JPH01224710A - Optical connector - Google Patents

Abstract

PURPOSE:To eliminate a need of complicated optical axis adjustment and to obtain a high coupling efficiency by closely bringing end parts of a pair of optical fibers into contact with converging rod lenses respectively to support them and supporting at least one optical fiber freely attachably to and detachably from the converging rod lens and freely turnably. CONSTITUTION:Since optical fibers 1 which are so supported that they are closely brought into contact with converging rod lenses 2 are supported freely turnably to converging rod lenses 2, optical fibers 1 generally supported with slight decentering are turned to perform such adjustment that a maximum coupling efficiency is obtained. Since optical fibers 1 are supported freely attachably to and detachably from converging rod lenses 2, contacting end faces of optical fibers 1 or converging rod lenses 2 are prevented from being flawed when optical fibers 1 are turned to converging rod lenses 2. Thus, a high optical coupling efficiency is obtained without complicated optical axis adjustment.

Description

[Detailed Description of the Invention] Summary The present invention relates to an optical connector for optically coupling optical fibers to each other, and the present invention aims to provide an optical connector that does not require complicated optical axis adjustment and can obtain high coupling efficiency. In an optical connector, the ends of a pair of optical fibers are supported in close contact with focusing rod lenses, and the focusing rod lenses are opposed to each other to optically couple the optical fibers. An optical fiber is supported so as to be freely rotatable toward and away from the focusing rod lens.

FIELD OF THE INVENTION The present invention relates to an optical connector for optically coupling optical fibers to each other, and more particularly to an optical connector in which a converging rod lens is interposed between the optical fibers to be coupled.

As a result of the dramatic advances in semiconductor lasers as transmission light sources and optical fibers as optical transmission lines, optical communication systems or optical transmission systems have come to be applied to various fields. Optical connectors for connecting these devices have come into widespread use. Optical connectors are required to have low optical loss, that is, high coupling efficiency, and good operability.

BACKGROUND OF THE INVENTION FIG. 5 is a diagram showing an example of the basic configuration of a conventional optical connector. In (a), an optical fiber 33 is inserted and fixed into a ferrule 32 in which a focusing rod lens 31 is embedded in the end.
The ferrules 32 are arranged to face each other within a hollow sleeve 34. (b) shows a vibrator 44 in which an optical fiber 43 is inserted and fixed to a ferrule 42 to which a focusing rod lens 41 is temporarily fixed in an adjustable position.
is inserted and fixed, and the ferrules 42 are opposed to each other within the sleeve 45. Although the focusing rod lenses are shown spaced apart from each other in both FIGS. 5(a) and 5(b), they may be in close contact with each other.

According to this configuration, by positioning the fiber at the focal point of the rod lens, the light emitted from the output-side optical fiber according to its numerical aperture is converted into a parallel beam by the converging rod lens, and this parallel beam is The beam is focused by a focusing rod lens provided on the incident side and introduced into the optical fiber on the incident side. The reason why the convergent rod lens is used in this way is mainly for the following reasons. Firstly, the allowable amount of axial deviation when a parallel beam is used is much larger than when the end faces of optical fibers are brought into close contact with each other without using a focusing rod lens.Secondly, This is because when performing connection work in the field, the diameter of the light beam at the exposed portion is increased, so that the influence of intervening dust or the like is relatively small.

Problems to be Solved by the Invention The structure shown in FIG. 5(a) is such that the ferrule 32 is
By inserting the ferrules 32 in a slidable manner, the relative positional relationship between the ferrules 32 is regulated and optical coupling is performed with a simple operation. Since the center lines of the outer diameter shapes do not necessarily match, there is a problem in that even if there is no positional shift between the opposing lenses, optical axis misalignment occurs, making it difficult to obtain high coupling efficiency.

The structure shown in FIG. 5(b) attempts to correct the deviation between the central axis and the optical axis by adjusting the position of the focusing rod lens 41, but adjusting the fixed position is complicated.

The present invention was created in view of these circumstances, and aims to provide an optical connector that does not require complicated optical axis adjustment and can obtain high coupling efficiency.

One way to solve problems FIG. 1 is a diagram showing the principle of the present invention.

This optical connector supports the ends of a pair of optical fibers 1.1 in close contact with focusing rod lenses 2, 2, respectively,
The converging rod lenses 2, 2 are arranged to face each other to optically couple the optical fibers 1.1.

At least one of the optical fibers 1 is supported so as to be able to move toward and away from the focusing rod lens 2 and to be rotatable.

Function: In the optical connector of the present invention, the optical fiber that is supported in close contact with the converging rod lens is rotatably supported with respect to the convergent rod lens. This is because by rotating the optical fiber supported by the optical fiber, adjustment can be made to obtain the maximum coupling efficiency. In addition, the optical fiber is supported so as to be able to move toward and away from the focusing rod lens. When the optical fiber is rotated relative to the focusing rod lens, the optical fiber or the focusing rod lens is supported at the abutting end surface. This is to prevent scratches from occurring.

Example Embodiments of the present invention will be described below based on the drawings.

