WO2009099281A2

WO2009099281A2 - Optical fiber connecting device and optical fiber quality measuring system using same

Info

Publication number: WO2009099281A2
Application number: PCT/KR2009/000422
Authority: WO
Inventors: Tae-Kyoung Yook; Lae-Hyuk Park; Ji-Sang Park; Soon-Il Sohn; Hyung-Soo Shin
Original assignee: Ls Cable Ltd.
Priority date: 2008-02-05
Filing date: 2009-01-29
Publication date: 2009-08-13
Also published as: WO2009099281A3; KR20090085885A; WO2009099281A4; KR100956485B1

Abstract

The present invention relates to an optical fiber connecting device and an optical fiber quality measuring system using same. The optical fiber quality measuring system of the present invention includes a measuring unit for measuring optical fiber quality including PMD (Polarization Mode Dispersion) or optical loss of optical fiber; a connecting optical fiber including a first optical fiber connected to a transmitter end of the measuring unit and a second optical fiber connected to a receiver end of the measuring unit; an objective optical fiber connected to the first optical fiber and the second optical fiber such that optical quality of the objective optical fiber can be measured by the measuring unit; and a connector for physically and optically connecting the connecting optical fiber and the objective optical fiber. The connector includes a vacuum pump for generating vacuum pressure; and a contact retention unit for supporting the connecting optical fiber and the objective optical fiber which are uncoated and connected to each other, and retaining the contact state by sucking the connecting optical fiber and the objective optical fiber through the use of the vacuum pressure generated from the vacuum pump. The vacuum connection system of the present invention has a connection setting time shorter than that of a mechanical connection system and is suitable for use in the mass-produced optical fiber industry.

Description

Optical fiber quality measuring system by optical fiber connection device and device

The present invention relates to an apparatus for connecting optical fibers, and more particularly, to an apparatus for connecting an optical fiber under measurement connected to measurement equipment and a measuring optical fiber to be measured, and an optical fiber quality measuring system by the apparatus.

As optical communication speeds and long distances progress in recent years, standard specifications for optical loss and polarization mode dispersion (PMD) have been strengthened among optical fiber quality characteristics. Optical loss refers to a phenomenon in which an optical signal propagated to an optical fiber is weakened inside, and the optical loss acts as a factor for limiting a transmission distance of the optical signal. In addition, polarization mode dispersion refers to a phenomenon in which a speed difference occurs between polarization modes transmitted to the inside of the optical fiber due to refractive index anisotropy (asymmetry) on the optical fiber cross section (ie, core layer) that occurs in optical fiber manufacturing. The optical fiber in which the polarization mode dispersion occurs has a narrow transmission bandwidth and a short transmission distance.

In order to prevent the shipment of the optical fiber in which the optical loss or polarization mode dispersion occurs, the business establishment of the optical fiber measures the quality of the optical fiber before the optical fiber is shipped and searches for the optical fiber that does not meet a predetermined standard value. In other words, the optical fiber produced by the measurement of the optical loss and the polarization mode dispersion is measured by the measurement equipment, and the optical fiber that does not meet a certain standard value is discarded.

In order to measure the final manufactured optical fiber quality, the ends of the optical fiber to be respectively connected to the transmitter and the receiver of the PMD measuring device or the optical loss measuring device are connected to both ends of the finally manufactured optical fiber (ie, the measuring optical fiber). When the optical signal is transmitted from the measuring equipment, the optical signal is received through the transmitter, the transmitter connection fiber, the measurement fiber and the receiver connection fiber in sequence, and finally received by the receiver of the measurement equipment. Then, the measurement equipment analyzes the received optical signal to confirm whether the optical loss or polarization mode dispersion of the measurement optical fiber meets a reference value.

However, connection loss such as axial misalignment, angular tilt, and end separation may appear in the process of connecting the measurement optical fiber and the optical fiber to be measured. The measured values of light loss and polarization mode dispersion are distorted. Therefore, the process of connecting the final optical fiber and the optical fiber to be measured serves as an important parameter in the process of measuring the quality of the final optical fiber.

