sufficiently short time without performing image processing using a computer.

Further, by condensing the laser beam output from the laser light source by the lens, the laser beam is efficiently irradiated to the end face of the optical fiber, and the intensity of the laser beam reflected by the end face of the optical fiber is increased. The position of the upper spot becomes clear. Then, an optical fiber holder is installed on the moving stage, which is a moving means, and the moving stage moves the optical fiber in a direction perpendicular to the longitudinal direction of the optical fiber to change the end face of the optical fiber irradiated with the laser beam. can do.

Further, since the optical fiber holder holds a plurality of optical fibers in parallel with each other, when the laser beam is applied to the end face, the central axes of all the optical fibers are directed in the same direction. The upper reference position is a fixed position. The optical fiber holder that holds the optical fibers parallel to each other can be easily configured by using the V-groove substrate. The number of optical fibers that can be held in the optical fiber holder is also determined according to the number of V-grooves.
Even more than one optical fiber can be held in the optical fiber holder at the same time and continuously inspected.

Further, when the optical fiber is held in the optical fiber holder, the position of the end face of the optical fiber in the longitudinal direction is accurately set because the laser beam is applied to the optical fiber even if the position is changed a little. do not have to. Further, in the optical fiber holder, each optical fiber is required to be held in parallel, and the position in the lateral direction is also arbitrary. In other words, the optical fiber can be easily set in the optical fiber holder. When the end face of the optical fiber is extremely deformed due to chipping or breaking, the light intensity of the spot is weak, the spot shape is not circular, or the spot does not appear. Can detect abnormalities.

In order to enable the naked eye to accurately determine the distance from the reference position to the center point of the spot on the screen, which is the measuring means, the optical path of the reflected laser beam from the end face of the optical fiber to be inspected to the screen. Although some length is required, the maximum size of the device can be reduced by introducing a mirror or a half mirror and bending the optical path of the reflected laser beam.

[0029]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail based on the embodiments, but the present invention is not limited to these embodiments.

[First Embodiment] FIG. 1 is a diagram for explaining a first embodiment of an optical fiber end face inspection apparatus according to the present invention. 1 is a plan view showing the structure of the entire apparatus, FIG. 2 is an enlarged perspective view showing the optical fiber 1 and the optical fiber holder 2 in FIG. 1 when viewed from the optical fiber end face 1a side, and FIG. 3 is a measurement in FIG. It is the top view which expanded the screen 7 which is a means from the front. The optical fiber end face inspection apparatus according to the present embodiment is provided with a plurality of optical fibers 1
On the other hand, an optical fiber holder 2 for aligning the positions of the optical fiber end faces 1a and holding them in parallel with each other, a laser light source 3 for irradiating the optical fiber end face 1a with a laser beam, and an optical fiber for the laser beam 4a. A lens 5 that collects a light beam having a diameter smaller than the center distance between the optical fibers 1 on the end face 1a and a laser beam 4b reflected by the optical fiber end face 1a is received to measure the inclination of the optical fiber end face 1a. A screen 7 which is a measuring means for
It is provided with a feed stage 15 which is a moving means for moving the optical fiber holder 2 or the light source 3 so that the optical fiber end face 1a irradiated with the laser light is changed.

Here, as shown in FIG. 1, a plurality of arrayed optical fibers 1 whose end faces are to be inspected are held by an optical fiber holder 2. The laser beam 4a emitted from the laser light source 3 of visible light passes through the lens 5 so that the beam diameter is reduced and reaches the optical fiber end face 1a. The laser beam 4b reflected by the end face 1a of the optical fiber reaches the screen 7. Then, the angle error (Δθ) is obtained from the position on the screen 7 where the reflected laser beam 4b has reached, that is, the distance (R) between the spot 13 and the reference position 7b. If Δθ obtained with respect to the specified allowable value of Δθ is small, it is judged as acceptable (usable), and if large, it is judged as unacceptable (unusable). Feeding stage 15
When the optical fiber holder 2 is moved laterally by the moving means, the end face 1a of the optical fiber irradiated with the laser beam 4a is changed, and the other optical fibers 1 are similarly inspected. As the moving means, for example, a moving feed stage can be exemplified.

That is, the procedure for inspecting the end face 1a of the optical fiber using this inspection apparatus is roughly as follows. First, an operator sets the array of optical fibers 1 on the optical fiber holder 2. Next, the feed stage 15 is operated to change the optical fiber end face 1a irradiated with the laser beam 4a, and the position of the spot 13 on the screen 7 is observed to determine whether the optical fiber end face 1a has an angular error.

