JP2005099748A - Optical receptacle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical receptacle which maintains high precision and high reliability and is small-sized, small in the number of components, and low in manufacturing cost. <P>SOLUTION: The optical receptacle 11 is equipped with a precise sleeve 12, a stub 14 with an optical fiber which is inserted into one end of an inner hole 12a of the precise sleeve 12 across an adhesive, and a sleeve holder 13 which is pressed in or fixed onto the outer periphery of the precise sleeve 12 with the adhesive 16, the Ra value of surface roughness of the outer peripheral surface of the stub 14 with the optical fiber and/or the surface of the inner hole 12a of the precise sleeve 12 is 0.1 to 0.5 μm. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an optical receptacle used for optically connecting an optical signal between an optical fiber connector and a light receiving / emitting element.

  As shown in FIG. 3A, the conventional optical receptacle 1 is a type using a split sleeve 2, and a stub 4 with an optical fiber is fixed to the stub holder 3 by press-fitting or an adhesive, so that it has sufficient elasticity. The stub 4 with an optical fiber is held by the split sleeve 2 having a structure, and is closed and held by the tightening margin of the split sleeve 2. The ferrule 7 of the optical connector is inserted from the opening 5a of the split sleeve cap 5 of the optical receptacle 1, and is precisely aligned coaxially with the stub 4 with optical fiber by the split sleeve 2, so that it is arranged behind the optical receptacle 1. The provided optical semiconductor 6a, the lens 6b, the light receiving / emitting element 6 having the holder 6c for holding them, and the optical fiber 7a in the ferrule 7 are optically coupled via the stub 4 with optical fiber. It has a structure.

  The optical receptacle 1 in FIG. 3A is the most orthodox, and is an early style devised for coaxial connection with an optical connector using a stub with an optical fiber. Recently, there is a high need for miniaturization of the transmission device itself, and the demand for shortening the optical receptacle used for it is severe. Various forms have been taken to achieve this miniaturization. For example, in Patent Document 1, as shown in FIG. 3B, a short stub 4 with an optical fiber can be precisely aligned on the same axis, and even if the stub 4 with an optical fiber is short, it is firmly attached to the split sleeve 2. There is disclosed a small optical receptacle 1a having four parts having a structure in which a holding ring 8 is press-fitted between a split sleeve 2 and a split sleeve cap 5 so as not to be held and loosened.

  Further, in Patent Document 2, as shown in FIG. 3C, the entire split sleeve is not split, but only the insertion side of the optical connector ferrule 7 is split. The stub 4 with an optical fiber is bonded and fixed to a split sleeve 9 that is not split on the side with the stub 4 so that the total length of the stub 4 with an optical fiber is shortened and can be precisely aligned on the same axis as described above. A small receptacle 1b is disclosed. In this optical receptacle 1b, the stub 4 with optical fiber is fixed to the stub holder 3 by press-fitting or an adhesive, and the above-mentioned special split sleeve 9 is fixed to the stub 4 with optical fiber and covers the split sleeve 9. The cap 5 is fixed, and a total of four parts are used.

  On the other hand, in Patent Document 3 by the inventors of the present invention, in order to ensure concentricity between the inner hole of the capillary tube for optical fiber and the optical fiber, the Ra value of the surface roughness of the inner hole is from 0.1 μm. An optical fiber capillary of 0.5 μm and an optical fiber stub using the same are disclosed.

  Patent Document 2 and Patent Document 4 disclose an optical receptacle in which the outer peripheral surface of the ferrule and the inner peripheral surface of the sleeve have an Ra value of surface roughness of 0.2 μm or less in order to ensure the sleeve insertion property of the ferrule. Is disclosed.

Japanese Patent Laid-Open No. 10-332988 JP 2003-107288 A JP 2003-149502 A Japanese Patent Laid-Open No. 2003-222864

  In the conventional optical receptacle 1 described above, the stub 4 with an optical fiber is fixed to the stub holder 3, and a split is provided as a component for coaxially aligning the optical connector ferrule 7 and the stub 4 with optical fiber. Sleeve 2 is used. However, since the split sleeve 2 only holds the stub 4 with an optical fiber and is not fixed, the split sleeve cap 5 is necessary to prevent the optical connector ferrule 7 from being pulled out when it is inserted and removed. Become. As a result, at least four parts are required to construct the optical receptacle 1. Since these components are indispensable elements for constructing the optical receptacle of this form, there is a problem that the number of components cannot be reduced any more and cost reduction is difficult.

  Further, in order to realize miniaturization of the optical device, the stub 4 with an optical fiber is desired to be as short as possible when mounting a high-density light guide member. However, if the stub 4 with optical fiber is shortened, the gripping force of the split sleeve 2 is weakened, and the coaxial alignment is maintained when a lateral load is applied when the ferrule 7 of the optical connector is inserted into the split sleeve 2. Can not be. For this reason, an angle shift occurs between the optical axis of the short stub 4 with an optical fiber and the optical axis of the ferrule 7 of the optical connector, so that it is impossible to maintain a precise coaxial alignment. Therefore, the optical fiber stub 4 cannot be further shortened.