As a method of connecting the optical fiber to be measured and the optical fiber to be measured, there are a fusion splice method and a mechanical connection method. However, the fusion splicing method has a low connection loss, but permanently connects the optical fiber under measurement and the optical fiber to be measured, and thus is not suitable as a method of connecting optical fibers shipped. In addition, in the mechanical connection method, the optical fiber under measurement is connected to the optical fiber by using a connector or the like, so that the connection loss varies depending on the skill of the operator. In addition, the mechanical connection method is not suitable for a workplace where a large amount of optical fiber is produced due to a long time for connecting the optical fiber to be measured and the optical fiber to be measured.

SUMMARY OF THE INVENTION The present invention has been proposed to solve the above problems, and provides an optical fiber splicing apparatus and a fiber quality measuring system by the apparatus, wherein the connection setting time is fast and the variation of splice loss is low without permanently fusion of the optical fiber under measurement and the optical fiber. Its purpose is.

Other objects and advantages of the present invention can be understood by the following description, and will be more clearly understood by the embodiments of the present invention. Also, it will be readily appreciated that the objects and advantages of the present invention may be realized by the means and combinations thereof indicated in the claims.

According to a first aspect of the present invention for achieving the above object, a measuring device for measuring the optical quality characteristics, such as PMD or optical loss of the optical fiber; A connecting optical fiber comprising a first optical fiber connected to a transmitting end of the measuring device and a second optical fiber connected to a receiving end of the measuring device; A measurement optical fiber connected to the first and second optical fibers to measure an optical quality characteristic by the measuring device; And a connection device for physically connecting the connection optical fiber and the measurement optical fiber to optically connect the connection optical fiber, wherein the connection device comprises: a vacuum pump for generating a vacuum pressure; And contact holding means for holding the connection optical fiber and the measurement optical fiber in contact with each other with the coating removed while maintaining the contact state by sucking the connection optical fiber and the measurement optical fiber using the vacuum pressure generated in the vacuum pump. Characterized in that.

The optical fiber quality measuring system further comprises a vacuum pipe for transmitting the vacuum pressure of the vacuum pump to the contact holding means.

And the contact holding means comprises a V-shaped groove for supporting the connecting optical fiber and the measuring optical fiber; A slot formed in the bottom surface of the V-shaped groove; And an exhaust passage communicating the vacuum pipe and the slot. Preferably, the width of the slot is smaller than the diameter of the connecting optical fiber and the measuring optical fiber.

On the other hand, the vacuum pressure of the vacuum pump is preferably maintained at 0.15 bar to 0.40 bar when measuring the polarization mode dispersion of the measurement optical fiber, the vacuum pressure of the vacuum pump when measuring the optical loss of the measurement optical fiber It is preferable to keep it between 0.20 bar and 0.35 bar.

The contact holding means further includes a pressure sensor for measuring the pressure of the exhaust passage and a display device for displaying the pressure value measured by the pressure sensor to the outside.

According to a second aspect of the present invention for achieving the above object, an optical fiber connecting device includes a vacuum pump for generating a vacuum pressure; And contact holding means for supporting the two optical fibers which are in physical contact for optical connection while maintaining the contact state by suctioning and fixing the two optical fibers at the support surface using the vacuum pressure of the vacuum pump. It features.

The following drawings, which are attached to this specification, illustrate exemplary embodiments of the present invention, and together with the detailed description of the present invention, serve to further understand the technical spirit of the present invention. It should not be construed as limited to.

1 is a view showing the configuration of a system for measuring the optical fiber quality according to an embodiment of the present invention.

2 is a cross-sectional view of a jig according to an embodiment of the present invention.

3 is a perspective view of a jig according to an embodiment of the present invention.

110: vacuum pump 111: control switch

112: vacuum pipe 120: jig

121: pressure sensor 122: vacuum pressure display unit

123: coupling portion 124: exhaust passage

125: suction port 130: measuring optical fiber

140: measuring device 141: transmitting unit

142: receiver 143, 144: optical fiber to be measured

The above objects, features and advantages will become more apparent from the following detailed description taken in conjunction with the accompanying drawings, whereby those skilled in the art may easily implement the technical idea of the present invention. There will be. In addition, in describing the present invention, when it is determined that the detailed description of the known technology related to the present invention may unnecessarily obscure the gist of the present invention, the detailed description thereof will be omitted. Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

As shown in FIG. 1, a system for measuring optical fiber quality according to an embodiment of the present invention includes a vacuum pump 110 for generating a vacuum pressure, an

optical fiber

143 and 144 to be measured, and a measuring optical fiber ( Jig (120) to maintain the connection state while supporting the 130 and Polarization Mode Dispersion (hereinafter referred to as PMD) or measuring device 140 for measuring the optical loss.

