JPH0612365B2 - Optical connector - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a removable optical connector that positions and fixes an optical fiber and realizes coupling by using a guide pin.

(Prior Art) FIG. 11 is an explanatory view of an optical connector that realizes coupling by using a conventional guide pin. FIG. 11A is a coupling end view and FIG. 11B is a coupling explanatory view.

The optical fiber coupling member (50) is formed by transfer molding of epoxy resin or the like, and the optical fiber (2) with the coating of the optical fiber core wire (1) removed is provided in the optical fiber guide hole (51) inside. Position and fix with adhesive etc.
Insert the two guide pins (3) into the guide pin holes (52) as shown in (b).
The binding is realized by inserting into.

(Problems to be Solved) In the optical connector that realizes the coupling using the guide pin as described above, the inner diameter of the guide pin hole needs to be larger than the outer diameter of the guide pin to be inserted.

However, if the clearance between the inner diameter of the guide pin hole and the guide pin diameter is too large, the optical fiber cannot be positioned with high accuracy, and especially in the coupling of a single-mode optical fiber with a core diameter of only about 10 μm, a large coupling loss occurs. Occurs.
Therefore, there is a problem that the guide pin hole diameter and the guide pin diameter must be manufactured and managed with extremely high accuracy.

Also, considering the miniaturization of the optical connector, the wall thickness of the guide pin hole and the outer wall becomes smaller, but bending stress acts on the guide pin inserted into the guide pin hole when the optical connector is connected, The force is applied in the direction in which the force tends to spread the guide pin hole, and the optical fiber coupling member may be destroyed.

(Means for Solving the Problem) The present invention provides an optical connector that solves the above-mentioned problems, and is characterized by an optical fiber guide member for positioning and fixing an optical fiber by the optical connector, and a housing accommodating the same. The optical fiber guide member is formed on a groove substrate having an optical fiber guide groove and a guide pin groove on the upper surface, and at least a part of the guide pin groove is exposed to join a cover plate on the optical fiber guide groove. And the cover plate on the rear portion of the optical fiber guide groove of the optical fiber guide member is removed so that the rear portion of the optical fiber guide groove is exposed at this portion, and the exposed rear portion of the optical fiber guide groove is formed. There is a partition wall between the guide pin groove and the guide pin groove. Position to,
The guide pin insertion port side is equipped with a metal member that can be bent in the direction opposite to the groove substrate and that is variable in the vertical direction, and is inserted into the optical fiber hole formed by the groove substrate and cover plate of the optical fiber guide member. In the optical connector, the height of the central axis of the optical fiber to be arranged is almost the same as the height of the axial position of the guide pin.

FIG. 1 is an explanatory view of a concrete example of the optical connector of the present invention.
(A) is an overall structural view, and (B) is an external view of each component shown in (A). 2 is an explanatory view of the coupling of the optical connector of FIG. 1, FIG. 2A is an external view before coupling, and FIG. 2B is an external view in a coupled state.

The optical connector of the present invention comprises an optical fiber guide member (10) for positioning and fixing an optical fiber and a housing (2) accommodating the same.
0).

FIG. 3 is an explanatory view of the optical fiber guide member (10), FIG. 3 (A) is an external view, and FIG. 3 (B) is a sectional view taken along line XX of FIG.

The optical fiber guide member (10) is made of, for example, silicon single crystal, and has a guide pin groove (1) on a groove substrate (11) having an optical fiber guide groove (13) and a guide pin groove (14) on the upper surface.
At least a part of 4) exposed, and the optical fiber guide groove (13)
It is formed by joining a cover plate (12) on top with a thin film adhesive or the like.

This optical fiber guide member (10) has a notch (17) formed by removing the cover plate (12) on the rear part of the optical fiber guide groove (13) so that the optical fiber can be easily inserted into it.
The rear part of the optical fiber guide groove is exposed at this portion. A step portion (15) is formed at the rear of the exposed optical fiber guide groove (13), and a partition wall (15) is formed between the exposed optical fiber guide groove (13) and the guide pin groove (14). 16)
Exists.

