JP2001083365A - Optical loop back connector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a low-cost structure of an optical loop back connector having good handling property. SOLUTION: The optical loop back connector is equipped with a ferrule having a plurality of input and output parts 3 for light, and the ferrule 1 is coupled with fitting pins to an optical receptacle of an optical transceiver having the plurality of input and output parts for light so as to return a light signal outputted from the input and output parts for light of the receptacle of the optical transceiver to other parts of the receptacle. In the connector, a light guide mechanism 9 including input and output lens faces 4, 5 and reflection planes 6, 7 connecting the input and output lens faces 4, 5 to reflect the light signals is formed from a transparent material into one body in the input and output parts of the ferrule 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention has a function of folding an optical signal from a transmitting optical fiber to a receiving optical fiber.
The present invention mainly relates to an optical loopback connector used for testing an optical network.

[0002]

2. Description of the Related Art In recent years, the use of optical transmission in data communication has become very common, and an optical transceiver, which is a key device thereof, has been used in an extremely large amount.

For this reason, one transmission apparatus often has many optical input / output ports, and there is a demand for increasing the density of the optical input / output ports and compactly housing the wiring system.

In order to cope with such a situation, a new small optical connector and a small optical transceiver to be fitted therein have been proposed. Among them, there is one based on an MT connector for multi-core batch connection, in which a plastic ferrule is aligned using two fitting pins.

[0005] When an optical network is constructed and put into practical use, transmission equipment is tested first, and the "loopback" test is a typical test method.

In this method, an optical signal output from an optical transmitting side of an optical transceiver is folded back and input to an optical receiving side of the same optical transceiver. Can be tested to see if it works.

[0007] This test must be performed for all of a large number of optical input / output ports, and it takes a considerable amount of time to manually change the optical fiber cords one by one during the test. If a small loop-back test connector is connected to all the optical transceivers in advance, the test operation can be greatly simplified, and thus it is often used as an accessory of the optical transceiver.

FIGS. 4 and 5 show an optical transceiver 50 and a loopback connector 51 for performing a loopback test.
FIG. 4 is an overall view, and FIG. 5 is an enlarged view of a connecting portion.

First, as shown in FIG. 4, an optical transceiver 50 for performing a loop-back test includes an optical receptacle 52, and the optical receptacle 52 is fitted with an optical loop-back connector 51 to perform a loop-back test.

As shown in FIG. 5, the optical receptacle 52 is
A ferrule 54 having a plurality of light input / output sections 53 is provided therein, and the ferrule 54 has two optical fibers 55 serving as the input / output sections 53.
Are formed based on the MT connector technology in which a fitting pin 56 is formed on the end face of the connector.

On the other hand, the optical loopback connector 51 comprises a plastic ferrule 57 and an input / output section 58 of the ferrule 57 as shown in FIG.
Optical fiber 5 drawn out of 7 and bent into a loop
9 and a connector housing 60 for covering and protecting the ferrule 57 and the optical fiber 59.

As shown in FIG. 5, the ferrule 57 includes an optical receptacle 5 provided in the optical transceiver 50.
Two fitting holes 61 for inserting two fitting pins 56 are formed.

To perform a loopback test, first,
The two fitting pins 56 are inserted into the two fitting holes 61 to connect the optical transceiver 50 and the optical loopback connector 51.

Next, when an optical signal is transmitted from the optical transceiver 50 and output from the output section 62 of the optical fiber 55, the optical signal is input to the input section 63 of the ferrule 57 and is transmitted to the optical fiber 59.
After being looped back to the output section 64 of the ferrule 57 via the loop section, the signal is input to the input section 65 of the ferrule 54 and received by the optical transceiver 50.

The transmission / reception operation of the optical transceiver 50 at this time is inspected, and a loopback test is performed.

As described above, the conventional optical loopback connector 51 has basically the same structure as a normal connector used for optical transmission, and the same components can be used.

Therefore, the optical loopback connection is reliably performed with low loss.

Further, it is possible to manufacture the connector in the same manner as a normal connector without using any special parts and tools.

[0019]

However, the conventional technique has a problem that the optical loopback connector 51 becomes expensive.

The optical loopback connector 51 is not used except during the system test, and is almost always discarded after the test.