More specifically, based on a concrete example, the outer diameter of the coating portion of the optical fiber 1 is, for example, 0.25 mm.
It is in an array state in which it is aligned in parallel at 0.25 mm intervals. The optical fiber 1 is held by the optical fiber holder 2 in this state. The optical fiber holder 2 is parallel and 0.2
The optical fiber 1 is held parallel to each other along the V groove by sandwiching the optical fiber 1 with a substrate 2b having V grooves at 5 mm intervals and a pressing plate 2a. The optical fiber holder 2 is installed on the feed stage 15. The optical fiber holder 2 is moved in the direction perpendicular to the central axis of the optical fiber 1 by the feeding of the feeding stage 15, whereby the optical fiber end face 1a irradiated with the laser beam 4a is changed.

The laser light source 3 is a He-Ne laser, and the laser light is visible light. The beam diameter of the output laser beam 4a is about 2 mm. The focal length of the lens 5 was 300 mm, and the distance from the lens 5 to the optical fiber end face 1a was also approximately this length. The distance from the optical fiber end face 1a to the screen 7 was also set to 300 mm. The laser beam 4a is focused by the lens 5,
When reaching the end face 1a of the optical fiber, the beam diameter is 0.15.
It becomes about mm. With a beam diameter of this degree, the laser beam 4a is irradiated onto the entire end surface of the optical fiber having a diameter of about 0.125 mm, but is not irradiated onto the other adjacent end surface 1a of the optical fiber.

When the laser beam from the laser light source 3 is directly applied to the optical fiber end face 1a, the plurality of optical fiber end faces 1a are irradiated and a plurality of spots appear on the screen 7, and which spot corresponds to which optical fiber end face 1a. I don't know what to do. By constricting the laser beam 4a with the lens 5, the light intensity of the reflected laser beam 4b increases and the spot 13 becomes clear (see FIG. 3).

On the screen 7, the reference position 7b is
When the optical fiber end face 1b is ideally vertical (Δθ = 0 °)
It is the center position of the spot 13. The distance from the reference position 7b to the center of the spot 13 is R, the optical fiber end face 1a
When the distance from the screen to the screen 7 is L, the angle error Δθ of the optical fiber end face 1a is approximately expressed as follows. R≈L tan (2Δθ) As shown in FIG. 3, if the scale 7a of the concentric circle having the radius R corresponding to the specific angular error Δθ is drawn on the screen 7, the angular error Δθ can be easily read.

Generally, in the process of manufacturing an optical connector, it is not necessary to read the value of Δθ, and it is acceptable or unacceptable (Δ
It is only determined whether or not θ exceeds an allowable error). Therefore, draw a scale corresponding to the tolerance,
The pass / fail judgment can be made simply by observing whether or not the spot 13 exceeds the scale. R
Since the size of the spot 13 and the spot 13 changes depending on the distance from the lens 5 to the optical fiber end face 1a (focal length of the lens 5) and the distance from the optical fiber end face 1a to the screen 7, the spot 13 or the spot 13 such that Δθ can be accurately read. It is necessary to consider the size of the inspection device and determine the distance between them so that R has an appropriate size.

On the screen 7, Δθ can be obtained from R, and at the same time, the direction of inclination of the optical fiber end face 1a can be obtained from the direction of the spot 13 with respect to the reference position 7b. When the end face 1a of the optical fiber is not a flat surface but has a convex spherical surface shape, the laser beam 4b reflected by the end face 1a of the optical fiber spreads, so that the curvature of the convex spherical surface shape can be roughly calculated from the extent of the spread of the spot 13. You can estimate. However, in the case of this embodiment, the reflected laser beam 4b spreads even when the optical fiber end face 1a is a flat surface, so it is necessary to compare with the spot 13 when the optical fiber end face 1a is flat. further,
When the end face 1a of the optical fiber is chipped, the intensity of the reflected laser beam 4b is reduced, and the light intensity of the spot 13 is weakened or does not appear. Thereby, by observing the decrease in the intensity of the reflected laser beam 4b,
It is possible to detect that the optical fiber end face 1a has the above-mentioned abnormality.