Then, the optical fiber (2) is inserted into the optical fiber guide hole (13a) from the notch (17) of the cover plate (12) as shown in FIG. The optical fiber guide hole (13a)
It is processed to a size that a circle of about 0.127 mm is inscribed, and an optical fiber with a diameter of about 0.125 mmφ is inserted into this hole. At this time, the coating portion of the optical fiber core wire (1) is arranged on the step portion (15) formed at the rear portion of the groove substrate (11). In this state, drop the low-viscosity adhesive (4) to
(2) and optical fiber core wire (1) and optical fiber guide member (10)
Adhesively fix.

In the above, if there is no stepped portion (15) at the rear of the groove substrate (11), the optical fiber (2) is covered by the coating thickness of the optical fiber core wire (1).
Will be bent, resulting in passage loss due to bending. Also, when the adhesive is dropped, a part of the cover plate (12) exists as a partition wall (16) between the exposed portion of the optical fiber guide groove (13) and the guide pin groove (14), so that the viscous Even if a low-adhesive adhesive is used, the adhesive does not flow out toward the guide pin groove (14), and defects during assembly can be avoided.

Since the optical fiber guide member (10) is made of silicon single crystal as described above, it is necessary to devise to increase the strength against external force that acts intensively.

Therefore, a chamfer (41) as shown in FIG. 6 is performed so that the vicinity of the guide pin groove (14) entrance, which is likely to occur when the guide pin is inserted into the guide pin groove (14), does not become a sharp edge. This chamfer is the C chamfer as shown in Fig.
(B) such as the diamond blade (42), or the tapered diamond wheel (4)
There is a method of chamfering (41) into a tapered shape as in (c) according to 3). Either way, this guide pin groove (14)
Chamfer (41) at the entrance and guide pin as shown in FIG.
The tip taper (3a) of (3) can effectively effectively eliminate the silicon chip in the vicinity of the entrance of the groove (14). In addition,
In this case, the chip itself near the entrance of the guide pin groove (14) does not increase the coupling loss at the time of coupling the optical connector and does not deteriorate the performance of the optical connector, but Considering this, it is desirable to take measures against such chipping in appearance.

Further, in order to improve the strength of the optical fiber guide member (10), it is important to take a large V-angle tip R (see FIG. 7A) at the bottom of the guide pin groove (14) in order to reduce stress concentration. is there. Since the optical fiber guide groove (13) and the guide pin groove (14) of the optical fiber guide member (10) in the present invention are ground by the same V-shaped diamond blade, even if the V-angle tip has R, the optical fiber As long as the optical fiber is arranged in the guide groove (13), R cannot be set larger than the optical fiber radius, and if R is set too large, the optical fiber may be easily displaced. For R
It can be said that the upper limit is 30 to 40 μm. Larger R than this
If you try to find the bottom of the guide groove (14), for example, see Fig. 7
The "Y cut" (14 ') as shown in (B) is conceivable. In the embodiment of the present invention, this "Y cut" is practiced to improve the strength. FIG. 8 shows the effect of increasing the strength due to the presence of “Y-cut” obtained by the experiment. When the "Y cut" is not applied, the V groove tip R is about 10 μm, and when the "Y cut" is applied, the R is about 30 μm. Static V at that time
Groove breaking strength is "Y cut" as is clear from FIG.
Therefore, when R becomes large, it becomes several times stronger. By such measures, at least the guide pin groove
The V-groove is not broken by the insertion of the guide pin into the (14) at all during the operation associated with the attachment / detachment of an ordinary optical connector. However, even if R = 10 μm, it does not hinder the actual attachment / detachment operation, and is sufficient as compared with the V groove (R = several μm or less) formed by etching or the like.

Next, the housing (20) for housing the above-mentioned optical fiber guide member (10) will be described.

FIG. 1 (B) shows constituent members of the housing (20). The housing (20) is composed of a metal housing body (21), a plastic flange (24) and a rubber boot (25).
However, the plastic flange (24) and the rubber boot (25) may be an integrally molded product using an elastomer. The plastic flange can also be integrated by insert molding a G clamper.

