JPH11230865A - Method and device for measuring optical characteristic of optical fiber array with optical connector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a device and method capable of easily and accurately measuring connection losses of the connector part and array part of an optical fiber array with an optical connector. SOLUTION: An optical connector part at one end of an optical member to be measured 4 is fitted to a reference multi-conductor connector 3 formed at one end of a multi-conductor optical fiber 2, and an optical fiber array part at the other end is arranged at a location opposed to a reference optical fiber array 5 formed at one end of a multi-conductor optical fiber 7 to form a plurality of light transmission paths allocating one light transmission path for each conductor. The reference optical fiber array 5 moves along a predetermined circle by controlling the impressed voltage of an electrostrictive element 6 incorporating the reference optical fiber array 5 by a circular motion controller 9. Light is inputted to a plurality of light transmission paths from a light source 1, and changes in the intensity of transmitted light are detected by a power meter 8 to obtain connection losses of an optical fiber array joint and a connector part from the phase difference between the circular motion and the changes in the intensity of transmitted light, etc., by a CPU 10.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus and a method for measuring optical characteristics of an optical fiber array with an optical connector used in a multi-core optical module, and more particularly, to an optical fiber array and an optical connector which are integrated back to back. The present invention relates to an apparatus and a method suitable for measuring optical characteristics of a receptacle type optical fiber array.

[0002]

2. Description of the Related Art Conventionally, a multi-core optical module having a pigtail structure shown in FIG. 13 has been generally used as a multi-core optical module used in an optical transmission line. This multi-core optical module 110a forms a pigtail type optical fiber array 4a in which an optical fiber array 42 is attached to one end of an optical fiber tape 45 and a multi-core optical connector 41 is attached to the other end, and the optical fiber array 42 connects the lens array 101. In between, L
It has a structure in which it is aligned with the D (PD) array 102 and arranged on the module main body 100. Here, the LD (PD) array 10
2 for controlling (detecting) the light emission (light reception) of each LD (PD).
It is preferable that the signal line 104 electrically connected to (PD) be drawn. Note that a structure (butt joint) in which the LD (PD) array 102 and the optical fiber array 42 are directly aligned and aligned without using the lens array 101 is also used.

On the other hand, recently, a multi-core optical module using a receptacle-type optical fiber array shown in FIG. 14 is being put to practical use. In this type of multi-core optical module 110b, a receptacle type optical fiber array 4b having a structure in which an optical fiber array 42 and a multi-core optical connector 41 are integrated back to back instead of the pigtail type optical fiber array 4a shown in FIG. By using this, the size of the module can be reduced.

[0004]

An optical fiber array with an optical connector having an optical connector at one end and an optical fiber array at the other end is an important component constituting a multi-core optical module. It is important to improve the arrangement accuracy of the optical fibers and to reduce the connection loss on the optical connector side, and it is necessary to accurately measure them when evaluating products.

In the case of a pigtail type optical fiber array,
First, a multi-core optical connector is attached to both ends of an optical fiber tape of a predetermined length, the connection loss of the optical connector is measured in this state, and then the optical fiber tape is cut at the center, and the cut portion is optically cut. In general, a method of processing into a fiber array and measuring the arrangement accuracy of the optical fibers in the optical fiber array section by microscopic observation is used.

However, this method cannot be applied to a receptacle type optical fiber array having no intermediate optical fiber tape. The arrangement accuracy of the optical fibers in the optical fiber array section can be measured by microscopic observation as in the case of the pigtail type optical fiber array described above, but it is difficult to accurately measure the connection loss of the optical connector section. Was. The factors are described below.

To measure the connection loss of the optical connector, FIG.
There is a method shown in FIG. First, as shown in FIG. 1A, the measurement light emitted from the light source 1 is transmitted through the single-core optical fiber 22 and the multi-core optical fiber 21 to the reference optical connector 3.
The guidance to a particular optical fiber, the intensity P _in the emitted light is measured in advance by the power meter 8.

Next, as shown in FIG. 1B, the optical connector section 44 of the receptacle type optical fiber array 4b to be measured is fitted with the reference optical connector 3 and the optical fiber array section 42 is measured. The receptacle type optical fiber array 4b is inserted and connected between the reference optical connector 3 and the power meter 8 by optically coupling the dummy optical fiber 7 'to the optical fiber. Then, the measurement light emitted from the light source 1 is guided to the receptacle type optical fiber array 4b via the optical fibers 21 and 22 and the reference optical connector 3, and the emitted light is measured by the power meter 8 via the dummy optical fiber 7 '. . The measured light intensity P _out and the already measured P
The connection loss of the connector part is calculated from the difference _in .