FIG. 2 is a sectional view of an optical connector configured to apply the present invention, and FIG. 3 is a view taken in the direction of arrow A in FIG. 2. Reference numeral 11 designates a connector adapter in which an optical coupling portion is formed, and plug bodies 12 and 13 are attached to this connector adapter 11. An annular projection 12a is formed on the plug body 12.
a is an annular recess 11 formed in the connector adapter 11;
By loosely fitting the plug body 12 into the hole a, the plug body 12 can be roughly positioned when it is installed.

From inside the plug body 12, an integrated structure formed by coupling the ferrule 14 and the flange portion 15 by screwing them together protrudes rightward in the figure due to the biasing force of the biasing member 16. Of these, the ferrule 14 portion passes through a circular hole 11b formed in the connector adapter 11 and tightly fits into the sleeve 21.

A focusing rod lens 17 on which a non-reflection film 17-a is formed is inserted and fixed into the inner end of the ferrule 14, and an optical fiber 28 and its coating 28a are inserted and fixed into the inner center of the ferrule 14. A pipe member 18 formed by the above is fitted in a movable manner.

The tip of the pipe member 18 is spherically polished together with the end of the optical fiber 28 to enable PC connection with the focusing rod lens 17, and the rear end of the pipe member 18 has a
A plurality of pieces (four in this embodiment) are arranged in the circumferential direction of the flange portion 15.
A protrusion 18a is formed that can engage with the groove 15a provided.

The pipe member 18 is biased to the right in the figure by the biasing member 20 via the spacer 19, so that the spherical polished portion abuts the focusing rod lens 17 with an appropriate contact force, thereby reducing optical loss. Growth is prevented. In this embodiment, the protrusion 18a and the groove 15a are engaged to enable stepwise rotational adjustment of the pipe member 18 and to ensure that the pipe member 18 and the focusing rod lens 17 are in contact with each other. This is to prevent the fiber end face from being damaged by not adjusting the rotation in this state.

Reference numeral 22 denotes a cap nut for ensuring the attachment of the plug body 12 to the connector adapter 11. By screwing the cap nut 22 onto the connector adapter 11, the plug body 12 is moved to the right in the figure. It's tightened.

The other plug body 1 attached to the connector adapter 11
3 is a fixed ferrule 23 that tightly fits into the sleeve 21;
The fixed ferrule 23 has a focusing rod lens 24 formed with a non-reflective film 24a and an optical beam located inside the fixed ferrule 23. A pipe member 26 into which a fiber 25 is inserted and fixed is provided.

27 is a cap nut for ensuring that the plug body 13 is securely attached to the connector adapter 11.

FIG. 4 is a diagram for explaining rotational adjustment for obtaining maximum optical coupling efficiency. In the figure, C indicates the center line of the convergent rod lens 17 and the pipe member 18, and OA indicates the center line of the convergent rod lens 17.
represents the actual optical axis (the part with the highest refractive index).

Generally, the center line C and the optical axis OA do not completely match due to the manufacturing technology of the focusing rod lens, and the pipe member 1
8, the optical fiber 28 and the center line C are not completely aligned. Therefore, as shown in the figure, the optical axis O
Since the optical coupling efficiency is minimized when A and the optical fiber 28 are in symmetrical positions with respect to the center line C, the optical fiber 28
By adjusting the rotation of the pipe member 18 so that the pipe member 8 is located on the same side of the centerline C as the optical axis OA, it is possible to obtain the maximum optical coupling efficiency. Note that the deviation from the center line C of the optical fiber 28 is extremely small, and there are cases where the deviation between the center line C and the optical axis OA in the focusing rod lens 17 cannot be completely corrected. It is also possible to investigate each production lot of converging A-rad lenses and to provide the optical fibers 28 in advance offset from the center line C by an amount commensurate with the investigation.

In this embodiment, the biasing member 16 biases the ferrule 14 in the direction of the seventh ferrule 23, and both ferrules 14.
However, as long as the relative positional relationship of the center axes of both ferrules 14.23 is secured within the sleeve 21, both ferrules 14.23 can be brought into contact with each other with an appropriate contact force. It is not necessary that they come into contact with each other. This is because the non-reflection films 17a and 24a are formed on the focusing rod lenses 17 and 24, respectively, so there is no risk of a decrease in optical coupling efficiency due to not bringing them into contact.

Effects of the Invention As detailed above, according to the configuration of the present invention, the maximum optical coupling efficiency can be easily obtained by adjusting the rotation of the optical fiber, so that it is possible to easily obtain the maximum optical coupling efficiency without making complicated optical axis adjustments. This has the effect of making it possible to obtain high optical coupling efficiency.

[Brief explanation of the drawing]

Fig. 1 is a diagram of the principle of the present invention, Fig. 2 is a sectional view of an optical connector constructed by applying the present invention, Fig. 3 is a diagram showing the direction of the Δ arrow in Fig. 2, and Fig. 4 is a diagram of the present invention. FIG. 5 is a diagram for explaining the prior art. 1.25.28...Optical fiber, 2.17.24...Focusing rod lens, 14.23
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Claims (1)

[Claims] The ends of a pair of optical fibers (1, 1) are supported in close contact with focusing rod lenses (2, 2), and the focusing rod lenses (2, 2) are opposed to each other. In the optical connector, the optical fibers (1, 1) are optically coupled to each other, wherein at least one of the optical fibers (1) can be moved toward and away from the focusing rod lens (2) and can be rotated. An optical connector characterized by supporting.