The vacuum pump 110 includes a control switch 111 for adjusting the vacuum pressure, and is connected to the removable vacuum pipe 112.

The jig 120 is connected to the detachable vacuum pipe 112, and the

optical fibers

143 and 144 and the optical fiber 130 to be measured are connected to each other with the cover removed in a groove formed in a V shape. Support. It is preferable to minimize the connection loss of the optical fiber (143, 144, 130) by spraying the index matching oil to the connection portion of the optical fiber (143, 144) and the measurement optical fiber (130).

In addition, an exhaust passage is formed from the bottom of the V-groove of the jig 120 to the point where the vacuum pipe 112 is connected, and thus, the air is formed between the vacuum pipe 112 and the bottom of the V-groove. Will flow. Therefore, when the vacuum pump 110 generates a vacuum pressure and sucks air, the measurement

optical fibers

143 and 144 and the measurement optical fiber 130 supported in the V-shaped grooves are sucked to fix the connection state.

The measuring apparatus 140 is a PMD measuring apparatus or an optical loss measuring apparatus, and includes a transmitter 141 for transmitting an optical signal and a receiver 142 for receiving an optical signal. The

optical fibers

143 and 144 to be measured are connected to each of the transmitter 141 and the receiver 142, and the measuring device 140 transmits an optical signal to the optical fiber 143 connected to the transmitter 141. Then, the optical signal is finally received by the receiving unit 142 via the measuring optical fiber 130 and the measuring optical fiber 144 connected to the receiving unit 142 sequentially. Accordingly, the measuring device 110 measures the optical loss or polarization mode dispersion based on the received optical signal.

As shown in FIG. 2, the jig 120 according to the exemplary embodiment of the present invention includes a pressure sensor 121 and a vacuum pressure display 122, and a coupling part 123, an exhaust passage 124, and an intake port. 125 is formed.

The pressure sensor 121 is connected to the vacuum pressure display unit 122 and measures the vacuum pressure generated in the exhaust passage 124.

The vacuum pressure display unit 122 displays the vacuum pressure measured by the pressure sensor 121.

The coupling part 123 inserts and couples the vacuum pipe 112 and transmits the vacuum pressure generated by the vacuum pump 110 to the exhaust passage 124.

The exhaust passage 124 is a passage for discharging air between the coupling part 123 and the suction port 125. When the vacuum pressure is generated in the vacuum pump 110, the exhaust passage 124 sucks the air around the suction port 125.

The suction port 125 is positioned on the bottom surface of the V-shaped groove in which the

optical fibers

143 and 144 and the optical fiber 130 to be measured are aligned, and extend along the length direction of the V-shaped groove. When the vacuum pressure is generated in the vacuum pump 110, the suction port 125 sucks the measurement optical fiber 130 and the

optical fiber

143, 144 to be maintained to maintain the connection state of the

optical fibers

130, 143, and 144.

Meanwhile, the measurement optical fiber 130 and the measurement

optical fiber

143 and 144 located on the bottom surface of the V-shaped groove may be sucked into the exhaust passage 124 due to the generation of vacuum pressure. Therefore, the size of the suction port 125 is preferably formed to be narrower than the diameter of the core wire of the optical fiber (130, 143, 144) to prevent the phenomenon.

Referring to FIG. 3, the suction port 125 is located at the bottom of the V-shaped groove and extends along the length direction of the V-shaped groove. Therefore, when a vacuum pressure is generated from the vacuum pump 110 while the measurement optical fiber 130 and the

optical fiber

143 and 144 to be connected are placed on the suction port 125, the two

optical fibers

130, 143, 144 is connected by the suction force of the suction port 125 is fixed. Accordingly, the connection state of the two

optical fibers

130, 143, and 144 may be prevented from being deformed due to the external environment such as the shaking of the jig 120 and the shaking of the

optical fibers

130, 143, and 144.

In addition, the vacuum pressure display unit 122 displays the vacuum pressure of the exhaust passage 124 measured by the pressure sensor 121 as a number.