  Although the optical receptacle of Patent Document 1 can be downsized, the positional relationship between the optical axis of the short optical fiber stub 4 and the optical axis of the ferrule 7 of the optical connector for single mode optical fiber is stably maintained. Therefore, the retaining ring 8 for reinforcement is required, and as a result, there is a problem that the number of expensive parts increases.

  In addition, the optical receptacle of Patent Document 2 can be reduced in size, but requires a special split sleeve 9 with a slit in the middle, and more complicated processing is required, so an increase in cost is inevitable. . Further, since the split sleeve cap 5 is required in the same manner as the conventional optical receptacle 1, the number of parts cannot be further reduced.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide an optical receptacle that maintains high accuracy and high reliability, is small, has a small number of parts, and is inexpensive to manufacture.

  An optical receptacle according to the present invention includes a precision sleeve, a stub with an optical fiber fixed to one end of an inner hole of the precision sleeve via an adhesive, and a sleeve fixed to the outer periphery of the precision sleeve by press-fitting or an adhesive A holder is provided, and the Ra value of the surface roughness of the outer periphery of the stub with optical fiber and / or the inner hole of the precision sleeve is 0.1 μm or more and 0.5 μm or less. In the present invention, the precision sleeve refers to a tubular sleeve that is not provided with a split like a split sleeve and has an inner hole with an inner diameter slightly larger than the outer diameter of the optical connector ferrule to be inserted.

  The surface roughness Ra of the outer surface of the stub with optical fiber and / or the inner hole of the precision sleeve is defined as JIS-B-0601 (contents equivalent to ISO 4287). If there is, the adhesive applied to the outer periphery of the stub with an optical fiber or the inner hole of the precision sleeve does not have a uniform thickness, and the stub with an optical fiber tends to approach the inner hole wall surface of the precision sleeve and become eccentric.

  On the other hand, at the outer periphery of the stub with an optical fiber, when the Ra value of the surface roughness exceeds 0.5 μm, the Ry value defined as the maximum roughness is expected to increase considerably, and the average of the outer surface roughness The center position of the smallest circumscribed cylinder on the outer periphery is often shifted from the center of the circle formed by the line, and the original roundness of the outer periphery itself is substantially deteriorated.

  In the present invention, it is important that the Ra value of the surface roughness of the outer periphery of the stub with an optical fiber is 0.1 μm or more and 0.5 μm or less, and the applied adhesive has a stable and uniform thickness. Therefore, the Ra value is preferably more than 0.2 μm. In addition, from the viewpoint of increasing the original roundness of the outer periphery by suppressing the deviation of the center position of the smallest circumscribed cylinder of the outer periphery with respect to the center of the circle formed by the average line of the outer surface roughness, The Ry value is preferably 4.0 μm or less, and the difference δ between the surface roughness average line and the peak line is also preferably 2.0 μm or less.

  In addition, when the Ra value of the surface roughness of the inner hole of the precision sleeve exceeds 0.5 μm, it is expected that the Ry value defined as the maximum roughness will increase considerably. In many cases, the center position of the maximum inscribed cylinder of the inner hole is displaced from the center of the circle formed by the average line of the surface roughness of the inner surface, and the original roundness of the inner hole itself is substantially deteriorated.

  In the present invention, the Ra value of the surface roughness of the precision sleeve inner hole is important to be not less than 0.1 μm and not more than 0.5 μm, and the applied adhesive has a stable and uniform thickness. In doing so, the Ra value is preferably more than 0.2 μm. From the viewpoint of increasing the original roundness of the inner hole by suppressing the deviation of the center position of the smallest circumscribed cylinder of the inner hole with respect to the center of the circle formed by the average line of the surface roughness of the inner hole, The roughness Ry value is preferably 4.0 μm or less, and the difference δ between the surface roughness average line and the peak line is preferably 2.0 μm or less.

  The outer peripheral surface or the inner hole surface having such a surface roughness can be achieved by controlling the size and amount of material particles of the stub with an optical fiber and the precision sleeve. Further, the Ra value of the surface roughness of the outer periphery of the stub with an optical fiber can be adjusted to 0.1 μm or more and 0.5 μm or less by machining.

  As a material of the sleeve holder, metal or resin can be used. It is particularly suitable if it is made of stainless steel or other metal material and has the desired rigidity, shape stability, and weather resistance, and the light receiving and light emitting element components arranged at the subsequent stage of the optical receptacle are made of metal. In many cases, SUS304 and SUS430 are more preferable in consideration of weldability and the like.

  In the present invention, the concentricity of the optical fiber core with respect to the outer periphery of the stub with optical fiber is preferably 0.5 μm or less.