In the optical fiber holder 2, the pressing plate 2
a has an appropriate weight, and is simply placed on the optical fiber 1 placed in each V groove. Although it is possible to press the pressing plate 2a against the optical fiber using a spring or a screw, if the pressing plate 2a is pressed excessively, the optical fiber 1 may be curved and the end face 1a may be tilted, resulting in a large Δθ measurement error. is there. In this embodiment, the optical fiber holder 2 has the covering 1
Although holding b, the optical fiber holder 2 holding the bare portion 1c may be used when the coating is removed from the tip by an appropriate length. In the V-groove substrate 2b forming the optical fiber holder 2, for example, if the V-groove spacing is 0.25 mm and the number is 100, then 0.25 m
Optical fiber holder 2 with 100 optical fibers 1 at m intervals
Can be held on the end face 1 of their optical fiber 1
a can be continuously inspected. Alternatively, a 16-fiber optical fiber array (16 optical fibers in an aligned state)
5 can be set, and the optical fiber arrays can be continuously inspected. When the optical fiber 1 is held in the optical fiber holder 2, the laser beam 4a is irradiated to the optical fiber end surface 1a even if the position of the optical fiber end surface 1a in the front-back direction is slightly deviated from the specified position. Absent. In other words, the optical fiber 1 can be easily set in the optical fiber holder 2.

As the optical fiber holder 2, a member having a plurality of holes each having an inner diameter substantially equal to the outer diameter of the coating portion 1b or the bare portion 1c of the optical fiber 1 can be used. In this case, the optical fibers 1 are aligned by inserting them into these holes. A visible light semiconductor laser or the like can also be used as the laser light source 3. When using a semiconductor laser,
A collimating lens attached to it can be used as the lens 5. Even when the area of the optical fiber end face 1a is reduced by chamfering the outer peripheral edge of the optical fiber tip 1a into a conical shape, the laser beam 4a is narrowed down, so that the reflected beam 4b having sufficient intensity can be obtained. .

In this embodiment, the angle error Δθ of the optical fiber end face 1a with respect to the ideally vertical end face is measured, but it is also possible to inspect the optical fiber end face which is arbitrarily polished by 8 °. In this case, the standard is 8
The position of the spot 13 when the laser beam 4a is reflected by an optical fiber having an oblique end face is set as the reference position 7b. Furthermore, in this embodiment, the end surface of the optical fiber is measured, but it can be applied to the measurement of the inclination of the end surface of a member such as a ferrule.

[Second Embodiment] FIG. 4 is a view for explaining a second embodiment of the optical fiber end face inspection apparatus according to the present invention. In this embodiment, as shown in FIG. 4, the basic configuration of the device is the same as that of the first embodiment described above. However, the laser beam 4a output from the laser light source 3 is reduced to an appropriate beam diameter by the collimator 6. It also has a mirror 9 for reflecting the laser beam 4a and the laser beam 4b reflected from the optical fiber 1a at a substantially right angle. By bending the optical paths of the laser beams 4a and 4b by the mirror 9, the maximum size of the device can be reduced as compared with the first embodiment.

If two or more mirrors are used, the device can be made more compact. It is possible to reduce the beam diameter by passing the laser beam 4a from the laser light source 3 through an opaque plate having holes, but there is a drawback that the power of the laser beam 4a is wasted.

[Third Embodiment] FIG. 5 is a view for explaining the third embodiment of the optical fiber end face inspection apparatus according to the present invention. As shown in FIG. 5, the laser beam 4a output from the laser light source 3 has its beam diameter reduced by the collimator 6, passes through the half mirror 10, and reaches the optical fiber end face 1a. Laser beam 4 reflected there
The beam b is reflected by the half mirror 10 and reaches the camera 11, which is a measuring unit. The camera 11 corresponds to the screen 7 of the first embodiment. The image captured by the camera 11 is displayed on the monitor 8 and the angular error Δθ of the optical fiber end face 1a is measured from the position of the spot 13.

Also, with this device, the angle error Δθ can be automatically measured as follows. The optical fiber holder 2 is installed on the automatic feed stage 15a, and the computer 12 controls the automatic feed stage 15a to capture the image and process the image to obtain Δθ of each optical fiber end face 1a. Accordingly, if the worker sets the optical fiber 1a in the optical fiber holder 2, the Δθ can be automatically measured thereafter. By reflecting the reflected laser beam 4b by the half mirror 10, the maximum size of the device can be reduced.