However, this optical loopback connector 51
Requires the same high-precision parts as those used in the system, so that the optical fiber 59 is bonded and fixed to the ferrule 57, and the end face of the ferrule 57 is also required to be precisely polished.
Since the price cannot be reduced, it is wasteful to use such an optical loopback connector 51 only for a test.

Further, the optical loopback connector 51 according to the prior art has a problem that the optical fiber 59 is hung in the form of a loop and becomes a hindrance. (The bending radius of the optical fiber 59 is actually larger than that shown in FIG. 4.)
Is connected to all the optical inputs and outputs of the device, there is also a problem that handling is difficult at all times, such as transportation and packing.

That is, there is a possibility that the optical loop-back connector 51 itself or, in the worst case, the connected optical transceiver 50 may be damaged by something caught in the loop portion of the optical fiber 59.

As described above, the optical loopback connector 51 according to the prior art requires improvement in both cost and usability.

The present invention has been made in view of the above circumstances, and provides a low-cost and easy-to-use optical loopback connector structure for use in testing optical transmission equipment and systems. The purpose is to:

[0026]

In order to achieve the above object, the present invention has a ferrule having a plurality of light input / output portions, and the ferrule has a plurality of fitting pins. An optical loopback connector coupled to an optical receptacle of an optical transceiver having an optical input / output unit and returning an optical signal output from the optical input / output unit of the optical transceiver receptacle to another location of the receptacle and inputting the optical signal. An optical loop characterized by forming a light guide mechanism in which an input / output lens surface and a reflection surface which folds an optical signal by connecting the input / output lens surfaces are integrated with a transparent material in an input / output section of the ferrule. It is a back connector.

According to a second aspect of the present invention, the light guide mechanism and two fitting pins of the receptacle are inserted into the ferrule.
2. The optical loopback connector according to claim 1, wherein the two fitting holes are integrally formed.

According to a third aspect of the present invention, a spring mechanism is provided at the rear end of the ferrule to apply an appropriate pressing pressure to the input / output end face of the receptacle.
An optical loopback connector as described.

The invention according to claim 4 is the optical loopback connector according to claim 3, wherein the spring mechanism at the rear end of the ferrule is formed integrally with the ferrule.

According to the above configuration, the optical loopback connector of the present invention can realize an optical loopback connector that can easily perform an optical transmission device and system test quickly, at low cost, and at low cost.

[0031]

Preferred embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 shows a ferrule of an optical loopback connector according to a preferred embodiment of the present invention, and FIG. 2 is an enlarged cross-sectional view showing a state where the ferrule is connected to a receptacle of an optical transceiver. It is.

As shown in FIGS. 1 and 2, the ferrule 1 of the optical loopback connector of the present invention comprises a light guide 2 integrally formed of a transparent material.

An input lens surface 4 and an output lens surface 5 serving as a plurality of light input / output portions 3 are formed at the center of the front end of the light guide 2, and the input / output lens surfaces 4 and 5 are connected to each other. A light guide mechanism 9 is configured by forming a space 8 forming the first reflection surface 6 and the second reflection surface 7.

The upper and lower portions of the light guide 2 are formed with two fitting holes 10 into which two fitting pins of the optical receptacle are inserted. A fixing protrusion 11 is formed.

FIG. 2 shows a state in which the ferrule 1 of the optical loopback connector of the present invention is connected to the ferrule 12 of the receptacle of the optical transceiver. It has two optical fibers 14A and 14B serving as the input / output unit 13,
An input lens surface 4 and an output lens surface 5 serving as an input / output unit 3 of the ferrule 1 of the optical loopback connector are formed with a space 15 from an end surface of the ferrule 1. , Optical fiber 14
A, 14B, the optical axes coincide with each other, and the focal positions of the input lens surface 4 and the output lens surface 5 are
A and 14B are provided at the end face positions.

Next, the operation of the present embodiment will be described.

The optical loopback connector having the ferrule 1 of the present invention, as described with reference to the conventional example of FIG. 5, is configured such that the two fitting pins of the optical receptacle provided in the optical transceiver are replaced with the two fitting pins of the ferrule 1. By inserting into the mating hole 10, it is used by being connected to the optical transceiver.