  When the concentricity of the optical fiber core with respect to the outer periphery of the stub with optical fiber exceeds 0.5 μm, the optical axis of the optical fiber held in the inner hole when the outer periphery of the stub with optical fiber is held by the precision sleeve There is a possibility that a deviation of 0.5 μm or more from the center of the precision sleeve inner hole may occur, and when other eccentric factors accumulate, the optical axis of the stub with optical fiber and the optical axis of the ferrule of the optical connector for single mode optical fiber It becomes impossible to align with the practical level.

  Further, the present invention is characterized in that the inner hole of the precision sleeve has an inner diameter that is 0 to 1.5 μm larger than the outer diameter of the ferrule for the optical fiber connector.

  If the inner diameter of the rigid precision sleeve is smaller than the outer diameter of the ferrule for an optical fiber connector, the material is not sufficiently elastic and not provided with a split so that the ferrule cannot be inserted. . In order not to increase the connection loss, it is preferable that the difference between the ferrule outer diameter of the optical connector and the inner diameter of the inner hole of the precision sleeve is small. Preferably, when the inner diameter of the inner hole of the precision sleeve is larger than the outer diameter of the ferrule for the optical fiber connector and the difference is 0 to 1.5 μm, the optical fiber core of the stub with optical fiber and the optical fiber of the optical connector ferrule The amount of axial misalignment of the core is 0.5 μm or less, and more stable connection characteristics can be achieved.

  In the optical receptacle of the present invention, the capillary of the stub with an optical fiber is preferably made of crystallized glass. The capillary that constitutes the stub with optical fiber in the present invention preferably has a dimensional accuracy such as an outer diameter, an inner diameter, and a concentricity equivalent to a ferrule of an optical connector that is butt-connected to the stub with optical fiber.

  Crystallized glass is the most suitable material for the capillaries and precision sleeves of the stubs with optical fibers of the present invention. When the capillaries and precision sleeves of stubs with optical fibers are made of crystallized glass, the surface roughness can be freely controlled by adjusting the material composition, heat treatment temperature, etc. in addition to adjusting the surface roughness by machining. . The crystallized glass used in the present invention is a crystallized glass having a crystal grain size and a crystal amount such that the Ra value of the surface roughness of the outer peripheral surface of the capillary tube is 0.1 μm or more and 0.5 μm or less. If the crystal grain size is about 0.1 μm to 1.0 μm and the amount of crystals is 30 to 70% by mass, it is preferable.

  In the present invention, the precision sleeve can be made of glass or crystallized glass.

  If the precision sleeve is made of glass or crystallized glass, it can be manufactured using a stretch molding technique rather than adjusting the dimensions by machining, which is suitable for cost reduction by mass production. When the precision sleeve is made of glass, it can be stretch-formed in a wide composition range, which is advantageous when it is necessary to adjust the thermal expansion coefficient. Further, when the precision sleeve is made of crystallized glass, the molding and the adjustment of the surface roughness can be performed at the same time, so that the material is most suitable. On the other hand, as the crystallized glass used for the precision sleeve in the present invention, it can be used as long as crystals having a Ra value of the inner surface roughness of 0.1 μm or more and 0.5 μm or less are precipitated. In particular, it is sufficient that the crystal grain size is about 0.1 μm to 1.0 μm as crystals precipitated in amorphous glass. For example, those containing β-spodumene solid solution as the main crystal are suitable.

  In the optical receptacle of the present invention, it is preferable that the adhesive contains 10% by volume or more of a filler having a maximum particle size of 0.5 μm or less and an average particle size of 0.3 μm or less.

  When the maximum particle size of the filler is 0.5 μm or more, or the average particle size is 0.3 μm or more, the filler itself does not evenly enter the gap between the precision sleeve and the stub with optical fiber. Also, if the stub with optical fiber is thinned to increase the gap between the precision sleeve and the stub with optical fiber, the thickness of the adhesive layer itself becomes too thick, and the stub with optical fiber is placed in the center of the inner hole of the precision sleeve. Not only is it difficult to hold in position, but an increase in the adhesive may reduce reliability such as weather resistance and optical stability. When the filler is 10% by volume or less, it is difficult to sufficiently suppress the effects of volume shrinkage at the time of curing of the adhesive and expansion / contraction due to temperature change. It is important that the adhesive used in the present invention contains 10% by volume or more of a filler having a maximum particle size of 0.5 μm or less and an average particle size of 0.3 μm or less. Note that an epoxy resin adhesive used for assembly causes a volume shrinkage of about 20% during curing. In order to prevent such displacement of the stub with an optical fiber due to such shrinkage, a filler having a maximum particle diameter of 0.5 μm or less and an average particle diameter of 0.3 μm or less made of glass, ceramic or metal is used as an adhesive. Mixing is effective. By mixing such fillers, thixotropic properties are imparted, and there is an effect of preventing dripping and improving the strength of the adhesive.