[Fourth Embodiment] FIG. 6 is a view for explaining a fourth embodiment of the optical fiber end face inspection apparatus according to the present invention. Here, the basic configuration of the device of the present embodiment is the same as that of the third embodiment described above. However, in this apparatus, the laser light source 3, the half mirror 10 and the screen 7 are installed on the feed stage 15. By moving the laser light source 3 and the like by the feed stage 15, the optical fiber end face 1a irradiated with the laser beam 4a is changed. Such a device is applied when it is inconvenient to move the optical fiber 1 such as when the optical fiber 1 has a large optical component 16 mounted thereon.

In the present embodiment, a screen or a camera has been exemplified as the measuring means, but in the present invention, the laser beam reflected by the end face of the optical fiber is received to measure the inclination of the end face of the optical fiber. The means that can be used are not limited to these.

[0048]

As is apparent from the above description,
By using the inspection apparatus of the present invention, it is possible to measure the angular error of the end faces of a plurality of optical fibers while they are aligned in an array. Further, in this apparatus, the operation including the handling of the optical fiber is simple, and the inspection time for each optical fiber is short. It is also applicable to 100 or more optical fibers in an array state. The size of this device can be made equal to or smaller than that of a general shape measuring device, and the manufacturing cost can be reduced.

Therefore, in manufacturing a multi-core optical connector including a plurality of optical fibers, a series of manufacturing steps such as end face polishing, end face inspection, and coating removal are performed on the plurality of optical fibers in an array state. Therefore, the manufacturing cost of the optical connector can be reduced.

[Brief description of drawings]

FIG. 1 is a plan view showing the entire structure of an end face inspection apparatus according to a first embodiment of the present invention.

FIG. 2 is a partially enlarged perspective view of FIG.

FIG. 3 is a plan view showing the screen in FIG. 1 in an enlarged manner from the front.

FIG. 4 is a diagram illustrating an apparatus for measuring an angle of an optical fiber end face according to a second embodiment of the present invention.

FIG. 5 is a diagram illustrating an apparatus for measuring an angle of an optical fiber end face according to a third embodiment of the present invention.

FIG. 6 is a diagram illustrating an apparatus for measuring an angle of an end face of an optical fiber according to a fourth embodiment of the present invention.

FIG. 7 is a cross-sectional view illustrating an optical fiber connector.

FIG. 8 is a cross-sectional view illustrating an optical waveguide / optical fiber connector.

FIG. 9 is a diagram illustrating a conventional device for measuring an angle of an end face of an optical fiber.

FIG. 10 is a diagram illustrating a conventional device for measuring an angle of an end face of an optical fiber.

FIG. 11 is a diagram illustrating a conventional device for measuring an angle of an end face of an optical fiber.

[Explanation of symbols]

1,1-1,1-2 optical fiber 1a Optical fiber end face 1b Cover 1c nude part 2 Optical fiber holder 2a Press plate 2b V-groove substrate 3 laser light source 4a laser beam 4b reflected laser beam 5 lenses 6 Collimator 7 screen 7a scale 7b Reference position 8 monitors 8a monitor screen 9 mirror 10 half mirror 11 cameras 12 computers 13 spots 13a Spot trajectory 14 microscope 15 feeding stage 15a Automatic feed stage 16 optical components 20, 20-1, 20-2 plug 21 Adapter 21a Alignment member 22 Jack 23 Guide member 23a insertion hole 24 Optical waveguide substrate 25 Optical Waveguide 26 Vacuum suction groove

Claims (3)

[Claims] 1. An optical fiber holder for holding a plurality of optical fibers in parallel with each other by aligning the positions of the end faces of the optical fiber, a laser light source for irradiating the end faces of the optical fiber with laser light, and the laser light On the other hand, a lens that collects a light beam having a diameter smaller than the center interval between the optical fibers at the end face of the optical fiber, and receives the laser light reflected by the end face of the optical fiber to measure the inclination of the end face of the optical fiber. An optical fiber end face inspection apparatus comprising: a measuring unit; and a moving unit that moves the optical fiber holder or the light source so that the optical fiber end face irradiated with the laser light is changed. 2. The optical fiber end face inspection apparatus according to claim 1, further comprising a mirror that receives the laser light reflected by the end face of the optical fiber, reflects the laser light, and sends the laser light to the screen or the camera. Optical fiber end face inspection device. 3. The optical fiber end face inspection device according to claim 1, wherein the measuring means is a screen or a camera.