Through the above-described embodiment, an operator can easily connect the

optical fibers

143 and 144 to the measurement optical fiber 130. In addition, by removing the vacuum pressure of the jig 120 through the control switch 111 of the vacuum pump 110, the operator can easily terminate the connection state between the

optical fibers

143, 144 and the measurement optical fiber 130 to be measured. have.

Table 1 is a table showing the polarization mode dispersion (PMD) values measured while varying the vacuum pressure to the optical fiber connected by the vacuum connect method according to the present invention.

Table 1

No	Vacuum pressure (bar)	PMD Measurement [ps / km ^1/2 ]
Experiment 1	0.05	Not measurable
Experiment 2	0.10	Not measurable
Experiment 3	0.15	0.059
Experiment 4	0.20	0.055
Experiment 5	0.25	0.050
Experiment 6	0.30	0.060
Experiment 7	0.35	0.072
Experiment 8	0.40	0.102
Experiment 9	0.45	0.157
Experiment 10	0.50	0.210

That is, when the two optical fibers are connected, when the

optical fibers

143 and 144 and the optical fiber 130 are connected by the conventional fusion splicing method, which is known to show the least connection loss, the PMD value is 0.058 ps / km ^1. Measured with ^{/ 2} (measurement error ± 0.05ps). Therefore, when the vacuum connection method according to the invention as it is set to the pressure is less than 0.15 bar and 0.40 bar in the binary jig (120), with the PMD ^{^{0.050ps / km 1/2 ~ 0.102ps}} / km 1/2 You can see that it is optimized.

Table 2 is a table showing the optical loss value measured while varying the vacuum pressure to the optical fiber connected by the vacuum connection system according to the present invention.

TABLE 2

No	Vacuum pressure (bar)	Optical loss measurement [db / km @ 1550nm]
Experiment 1	0.05	0.301
Experiment 2	0.10	0.290
Experiment 3	0.15	0.300
Experiment 4	0.20	0.180
Experiment 5	0.25	0.182
Experiment 6	0.30	0.182
Experiment 7	0.35	0.183
Experiment 8	0.40	0.186
Experiment 9	0.45	0.189
Experiment 10	0.50	0.200

When the two optical fibers are connected, when the optical fibers 143 and 444 and the measurement optical fiber 130 are connected by the conventional fusion splicing method, which is known to have the least splicing loss, the optical loss value is 0.182 dB / km. Error ± 0.002). Accordingly, in the case of the vacuum connection method according to the present invention, when the vacuum pressure generated in the jig 120 is set to 0.20 bar or more and 0.35 or less, the light loss value is optimized to 0.180db / km to 0.183db / km. You can see that.

Tables 3 and 4 are tables showing standard deviations of PMD values and standard deviations of optical loss values measured by the same operator repeatedly connecting the same optical fiber by a mechanical connection method and a vacuum connection method according to the present invention.

TABLE 3

division	Vacuum connection method	Mechanical connection method
Average	0.055	0.059
Standard Deviation	0.003	0.015
Connection setup time	5 sec	20 seconds

Table 4

division	Vacuum connection method	Mechanical connection method
Average	0.181	0.182
Standard Deviation	0.002	0.040
Connection setup time	5 sec	20 seconds

As can be seen from Table 3 and Table 4, the same operator repeatedly connected and disconnected the same optical fiber in the vacuum connection method according to the present invention and measured the quality (ie PMD or optical loss) of the optical fiber, The vacuum connection method has a lower standard deviation of PMD and light loss than the mechanical connection method. In addition, the vacuum connection method has an average connection setting time of 5 seconds, which is faster than the mechanical connection method. In the vacuum connection method according to the present invention, the PMD and the optical loss of the optical fiber 130 are measured lower than that of the mechanical connection method. That is, the vacuum connection method according to the present invention can be seen that the connection loss is reduced more than the mechanical connection method.

Table 5 is a table showing PMD values and light loss values measured by a plurality of workers connecting the same optical fiber by a mechanical connection method and a vacuum connection method according to the present invention. Through Table 5, it can be seen that the vacuum connection method according to the present invention has a lower standard deviation between the operators of the PMD and the light loss than the mechanical connection method. In other words, the mechanical connection method is severely varied according to the skill of the operator, while the vacuum connection method according to the present invention is less affected by the skill of the operator.