The housing body (21) is provided with a G clamper (22) vertically adjustable in each of the two guide pin grooves (14) of the optical fiber guide member (10) and a plastic flange (24) at the rear. It is composed of a rear member (23) for receiving, and is formed by precision press working using, for example, stainless steel as a material. The use of such a metal pressed product can easily obtain a large processing force for pressing the guide pin, and since the wall thickness is thin, it is not much different from the optical fiber guide member (10). This has the advantage that the housing can be formed in a size that does not exist, and that it has sufficient proof strength against repeated deformation of the G clamper (22) due to the insertion and removal of the guide pin.

The G clamper (22) of the housing body (21) is variable in the vertical direction of the groove, and when the guide pin (3) enters the guide pin groove (14), the guide pin (3) moves downward in the groove. Although it is for fixing under pressure, in order to facilitate the insertion of the guide pin (3), not only is the chamfer near the inlet of the guide pin groove (14) as described above, but also the G clamper (22). As shown in FIG. 9, it is desirable that the vicinity of the inlet be bent (22a) in the direction opposite to the groove substrate (11) and slightly opened.

In addition to the G clamper (22) that presses the guide pin downward in the groove as described above, the housing body (21) also has a rear member (2).
3) serves to receive and fix the plastic flange (24) located at the rear of the housing body (21).

This plastic flange (24) makes contact between the clamper (30) and the housing (20) when the clamper (30) (see FIG. 2B) that axially presses the end faces of the plastic connector when the optical connector is coupled is operated. The surface serves as a positioning member when the optical fiber guide member (10) is housed in the housing (20). When the clamper (30) directly contacts the optical fiber guide member (10) formed of a silicon material,
There is a risk of chipping, and it is difficult in design to form a large contact surface only with the shape of the optical fiber guide member.
Is the reason for setting up.

The fixing of the optical fiber to the above-mentioned optical fiber guide member (10) will be described below with reference to FIG.

Optical fiber guide member (10) in the optical connector of the present invention
Completely eliminates the problem induced by the clearance between the guide pin and the guide pin hole in the conventional optical connector by completely contacting the guide pin (3) with the guide pin groove (14). Similar problems exist for the fiber hole diameter and the optical fiber diameter. In fact, even if the clearance between the optical fiber and the optical fiber hole is made as small as possible, there is a limit to the reduction of the clearance as long as there are variations in the outer diameter of the optical fiber and variations in the machining size of the hole diameter.

Therefore, in the present invention, the optical fiber is similar to the guide pin,
The optical fiber guide groove (13) is fixed at a position in contact with the V groove side. Optical fiber outer diameter variation is 2μ
In the current situation where there is about m, fixing the optical fiber with the groove position as the reference plane results in the center position (YY) of the optical fiber rather than reducing the variation of the outer diameter to reduce the clearance. It is easy to adjust to the set position. In other words, the positional deviation of the optical fiber axis center (YY) is affected only by the variation in the outer diameter of the optical fiber (2) with respect to the groove position, and the optical fiber hole (13a) and the optical fiber (2) Clearance has no effect. Thus, as compared with the conventional optical connector, it is possible to eliminate the maximum factor that causes the axial deviation, which is the presence of the clearance.

However, in some cases, it may be better not to apply the method of fixing the optical fiber by bringing it into contact with the V groove side. For example, when an optical connector is installed in a manhole of an optical cable installed in an underground conduit, it is desirable that the assembling method is as simple as possible, and even if the connection loss is somewhat large, it is allowed. In such a case, various construction methods for fixing the optical fiber in contact with the optical fiber guide groove are troublesome, and it is a work that should be avoided as much as possible in terms of omission and simplification of assembly.
Therefore, it can be said that it is effective to prepare several kinds of hole diameters of the optical fiber guide member in advance so that the clearance between the optical fiber and the optical fiber hole should be as small as possible even if the loss is somewhat large. If there is some clearance, the optical fibers tend to gather in the center of the hole to some extent due to the aligning effect of the adhesive injected into the clearance, and an extremely bad loss does not occur.

