JPH08184420A - Method for measuring positional shift of core of mt connector - Google Patents

Abstract

PURPOSE: To enhance accuracy in the measurement of the position of an optical fiber in an optical MT connector. CONSTITUTION: A reference connector 100, for which the positional shift and shifting direction of core are known, is connected with a connector 101 to be measured using a guide pin being fitted in a guide pin hole in order to measure the connection loss of the connector. The guide pin is then replaced by a thinner one and the connector 101 to be measured is shifted in the direction of end face while connecting both connectors. A shifting amount for minimizing the connection loss is then determined, along with the shifting direction, for each optical fiber 16 and the relative positional shift to the reference connector 100 is determined thus measuring the positional shift of the core of connector 101 to be measured.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for measuring a displacement of an optical fiber position of an MT connector, and more particularly to improving the measurement accuracy thereof.

[0002]

2. Description of the Related Art An MT connector used as a multicore connector for an SM type optical fiber is as shown in FIG. In this MT connector, a plurality of fiber strands 103 of an optical fiber tape 104 are attached to a connector ferrule
The end face of the fiber wire is arranged in the same plane as the front end face of the ferrule 101. The guide pin 102 aligns and connects the optical fiber strand 103.

The end faces of the optical fiber wires are in strong contact with each other by the clip 105.

A connection loss of 0.35 dB is realized on average, and this MT connector is effective in reducing the work time of cable connection.

However, the connection loss of a multi-core connector is generally larger than the loss of fusion splicing. There is still a need to improve the connection loss of multicore connectors.

The factor that most affects the connection loss of this type of connector is the axial misalignment between the cores of the optical fibers to be connected. Against this background, there has been a demand for the development of a high-precision measurement technique for misalignment of the optical fiber core of a multi-fiber connector.

Conventionally, the following two methods are known as methods for measuring the displacement of the optical fiber core position of the MT connector.

One is an MT having two guide pin holes on both sides and a large number of fiber holes formed therebetween.
Illuminated by a light source from the rear end surface of the ferrule of the connector,
This is a method in which an image pickup device is arranged on the front end face side via an objective lens and an image of the front end face of the ferrule is picked up. In this method, the illumination light from the light source passes through the guide pin hole and the fiber hole and becomes transmitted illumination light and enters the imaging device.
Since the image processing device is provided with the image data of the transmitted illumination light from the front end face of the ferrule, the image processing device can obtain the contours of the edges of the front end faces of the guide pin hole and the fiber hole. From the result, the center position of the guide pin hole and the fiber hole can be obtained, and the deviation of the position of the fiber hole with reference to the center position of the guide pin hole can be measured. -3
43 "Development of high-precision dimension measurement technology for multi-core connectors").

Another method is disclosed in JP-A-6-2013.
56 published patent publications are known. This measurement method is shown in Figure 5.
As shown in FIG. 2, the dummy pin 91 having the dummy optical fiber 92 is inserted into the two guide pin holes 106 that determine the position when the MT connector is connected, and the plurality of optical fibers 10 are inserted.
3 is fixed in a plurality of fiber holes 107 in an inserted state,
The end faces of the optical fibers 92 and 103 are arranged on the front end face of the ferrule 101 in substantially the same plane. And the dummy pin 9
The illumination light is incident from the rear end face side of the optical fiber 92 and the optical fiber 103 inserted in the fiber hole 107, and the emitted illumination light of the respective optical fibers 92 and 103 is imaged at the front end face side, so that the guide pin The center positions of the hole 106 and the core of the optical fiber 103 are obtained. This is a method of measuring the deviation of the core center position of the optical fiber 103 from the design position based on the center position of the guide pin hole 106 and the design data.

[0010]

SUMMARY OF THE INVENTION In the above method,
The eccentricity of the fiber hole can be evaluated, but the eccentricity of the optical fiber itself inserted therein cannot be evaluated. Further, because of optical measurement, the influence of sagging on the end surface of the guide pin hole is large, and the center position cannot be calculated accurately. In the above method, since the light emitted from the fiber core of the front end face of the fiber hole is imaged in a non-contact manner, the inclination of the optical fiber with respect to the camera, the polishing angle of the optical fiber end face,
There are many measurement error factors such as the difference in focus points due to the height mismatch of the optical fiber end faces. Therefore, various measurement correction means are required.

