JPS5990809A - Optical fiber connector - Google Patents

Abstract

PURPOSE:To obtain easily a stable optical contact by narrowing the tip of a ferrule in an almost rectangular shape along the axial direction, and making it oppose in a line-up sleeve so as to cross the rectangular end face of the other ferrule with each other. CONSTITUTION:A ferrule 9 and 9' having butt faces 10, 10' formed in a rectangular shape by narrowing the tip by tapered parts 11, 11' are placed in line-up sleeve so that the longitudinal directions of the butt faces 10, 10' become almost orthogonal to each other. When they are placed in this way, the face to which each butt face 10, 10' of both ferrules 9, 9' contact becomes a small square face centering around optical fibers 1, 1' at the time of an opposed contact, a perfect mechanical contact having no air-gap is caused between the end faces of both optical fibers 1, 1' by applying a suitable pressing force to this contact face from the outside, and accordingly, a stable optical contact can be obtained.

Description

[Detailed description of the invention] [Technical field to which the invention pertains] The present invention relates to a communication optical fiber connector.

In particular, it relates to an optical fiber connector for connecting two optical fibers with low loss.

[Description of prior art]

Figure 1 shows the basic configuration of the optical power source 2,6 from fjL. In the same figure, ferrule 11
The ferrule 4 is made up of a ceramic pipe 2, a ceramic pipe 2, a circular ↑jiJ bamboo 3 placed on the same axis 1- and a ceramic pipe 2 centered on the optical fiber I, and this ferrule 4 butts against the mating ferrule 4' in the alignment sleeve 5. They are aligned together.

Note that J3.6.6' is a gesol with a nylon-coated optical fiber 1.1'.

Normally, when optical fibers are connected using the configuration described in -1-, a loss of 1g of connection is due to imperfections in the optical connector mechanism (e.g.,
(Angle '''-re, etc.), ■ 14 people against Tsurenel JLJ, are the main causes. As a countermeasure for this, Moeuchi introduced Ir1i integrated axial alignment and U technology, and the latter solved the air layer that occurs between the butt and 1 surfaces of the optical Soaiha 1 1' with each S scrap. Doing force hitting J
Node IP,) Zl.

As a practical method to eliminate the loss of Funnel reflection, the butting end surface of the ferrule 4.4' containing the optical fiber 1.1' shown in Fig. 1 should be made into a nearly mirror-like state.
When I used it, I directly touched 1.1' of Hikari Soaiha (18 degrees) (
Hereinafter referred to as "1-Optical Contact"). ) There is a force method. moreover,
In order to prevent this light from coming into contact with the ferrule 7.7' and the drum I as shown in Figure 2,
There is a light-emitting device that uses JS's alignment sleeve 8 and molds the material into plastic.

The disadvantages of these conventional optical fiber connectors include, in the case of FIG. The disadvantage is that voids are likely to be formed between the end faces due to the bending. For this reason, the reproducibility of optical contact deteriorates after multiple attachment/detachment operations, and variations in contact loss occur. Also, the second
In the case shown in the figure, the contact surface of the ferrules 7 and 7' is made small to minimize the possibility of creating a gap between the optical fibers 1 and 1'.
The fitting error caused by the combination of the alignment sleeve 8 and the alignment sleeve 8 creates a slight gap on one surface of the abutment 1011, making it difficult to make good (Ll') contact with the light 9. moreover,
This Fig. 2 4: 24;Zu 1,000 plus 1,000) Since it is configured to utilize the elastic effect of the evening moon in a 4/1 polar manner to perform I concubine, it may vary depending on the usage environment etc. If there is deformation of the lunar quality,
There is a risk that it will not be possible to maintain a good state of contact.

In this way, the quality of optical contact with conventional optical fiber connectors is greatly influenced by the mating structure and the shape of the ferrule surface, and it is important to ensure stable and reproducible performance. J1 seats were at a loss when it came to realizing fiber optics.

[L1 aspect of the invention] The present invention has been made in order to solve the above-mentioned drawbacks, and provides a low t
1- to provide optical fiber connectors for fiber loss.
1 target.

[Invention II! M-break]

4. In the invention, the tip is fixed in a ferrule whose tip is roughly rectangular and fitted in a U shape,
Align the pair of ferrules in the sleeve so that the axes of this approximately long length-shaped abutment intersect with each other.
It is characterized by every detail.

[Explanation based on examples]

Hereinafter, the present invention will be explained based on the drawings.

FIG. 3 is an external perspective view of a main part of an optical cable connector according to an embodiment of the present invention.