A part of the loss light at the connector portion travels inside the optical fiber as clad leakage light, and eventually leaks out of the fiber. A fiber length of at least several tens of cm is required until the clad leakage light completely leaks out of the fiber.To measure the connection loss of the connector part of the receptacle type optical fiber array, this fiber length must be set. To secure them, it is necessary to prepare a dummy optical fiber 7 'having a length of several tens of cm. On the other hand, this dummy optical fiber 7 '
If there is a connection loss between the optical fibers of the optical fiber array 42 and the optical fiber, the light intensity P _out measured by the power meter 8 includes this connection loss, so that the connection loss of the connector cannot be accurately evaluated. In order to suppress the connection loss value in this portion, it is necessary to align the dummy optical fiber 7 'and the optical fiber of the optical fiber array 42 with an accuracy of about 0.1 μm. This requires a great deal of labor, time and cost, and is not practical.

In view of the above problems, an object of the present invention is to provide an apparatus and a method capable of easily and accurately measuring a connector portion of an optical fiber array with an optical connector and a connection loss of the array portion.

[0011]

In order to solve the above problems, an optical characteristic measuring apparatus for an optical fiber array with an optical connector according to the present invention is configured by arranging a plurality of optical fibers, and a multi-core optical connector is provided at one end. A device for measuring optical characteristics of an optical member to be measured having an optical fiber array at the other end, comprising: (1) a reference multi-core optical connector which is mated with a multi-core optical connector section of the optical member to be measured; (2) a reference optical fiber array comprising a plurality of optical fibers, each end face of which is arranged to face each optical fiber end face of the optical fiber array section of the optical member to be measured; and (3) a reference multi-core optical connector. A measurement light source that causes measurement light to be incident from one end face to each of a plurality of optical transmission paths independently configured for each core by connecting the optical member to be measured and the reference optical fiber array in series; ) A photodetector for independently detecting each of the output lights emitted from the other end face of each of the plurality of optical transmission lines due to the incident constant light, and (5) each of the optical fibers of the reference optical fiber array and the optical member to be measured. A driving device that supports one or both of the optical fibers of the optical fiber array unit and moves one of the optical fibers relative to the other in a plane substantially perpendicular to the optical axis with a predetermined radius; ) From the amplitude of the intensity fluctuation of each output light detected by the photodetector and the phase difference between this intensity fluctuation and the circular motion, the relative position of each optical fiber array portion of the optical member to be measured and the reference optical fiber array for each core. The amount and direction of displacement are determined, the connection loss at the optical coupling portion between the optical fiber array portion of the optical member to be measured and the reference optical fiber array is determined from the relative displacement amount and direction, and the connection loss and the measurement are measured. An analysis unit for calculating a connection loss for each core between the reference multi-core optical connector and the multi-core optical connector unit of the optical member to be measured based on a difference between the amount of light and the amount of output light. It is characterized by the following.

According to this configuration, by connecting the reference multi-core optical connector, the measured optical member, and the reference multi-core optical fiber array in series, a plurality of optical transmission paths configured for each core are formed. You. The driving device changes the relative position between the reference optical fiber array and the optical fiber array portion of the measured optical member while transmitting the measuring light through each of the plurality of optical transmission lines. Then, the relative positional deviation amount of each center between the reference optical fiber array and the optical fiber array portion changes in accordance with the change in the relative positional deviation amount of both of these arrays as a whole. Therefore, the intensity of the light transmitted through each transmission path, that is, transmitted from each transmission path and emitted from the other end surface varies. If the relative position change of each fiber at this time is controlled to be a circular motion in a plane perpendicular to the optical axis, the relative positional deviation amount and direction for each core can be easily obtained from the output light intensity for each core described above. Desired. The connection loss at the optical coupling section between the optical fiber array section and the reference optical fiber array is mainly due to the relative displacement and the gap between the two arrays. Since the latter is known, the connection loss value is determined from the relative displacement.
Further, based on this, the connection loss of each core between the reference multi-core optical connector and the multi-core optical connector of the optical member to be measured is also obtained.

