JP2011175069A - Optical sleeve and optical receptacle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical receptacle in which an optical sleeve surely holds a fiber stub and a ferrule, both being inserted into the optical sleeve, without being affected by an outside diameter difference between the fiber stub and the ferrule, and which has excellent optical characteristics and stability. <P>SOLUTION: The cylindrical optical sleeve 11 for aligning ferrules each holding an optical fiber 17 with each other and connecting them together has a slit 12 in the axial direction thereof and first and second notches 16a, 16b which are arranged on both sides of the slit 12 at the positions where the ferrules butt against each other and which are formed in the peripheral direction thereof, wherein an axial-direction distance between one end 11a of the optical sleeve and the first notch 16a is made equal to that between the other end 11b thereof and the second notch 16b. The optical sleeve 11 can hold the ferrules without being affected by the outside diameter difference between the ferrules which are inserted from both sides of the optical sleeve and butt against each other. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an optical sleeve used in a connector portion or the like for connecting optical fibers in alignment in optical communication, and an optical receptacle using the same.

  Conventionally, when optical fibers are connected to each other, a ferrule is attached to the tip of the optical fiber, and the ferrule is inserted from both ends of a cylindrical optical sleeve (hereinafter also simply referred to as a sleeve) to butt the tips. Is used to connect the optical fibers held inside the ferrule. FIG. 3 shows a conventional optical receptacle, FIG. 3 (a) is a perspective view showing an example of a split sleeve 111 having slits 112 in the axial direction used for the optical receptacle, and FIG. 3 (b) shows the split sleeve 111. An example of an optical receptacle 115 in which is used is shown in a longitudinal sectional view.

  In the optical receptacle 115, a fiber stub 114 containing an optical fiber is inserted into one end of a cylindrical sleeve 111 having a slit 112 in the axial direction, and a ferrule 113 is inserted into the other side of the sleeve 111. As a result, the optical fibers 117a and 117b are connected to each other with the core centers of the optical fibers 117a and 117b arranged on the central axes of the fiber stub 114 and the ferrule 113 abutted inside the sleeve 111 coaxially positioned. Note that the fiber stub 114 is an optical fiber inserted into the ferrule.

  By the way, since the fiber stub 114 and the ferrule 113 inserted into the optical receptacle 115 are not easily formed to have the same outer diameter, a difference in outer diameter occurs. When such a fiber stub 114 and the ferrule 113 are inserted from both ends of the sleeve 111, the inner diameter of the sleeve 111 is expanded according to the outer diameter of the fiber stub 114 or the ferrule 113 having the larger outer diameter, and the fiber stub 114 having a smaller outer diameter. Alternatively, the gripping force of the ferrule 113 may not be sufficient.

  Further, since the fiber stub 114 is usually shorter than the ferrule 113, the length that the sleeve 111 holds the fiber stub 114 becomes shorter than the length that holds the ferrule 113, and the gripping force of the fiber stub 114 becomes smaller than the ferrule 113. In this case, since the force with which the sleeve 111 holds the fiber stub 114 becomes weak, a lateral load is applied to the optical fiber 117b fixed to the ferrule 113, or an external force such as vibration or impact is applied to the optical receptacle 115. In addition, the sleeve 111 is deformed as a whole and the connection state between the fiber stub 113 and the ferrule 114 is changed, so that optical characteristics such as connection loss are extremely unstable.

  Further, in addition to the case where the outer diameter of the ferrule 113 is larger than that of the fiber stub 114, if the gripping force is insufficient due to this holding length, the gripping force of the fiber stub 114 is further reduced, and the light fixed to the ferrule 113. The optical characteristics against external force such as lateral load on the fiber 117b and vibration or impact on the optical receptacle 115 are further deteriorated.

  On the other hand, in Patent Document 1, as shown in FIG. 4, one ferrule 213 is inserted and fixed to the sleeve 211, and the shaft 211 is attached to the empty portion 211 a of the sleeve 211 where the ferrule 213 is not inserted. An optical connector is shown that uses a sleeve 211 in which a directional split groove 212 is provided and a notch 216 or notch 216 is provided between the ferrule 213 and the empty portion 211a.