Table 5

division	PMD [ps / km ^1/2 ]		Optical loss [db / km]
division	Mechanical connection method	Vacuum connection method	Mechanical connection method	Vacuum connection method
Worker 1	0.075	0.059	0.182	0.182
Worker 2	0.089	0.061	0.183	0.183
Worker 3	0.065	0.061	0.185	0.183
Worker 4	0.088	0.061	0.189	0.183

As described above, the vacuum connection method according to the present invention has a shorter connection setting time than the mechanical connection method, which is useful for a business that mass-produces optical fibers. In particular, the vacuum connection method according to the present invention can be usefully used in the field of optical fiber inspection in which the optical fiber has to be temporarily connected to measure the quality state of the optical fiber without permanently connecting the optical fiber.

The present invention described above is capable of various substitutions, modifications, and changes without departing from the technical spirit of the present invention for those skilled in the art to which the present invention pertains. It is not limited by the drawings.

The vacuum connection method according to the present invention has a shorter connection setting time than the conventional mechanical connection method and is useful for a business for mass production of optical fibers.

In particular, the present invention can minimize the deviation of light loss and polarization mode dispersion (PMD) that depends on the skill of the operator.

In addition, the vacuum connection method according to the present invention can be usefully used in the field of optical fiber inspection for measuring the quality of embedded or installed optical fiber.

Claims

A measuring device for measuring optical quality characteristics such as PMD and optical loss of an optical fiber; A connecting optical fiber comprising a first optical fiber connected to a transmitting end of the measuring device and a second optical fiber connected to a receiving end of the measuring device; A measurement optical fiber connected to the first and second optical fibers to measure an optical quality characteristic by the measuring device; And a connection device for physically connecting the connection optical fiber and the measurement optical fiber to optically connect the optical fiber.

The connection device,

A vacuum pump for generating a vacuum pressure;

And contact holding means for holding the connection optical fiber and the measurement optical fiber in contact with each other with the coating removed while maintaining the contact state by sucking the connection optical fiber and the measurement optical fiber using the vacuum pressure generated in the vacuum pump. Optical fiber quality measurement system, characterized in that.
The method of claim 1,

And a vacuum pipe for transmitting the vacuum pressure of the vacuum pump to the contact holding means.
The method of claim 2,

The contact holding means,

A V-shaped groove for supporting the connecting optical fiber and the measuring optical fiber;

A slot formed in the bottom surface of the V-shaped groove;

And an exhaust passage communicating the vacuum pipe and the slot.
The method of claim 3, wherein

And the width of the slot is smaller than the diameter of the connecting fiber and the measuring fiber.
The method according to any one of claims 1 to 4,

And the vacuum pressure of the vacuum pump is maintained at 0.15 bar to 0.40 bar when measuring the polarization mode dispersion of the measuring optical fiber.
The method according to any one of claims 1 to 4,

When measuring the optical loss of the optical fiber, the vacuum pressure of the vacuum pump, the optical fiber quality measurement system, characterized in that maintained at 0.20 bar ~ 0.35 bar.
The method of claim 4, wherein

The contact holding means,

A pressure sensor for measuring pressure in the exhaust passage;

And a display device for displaying the pressure value measured by the pressure sensor to the outside.
A vacuum pump for generating a vacuum pressure; And

An optical fiber connection including contact holding means for holding two optical fibers that are in physical contact for optical connection while maintaining the contact state by suctioning and fixing the two optical fibers at their support surfaces using the vacuum pressure of the vacuum pump Device.
The method of claim 8,

Further comprising a vacuum pipe for transferring a vacuum pressure of the vacuum pump;

The contact holding means,

A support groove formed along the longitudinal direction of the optical fiber for supporting the two optical fibers in a received state, a slot extending along the longitudinal direction of the optical fiber at a bottom surface of the support groove, and communicating the slot with the vacuum pipe And an exhaust passage for discharging the optical fiber.
The method of claim 8,

And the width of the slot is smaller than the diameter of the two optical fibers.
The method of claim 10,

The contact holding means,

A pressure sensor for measuring pressure in the exhaust passage;

And a display device for displaying the pressure value measured by the pressure sensor to the outside.