[0011]

A method for measuring a core position deviation of an MT connector according to the present invention is a connector for measuring the position deviation between a connector (reference connector) whose core position deviation amount and deviation direction are known in advance. (Connector under test)
Are connected using guide pin holes and guide pins having almost no clearance between the guide pins, and the amount of attenuation of the optical power incident on the optical fiber is measured to measure the connection loss of the connector. Next, replace the guide pin with a thinner one, shift the connector end face to be measured in the connector shearing direction, find the shift amount and shift direction that minimizes the connection loss for each optical fiber, and measure the relative shift relative to the reference connector. The gist is to find the displacement.

In addition, instead of connecting the reference connector and the connector to be measured, for example, connecting a pair of connectors of the same manufacturing lot and determining the relative core position deviation of the pair of connectors by the above method. Use as a summary.

[0013]

[Function] Since the connectors are directly connected to each other and the end face of the connector to be measured is shifted in the shearing direction of the connection surface to measure the optical power attenuation of the optical fiber incident light, when there is no relative displacement of the core of the connector, The attenuation, that is, the splice loss is the lowest. Therefore, the core position deviation of the connector under measurement can be known by obtaining the position where the connection loss is the smallest for each optical fiber.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view showing an overall configuration of a measuring apparatus to which an optical fiber core position displacement measuring method for an MT connector is applied.

A connector (hereinafter referred to as a reference connector) 100 whose displacement amount and displacement direction of the optical fiber core position are known.
Is attached to a dedicated chuck 12 that is fixed to the apparatus body and does not move. Connector under test 101
Is fixed to the X-axis and Y-axis stages 22 and attached to a dedicated chuck 14 that moves together with the stages.

The optical fiber 1 is provided on the rear end side of the reference connector 100.
6, a light source 18 is provided, and a power meter 20 is provided on the rear end side of the connector 101 to be measured through an optical fiber 16. A linear scale is drawn on the side surface of the stage 22 that moves in parallel with the X axis and the Y axis, and the movement is detected by the sensors 24 and 26, and a pulse according to the movement amount is output.

FIG. 2 is a block diagram showing the functional arrangement of the measuring device. As shown in FIG. 2, the X-axis stage 22
Is movable by the X-axis drive mechanism 28, and the Y-axis stage 22 is movable by the Y-axis drive mechanism 30.
Reference numerals 8 and 30 are composed of stepping motors and the like, and are controlled by the stage driver 32. The output pulses of the sensors 24 and 26 are counted by the counter 34, and the movement amount is monitored, and at the same time, the CPU 36
Is input to

The output (optical power data) of the power meter 20 is sent to the CPU 36, and the core position is calculated.
It is properly displayed on the CRT 38. The CPU 36 controls the stage driver 32.

FIG. 3 shows the state of the MT connector ferrule 101 in the embodiment. Guide pins 10 on both sides
5 is inserted into the guide pin hole of the ferrule of the reference connector through the guide pin hole 106. Four optical fiber holes 107 are formed between the guide pin holes, and the optical fiber 16
Is inserted. The optical fiber 16 is polished so as to be flush with the front end face of the ferrule 101, and the end face is exposed from the fiber hole 107.

Next, a method of measuring the positional deviation of the optical fiber core of the MT connector, which is executed by using the apparatus shown in FIG. 1, will be described.
The measurement is sequentially performed in the next step.

1) The reference connector 100 and the connector to be measured 101 are connected using a guide pin hole and a guide pin having almost no clearance between the guide pins, the optical power at this time is measured by the power meter 20, and the connector connection loss. To measure.

2) With the above connectors connected, the reference connector 100 is fixed to the chuck 12 which is fixed to the main body of the apparatus and does not move, and the measured connector 101 is connected to the X-axis and Y-axis.
It is fixed to the dedicated chuck 14 fixed to the shaft stage.
After fixing, check that the power meter value does not fluctuate from (1) above. Then, the X of the stage at this time,
The Y coordinate is (0,0).

3) Replace the guide pin with a thin one with each connector fixed to the chuck. At this time, it is confirmed that the coordinates of the stage are (0, 0) and that the value of the power meter does not change.