  Further, in Patent Document 2, one of the single-mode fiber and the multi-mode fiber has a small diameter, while a part of the axial direction is a continuous body, a slit in the axial direction, and a notch in the central part. A cylindrical or polygonal sleeve is shown in which two ferrules having different diameters are pressed in the radial direction at the notch. A mode converter provided in an adapter for fastening the sleeve to the optical connector is shown. The optical fiber is intentionally connected in an off-axis state with different ferrule diameters.

  In this way, attempts have been made to hold each ferrule in an independent part through a notch provided in the slit of the split sleeve. In this case, the basic problem that the gripping force on the side of the fiber stub becomes weak and the gripping force between the fiber stub and the ferrule becomes unbalanced is solved, although it is difficult to be influenced by the outer diameter difference between the fiber stub and the ferrule. Not.

Registered Utility Model No. 2594643 Japanese Patent Laid-Open No. 2-93610

  Accordingly, the present invention has been made to solve such a conventional problem, and the object of the present invention is to make the fiber stub and ferrule unaffected by the difference in outer diameter between the fiber stub and the ferrule inserted into the optical receptacle. An object of the present invention is to obtain a sleeve that can be gripped and obtain excellent optical characteristics and stability, and an optical receptacle using the sleeve.

  The optical sleeve of the present invention is a cylindrical optical sleeve that connects and connects ferrules that hold an optical fiber, and has a slit in the axial direction, on both sides of the slit where the ferrule is abutted. The first and second cuts are provided in the circumferential direction, and the axial lengths from one end to the first cut and from the other end to the second cut are equal.

  In the optical sleeve of the present invention, the width of the second cut is made wider than the width of the first cut, and the length from the position where the ferrule is butted to the other end is from the position where the ferrule is butted It may be longer than the length to the one end.

  In the optical sleeve of the present invention, it is preferable that the depths of the first and second cuts are in the range of 0.64 to 0.88 times the outer diameter of the cylinder.

  An optical receptacle of the present invention includes a fiber stub that holds an optical fiber, a holder that holds a rear end side of the fiber stub, and the optical sleeve in which the one end side is inserted into a front end portion of the fiber stub. .

An optical sleeve according to the present invention is a cylindrical optical sleeve in which ferrules holding optical fibers are aligned and connected to each other, and has a slit in the axial direction. And the second incision is provided in the circumferential direction, and the axial length from one end to the first incision and from the other end to the second incision is equalized. It is possible to prevent the gripping force of the optical sleeve from becoming insufficient due to the influence of the diameter difference, and to equalize the force with which the optical sleeve grips the fiber stub and the force to grip the ferrule so that the fiber stub and the ferrule can be gripped in a balanced manner. it can.

  In the optical sleeve of the present invention, the width of the second cut is wider than the width of the first cut, and the length from the position where the ferrule is butted to the other end is longer than the length from the position where the ferrule is butted to one end. Assuming that the length is long, it is possible to grip a pair of different lengths such as a connection between a fiber stub and a ferrule in a balanced manner.

  In the optical sleeve of the present invention, if the depth of the first and second cuts is in the range of 0.64 times to 0.88 times the outer diameter of the cylinder, the outside of the fiber stub and the ferrule It is possible to eliminate the influence of the diameter difference and to prevent the deterioration of the strength of the optical sleeve.

  The optical receptacle of the present invention comprises a fiber stub for holding an optical fiber, a holder for holding the rear end side of the fiber stub, and the optical sleeve having one end inserted into the tip end of the fiber stub. Excellent gripping the fiber stub and ferrule at both ends of the sleeve without being affected by the outer diameter difference between the fiber stub and ferrule, and connecting the optical fibers held inside the fiber stub and ferrule Optical properties and stability can be obtained.