  An optical receptacle of the present invention includes a precision sleeve, a stub with an optical fiber fixed to one end of an inner hole of the precision sleeve via an adhesive, and a sleeve holder fixed to the outer periphery of the precision sleeve by press-fitting or using an adhesive And the Ra value of the surface roughness of the outer periphery of the stub with an optical fiber and / or the inner diameter of the precision sleeve is not less than 0.1 μm and not more than 0.5 μm, and thus has such a surface roughness. Due to the surface properties, the adhesive spreads uniformly around the outer periphery of the stub with optical fiber in the precision sleeve, and the stub with optical fiber can be positioned at the center of the precision sleeve. For this reason, it becomes possible to stably hold the stub with an optical fiber in the center of the precision sleeve more accurately than before through an adhesive layer of uniform thickness, and substantially without using a split sleeve. A low-loss optical receptacle that is sufficiently practical can be constructed. In addition, since each member is fixed with an adhesive, a conventional split sleeve cap having a gap is not required, and the number of components is reduced, so that a cheaper optical receptacle can be provided.

  In addition, the optical receptacle of the present invention employs a configuration in which the Ra value of the surface roughness of the precision sleeve inner hole is 0.1 μm or more and 0.5 μm or less, so that the surface roughness of the precision sleeve inner hole and Using the surface roughness of the outer periphery of the stub with optical fiber, the stub with optical fiber can be stably held and fixed at the center position of the precision sleeve via an adhesive layer having a uniform thickness.

  Furthermore, since each member is firmly fixed by the adhesive compared to the gripping force of the split sleeve, it is easy to shorten the overall length of the stub with an optical fiber and realize it without degrading the performance. Can do. Further, it is not necessary to add and use a special member such as a retaining ring for reinforcement unlike the split sleeve type optical receptacle.

  Further, in the optical receptacle of the present invention, it is preferable that the concentricity of the optical fiber core with respect to the outer periphery of the stub with an optical fiber is 0.5 μm or less in order to suppress loss of the optical signal propagating through the optical receptacle. More preferably, the inner hole of the sleeve has an inner diameter that is 0 to 1.5 μm larger than the outer diameter of the ferrule for the optical fiber connector.

  Furthermore, the optical receptacle of the present invention can obtain a capillary having a high-precision dimension easily by wire drawing by devising the composition by making the capillary of the stub with optical fiber made of crystallized glass, and By controlling the crystal precipitation state, it is possible to easily obtain a capillary having an outer surface roughness Ra value of 0.1 μm or more and 0.5 μm or less.

  In addition, the optical receptacle of the present invention can be easily made in shape and size by drawing by devising the composition by making the precision sleeve made of glass or crystallized glass. In the case of crystallized glass, a precision sleeve having an Ra value of the surface roughness of the inner hole of 0.1 μm or more and 0.5 μm or less can be easily realized depending on the crystal precipitation state.

  Furthermore, the optical receptacle of the present invention has a precision sleeve in which the adhesive contains 10% by volume or more of a filler having a maximum particle size of 0.5 μm or less and an average particle size of 0.3 μm or less. The adhesive layer between the optical fiber and the stub with optical fiber can be easily formed uniformly in the circumferential direction, and the stub with optical fiber can be stably held at the center of the precision sleeve more easily.

  Furthermore, the optical receptacle according to the present invention does not use a split sleeve, but adhesively fixes a stub with an optical fiber by self-aligning within an inner hole of a precision sleeve having a desired rigidity. When the is inserted, there is almost no deformation, and the stub with optical fiber and the ferrule of the optical connector are coaxially arranged with high accuracy. Therefore, the optical receptacle of the present invention can make the stub with an optical fiber as short as possible without degrading the performance, and can be mounted with higher density.

  As described above, the present invention has a practically excellent effect that can provide an optical receptacle that maintains high accuracy and high reliability, is small, has a small number of parts, and is inexpensive to manufacture. It is.

  Hereinafter, an example according to an embodiment of the present invention will be described in detail with reference to FIG. In the figure, 11 and 21 are optical receptacles, 12 and 22 are precision sleeves, 12a and 22a are inner holes, 13 and 23 are metal sleeve holders, 14 is a stub with an optical fiber, and 15 is an optical connector. The ferrules 16 and 16 are adhesives.

  The connection loss between the ferrule for an optical connector and the stub with optical fiber, that is, Loss (unit: dB), is determined by the amount of axial misalignment of the optical fiber core at each end face to be abutted, and is estimated by the following formula 1. Here, d in Equation 1 indicates the amount of axial deviation of the optical fiber core, and w indicates the mode field diameter of the optical fiber.

  In the conventional optical receptacle, the concentricity of the optical fiber core in the outer periphery of the stub or ferrule with optical fiber and the inner hole is 1.0 μm at the maximum, and the eccentricity of the optical fiber core is 0.5 μm, which is ½ each. Since the eccentricity of the core of the optical fiber itself is very small, ignoring this, the eccentricity of the optical fiber within the inner diameter of the stub with optical fiber or the optical connector ferrule is 0.5 μm at the maximum. When the mode field diameter w = 10 μm, the displacement amount is 2.0 μm at the maximum, and the connection loss (that is, Loss) is about 0.7 dB when calculated by Equation (1). In the case of the split sleeve type optical receptacle, the above-mentioned coaxial alignment is achieved only by the gripping force. Therefore, if the stub with an optical fiber is shortened to reduce the size, the gripping force of the split sleeve becomes weak. When a lateral load is applied, the coaxial alignment cannot be maintained. Therefore, the connection loss is worse than the calculated value.

