JPS6355507A - Optical connector ferrule - Google Patents

Abstract

PURPOSE:To stably attain good coupling by providing extended clearance parts in guide pin holes and to absorb the variance of guide hole pitch and the deformation of guide pins. CONSTITUTION:Optical fiber guide grooves 3 and guide pin holes 4 are worked on V-grooved substrates consisting of silicon materials and flat plates are joined thereon to form ferrules 10 and 11, and guide pin holes 4 are provided with extended clearance parts 5. Though the guide pin 6 is inserted into a guide groove which is formed into a triangle to which the guide pin 6 is inserted, the extended clearance part 5 having 0.6mm depth is formed by drilling whose diameter corresponds to that of a circle circumscribed to the triangular guide groove. When guide pins having 0.35mm diameter are used to couple multicore optical connector ferrules having 4+ or -0.002mm guide pin hole pitch out of multicore optical connector ferrules obtained in this manner at random, they are coupled without problem even if the clearance between guide pins and guide pin holes is about 0.5mum.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an optical connector ferrule that realizes positioning and coupling using two guide pins.

(Prior art and problems to be solved) Fig. 4 is a front view of the end face of an example of a conventional multi-fiber optical connector ferrule (20), in which (21) is an optical fiber guide hole, (22)
The one for inserting the guide pin is the one for inserting the guide pin.

It has one hole. This kind of multi-core optical connector ferrule (2
A pair of optical fibers are positioned and fixed in the optical fiber guide hole (21) of 0), and the pair is placed facing each other as shown in FIG. Realize the bond.

In order to achieve high-precision coupling in such multi-core optical connectors, it is better to have a small clearance between the guide pin hole (Φ) and the guide pin; in reality, the clearance is 1 μm.
It is necessary to use the following guide pins. However, even in this case, if the pitch (P) of the guide pin holes (22) of the bonded sulferule (20) is PI>P2 as shown in FIG. As shown in Figure 5 (Q), the opposing ferrule end faces are not completely joined, but the ferrules are joined with a slight gap (9) left. This gap (9) is caused by the pressure force of the ferrule joining. Related to this, there is a pressure point where the ferrule itself or the guide pin itself will be damaged if too much force is applied.

(Means for Solving the Problems) The present invention eliminates the above-mentioned pressure point, absorbs the guide pin hole pitch tolerance by effectively utilizing the allowable deformation of the guide pin, and completely joins the ferrule end faces. This optical connector ferrule is characterized in that a guide pin hole for inserting a guide pin is provided with an expanded clearance portion having a diameter larger than the guide pin diameter from the entrance to a certain depth.

Figure 1 is an explanatory diagram of a specific example of the optical connector ferrule of the present invention, where (A) is a front view of the ferrule end face, and (B) is a top view with the flat plate of Figure (A) removed. It is.

In the drawing, (1) has an optical fiber guide groove <3 on the top surface.
Guide pin hole (4) for inserting the guide pin in 3 and both images.
), ■ is a flat plate bonded on the V-groove substrate (1), ■ is an expanded clearance section provided from the entrance of the guide pin hole (4) to a certain depth in the axial direction,
Its diameter at the entrance is larger than the guide pin diameter. In the figure, (A) is a cored optical fiber, and (B) is an optical fiber positioned and fixed in the optical fiber guide groove (3) of the groove substrate (1).

(Function) Figure 2 is a top view of the guide pin holes (ferrules (10) with different pitches of Φ) in the connected state. When connected, the guide pin ■ is deformed within the expanded clearance part ■ .

As shown in Fig. 3, the stress required for deformation is as follows: where the diameter of the guide pin (θ is d1, the Young's modulus is E1, the amount of deformation is δ, and the sum of the axial lengths of the expansion clearance part at the time of connection is Q). The bending stress σb and the shearing force generated at the root of the guide pin (■) are given by the following equations.

In this case, σhτ must be below the allowable range of the guide pin F3). Of course, the strength of the ferrule itself must be greater than this.