A storage means for storing data of the eccentric direction and the amount of eccentricity of each center of the reference optical fiber array obtained in advance is provided, and the analyzing section stores the eccentric direction and eccentricity of each center of the reference optical fiber array stored in the storage means. The eccentric direction and the amount of eccentricity of each center of the optical fiber array portion of the optical member to be measured may be obtained based on the amount data.

As described above, according to the present invention, the relative displacement and direction of each center between the reference optical fiber array and the optical fiber array portion of the optical member to be measured can be determined. If the eccentric direction and the amount of eccentricity of each center of the optical fiber array are known, the relative positional shift amount and direction of each center of the other optical fiber array unit can be easily obtained.

Here, the driving device may be constituted by an electrostrictive element. By using the electrostrictive element, one or both optical fiber arrays can be accurately driven with a simple configuration.

The diameter of the circular motion is preferably smaller than one half of the core diameter of the optical fiber of the optical member to be measured, and more preferably larger than one tenth of the core diameter. If the diameter of the circular motion is too large, the loss due to misalignment will be too large and the output light will be small, and the measurement accuracy will deteriorate,
If the diameter of the circular motion is too small, the loss due to the axial deviation is too small, the output change due to the circular motion is small, and the measurement accuracy is also deteriorated.

Preferably, the driving device drives only the reference optical fiber array. Such a configuration is preferable because the driving device and the reference optical fiber array can be integrated, and the optical member to be measured can be easily attached and detached.

Further, it is preferable that the measurement light source is arranged on the reference multi-fiber optical connector side of the plurality of optical transmission lines, and the photodetector is arranged on the reference optical fiber array side of the plurality of optical transmission lines. Such a configuration is preferable because the input light intensity to the optical connector is not affected by the circular motion.

On the other hand, the method for measuring optical characteristics of an optical fiber array with an optical connector according to the present invention corresponds to the method for measuring optical characteristics performed by each of the above-described apparatuses. The reference multi-core optical connector is fitted into the optical connector section, and the end faces of the respective optical fibers constituting the reference optical fiber array are arranged to face the respective optical fiber end faces of the optical fiber array section. Forming a plurality of independently configured optical transmission paths;
(2) In a plane substantially perpendicular to the optical axis of each optical fiber of the reference optical fiber array and each optical fiber of the optical fiber array section of the measured optical member, one of the optical fibers is moved relative to the other by a predetermined radius with respect to the other. Meanwhile, the step of causing the measurement light to enter each of the plurality of optical transmission lines from one end face and detecting each of the output lights emitted from the other end face; and (3) the amplitude and amplitude of the respective intensity fluctuations of the output light. A step of obtaining the relative displacement and direction of each center between the optical fiber array portion of the optical member to be measured and the reference optical fiber array from the phase difference between the intensity fluctuation and the circular motion; and (4) the relative displacement Determining the connection loss at the optical coupling portion between the optical fiber array portion of the optical member to be measured and the reference optical fiber array from the direction and the direction; and (5) determining the difference between the connection loss, the light amount of the measurement light, and the light amount of the output light. Based on Characterized in that it and a step of calculating the connection loss for each heart with multiple-core optical connector portion of the reference multiple-core optical connector and the measured optical member Te.

A step of previously determining the eccentric direction and the amount of eccentricity of each center of the reference optical fiber array, and the light of the optical member to be measured based on the obtained eccentric direction and the amount of eccentricity of each center of the reference optical fiber array. Determining the eccentric direction and the amount of eccentricity of each center of the fiber array unit.

[0021]

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. To facilitate understanding of the description, the same reference numerals are given to the same constituent elements in each drawing as much as possible, and duplicate description will be omitted.

FIG. 1 is a schematic explanatory view showing a preferred embodiment of the optical characteristic measuring apparatus of the present invention.

In this embodiment, a light source 1 for emitting measurement light
And a multi-core optical fiber 2 configured by bundling a plurality of optical fibers to guide the light emitted from the light source 1, and a receptacle to be measured which is attached to the multi-core optical fiber 2 on the side opposite to the light source 1. A reference multi-fiber optical connector 3 in which a connector type optical fiber array 4 is fitted with a connector, and a reference optical fiber array 5 in which a plurality of optical fibers are arranged are opposed to the fiber array portion of the receptacle type optical fiber array 4 to be measured and are internally provided. And an electrostrictive element 6 for causing the reference optical fiber array 5 to perform a predetermined circular motion, a multi-core optical fiber 7 connected to the reference optical fiber array 5, and an output from each core of the multi-core optical fiber 7. A power meter 8 for detecting the intensity of the emitted light, a circular motion controller 9 for controlling the driving of the electrostrictive element 6, and a power meter for controlling the circular motion controller 9 CPU10 for calculating the optical characteristics of the connection loss etc. of the measurement target optical fiber array 4 from the output of the motor 8
It is composed of

The light source 1 may have a plurality of light sources independently of each other, or may be a light source that splits light output from one light source into a plurality of optical paths.