  In the optical receptacle 11 of the present embodiment, the inner surface 12a of the precision sleeve 12 and / or the outer periphery of the stub 14 with optical fiber has the above surface roughness, so that the thickness of the intervening adhesive 16 becomes uniform, Because of the alignment effect, the outer periphery of the stub 14 with an optical fiber is positioned at the center of the precision sleeve 12, and for example, when the difference between the outer diameter of the stub 14 with an optical fiber and the inner diameter of the precision sleeve 12 is 1.5 μm at the maximum. Since the eccentricity of the outer periphery of the optical connector ferrule 15 in the precision sleeve 12 is 0.75 μm and the concentricity of the inner hole with respect to the outer periphery of the stub 14 with optical fiber is 0.5 μm, the outer periphery of the stub 14 with optical fiber is The eccentricity of the inner hole with respect to is 0.25 μm, and the concentricity of the inner hole of the optical fiber 15 a with respect to the outer periphery of the optical connector ferrule 15 is usually 1.0 μm. .5Myuemu, eccentricity of the optical fiber within the inner diameter of the optical connector ferrule 0.5 [mu] m, the sum is 2.0 .mu.m. Therefore, in this example, the maximum amount of axial deviation at the connection portion between the optical connector ferrule 15 and the stub 14 with optical fiber is 2.0 μm, and the maximum connection loss is 0.7 dB from the above equation (1). Thus, the optical receptacle 11 of this embodiment has the same performance as the conventional one and can be used sufficiently. In the case of the precision sleeve 12, since the coaxial alignment is ensured by dimensional accuracy, the same performance as described above is maintained even if the stub with an optical fiber is shortened for miniaturization.

  1B is a crystal in which the surface roughness of the inner hole surface of the short sleeve holder 23 is Ra value of 0.1 μm or more and 0.5 μm. A precision sleeve 22 made of vitrified glass is fixed by press-fitting.

  As an example of the stub with optical fiber and the precision sleeve of the present invention, for example, crystallized glass having the composition shown in Table 1 was used.

  As shown in FIG. 1 (A), an optical receptacle 11 of the present invention includes a precision sleeve 12 made of crystallized glass having an inner hole whose inner diameter is 0 to 1.5 μm larger than the outer diameter of the ferrule 15 for an optical connector, A stub 14 with an optical fiber is provided using a crystallized glass capillary 14b inserted into one end of the inner hole and fixedly bonded by an adhesive 16. The end face 14c is polished so as to form an angle of 8 ° with respect to a plane perpendicular to the incident axis of the optical signal so that the reflected light does not enter the laser diode and become noise. The front end surface is chamfered at the peripheral edge and polished to a convex spherical surface for connecting a PC (physical contact) with the core of the optical fiber 14a as the center. Since the concentricity of the inner hole with respect to the outer periphery of the stub 14 with optical fiber is 0.5 μm, the eccentricity of the core of the optical fiber 14a itself is very small and can be ignored. The concentricity between the outer periphery of the stub 14 with optical fiber and the core of the optical fiber 14a is 0.5 μm or less. The outer diameter of the stub 14 with optical fiber has the same outer diameter and tolerance as the optical connector ferrule 15 to be inserted (the outer diameter is 2.499 mm +/− 0.0005 mm, or the outer diameter is 1.249 mm + / −0.0005 mm).

  FIG. 2 shows a chart in which the surface roughness of the members constituting the optical receptacle 11 of the present invention is measured. FIG. 2A is a chart in which the surface roughness of the outer periphery of the stub 14 with optical fiber is measured. The Ra value is 0.29 μm, the Ry value is 2.17 μm, the average line of the surface roughness and the peak line. The difference δ was 1.05 μm. FIG. 2B is a chart in which the surface roughness of the inner surface 12a of the precision sleeve 12 is measured. The Ra value is 0.30 μm, the Ry value is 2.18 μm, and the average line of the surface roughness and the peak line are shown. The difference δ was 1.15 μm.

  When a stub 14 with an optical fiber is used, a crystallized glass capillary 14b having a surface roughness Ra of 0.1 μm or more and 0.5 μm is used for the stub 14 with an optical fiber. The optical fiber 14a in the optical fiber 14a is self-aligned by the adhesive within the inner hole due to the effect of the surface roughness of the inner hole of the stub 14 with the optical fiber, so that the eccentricity of the optical fiber 14a in the inner hole of the capillary tube 14b. Can be ignored. Accordingly, the eccentricity of the core of the optical fiber 14a in the stub 14 with optical fiber is determined only by the concentricity of 0.5 μm of the inner diameter with respect to the outer periphery of the stub with optical fiber, with the concentricity being 0.5 μm or less and the eccentricity being 0.25 μm or less. For example, it was 0.175 μm.

