JP2009058555A - Optical communication component and its manufacturing method, and optical receptacle and optical module using same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical component having superior electric insulation and high reliability. <P>SOLUTION: The optical communication component includes an electrically insulated ferrule 2 in which light is propagated inside a through hole 2a, a cylindrical metallic first holder 4 which has a bore 4a with a part of the ferrule 2 force-fitted, a bore 5a in which a part of the ferrule 2 except that a part is force-fitted, and a cylindrical second holder 5 which is arranged via the first holder 4 and a gap S. On the outer circumferential face of the ferrule 2, there is formed a groove 2d that opens to the gap S. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an optical receptacle and an optical module used for optical communication, and more particularly to an optical receptacle and an optical module for optical communication.

  An optical module for converting an optical signal into an electrical signal contains an optical element such as a laser diode (LD) or photodiode (PD) in a metal case, and introduces the optical signal into an optical fiber through a lens or the like. Alternatively, the structure is derived. In addition, a receptacle-type optical module connects an optical fiber by joining a metal case containing an optical element to one end of the optical receptacle, and connecting a plug ferrule with a built-in optical fiber from the other end of the optical receptacle. Optical communication.

  An example of an optical module provided with such an optical receptacle is shown in FIG. The optical receptacle 100 includes a ceramic precision sleeve 101, a fiber stub 102 press-fitted into the rear end of the precision sleeve 101, a metal holder 103 that holds the precision sleeve 101 and the fiber stub 102, and a metal holder 103. And a flange 104 provided on the outer periphery of the precision sleeve 101 at a distance from each other. The optical module 200 includes a metal case 105 in which a lens 106 and an optical element 107 that is an LD or PD are disposed, and is bonded to an end surface of the metal holder 103 of the optical receptacle 100.

  In this optical module 200, for example, when the optical element 107 is a PD, the light emitted from the PD is collected by the lens 106 and then coupled to the optical fiber 102a, and the tip of the precision sleeve 101 is passed through the optical fiber 102a. Optical communication is performed by transmitting to the optical fiber 108a held inside the plug 108 inserted from the side.

Such an optical receptacle 100 is manufactured by the following method. First, the fiber stub 102 is inserted and fixed in the precision sleeve 101. Next, the metal holder 103 is press-fitted from the front end side of the precision sleeve 101. Finally, the optical receptacle 100 is manufactured by inserting and fixing the flange 104 from the front end side of the precision sleeve 101 so as to leave a gap with the metal holder 103. Thus, in the optical receptacle 100, the metal holder 103 and the flange 104 are arranged so as to be separated from each other, so that noise of an electric signal transmitted from the outside to the flange 104 is reduced from being transmitted to the optical element 107 via the metal holder 103 and the metal case 105. .
JP-A-2005-70499

  In recent optical communications, as the amount of information transmitted by light increases, high reliability is required for driving optical elements. In the optical receptacle 100, since the metal holder 103 is press-fitted from the front end side of the precision sleeve 101, minute metal scratches are generated on the outer peripheral portion of the precision sleeve 101. Then, the flange 104 is press-fitted into the outer peripheral portion of the precision sleeve 101 where the metal scratch is formed. For this reason, in the optical receptacle 100, even when the metal holder 103 and the flange 104 are separated from each other, there is an increased possibility that electrical conduction is made through minute metal scratches, and noise of the electric signal is transmitted to the optical element.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a more reliable optical component by extremely reducing transmission of electric signal noise to an optical element.

  An optical communication component of the present invention includes a ferrule having electrical insulation for transmitting light through a through hole, a cylindrical metal first holder having an inner hole into which a part of the ferrule is press-fitted, and A portion of the ferrule excluding the part has a press-fitted inner hole, and the first holder and a cylindrical second holder disposed via a gap, the ferrule having an outer peripheral surface A groove portion that opens toward the gap portion is formed along the circumferential direction.