FIGS. 2 and 3 show a basic configuration of the receptacle type optical fiber array 4 to be measured. In order to facilitate understanding of the structure, FIG. 2 is a partially cut perspective view in which both ends are partially cut, and FIGS. 3A and 3B are views showing respective end faces. The receptacle-type optical fiber array 4 is composed of a plurality of optical fibers 44. At one end, optical fibers 44 are arranged at regular intervals perpendicular to the end face, and guide pin holes 43 for fixing are provided on both sides. Are provided to form the optical connector 41. The other end is formed as an optical fiber array 42 with only optical fibers 44 arranged at regular intervals perpendicular to the end face.

Next, the structure of the electrostrictive element 6 incorporating the reference optical fiber array 5 will be described with reference to FIG. FIG.
(A) is a perspective view of the electrostrictive element 6, and (b) is a longitudinal sectional view thereof. The electrostrictive element 6 has an optical fiber 7 fixedly disposed on the front side (right side in the drawing) of the reference optical fiber array 5 inserted from the rear side (left side in the figure). Is provided with four piezoelectric units. That is, the piezoelectric material layer 62 is deposited on the ground electrode 61G provided on the outer surface of the tip of the electrostrictive element 6, and the four electrodes 61X are formed on the upper surface of the piezoelectric material layer 62.
1, 61X2, 61Y1, and 61Y2 are arranged side by side in the circumferential direction.

The four electrodes are a plus X electrode 61X1
And the minus X electrode 61X2 are arranged at positions facing each other, and similarly, the plus Y electrode 61Y1 and the minus Y electrode 6
1Y2 are also arranged at positions facing each other. The opening (right side in the drawing) of the electrostrictive element 6 has a cap 6
A reference optical fiber array 5 fixed to a stage 64 is supported in the cap 63.

According to the above structure, the tip of the electrostrictive element 6 can be finely or rotationally moved horizontally (horizontally with respect to the end face of the optical fiber array 42 to be measured).
As a result, the tip of the reference optical fiber array 5 can be driven according to the above movement.

This driving will be described with reference to FIGS. As shown in FIG. 5, among the electrodes, a plus X electrode 61X1 and a minus X
When a voltage of opposite polarity is applied to the electrode 61X2 or the positive Y electrode 61Y1 and the negative Y electrode 61Y2, tensile or compressive strain is generated in the piezoelectric material layer 16, thereby slightly deforming the electrostrictive element 6. And
Fine movement in the displacement directions indicated by arrows (circles 1 to 4) shown in FIG. 5 is realized. FIG. 6 shows the correspondence between the voltage applied to each electrode and the displacement direction.

Accordingly, the circular motion controller 9 applies a sine wave voltage having a phase shift of 180 ° to the plus X electrode 61X1 and the minus X electrode 61X2, and
Y1 and minus Y electrode 61Y2 plus plus X electrode 61X1
When a sine wave voltage having a phase shift of ± 90 ° with respect to the sine wave voltage to be applied is applied, the tip of the electrostrictive element 6 rotates. Further, the above electrodes 61X1, 61X2, 61Y
When the DC bias of the AC voltage applied to the first and 61Y2 changes, the tip of the electrostrictive element 2 is
It will be slightly moved in the direction perpendicular to the end face.

That is, high-speed rotational movement of the reference optical fiber array 5 and fine adjustment of the horizontal rotational center position can be performed by the same electrostrictive element 6.

The multi-core optical fiber 7 has a length sufficient to allow clad leakage light generated at the fiber array connection portion (the connection portion between the receptacle type optical fiber array 4 and the reference optical fiber array 5) to escape outside the optical fiber. It is preferable to have. That is, a length of several tens cm is required.

Next, the operation of this embodiment will be described. FIG. 7 is a flowchart showing the operation of the present embodiment.