  In the optical receptacle 11 of the present invention, the Ra value of the surface roughness of the outer periphery of the stub 14 with optical fiber and the inner hole 12a of the precision sleeve 12 is the above value, and due to the effect of this surface roughness, the optical fiber Since the attached stub 14 is self-aligned by the adhesive 16 in the inner hole 12a of the precision sleeve 12, the eccentricity of the stub 14 with optical fiber in the inner hole 12a of the precision sleeve 12 is almost eliminated.

  Further, by forming the precision sleeve 12 and the capillary tube 14b of the stub 14 with optical fiber from a crystallized glass material, the surface roughness of the inner hole 12a of the precision sleeve 12 has a Ra value of 0.1 μm or more and 0.5 μm. The following can be facilitated. As described above, the stub 14 with an optical fiber is aligned within the inner hole 12a of the precision sleeve 12 and is positioned at the center of the inner hole 12a. Therefore, the core of the optical fiber 14a and the optical connector ferrule at the connection portion are arranged. The maximum axis misalignment with the core of the 15 optical fibers 15a is 2.0 μm, and the connection loss can be 0.7 dB or less. Even if a short stub with an optical fiber is used, the performance equivalent to that of the conventional product is achieved. Obtained.

  Further, when the ferrule 15 of the optical connector to be inserted is formed of crystallized glass and the surface roughness of the inner hole is 0.1 μm or more in terms of Ra value and 0.5 μm, the effect of this surface roughness As a result, the optical fiber 15a is self-aligned in the inner hole of the ferrule 15 and is located in the center. Therefore, the amount of axial misalignment between the core of the optical fiber 14a and the core of the optical fiber 15a of the optical connector ferrule 15 is The maximum was 1.5 μm, and the connection loss was 0.4 dB or less, and more excellent characteristics were obtained.

  Next, a precision sleeve 12 made of crystallized glass having a surface roughness Ra value of 0.3 μm, an outer diameter of 1.80 mm, and an inner diameter of 1.2495 + 0.0005 / −0 mm was manufactured. Further, the optical fiber 14a is inserted into a capillary tube 14b made of crystallized glass having a Ra value of the surface roughness of the inner hole and the outer periphery of 0.3 μm, an outer diameter of 1.2490 +/− 0.0005 mm, and a concentricity of 0.5 μm. It fixed and the stub 14 with an optical fiber was produced. Then, the optical fiber stub 14 is fixed in the inner hole 12 a of the precision sleeve 12 with the epoxy adhesive 16, and the precision sleeve 12 is fixed in the inner hole of the sleeve holder 13 with the epoxy adhesive 16 and the optical receptacle 11. Was made. The number of samples of the manufactured optical receptacle 11 was ten. The optical connector ferrule 15 is inserted into the inner hole 12a of the precision sleeve 12 of the optical receptacle 11 manufactured as described above and is brought into contact with the stub 14 with optical fiber, and the core of the optical fiber 14a and the optical fiber 15a of the optical connector ferrule 15 are aligned. The core was connected to the PC and the connection loss was measured in that state. For the measurement of the connection loss, the optical connector ferrule 15 was attached and detached 10 times for each sample of the optical receptacle 11, and the measurement was performed 10 times.

  In a state where the optical connector ferrule 15 is connected to the optical receptacle 11, the maximum difference between the outer diameter of the optical connector ferrule 15 and the inner diameter of the inner hole 12 a of the precision sleeve 12 is 1.5 μm, and the inner hole 12 a of the precision sleeve 12. The maximum eccentricity of the optical connector ferrule 15 is 0.75 μm. To this is added 0.25 μm of the center of the inner hole with respect to the center of the outer periphery of the capillary tube 14b due to the concentricity of the stub 14 with optical fiber, and further, the eccentricity of the center of the inner hole with respect to the center of the outer periphery of the ferrule 15 due to the concentricity of the optical connector ferrule 15 The sum of the eccentricity Y μm of the optical fiber 15 a in the inner hole of the optical connector ferrule 15 and (1.0 + X + Y) μm is the maximum amount of axial displacement of the PC connection portion. In the present invention, the stub 14 with an optical fiber is aligned within the inner hole 12a of the precision sleeve 12, and therefore, the eccentricity of the both does not have to be taken into consideration.

  When the optical connector ferrule 15 is formed of crystallized glass, the concentricity is 0.7 μm, and the inner diameter of the inner hole is 0.5 μm larger than the diameter of the optical fiber 15a, the average connection loss is 0.14 dB, the maximum A connection loss of 0.31 dB and excellent characteristics were obtained. Table 2 shows the measurement data.