(Example) The optical connector of the present invention shown in FIG. 1 was prototyped and evaluated as follows.

As shown in FIG. 4, a diamond abrasive grain blade having an apex angle of about 90 ° was rotated on the upper surface of a silicon wafer to be a groove substrate at a high frequency spindle at 30,000 rpm to form optical fiber guide grooves and guide pin grooves. Grinding was performed. Although the optical fiber guide groove and the guide pin groove have different depths, these V grooves can be continuously processed by controlling the height position of the blade with the same blade. There are twelve optical fiber guide grooves with a 0.25 mm pitch, and two guide pin grooves (the guide pin diameter used for the purpose is 0.699 mmφ) pitch is 5.2 mm.

Also prepare another silicon wafer that will become a cover plate with a square window hole by ultrasonic processing in advance, thoroughly wash the bonding surface of this silicon wafer, and then spin coat the thin film of photoresist. It was formed on the joint surface to a thickness of about 1 μm, and was bonded to the above-mentioned V-grooved silicon wafer and heat-cured.

As a result, both silicon wafers were completely bonded with the resist thin film as an adhesive layer, and this was cut and separated into a desired size to obtain a plurality of chip-shaped optical fiber guide members.

An optical fiber was adhered and fixed to the thus obtained chip-shaped optical fiber guide member, the chip was chamfered, housed in a housing, and adhered to form an optical connector with 12 cores collectively.

When a 0.699 mmφ stainless steel guide pin was inserted into the guide pin hole of this optical connector, the two optical connectors were combined, and 12-core tapes of single-mode optical fiber were collectively connected and the coupling loss was measured. = 560 hearts average 0.21d
B and an extremely low loss optical connector were obtained. Assemblability was also good, and a structure in which a notch portion was provided in the rear portion of the cover plate of the optical fiber guide member and a part of the optical fiber guide groove was exposed was effective for improving the assemblability.

In addition, in order to confirm the reliability of the joint strength between the groove substrate of the optical fiber guide member and the cover plate, a heat cycle test (-30 to + 60 ° C, 1 cycle 6hr, 10 cycles), a moor heat test (80 ° C, 95% RH) After leaving it for 3 days), an impact test and the like were carried out, and it was confirmed that there was no problem in practical use. In particular, regarding the impact test, although a silicon material was used, the chamfering effect of the end face worked well, and since the whole was housed in the housing, no chipping occurred at all.

(Effect of the Invention) As described above, according to the optical connector of the present invention, the guide pin is pressed downward in the guide pin groove, so that the clearance between the guide pin and the guide pin groove is different from the conventional one. It is possible to realize an optical connector with high performance and high reliability that not only does not exist but realizes extremely low loss connection and also has good reproducibility of repeated attachment and detachment. By the way, 500
The fluctuation loss was within 0.1 dB even after consecutive removal and attachment.