First, an optical member to be measured, in the case shown in FIG. 1, a receptacle type optical fiber array 4 is fitted into the reference multicore optical connector 3 by a connector, and is supported in the electrostrictive element 6 by a precision stage (not shown). Reference optical fiber array 5
(S1). The electrostrictive element 6 is also supported by a precision stage (not shown), and the end faces of both optical fibers are held at an interval of about 30 μm, and the gap has a low viscosity in order to prevent reflection loss at the interface. Is applied. Thereby, the multi-core optical fiber 2-reference multi-core optical connector 3-receptacle type optical fiber array 4-reference optical fiber array 5
-The multi-core optical fibers 7 are connected in series, and a plurality of optical transmission lines are formed for each core.

Subsequently, the intensity of the light transmitted through each optical transmission line and output is measured. This is because the CPU 10 controls the circular motion controller 9 based on the circular motion setting information input to the CPU 10 in advance and drives the electrostrictive element 6 to cause the receptacle-type optical fiber array 4 to operate with respect to the reference optical fiber array. This is performed by measuring the change in intensity of each of the light emitted from the light source 1, transmitted through each optical transmission line, and output by the power meter 8 while making the circular motion 4 (S2).

Here, the principle of measuring the displacement between the optical fibers whose end faces are opposed to each other by making the end face of one optical fiber circularly move with respect to the end face of the other optical fiber will be described in detail.

For the sake of simplicity, it is assumed that the end faces of the optical fibers 71 on the side of the reference optical fiber array 5 are accurately arranged at equal intervals. On the other hand, each optical fiber 44 on the optical fiber array 42 side of the receptacle type optical fiber array 4 on the measured side is arranged at substantially the same interval as the reference optical fiber array 5, but each is slightly different from the ideal position. It is assumed that there is a gap. FIG. 8 shows the state of this displacement. ● mark indicates the core center C _a at the end face 71a of the optical fibers 71 of the reference optical fiber array 5 side,
+ Sign represents the core center C _b of the end face 44a of the optical fibers 44 of the optical fiber array 42 side. Hereinafter, a single optical fiber pair 44, 71 will be described as an example.

FIG. 9 is an explanatory view showing a state where the end face 71a of the optical fiber 71 is moved circularly with respect to the end face 44a of the optical fiber 44. Here, both end faces 71a, 44
a is parallel, that is, the optical axes of the two fibers 44 and 71 are parallel to each other, and the end face 71a of the optical fiber 71 is circularly moved in a plane orthogonal to these optical axes. C _R indicated by a circle in the drawing is the rotation center of this circular motion. This C _R
Usually, it is preferable to match Ca in _a state where no circular motion is performed, that is, in a stationary state. When the end face 71a of the optical fiber 71 is rotated around C _R , the trajectory of the core center C _a draws a circle as shown in FIG. 3A, and the end faces 71a of the fiber are indicated by circles 1 to 5. Move like so. The respective states are individually shown in FIGS. With the movement of the apparent to C _a from FIG (b) ~ (f), two fiber end faces 44a, distance 71a is varied. At this time, since the optical coupling loss increases as the distance between C _a and C _b increases, the amount of measurement light transmitted through the connection portion and detected decreases.

Accordingly, the positional relationship between the center positions C _a and C _{b of} the two fiber end faces 44 a and 71 a and the position of the rotation center C _{R of the} circular movement, the phase of the rotation and the light quantity of the measuring light detected by the power meter 8. FIG. 10 shows the relationship between the fluctuation and the phase. Here, the phase of the rotational motion indicates the position of the core CR with respect to the center of rotation.
This corresponds to the phase of the voltage applied to the plus X electrode 61X1 arranged in the plus x direction.

FIG. 3A shows that the rotation center C _{R of the} circular motion is shifted in the minus x direction (left side in the figure) with respect to the core center position C _b on the optical fiber end face on the optical fiber array 42 side to be measured. In the position shown in FIG. From this figure, it can be seen that in this case, the phase of the rotational movement coincides with the phase of the light quantity fluctuation (phase difference 0 °).

Further, FIG. (B), (c), (d), respectively, minus y-direction rotation center C _R is the core center position C _b (lower side in the figure), the positive x direction (in the figure Right),
The case where the position is shifted in the plus y direction (the upper side in the figure) is shown, and it can be seen that the phase difference between the rotational motion and the light amount variation in these cases is 90 °, 180 °, and 270 °, respectively.