  From the above measurement results and Equation 1, the amount of axial misalignment between the core of the optical fiber 14a of the stub 14 with optical fiber and the core of the optical fiber 15a of the optical connector ferrule 15 is 0.9 μm on average and 1.34 μm at maximum. . In this case, the eccentricity X of the inner hole due to the concentricity of the optical connector ferrule 15 is 0.35 μm, and the eccentricity Y of the optical fiber 15a in the inner hole of the optical connector ferrule 15 is made of crystallized glass. Therefore, the theoretical maximum axis deviation is 1.35 μm. Since this value is obtained even when the amount of axial deviation is maximum, it can be said that the effect of this embodiment is great.

  Further, when the optical connector ferrule 15 is formed of zirconia, the concentricity is 1.0 μm, and the inner diameter of the inner hole is 0.5 μm larger than the diameter of the optical fiber 15a, the average connection loss is 0.25 dB and the maximum connection loss is 0. A characteristic of .43 dB was obtained. Table 3 shows the measurement data.

  From the above measurement results and Equation 1, the amount of axial misalignment between the core of the optical fiber 14a of the stub 14 with optical fiber and the core of the optical fiber 15a of the optical connector ferrule 15 is 1.2 μm on average and 1.57 μm at maximum. . In this case, the eccentricity X of the inner hole due to the concentricity of the optical connector ferrule 15 is 0.5 μm, and the eccentricity Y of the optical fiber 15 in the inner hole of the optical connector ferrule 15 is 0.25 μm, which is the theoretical maximum axis. The amount of deviation is 1.75 μm. Since this value is obtained even when the amount of axial deviation is maximum, the effect of this embodiment is significant.

  Next, a precision sleeve 12 made of borosilicate glass having an outer diameter of 1.80 mm and an inner diameter of 1.2495 + 0.001 / −0 mm was produced. Further, the optical fiber 14a is inserted into a capillary tube 14b made of crystallized glass having a Ra value of the surface roughness of the inner hole and the outer periphery of 0.3 μm, an outer diameter of 1.2490 +/− 0.0005 mm, and a concentricity of 0.5 μm. It fixed and the stub 14 with an optical fiber was produced. Then, the optical fiber stub 14 is fixed in the inner hole 12 a of the precision sleeve 12 with the epoxy adhesive 16, and the precision sleeve 12 is fixed in the inner hole of the sleeve holder 13 with the epoxy adhesive 16 and the optical receptacle 11. Was made. The number of samples of the manufactured optical receptacle 11 was ten. The optical connector ferrule 15 is inserted into the inner hole 12a of the precision sleeve 12 of the optical receptacle 11 manufactured as described above and is brought into contact with the stub 14 with optical fiber, and the core of the optical fiber 14a and the optical fiber 15a of the optical connector ferrule 15 are aligned. The core was connected to the PC and the connection loss was measured in that state. For the measurement of the connection loss, the optical connector ferrule 15 was attached and detached 10 times for each sample of the optical receptacle 11, and the measurement was performed 10 times.

  In a state where the optical connector ferrule 15 is connected to the optical receptacle 11, the difference between the outer diameter of the optical connector ferrule 15 and the inner diameter of the inner hole 12a of the precision sleeve 12 is 2.0 μm at the maximum, and the inner hole 12a of the precision sleeve 12 The maximum eccentricity of the optical connector ferrule 15 is 1.0 μm. To this is added 0.25 μm of the center of the inner hole with respect to the center of the outer periphery of the capillary tube 14a due to the concentricity of the stub 14 with optical fiber, and further, the eccentricity of the center of the inner hole with respect to the center of the outer periphery of the ferrule 15 due to the concentricity of the optical connector ferrule 15 The sum of the eccentricity Yμm of the optical fiber 15a in the inner hole of the optical connector ferrule 15 and (1.25 + X + Y) μm is the maximum axial displacement amount of the PC connection portion. In the present invention, the stub 14 with an optical fiber is aligned within the inner hole 12a of the precision sleeve 12, and therefore, the eccentricity of the both does not have to be taken into consideration.

  When the ferrule 15 of the optical connector is formed of crystallized glass and has a concentricity of 0.7 μm, excellent characteristics such as an average connection loss of 0.18 dB and a maximum connection loss of 0.35 dB were obtained. Table 4 shows the measurement data.

  From the above measurement results and Equation 1, the amount of axial misalignment between the core of the optical fiber 14a of the stub 14 with optical fiber and the core of the optical fiber 15a of the optical connector ferrule 15 is 1.02 μm on average and 1.42 μm at maximum. . In this case, the eccentricity X of the inner hole due to the concentricity of the optical connector ferrule 15 is 0.35 μm, and the eccentricity Y of the optical fiber 15a in the inner hole of the optical connector ferrule 15 is made of crystallized glass. Therefore, the theoretical maximum axis deviation is 1.60 μm. Since this value is the maximum even when the amount of axial deviation is maximum, it can be said that the effect of this embodiment was great.