Further, since the optical fiber guide member has a notch in the cover plate at the rear portion and the optical fiber guide groove is exposed, the optical fiber can be easily inserted and fixed by adhesion, and the assembling property is excellent. Since the partition wall exists between the exposed portion of the guide groove and the guide pin groove, the adhesive for fixing the optical fiber can be prevented from flowing out to the guide pin groove, and the defective assembly is reduced.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an explanatory view of a specific example of the optical connector of the present invention.
(A) is an overall structural view, and (B) is an external view of each component shown in (A). FIG. 2 is an explanatory view of the coupling of the optical connector of FIG.
(A) is an external view before combination, and (B) is an external view in a combined state. FIG. 3 is an explanatory view of an optical fiber guide member in the optical connector of the present invention. The figure (a) is an external view, and the figure (b) is X in the figure (a).
It is a -X sectional view. FIGS. 4 (a) to 4 (d) are explanatory views of an example of a manufacturing procedure of the optical fiber guide member of FIG. FIG. 5 is an explanatory view of adhesive fixing of an optical fiber to the optical fiber guide member of FIG. 6 (a) and 6 (c) are explanatory views of chamfering of the end surface of the guide pin groove, and FIGS. 6 (b) and 6 (d) are explanatory views of tools used for chamfering, respectively. 7 (a) and 7 (b) are explanatory views of the processing of the bottom portion of the guide pin groove, and FIG. 8 is an experimental characteristic view of the relationship between the above-mentioned processing of the bottom portion and the fracture strength. FIG. 9 is an explanatory diagram of the G clamp and the guide pin for facilitating the insertion of the guide pin into the guide pin groove. FIG. 10 is an explanatory view of positioning the optical fiber in the optical fiber guide hole of the optical fiber guide member. FIG. 11 is an explanatory diagram of an example of a conventional optical connector of a guide pin coupling system, FIG. 11A is a coupling end view, and FIG. 11B is a coupling explanatory diagram. 1 ... Optical fiber core wire, 2 ... Optical fiber, 3 ... Guide pin, 10 ... Optical fiber guide member, 11 ... Groove substrate, 12 ... Cover plate, 13 ... Optical fiber guide groove, 14 ... … Guide pin groove, 15 …… Groove substrate step, 16 …… Partition, 17 …… Cover plate notch, 20 …… Housing, 21 …… Housing body, 22 …… G clamp, 23 …… Housing rear member, 24 …… Plastic flange, 25 …… Rubber boot, 30 …… Clamper.

Front page continuation (72) Inventor Shuzo Suzuki 1 Taya-cho, Sakae-ku, Yokohama-shi, Kanagawa Sumitomo Electric Industries, Ltd. Yokohama Works (56) Reference JP-A-55-151610 (JP, A) JP-A-55- 70810 (JP, A) JP 62-56906 (JP, A) JP 61-209404 (JP, A) JP 56-114910 (JP, A) Actual development 55-141103 (JP, U) Actually open 56-15116 (JP, U) Actually open 61-124004 (JP, U) Actually open 57-175106 (JP, U) Actually open 52-34239 (JP, U) Actually open 56-126607 (JP, U)

Claims (8)

[Claims] 1. An optical connector for realizing coupling by using a guide pin, wherein the optical connector comprises an optical fiber guide member for positioning and fixing an optical fiber and a housing accommodating the optical fiber guide member. At least a part of the guide pin groove is exposed and a cover plate is joined to the optical fiber guide groove on a groove substrate having an optical fiber guide groove and a guide pin groove on an upper surface, and the optical fiber guide member is further formed. The cover plate on the rear part of the optical fiber guide groove of is removed, and the rear part of the optical fiber guide groove is exposed at this part,
Further, a partition wall is present between the exposed rear portion of the optical fiber guide groove and the guide pin groove, the housing is located on the guide pin groove of the optical fiber guide member, and the groove substrate is provided on the guide pin insertion port side. A groove bent in the direction opposite to that of the optical fiber guide member, which has a metal member that can be changed in the vertical direction, and the center axis position of the optical fiber that is placed in the optical fiber hole formed by the substrate and cover plate of the optical fiber guide member. An optical connector whose height is almost the same as the axial position height of the guide pin. 2. The optical fiber is positioned and fixed so as to substantially contact the groove substrate of the optical fiber guide member and the groove substrate side in the optical fiber guide hole formed by the cover plate. ) Optical connector described. 3. The stepped portion is formed at the rear portion of the exposed optical fiber guide groove.
The optical connector described. 4. The chamfering process is applied to the guide pin groove entrance of the optical fiber guide member.
(1) The optical connector described. 5. The guide pin groove is substantially V-shaped, a slit is formed in the bottom portion along the groove direction, and R of the slit bottom portion is at least 10 μm or more. ) Optical connector described. 6. The optical connector according to claim 1, wherein a tip of a guide pin used for connecting the optical connector is tapered. 7. The housing is provided with a flange member forming a rear end surface for contacting a clamper for axially pressing the coupling end surface when the optical connector is connected. Optical connector. 8. The optical connector according to claim 1, further comprising a rubber boot for protecting the optical fiber core near the boundary between the optical fiber core and the rear end face of the optical connector.