On the other hand, FIG. 11 shows the relationship between the amplitude of light quantity fluctuation and the amount of eccentricity. As shown in FIG. 6 (a), the center of rotation C _R
And if the core center position C _b in the optical fiber end face of the optical fiber array 42 side for the measurement are identical,
Since the distance between the core center position C _a and the core center position C _b unchanged in the optical fiber end surface of the reference optical fiber array 5 side, the light amount becomes its amplitude course zero does not change. As shown in FIGS. 8B to 8D, as the distance between the rotation center C _R and the core center position C _b increases, even if the rotation radius is the same, the fluctuation value of the light amount, that is, the amplitude of the light amount fluctuation, increases. It is getting bigger.

When the value exceeds a certain value (approximately 2.5 μm between single mode fibers), the amplitude decreases as the deviation increases, and FIG. 12 shows this. In FIG. 12, when the amplitude of the light amount is equal to or less than the level (specified value) indicated by the dotted line, the signal component is buried in the noise component. Either it is in a range where it is considered that the alignment (the core position matches) or the center position is largely off.

If the rotation radius of the circular motion is small, the fluctuation of the light amount is too small and the phase difference between the fluctuation of the light amount and the rotation cannot be accurately evaluated. In the case of a general single mode optical fiber, the core diameter is about 10 μm, but the amount of axis deviation is 1 μm.
In the case of the above, the connection loss due to the axis deviation is about 0.2 dB,
If the radius of the rotational movement is smaller than this, the fluctuation of the light amount becomes too small, which is not preferable. Therefore, it is preferable that the radius of the rotational movement is 1/10 or more of the core diameter.

On the other hand, if the rotation radius of the circular motion is too large,
The axis deviation during the rotation motion becomes too large, the connection loss also becomes large, and the detected light amount itself becomes too small, thus deteriorating the reliability of measurement. In the case of the above-mentioned general single mode optical fiber, if there is an axis deviation of 5 μm which is a half of the core diameter, the connection loss becomes 5 dB or more. If the radius of gyration is further increased, the measured amount of light becomes too small, which is not preferable. Therefore, it is preferable that the radius of the rotational movement be within 1/2 of the core diameter.

Here, the radius of the rotational motion is set to 20 core diameters.
%, Which is about 2 μm.

Returning to the description of the flowchart of FIG. 7 again, based on the above-described principle, the CPU 10 controls each of the optical fiber array units 42 based on the output of the power meter 8 and the phase of the rotational motion given by the circular motion controller 9. The relative displacement and direction of the optical fiber 44 relative to the reference optical fiber array 5 for each core are determined (S3). here,
If the positional deviation amount and direction of each center of the reference optical fiber array 5 are known in advance (this may be measured using, for example, a microscope observation method), the measurement is performed based on this information. The displacement amount and direction of each optical fiber 44 of the target optical fiber array unit 42 can be obtained.

Next, based on the amount and direction of the displacement, CP
In U10, the connection loss at the fiber array connection portion is determined theoretically or quantitatively from experimental results or the like (S4). Optical loss at the fiber array connection is caused by three factors: axial misalignment, angular misalignment, and gap. In the present embodiment, the gap is known, and the angular deviation of the two items is small and negligible compared to the axis deviation and the gap. Therefore, if the above-mentioned axis deviation is obtained, the optical loss can be calculated theoretically or quantitatively.

Since the optical loss due to the multi-core optical fibers 2 and 7 itself can be ignored, the optical loss of the entire optical transmission line is mainly caused by both the connector connection portion and the fiber array connection portion. As described above, the light loss at the fiber array connection portion is obtained, so that the light loss at the connector connection portion can be obtained from the difference between this and the actually measured light loss (S5). Actually, there is also an optical loss at the connection between the multi-core optical fibers 2 and 7 and the light source 1 or the power meter 8, but if the optical loss at this portion is at a level that cannot be ignored, each of them is removed. What is necessary is just to measure beforehand and to calibrate. As described above, the connection loss between the connector connection portion and the fiber array connection portion can be accurately evaluated.

The positions of the light source 1 and the power meter 8 are exchanged,
The same measurement can be performed even if the traveling direction of light is reversed. However, it is preferable that the light is incident from the connector side because the input light intensity to the connector section does not fluctuate and the light loss at the connector connection section does not fluctuate.