- As an example, let the allowable bending stress of the guide pin 0 be 1ook / ■ 1, E = 21000 / ■■ 1, guide pin diameter d = 0.35 layer of snow, deformation amount δ = o, oos. Then, ρ = 1.05 m. In other words, the axial length of the expanded clearance section of the ferrule on one side is approximately 0.5 m.
It turns out that 3 or more times are required. Similarly, if the allowable shear stress is 35 hg/m, *'h Q = 0.85@
II, but since the distance corresponding to the bending stress is 1.05 m, in this case, only the bending stress needs to be considered.

As for the shape of the expansion clearance part, the entire part may be tapered as shown in the figure, or a straight part may be provided to a certain depth, or only the bottom part may be tapered, and it goes without saying that various shapes can be used.

Note that although the above description has been made regarding a multi-fiber optical connector ferrule, it goes without saying that the present invention can also be applied to a single-fiber optical connector ferrule.

(Example) An optical fiber guide groove and a guide pin groove are formed on a silicon V-groove substrate, a flat plate is bonded thereon to create a ferrule, and the guide pin groove is expanded as shown in Figure 1. A clearance section was provided.

The guide pin is inserted into the triangular inscribed guide groove, but the expansion clearance part is machined with a drill having a diameter corresponding to the circumscribed circle of the triangular guide groove, and has a depth of O8B.
An expanded clearance section was formed for the meeting.

When the multi-core optical connector ferrules obtained in this way were randomly connected using guide pins with a diameter of 0.35--φ with a guide pin hole pitch of 4 mm ±0.002 seconds, the guide Even if you use a combination of pin and guide pin hole clearance of 0.5μml'1 degree,
Everything was connected without any problems.

In addition, as a result of a test using 8 single-mode optical fibers with a core diameter of 10 μm, the average coupling loss was 0.35 dB, and the maximum was 0.82 dB, confirming that variations in guide pin hole pitch were absorbed. It was done.

(Effects of the Invention) As described above, according to the optical connector ferrule of the present invention, by providing the expanded clearance part in the guide pin hole, the variation in the guide pin hole pitch can be reduced and the deformation of the guide pin can be reduced by the expanded clearance part. It is possible to absorb it by forming it, and it is possible to stably realize good bonding.

-Also, the expansion clearance part is difficult to grasp when inserting the guide pin.

It also works effectively as a guide pin, and furthermore, abrasion powder and dirt caused by attaching and detaching the guide pin can escape into this expanded clearance, allowing direct bonding without damaging the ferrule end face.

[Brief explanation of the drawing]

Figure 1 is an explanatory diagram of a specific example of the optical connector ferrule of the present invention, where (A) is a front view of the ferrule end face, and (B) is a top view with the flat plate of Figure (A) removed. It is. ~ Fig. 2 is a top view of the coupled state of ferrules with different guide pin hole pitches, and Fig. 3 is an explanatory view of the action of the expanded clearance portion in Fig. 2. FIG. 4 is a front view of the ferrule end face of an example of a conventional multi-core optical connector ferrule, and FIGS. 5(a) and 5(o) are illustrations of problems in the conventional example. A... Optical fiber core wire, B... Optical fiber, 1...
- V-groove bar plate, 2... Plane plate, 3... Optical fiber guide groove, 4... Guide pin hole, 5... Expansion clearance part, 6... Guide pin. Vines 1 rin S 2 times'J44 diagram 5 Close

Claims (2)

[Claims] (1) In an optical connector ferrule that realizes positioning connection using two guide pins, the guide pin hole for inserting the guide pin is provided with an expansion clearance part with a diameter larger than the guide pin diameter from the entrance to a certain depth. An optical connector ferrule characterized by: (2) The radial expansion dimension of the expansion clearance section is greater than the guide pin hole pitch tolerance at the guide pin hole entrance end;
The expansion depth in the axial direction is determined by the guide pin being deformed within the expansion clearance area in accordance with the tolerance amount of the guide pin hole pitch, and the guide pin bending stress and shear stress required for deformation being both the allowable stress for guide pin and ferrule deformation. The optical connector ferrule according to claim 1, characterized in that it is set as follows.