(A) is a perspective view which shows an example of embodiment of the optical sleeve of this invention, (b) is an example of the optical receptacle using the optical sleeve shown to (a), and is a longitudinal cross-sectional view of a central-axis part. . (A) is a perspective view which shows the other example of embodiment of the optical sleeve of this invention, (b) is a longitudinal cross-sectional view of the center axis | shaft part which shows the example of the optical connector using the optical sleeve shown to (a). is there. (A) is a perspective view which shows the example of the conventional optical sleeve, (b) is a longitudinal cross-sectional view which shows the example of the optical receptacle using the optical sleeve. (A) is a perspective view which shows the other example of the conventional optical sleeve, (b) is a longitudinal cross-sectional view which shows the other example of the optical receptacle using the optical sleeve.

  Hereinafter, the optical sleeve and optical receptacle of the present invention will be described in detail with reference to the accompanying drawings. FIG. 1A is a perspective view showing an example of an embodiment of an optical sleeve 11 of the present invention, and FIG. 1B is an optical receptacle 15 of the present invention using the optical sleeve 11 of FIG. It is sectional drawing which showed an example of embodiment with the longitudinal cross-section containing a central axis.

  As shown to Fig.1 (a), the sleeve 11 has a cylinder shape, and has the slit 12 to the axial direction from the one end 11a to the other end 11b. As shown in FIG. 1B, for example, a ferrule 13 and a fiber stub 14 are inserted into the sleeve 11 from both sides and the leading ends thereof are abutted, but the position where the ferrule 13 and the fiber stub 14 are abutted. The first notch 16 a and the second notch 16 b are provided in the circumferential direction of the sleeve 11 so as to intersect the slit 12.

  The axial gripping length L1 from one end 11a of the sleeve 11 to the first cut 16a and the gripping length L2 from the other end 11b to the second cut 16b grip the ferrule 13 and the fiber stub 14. The same length is formed so that the gripping force is balanced. Since the holding portion lengths L1 and L2 are the same, the sleeve 11 has an equal gripping force with respect to the ferrule 13 and the fiber stub 14.

  Further, the grips on both ends of the sleeve 11 are independent by the provided cuts 16a and 16b, and the grips on both sides of the sleeve 11 are affected by the difference between the outer diameter of the opposing ferrule 13 and the outer diameter of the fiber stub 14. In this case, the ferrule 13 and the fiber stub 14 can be held independently.

  In FIG. 1 (a), the width (axial length) M2 of the second cut 16b is made wider (longer) than the width (axial length) M1 of the first cut 16a. The length from the butting position of the ferrule 13 and the fiber stub 14 to the one end 11a and the length from the butting position of the ferrule 13 and the fiber stub 14 to the other end 11b are different. Although the lengths of the fiber stub 14 and the ferrule 13 are usually different, the preferred positions of the outer peripheral surfaces of the fiber stub 14 and the ferrule 13 by making the widths of the first cut 16a and the second cut 16b different in this way. Can be gripped by the sleeve 11 and the gripping force can be balanced.

  Further, a C-plane or R-plane portion is usually formed between the distal end surface and the outer peripheral surface of the fiber stub 14 and the ferrule 13 inserted from both sides of the sleeve 11, and this C-plane or R-plane is included. The distal end of the fiber stub 14 and the ferrule 13 are formed so that the distal end of the fiber stub 14 and the distal end of the ferrule 13 are located at two notches in the sleeve 11, that is, between the first cut 16a and the second cut 16b. Is held between the first cut 16a and the second cut 16b of the sleeve 11. The holding part sandwiched between the two cuts 16a and 16b plays a role of holding the ferrule 13 and the end of the fiber stub 14 so as not to cause axial misalignment, and stabilizes the gripping force of both by the optical sleeve. To prevent deterioration of optical characteristics due to external force.