In the above description, the example in which the reference optical fiber array is driven is described. However, the fiber array to be measured may be driven. However, it is preferable to drive the reference optical fiber array side because the optical member to be measured can be easily replaced.

The optical member to be measured is not limited to the receptacle type optical fiber array, but the measurement can be similarly performed for the pigtail type optical fiber array.
INDUSTRIAL APPLICABILITY The present invention is suitable for evaluating the connection loss at both ends of an optical fiber array with an optical connector in which the distance between the optical connector section and the optical fiber array section is short, and particularly suitable for measuring the optical characteristics of the receptacle type optical fiber array. Things.

[0053]

As described above, according to the present invention,
It is possible to simultaneously and easily and accurately measure the connection loss between the optical connector unit and the optical fiber array unit of the optical fiber array with the optical connector in which the distance between the optical connector unit and the optical fiber array unit is short, which has been conventionally difficult.

In particular, by performing measurement using a reference optical fiber array whose eccentricity and direction are known in advance, the eccentricity and direction of the optical fiber array portion to be measured can be measured.

[Brief description of the drawings]

FIG. 1 is an overall schematic diagram of an embodiment according to the present invention.

FIG. 2 is an exploded perspective view of a receptacle type optical fiber array of an optical member to be measured.

FIG. 3 is an end view of a connection portion of the optical member of FIG. 2;

FIGS. 4A and 4B are views showing an electrostrictive element having a built-in reference optical fiber array according to the embodiment of FIG. 1, wherein FIG. 4A is a perspective view and FIG.
Is a longitudinal sectional view.

FIG. 5 is a diagram illustrating the operation of the electrostrictive element of FIG.

6 is a table summarizing the operation of the electrostrictive element of FIG.

FIG. 7 is a flowchart of the operation of the embodiment of FIG. 1;

FIG. 8 is a diagram showing a positional relationship between a fiber end face of a reference optical fiber array and a fiber end face of an optical fiber array to be measured.

FIG. 9 is a diagram illustrating a circular motion of a reference optical fiber array.

FIG. 10 is a diagram showing a change in output of an optical transmission line due to a circular motion of a reference optical fiber array.

FIG. 11 is a diagram illustrating an output change of an optical transmission line due to an eccentric amount of an optical fiber and a circular motion of a reference optical fiber array.

FIG. 12 is a diagram showing the relationship between the amount of eccentricity of an optical fiber and the output amplitude of an optical transmission line.

FIG. 13 is a structural diagram of an optical module using a pigtail type optical fiber array.

FIG. 14 is a structural diagram of an optical module using a receptacle-type optical fiber array.

FIG. 15 is a diagram illustrating a method for measuring optical characteristics of a conventional receptacle-type optical fiber array.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Light source, 2, 7 ... Multi-core optical fiber, 3 ... Reference multi-core optical connector, 4 ... Receptacle type optical fiber array, 5 ... Reference optical fiber array, 6 ... Electrostrictive element, 8 ... Power meter, 9 ... Circle Motion controller, 10 CPU, 41 optical connector section, 42 optical fiber array section, 44 71
Optical fiber, 61 ... electrode,

Claims (14)