In the same figure, 1.1' is an optical fiber, 2.2' is a ceramic pipe, 9.9' is a ferrule, and 10.10' is a ceramic pipe.
The tip of the ferrule 9.9' is connected to the tapered part 11, II'
Butt narrowed to Iiii force shape ui/+i
'C is there. The butt-to-mouth surface 10.10' is the optical fiber 1.
1' to the optical axis (perpendicular plane) - ii horizontally 0.7
mm x 2.5 mm, and its surface has an almost mirror-like optical structure, including the optical fiber 1.1'.
1/1' polished and "C". Ferrule 9.9' is the first
It has a cylindrical structure similar to the one shown in the figure, but the first part is v8, part 1 is
The feature is that 0.10' is a j-force type cross section.

The ferrule 9', which faces the ferrule 9 and the dirt χ1, is aligned with the alignment sleeve 5 of FIG. 1, as shown in FIG. are arranged so that they are substantially perpendicular to each other. When arranged in this way, opposing contact stiffness: Sometimes both ferrules 9 and 9' butt-1 and 10
．． The mutually contacting surfaces of the optical fibers 1 and 10' form a small square surface with the optical fiber 1.1' as the center, and by applying an appropriate pressing force from the outside to this contact surface, there is no gap between the end surfaces of the two optical fibers. Full mechanical contact can be created. By the way, the cylindrical ferrules 9 and 9' are connected to each other by a circle Ti? After aligning and fitting within the sleeve 5, and fitting the butt and l contact surfaces of the ferrules 9 and 9' into -U, they are crossed in a cross-shape -1, so that they face each other by pressing.
It is possible to extremely reduce gaps in the contact surface caused by imperfections in mechanism (2) such as axial deviation and angular deviation of I. In this case, the criss-crossed surfaces as described above are affected by external forces in the axial and rotational directions, especially external forces from the screw fasteners placed outside +, ', and i of the ferrule 9.
．． Even when a rotational moment is applied to 9', the displacement exerted on the contact surface is extremely small. However, in the case of the conical ferrule shown in Fig. 2, it is difficult to make stable optical contact because the rotating ferrule causes changes in the contact surface at any position within 360 degrees. The validity of the above effect is also supported by actual measurement data on the connectivity of optical fiber connectors, which will be described later.

Furthermore, since the butt-U surface of the optical fiber connector of this example is mainly made of ceramic material, the contact surface protects the optical fiber and has excellent abrasion resistance, resulting in good mechanical strength performance. can be maintained. Therefore, stable optical contact can always be achieved even during repeated attachment and detachment, and connection characteristics with good Pi reproducibility can be obtained.

In addition, regarding the phenomenon in which dust, etc. generated during attachment/detachment sticks to the contact surface of the ferrule 1, the structure of the present invention has fewer contact surfaces and has a shape similar to a Taber edge, so the influence of this is extremely minimized. , good optical IU FIJ
! The product can be used at T4J.

In addition, the ratio of the long axis to the short axis of the dimension of the abutting surface 10.10' is in the range of about 1.5 to 15 times for a sufficient effect (
), and a ratio of about 3 to 4 times is particularly desirable.

FIG. 4 shows a specific embodiment of the present invention, and is a structural diagram of an FC type optical fiber connector, which is currently being standardized.

This optical connector is plug 12 and adapter 1.
It consists of 7. The plug 12 includes an optical fiber 1, a ferrule 9 having the same configuration as in FIG.
0, a spring 13 that presses the ferrule, a frame 14 that holds the optical fiber (1) coated with nylon (the core wire 6), a frame 14 that holds the ferrule 9, a positioning key 15 placed on the outer periphery of the frame 14, and a coupling for screw fastening. It is composed of nuts 16.

- force, the adapter 17 is aligned with the alignment sleeve 18 and the housing 1
9), and grooves 20 and 20' are formed at the input and output ends of the housing 19, respectively, so as to be offset by 90 degrees from each other.

To operate the connector 12, place the plug 12 into the adapter 17 by aligning the positioning key 15, which has been taken out in advance in the axial direction or short axis direction of the mating and mating end surfaces, with the notch grooves 20 and 20' of the attacher I7. By installing and fastening the sleeve I, the 2° ferrules are aligned.
As a result, the end faces of the two optical fibers are always brought into optical contact.

FIGS. 5 to 7 show test results for structures according to the present invention. This figure shows the characteristics of connection loss when two thin optical fibers are connected to a component with a core diameter of 10 μm using a connector, and Figure 5 shows the characteristics when using a conventional optical fiber connector. FIG. 6 shows the characteristics of the optical fiber connector according to the embodiment of the invention shown in FIG.

The method for measuring this characteristic is to use two ferrules as a master, connect a sample ferrule to each of these two ferrules 5 to 10 times, and calculate the average value. A ferrule is used. Figure 7 is shown for reference, and is a characteristic diagram when the optical fiber coil with the structure shown in Figure 4 and the lid are connected with their ferrule tips butting (with the surfaces not perpendicular to each other). be.