  Further, when the ferrule 15 of the optical connector is formed of zirconia and the concentricity is 1.0 μm, characteristics of an average connection loss of 0.25 dB and a maximum connection loss of 0.50 dB were obtained. Table 5 shows the measurement data.

  From the above measurement results and Equation 1, the amount of axial misalignment between the core of the optical fiber 14a of the stub 14 with optical fiber and the core of the optical fiber 15a of the optical connector ferrule 15 is 1.2 μm on average and 1.7 μm at maximum. . In this case, the eccentricity X of the inner hole due to the concentricity of the optical connector ferrule 15 is 0.5 μm, and the eccentricity Y of the optical fiber 15a in the inner hole of the optical connector ferrule 15 is 0.25 μm, which is the theoretical maximum axis. The amount of deviation is 2.0 μm. Since this value is the maximum even when the amount of axial deviation is maximum, it can be said that the effect of this embodiment was great.

  In adhering the stub 14 with an optical fiber and the precision sleeve 12 made of borosilicate glass, the adhesive 16 containing a filler having an average particle diameter of 0.3 μm and a maximum particle diameter of 0.5 μm was used. The optical connector ferrule 15 is made of crystallized glass and has a concentricity of 0.7 μm. Then, when the connection loss was measured in the same manner as described above, excellent characteristics such as an average connection loss of 0.15 dB and a maximum connection loss of 0.31 dB were obtained. Table 6 shows the measurement data.

  From the above measurement results and Equation 1, the amount of axial misalignment between the core of the optical fiber 14a of the stub 14 with optical fiber and the optical fiber 15a core of the optical connector ferrule 15 is 0.93 μm on average from Equation 1 and 1.34 μm at maximum. It becomes. In this case, the eccentricity X of the inner hole due to the concentricity of the optical connector ferrule 15 is 0.35 μm, and the eccentricity Y of the optical fiber 15a in the inner hole of the optical connector ferrule 15 is made of crystallized glass. The upper limit is 0, and the theoretical maximum axis deviation is 1.35 μm. Since this value is the maximum even when the amount of axial deviation is maximum, it can be said that the effect of this embodiment was great.

  In addition to the alignment effect, the filler-containing adhesive 16 is made of a stub 14 made of crystallized glass or the like made of crystallized glass to which the thermal expansion is adhered by adjusting the blending ratio of the filler for thermal expansion, borosilicate glass, etc. The effect of preventing the deterioration of the fixing strength according to the precision sleeve 12 and the effect of increasing the water resistance of the bonded portion and improving the long-term reliability were also obtained.

It is explanatory drawing of the optical receptacle of this invention, Comprising: (A) is principal part sectional explanatory drawing by which an optical connector is connected to the optical receptacle using the precision sleeve made from crystallized glass or glass, (B) is crystallization The principal part cross-section explanatory drawing of the optical receptacle which press-fitted the precision sleeve made from glass to the sleeve holder. FIG. 2 is a chart obtained by measuring the surface roughness of components of the optical receptacle according to the present invention, in which (A) is a chart obtained by measuring the surface roughness of the outer periphery of a stub with an optical fiber, and (B) is a surface roughness of a precision sleeve inner hole. The chart which measured the thickness. It is explanatory drawing of the conventional optical receptacle, (A) is principal part sectional explanatory drawing by which an optical connector is connected to the optical receptacle using a split sleeve, (B) is a case where a split sleeve is used, and a holding ring is used. The principal part sectional explanatory drawing of the optical receptacle miniaturized using, (C) is principal part sectional explanatory drawing of the optical receptacle miniaturized using the sleeve which was partially split.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11, 21 Optical receptacle 12, 22 Precision sleeve 13, 23 Sleeve holder 14 Optical fiber stub 14a, 15a Optical fiber 14b Capillary 15 Optical connector ferrule 16 Adhesive

Claims (6)

  A precision sleeve, a stub with an optical fiber fixed to one end of an inner hole of the precision sleeve via an adhesive, and a sleeve holder fixed to the outer periphery of the precision sleeve by press-fitting or an adhesive. An optical receptacle characterized in that the Ra value of the surface roughness of the outer periphery of the attached stub and / or the precision sleeve inner hole is 0.1 μm or more and 0.5 μm or less.   2. The optical receptacle according to claim 1, wherein the concentricity of the optical fiber core with respect to the outer periphery of the stub with optical fiber is 0.5 [mu] m or less.   3. The optical receptacle according to claim 1, wherein the inner hole of the precision sleeve has an inner diameter that is 0 to 1.5 μm larger than an outer diameter of the ferrule for the optical fiber connector.   The optical receptacle according to any one of claims 1 to 3, wherein the capillary tube of the stub with an optical fiber is made of crystallized glass.   The optical receptacle according to any one of claims 1 to 4, wherein the precision sleeve is made of glass or crystallized glass. 6. The light according to claim 1, wherein the adhesive contains 10% by volume or more of a filler having a maximum particle size of 0.5 μm or less and an average particle size of 0.3 μm or less. Receptacle.