[Claims] An optical fiber array with an optical connector for measuring the optical characteristics of a measured optical member having a multi-core optical connector at one end and an optical fiber array at the other end. In the characteristic measuring device, a reference multi-core optical connector fitted with the multi-core optical connector section of the optical member to be measured, and a plurality of optical fibers, each end face of which is an optical fiber array section of the optical member to be measured. A reference optical fiber array arranged opposite to each optical fiber end face, the reference multi-core optical connector, the optical member to be measured, and the reference optical fiber array connected in series to be independent for each core. A measurement light source that causes measurement light to enter from one end face to each of the plurality of optical transmission paths, and the other end face of each of the plurality of optical transmission paths by the measurement light incidence A photodetector that independently detects each of the output lights emitted from the optical fiber, and one or both of each optical fiber of the reference optical fiber array and each optical fiber of the optical fiber array section of the measured optical member. A driving device that supports and moves the one relative to the other with a predetermined radius in a plane substantially perpendicular to the optical axis of both, and the amplitude of the intensity fluctuation of each output light detected by the photodetector and From the phase difference between each intensity fluctuation and the circular motion, the relative position shift amount and direction of each center between the optical fiber array section of the optical member to be measured and the reference optical fiber array are obtained, and the relative position shift amount and direction are obtained. From the optical fiber array section of the optical member to be measured and the optical coupling section of the reference optical fiber array, the connection loss for each core is determined. An analysis unit for calculating a connection loss for each core between the reference multi-core optical connector and the multi-core optical connector unit of the measured optical member based on a difference between the optical fiber array and the optical fiber array with the optical connector. Optical property measuring device. 2. The apparatus according to claim 1, further comprising storage means for storing data on the eccentric direction and the amount of eccentricity of each center of the reference optical fiber array obtained in advance. 2. The optical characteristic measuring apparatus for an optical fiber array with an optical connector according to claim 1, wherein the eccentric direction and the eccentric amount of each center of the optical fiber array portion of the optical member to be measured are further determined based on the eccentric direction and the eccentric amount data. 3. The optical characteristic measuring device for an optical fiber array with an optical connector according to claim 1, wherein the driving device makes a circular motion by an electrostrictive element. 4. The optical characteristic measuring apparatus for an optical fiber array with an optical connector according to claim 1, wherein the diameter of the circular motion is smaller than half the core diameter of the optical fiber of the optical member to be measured. . 5. The optical characteristic measuring apparatus for an optical fiber array with an optical connector according to claim 1, wherein the diameter of the circular motion is larger than one tenth of a core diameter of the optical fiber of the optical member to be measured. . 6. The apparatus according to claim 1, wherein the driving device drives only the reference optical fiber array. 7. The measuring light source is disposed on an end face of the plurality of optical transmission paths on the reference multi-core optical connector side, and the photodetector is disposed on an end face of the plurality of optical transmission paths on the reference optical fiber array side. 2. The optical characteristic measuring device for an optical fiber array with an optical connector according to claim 1, wherein the measuring device is arranged. 8. An optical fiber array with an optical connector for measuring optical characteristics of a measured optical member having a multi-core optical connector at one end and an optical fiber array at the other end. In the characteristic measuring method, a reference multi-fiber optical connector is fitted into the multi-fiber optical connector of the optical member to be measured, and each of the optical fibers constituting the reference optical fiber array is formed on the end face of each optical fiber of the optical fiber array. Forming a plurality of optical transmission paths configured for each core by arranging the end faces to face each other, each optical fiber of the reference optical fiber array and each optical fiber of the optical fiber array section of the optical member to be measured. In a plane substantially perpendicular to the optical axis with the fiber, one of the plurality of optical transmission paths is measured from one end face while making one circular motion relative to the other with a predetermined radius. Incident, detecting each of the output lights emitted from the other end face; and the light of the optical member to be measured from the amplitude of the respective intensity fluctuations of the output light and the phase difference between the respective intensity fluctuations and the circular motion. A step of determining a relative displacement and direction of each fiber core between the fiber array section and the reference optical fiber array; and an optical fiber array section of the measured optical member and the reference optical fiber array from the relative displacement and direction. Obtaining a connection loss at an optical coupling portion between the reference multi-core optical connector and the multi-core optical connector of the optical member to be measured based on the connection loss and the difference between the light amount of the measurement light and the light amount of the output light. Calculating a connection loss for each core with the optical fiber, and a method for measuring the optical characteristics of an optical fiber array with an optical connector, comprising: 9. An optical member to be measured based on the data of the eccentric direction and the amount of eccentricity of each center of the reference optical fiber array in advance, and the eccentric direction and the amount of eccentricity of each center of the reference optical fiber array obtained. 9. The method for measuring the optical characteristics of an optical fiber array with an optical connector according to claim 8, further comprising: determining an eccentric direction and an eccentric amount of each of the optical fiber arrays. 10. The method according to claim 8, wherein the circular motion is performed by an electrostrictive element. 11. The method for measuring optical characteristics of an optical fiber array with an optical connector according to claim 8, wherein the diameter of the circular motion is smaller than half the core diameter of the optical fiber of the optical member to be measured. . 12. The method for measuring optical characteristics of an optical fiber array with an optical connector according to claim 8, wherein the diameter of the circular motion is larger than one tenth of a core diameter of the optical fiber of the optical member to be measured. . 13. The method according to claim 8, wherein the circular movement is performed by driving only the reference optical fiber array. 14. The method for measuring the optical characteristics of an optical fiber array with an optical connector according to claim 8, wherein said measuring light is incident from said reference multi-core optical connector side of said transmission line.