4) In the above condition (3), the stage 22 is shifted in the X-axis direction and the Y-axis direction while monitoring the measured value of the connection loss, and the X and Y coordinates at which the connection loss is the lowest are obtained.

5) The positional deviation of the optical fiber core of the connector to be measured is found from the coordinates found in (4) above and the known positional deviation of the core of the reference connector 100.

The above-mentioned measurements are carried out for each fiber strand.

[0027]

According to the measuring method of the present invention, since the optical fiber cores directly connected to the connector are in contact with each other, the measurement error factor inherent in the conventional optical non-contact measurement is present. This has made it possible to measure the core position of a connector with a small displacement of the core (1 μm or less), which has been difficult to measure until now.

Further, since it is particularly excellent in measuring the relative displacement of the cores between the pair of connectors, the relative displacement direction of the cores of the connectors manufactured under the same conditions is obtained to obtain the connector production of the measurement result. The feedback to was more accurate, and it became possible to manufacture highly accurate connectors.

[Brief description of drawings]

FIG. 1 is a perspective view of an apparatus to which a method for measuring a core position deviation of an MT connector according to an embodiment is applied.

FIG. 2 is a block diagram of an apparatus to which the method of measuring the core position deviation of the MT connector of the embodiment is applied.

FIG. 3 is a partial cross-sectional perspective view of the MT connector ferrule according to the embodiment.

FIG. 4 is a perspective view showing the configuration of an MT connector.

FIG. 5 is a partial sectional perspective view of a conventional connector.

[Explanation of symbols]

 100 Reference Connector 101 Measured Connector 105 Guide Pin 106 Guide Pin Hole 107 Optical Fiber Element Hole 12,14 Chuck 16 Optical Fiber 18 Light Source 20 Power Meter 22 X-axis, Y-axis Stage 24,26 Position Sensor 28,30 Stage Drive Mechanism

Claims (2)

[Claims] 1. A reference connector and a connector to be measured, wherein at least two guide pin holes for determining a position at the time of connection are formed, and a plurality of optical fiber element wires are fixed in a plurality of fiber holes respectively in an inserted state. A first step of inserting and connecting a guide pin that fits in the guide pin hole, and light from the rear end side of the optical fiber bare wire inserted in the fiber hole of the reference connector, The second step of measuring the optical power of the incident light at the rear end of the optical fiber element wire inserted into the fiber hole, and in the state of the first step, the reference connector is the stationary chuck and the connector to be measured is of the moving stage. A third step of fixing the guide pin to a chuck and replacing the guide pin with a guide pin thinner than the guide pin, and in the state of the third step, the light inserted into the reference connector. When light is incident from the rear end side of the fiber strand and the optical power of the incident light is measured at the rear end side of the optical fiber strand inserted in the connector to be measured, the X-axis and Y-axis stages are moved to move the light. Fourth to find the X and Y coordinates that maximize the power
And a fifth step of calculating a core position shift of the connector to be measured from the X and Y coordinates obtained in the fourth step and previously known and known core position shift coordinates of the reference connector, The MT for measuring the positional deviation of the optical fiber element core inserted into the fiber hole of the connector to be measured.
How to measure misalignment of connector core position. 2. A pair of connectors in which at least two guide pin holes for determining a position at the time of connection are formed, and a plurality of optical fiber element wires are fixed in the plurality of fiber holes in an inserted state, respectively. A first step of inserting and connecting a guide pin that fits in a pin hole, and light is incident from the rear end side of the optical fiber element wire inserted in one fiber hole of the pair of connectors, and the fiber of the other connector The second step of measuring the optical power of the incident light at the rear end of the optical fiber element wire inserted in the hole, and in the state of the first step, one connector is a stationary chuck and the other connector is a movable stage. A third step of fixing the guide pin to a chuck and replacing the guide pin with a guide pin thinner than the guide pin, and an optical fiber bare wire inserted into one connector in the state of the third step. When light is incident from the rear end side and the optical power of the incident light is measured at the rear end side of the optical fiber element wire inserted in the other connector, the X-axis and Y-axis stages are moved to maximize the optical power. A fourth step of obtaining X, Y coordinates, and measuring the relative displacement amount and displacement direction of the core position displacement of the optical fiber element wires inserted into the fiber holes of the pair of connectors. Measuring method of core misalignment.