  If the distance between the two notches 16a and 16b provided in the slit 12 is too short, the tip of the fiber stub 14 and the ferrule 13 cannot be sufficiently grasped, and if too long, the fiber stub 14 and the ferrule 13 Will be affected by the outer diameter of each other. From the above, the preferable distance between the notches 16a and 16b is 1.2 mm to 3.8 mm in the case of the φ2.5 type sleeve 11 and 0.9 mm to 2 mm in the case of the φ1.25 type sleeve 11. It is good to be about 4 mm.

  As a result, the holding force against lateral load, mechanical vibration, or mechanical shock can be maintained.

Such a sleeve 11 is produced by processing a metal such as phosphor bronze or a ceramic material such as zirconia ceramics. As an example of the manufacturing method, for example, a sleeve 11 made of zirconia ceramics is prepared by mixing a powder raw material obtained by adding a stabilizing material to zirconia (ZrO ₂ ) powder, a binder, and a solvent, and obtaining a mixed raw material (cup cup) Soil) is extruded from the mold, injected into the mold, or pressed into the mold to form a cylindrical shape, and then fired at about 1400 ° C. Thereafter, the inner diameter, outer diameter, and total length are ground and finished to predetermined dimensions.

  The slit 12 and the first and second cuts 16a and 16b are formed by turning a disk-shaped blade in the axial direction of the cylindrical body whose inner diameter, outer diameter, and full length have been polished to make a slit 12 Further, the first and second cuts 16a and 16b are cut in a direction perpendicular to this. In addition, when the width | variety of 1st and 2nd cut 16a, 16b is different, it cuts using a blade | wing with a different width | variety, respectively, or cuts several times using the blade | wing of the same width | variety.

At this time, the depths of the first and second cuts 16a and 16b, that is, the axial centers of the slit 12 and the sleeve 11 from the outer peripheral surface of the sleeve 11 at the slit 12 position to the tips of the first and second cuts 16a and 16b. It is preferable that the length of the distance N in the direction parallel to the direction connecting the two is 0.64 to 0.88 times the diameter of the outer surface of the sleeve 11. When the depth of cut is 0.64 times or more, the portions of the sleeve 11 that hold the fiber stub 14 and the ferrule 13 are easily kept independent, and the gripping force of the two is hardly affected by the difference in the outer diameter of each other. Tend to occur. If it is smaller than 0.88 times, the strength of the sleeve 11 tends to be kept low.

  For example, in the case of φ2.5 type sleeve 11 (outer diameter 3.2 mm), the depths of cuts 16a and 16b are 2.05 mm to 2.82 mm, and φ1.25 type sleeve 11 (outer diameter 1.62 mm). In this case, the depth is desirably 1.04 mm to 1.43 mm.

  In addition, if the corner portions of the cuts 16a and 16b are formed to have curved surfaces of, for example, R 0.05 mm or more, cracks are unlikely to enter the corner portions that become the stress concentration portions of the cuts 16a and 16b.

  Next, an example of the embodiment of the optical receptacle of the present invention will be described. As shown in FIG. 1B, the optical receptacle 15 holds the fiber stub 14 by fitting the fiber stub 14 holding the optical fiber 17a to the central axis and the rear end side of the fiber stub 14 by press fitting or the like. This is basically composed of a metallic holder 18 and a sleeve 11 in which one end side 11a is inserted into the distal end portion of the fiber stub 14. Further, there is a case in which a sleeve cover 19 made of metal or resin covering the outside of the sleeve 11 is incorporated so that the sleeve 11 does not fall off the fiber stub 14.

  Then, by inserting the ferrule 13 having the optical fiber 17b as the central axis from the other end 11b of the sleeve 11 of the optical receptacle 15, the optical fibers 17a and 17b are coaxially connected to each other, and the optical fibers 17a and 17b are connected. Through this, the optical signal can be transmitted.

  The ferrule 13 is biased by a spring or the like so that its front end surface is pressed against the front end surface of the fiber stub 14 with a predetermined force. Thereby, the front-end | tip part of the fiber stub 14 and the ferrule 13 deform | transforms moderately, and more reliable optical connection can be achieved. For this purpose, the stub 14 is made of zirconia ceramics, which is the same material as the ferrule 13, and the tip surface thereof is usually subjected to spherical processing similarly to the ferrule 13.