In this state, first, an optical signal from the optical transceiver is transmitted to the optical fiber 14A in the ferrule 12, as shown in FIG.

The signal light 16A passes through the optical fiber 14A in the ferrule 12 and passes through the output section 17 of the ferrule 12.
The light enters the input lens surface 4 of the ferrule 1 of the connector through the space portion 15 and becomes a signal light 16B collimated by the input lens surface 4.

The signal light 16B is transmitted to the light guide 2 made of a transparent resin.
In the axial direction of the ferrule 1, and at the first reflecting surface 6,
The signal light 16C is reflected at a right angle to become a signal light 16C in the radial direction, and becomes a signal light 16D which is in the opposite direction to the signal light 16A on the second reflection surface 7, and condensed on the output lens surface 5 which becomes an output part of the ferrule 1. Then, the light enters the input section 18 of the ferrule 12 of the receptacle and becomes the signal light 16E.

The signal light 16E is received by the optical transceiver through the optical fiber 14B.

That is, since the light guide 2 of the ferrule 1 of the optical loopback connector of the present invention has the light guide mechanism 9 formed at the center of the tip, the optical signal transmitted from the optical transceiver is guided. A total of 18 in the optical mechanism 9 alone
The direction is changed by 0 ° and the optical transceiver is turned back so that it can be received by the optical transceiver as it is.

In the above description, it is preferable to use, for example, a transparent resin for the light guide 2, and it is preferable that the transparent resin is integrally formed by injection molding.

The input lens surface 4 and the output lens surface 5
For example, the ferrule 1 is preferably formed in a convex hemispherical lens shape so as to protrude toward the input / output unit 3 side.

The first reflecting surface 6 is preferably formed, for example, in a plane inclined upward with respect to the optical axis of the input lens surface 4, and the second reflecting surface 7 is formed, for example, on the output lens surface. 5 is preferably formed in a plane inclined downward with respect to the optical axis.

The light guide 2 of the ferrule 1 of the optical loopback connector according to the present invention having such a configuration has the same outer diameter as that of the conventional ferrule. You can incorporate it.

A metal spring for holding the ferrule is provided in the housing.

The light guide 2 needs to be pressed against the end face of the optical input / output portion of the optical transceiver, like the ferrule of a normal connector. However, if the above-mentioned metal spring or the like is used, this function can also be provided. it can.

If an optical loopback connector is constructed by the above method, no optical fiber is required, and the precise and time-consuming work of fixing the optical fiber to a capillary (capillary tube) and polishing the fiber end face is also omitted. be able to.

The necessary parts can be easily formed by injection molding a transparent resin, so that the parts can be produced at extremely low cost.

In the optical loopback connector having the ferrule 1 of the present invention, it is only necessary to fold the incident light,
Since there is no need to consider the loss of the optical fiber for transmission,
Some optical coupling loss is acceptable.

For this reason, the light guide 2 of the ferrule 1 does not require as high a manufacturing accuracy as a normal ferrule for an optical connector, so that the cost can be kept low in this aspect as well.

In this embodiment, the light guide 2 of the ferrule 1 is integrally formed with a fitting hole into which the fitting pin of the optical transceiver is inserted, and the lens, the reflection surface and the fitting pin are formed. The positional relationship can be accurately determined, and the number of parts can be reduced.

In order to optimize the resin material, the light guide including the lens and the reflection surface and the fitting mechanism such as the fitting pin insertion hole may be assembled as separate parts.

In this embodiment, two lenses are formed as the input / output unit of the ferrule 1. However, if a lens having a short focal length is used, the same function can be obtained by forming only one lens. Is possible.

Although it is usually advantageous to form two reflecting surfaces, the number of reflecting surfaces may be increased.

The loopback function as described above can be used not only when connected to a receptacle of an optical transceiver,
It is also effective when connected to a relay adapter (receptacle) in the middle of the optical transmission path.

Next, another embodiment of the present invention will be described.

FIG. 3 is a cross-sectional view of an optical loopback connector according to another embodiment of the present invention.

As shown in FIG. 3, the optical loopback connector 30 includes a ferrule 32 composed of a light guide 31 integrally formed of a transparent material and a housing 33.