As is clear from Figures 21-5 and 6, the connection tlJ loss of the carp and kuku of the present invention is 0.13 dB on average, which is significantly lower than that of the conventional connector, which is 0.63 dB on average. becomes smaller. In particular, when attaching/detaching the 11i current (!I), the C standard deviation is stable with less than 11 dB compared to the standard deviation of 0.33 dB for the conventional -1 I. can be realized.

In addition, in the optical fiber connector of the present invention, it is possible to achieve good optical contact by making the long axes or short axes of the abutting surfaces at the ends of the J-rule substantially intersect with each other. It is also clear that ζ exists by comparing the characteristics of both Figures 6 and 7.

In the embodiment described above, the ferrule tip)
Although the first side is shaped like a long sword with the side containing the light ferrule narrowed, the present invention is not limited to this embodiment. Variations included in the present invention and equivalent to these 9)
J fruit 7. +7 I can do things like that.

Zunawara ■ The same rectangle 22 is also narrowed in the long axis direction at the same time ■
Narrowed into an oval shape 23 (Fig. 9), ■ Hyperbolic shape 24
These include: (Fig. 10) narrowed into a cocoon-shaped 25 (Fig. 11), and (Fig. 12) narrowed into a trapezoid 2G. Also, regarding the structure of the ferrule body,
In addition to the cylindrical shape, the present invention can also be applied to fan-shaped, rectangular, semicircular, etc., and for the optical fiber fixing part)), a ceramic pipe is used for the optical fiber fixing part)) as in the present embodiment. In addition, you can also use plan, thousand, etc.

[Invention glue J fruit]

As explained above, the present invention narrows the ferrule tip along the axial direction into a roughly taut shape, and faces the rectangular end face of the phase f soerrule so as to intersect with each other. The fibers can be brought into optical contact with each other in a good condition, the contact t+Jεfis loss can be reduced, and furthermore, it is possible to achieve stability during attachment and detachment. As described above, the present invention plays an extremely large role in improving the performance of optical transmission systems.

[Brief explanation of drawings]

Figures 1 and 21 show a conventional optical fiber connector.
Li side view. FIG. 3 is an external perspective view of an optical soaiper connector according to an embodiment of the present invention. ? FIG. 134 is a partially cutaway view of a fiber optic connector according to a more integrated embodiment of the present invention. Figure 5 shows the conventional optical fiber: J2 connection 1t1
Disadvantage 1 (Fig. 1. Fig. 6 shows the connection I of the optical fiber connector according to the embodiment of the present invention.
N lose'I! rf! L l so 1゜Figure 7 is a diagram of the loss characteristics of the joint eli4 for reference. FIGS. 8 to 12 are views showing modifications of the ferrule tip. 1.1'...Hikari Soaiha, 5...Coffin line sleeve, 2
．． 2'... Setsumic pipe, 9.9'... Ferrule, 10.10'... Butt-1, 11, II.
...Tapered part, I2...Plug, 13...Spring, 15...Positioning key, 17...Attabuter, 2
0.20'...Notch groove. Patent applicant 1” Telegraph and Telephone Public Corporation] Agent 4?
Rido Ide Naotaka M 1 Mi M 3 Figure 9 , +%8[k,'l1ti9ts M+oi
Volume 11, tail 12 group

Claims (1)

[Claims] (■) The ends of the two optical fibers are inserted and fixed, and the end faces of the two optical fibers are respectively inserted and fixed in the part (for sale). The formed pair of ferrules and an alignment sleeve that aligns the pair of ferrules so that the end surfaces of the two optical fibers face each other are assembled into an alignment sleeve. An optical fiber C is inserted from both ends of the optical fiber C, and the end surfaces of the optical fibers on the abutting surfaces are brought into opposing contact with each other, so that the two optical fibers are optically connected by each. In the connector ζ, each of the two abutting and opening surfaces is a flat IH7 perpendicular to the optical axis of the end face of the optical fiber, and the shape of one circumference of the plane is perpendicular to the optical axis. They are shaped to have different lengths, so that when the two abutting surfaces on the plate face each other in the alignment sleeve, the outer circumferential shapes of the abutting surfaces of the pair of ferrules on the plate are perpendicular to each other. An optical fiber ferrule characterized in that it is configured so that it butts against the ferrule. The optical fiber connector described in patent scope No. (1) is characterized in that it is matched with the optical fiber connector. +31 At least the part of the ferrule into which the optical fiber is inserted and fixed is formed of a ceraminochrome material.
The optical fiber connector described in item 2).