  In some cases, a resilient metal such as phosphor bronze is used for the sleeve 11, but if the ferrule 13 is repeatedly inserted and removed, the wear is severe and the characteristic is likely to change. A sleeve 11 made of high zirconia ceramics is the mainstream.

  Further, the end face of the fiber stub 14 opposite to the end face to be joined with the ferrule 13 is generally an 8 ° oblique polished face. This is to prevent characteristic deterioration due to unnecessary reflection when a signal is propagated in the air via a PD (photodiode) or LD (laser diode) and a lens.

  The holder 18 presses the fiber stub 14 inside the through hole, and presses the sleeve cover 19 into the recess provided in the opening of the through hole, thereby fixing and holding them. For the holder 18, a highly reliable stainless steel material is often used. In addition, a material suitable for YAG welding may be selected depending on the purpose of use.

According to the optical receptacle according to the embodiment of the present invention, the sleeve 11 has the first notch 16.
Since a and the second cut 16b are formed, each can be gripped individually without being affected by the difference in outer diameter between the fiber stub 14 and the ferrule 13. Further, by balancing the lengths of gripping the fiber stub 14 and the ferrule 13 as the same, the optical receptacle 15 having excellent optical characteristics and stability for connecting the optical fibers 17a and 17b can be obtained.

  Further, the portion of the sleeve 11 sandwiched between the first cut 16a and the second cut 16b grips the tips of the fiber stub 14 and the ferrule 13, so that the lateral load applied to the fiber stub 14 or the ferrule 13 Resistance to the eccentricity generated at the core center of the optical fibers 17a and 17b increases, and the effect of preventing the tilt of the ferrule 13 and the like against the moment caused by the external force is exhibited.

  The present invention is not limited to the above-described embodiments and examples, and various modifications can be made without departing from the scope of the present invention. For example, in the above-described embodiment, the fiber stub 14 and the ferrule 13 are connected in the optical receptacle 15 in which the sleeve 11 is used. However, the present invention is not limited to this, and as shown in FIG. It goes without saying that it can also be used for an optical connector or the like in which two ferrules 13a and 13b are connected in the sleeve 11.

  In the optical connector shown in FIG. 2, since the ferrule 13a and the ferrule 13b have substantially the same length in the axial direction, the front end butting surfaces of the ferrule 13a and the ferrule 13b are substantially the center of the sleeve 11, and are symmetrical with respect to the center. A first cut 16a and a second cut 16b having the same width are formed at the positions. The distance from one end 11a of the sleeve 11 to the first cut 16a and the distance from the other end 11b to the second cut 16b are also equal.

  In the description of the above embodiment, the terms “upper, lower, left and right” are merely used to describe the positional relationship on the drawings, and do not mean the positional relationship during actual use.

11: Sleeve 12: Slit 13: Ferrule 14: Fiber stub 15: Optical receptacle 16a: First cut 16b: Second cut 17a, 17b: Optical fiber 18: Holder 19: Sleeve cover

Claims (4)

A cylindrical optical sleeve for connecting ferrules holding optical fibers in alignment with each other, having a slit in the axial direction, on both sides of the slit where the ferrule is abutted, the first and second An optical sleeve characterized in that incisions are provided in a circumferential direction, and axial lengths from one end to the first incision and from the other end to the second incision are equal. The width of the second cut is made wider than the width of the first cut, and the length from the position where the ferrule is butted to the other end is longer than the length from the position where the ferrule is butted to the one end The optical sleeve according to claim 1, wherein: 3. The optical sleeve according to claim 1, wherein a depth of each of the first and second cuts is in a range of 0.64 to 0.88 times an inner diameter of the cylinder. A fiber stub for holding an optical fiber, a holder for holding a rear end side of the fiber stub, and the optical sleeve according to any one of claims 1 to 3, wherein the one end side is inserted into a distal end portion of the fiber stub. An optical receptacle comprising:

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