On the rear side surface of the light guide 31 of the ferrule 32, a nail 34 for fixing in the housing is formed, and at the rear end thereof, an appropriate pressing pressure is applied to the input / output end surface of the optical transceiver. A spring mechanism 35 is formed.

A space 36 having a first reflecting surface 6 and a second reflecting surface 7 connecting the input / output lens surfaces 4 and 5.
Is different from the space 8 described in FIG. 1 in that the light guide 31 is not formed behind the first reflection surface 6 and the second reflection surface 7.

The other parts of the ferrule 32 are configured to have the same configuration as the ferrule 1 shown in FIG.

On the other hand, a ferrule housing hole 37 for housing the ferrule 32 is formed at the tip of the housing 33, and two fixing holes 38 for hooking the claws 34 are formed on the side surface thereof.

Further, on the rear side surface of the housing 33,
A housing 33 is formed by forming a protrusion 39 for removing the connector 30 connected to the optical transceiver.

The ferrule 32 is pushed in from the tip of the housing 33, and the claw 34 of the ferrule 32 is caught in the fixing hole 38 of the housing 33 and stopped.

At this time, the spring mechanism 35 comes into contact with the bottom of the ferrule receiving hole 37 and bends, and the repulsive force pushes the ferrule 32 against the end face of the optical input / output unit of the optical transceiver with an appropriate pressing pressure.

In this way, the optical loopback connector 30 is assembled.

In the preferred embodiment shown in FIG. 1, an example in which the ferrule 1 is fixed to the housing side with a metal spring has been described. However, as in the connector 30 shown in FIG.
If the light guide 31 is provided with a spring mechanism 35 and formed integrally, it can have the same function as the above-mentioned metal spring, and also greatly reduces the cost of parts and assembly. be able to.

[0071]

As is apparent from the above description,
According to the present invention, the following excellent effects are exhibited.

(1) The optical loopback connector can be realized at low cost. This makes it possible to test the optical transmission equipment quickly and at low cost.

(2) No optical fiber is required, and the precise and time-consuming work of fixing the optical fiber to the capillary (capillary tube) and polishing the fiber end face can be omitted altogether.

(3) Necessary parts can be easily formed by injection molding a transparent resin, so that they can be produced at extremely low cost.

(4) It is only necessary to turn the incident light back.
Since there is no need to consider the loss of the optical fiber for transmission,
Some optical coupling loss is acceptable.

(5) Since the ferrule light guide is not required to be as precise as a normal ferrule for an optical connector, the cost can be kept low in this aspect as well.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a preferred embodiment of the present invention.

FIG. 2 is an enlarged cross-sectional view showing a state where the ferrule of the optical loopback connector and the receptacle of the optical transceiver shown in FIG. 1 are coupled.

FIG. 3 is a cross-sectional view showing another embodiment of the present invention.

FIG. 4 is an overall view of the connection between an optical transceiver and a conventional optical loopback connector.

FIG. 5 is an enlarged view of a coupling portion between the optical transceiver shown in FIG. 4 and a conventional optical loopback connector.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Ferrule 2 Light guide 3 Light input / output part 4 Input lens surface 5 Output lens surface 6 First reflection surface 7 Second reflection surface 8 Space 9 Light guide mechanism 10 Fitting hole 11 Projection

Claims (4)

[Claims] A ferrule having a plurality of optical input / output sections, the ferrule being coupled to an optical receptacle of the optical transceiver having a plurality of optical input / output sections by fitting pins, and having a light input port of the optical transceiver receptacle. In an optical loopback connector for returning an optical signal output from a location of an output section to another location of a receptacle and inputting the same, the input / output section of the ferrule, an input / output lens surface, and a connection between the input / output lens faces. An optical loopback connector, wherein a light guide mechanism is formed by integrating a reflection surface that folds an optical signal with a transparent material. 2. The optical loopback connector according to claim 1, wherein the ferrule is integrally formed with a light guide mechanism and two fitting holes into which two fitting pins of the receptacle are inserted. 3. The optical loopback connector according to claim 1, wherein a spring mechanism is provided at a rear end of the ferrule for applying an appropriate pressing pressure to an input / output end face of the receptacle. 4. The optical loopback connector according to claim 3, wherein the spring mechanism at the rear end of the ferrule is formed integrally with the ferrule.