  In the present invention, it is preferable that the width of the groove in the longitudinal direction of the ferrule is smaller than the width of the gap in the longitudinal direction of the ferrule.

  Moreover, in this invention, it is preferable that the angle which the side surface of the said groove part and the said ferrule outer peripheral surface comprise is an obtuse angle.

  In the method for manufacturing an optical communication component of the present invention, the step of forming the groove in the ferrule, the first holder is press-fitted into the inner hole of the first holder from one end side of the ferrule, and the ferrule A step of exposing the groove portion from one end surface of the first holder; and the second holder is press-fitted into the inner hole of the second holder from one end side of the ferrule, and between the one end surface of the first holder. A step of providing a gap and press-fitting the groove to a portion opening in the gap.

  An optical receptacle according to the present invention includes the above-described optical communication component, an optical fiber disposed in a through-hole of the ferrule, and a sleeve into which the other end of the ferrule is inserted. .

  The optical module of the present invention is connected to the optical receptacle described above, an optical element that emits light toward the optical fiber, or receives light through the optical fiber, and the second holder of the optical receptacle. And the housing | casing which accommodates the said optical element is provided, It is characterized by the above-mentioned.

  According to the optical communication component and the optical receptacle according to the present invention, in the gap portion between the first holder and the second holder, the groove portion that opens toward the gap portion is formed on the outer peripheral surface of the ferrule. Even if the first holder is press-fitted, no metal scratch is formed in the groove. As a result, in the present invention, since the first holder and the second holder can be electrically insulated, for example, an optical module is configured by joining a conductive housing containing optical elements in the second holder. Even so, it is possible to reduce the influence of electrical signal noise on the optical element, and to improve the reliability.

  Hereinafter, preferred embodiments of an optical receptacle including an optical communication component according to the present invention and an optical module using the same will be described in detail with reference to the drawings.

  FIG. 1 is a cross-sectional view of an optical receptacle according to the first embodiment of the present invention. The optical receptacle is connected to a plug having an optical fiber such as an optical connector (SC connector or the like).

  An optical receptacle X according to the first embodiment of the present invention includes a ferrule 2 in which an optical fiber 1 is disposed in a through hole 2a, a sleeve 3 inserted in a tip (other end) portion 2b of the ferrule 2, and a ferrule. A first holder 4 having an inner hole 4a into which a part of 2 is press-fitted, a second holder 5 having an inner hole 5a into which a rear end (one end) portion 2c of the ferrule 2 is press-fitted, and one of the first holders 4 A sleeve case 6 that is press-fitted into the portion and arranged to cover the sleeve 3. The optical communication component constituting a part of the optical receptacle is constituted by members other than the sleeve 3 and the sleeve case 6 of the optical receptacle X, and the optical fiber may not be provided in the through hole 2a of the ferrule 2.

  The optical fiber 1 has a function of transmitting light. Examples of the optical fiber 1 include a silica-based optical fiber, a plastic-based optical fiber, and a multi-component glass-based optical fiber. A single-mode fiber that transmits light in a single mode, and a multi-mode that transmits light in a plurality of modes. Various types of fiber such as mode fiber can be used depending on the application.

The ferrule 2 is a member for protecting the optical fiber 1 and for coordinating the central axis of the optical fiber 1 with the central axis of the optical fiber of the plug in cooperation with a sleeve 3 described later. The ferrule 2 is made of an electrically insulating material, and examples thereof include plastics such as epoxy and ceramics such as alumina and zirconia. Among these materials, ZrO ₂ as a main component, and at least one of Y ₂ O ₃ , CaO, MgO, CeO ₂ , Dy ₂ O _{3 and the} like as a stabilizer and a portion mainly composed of tetragonal crystals It is preferable to use stabilized zirconia ceramics, and such partially stabilized zirconia ceramics are advantageous in fixing by press-fitting because they have excellent wear resistance and moderate elastic deformation.

  As a method for processing the ferrule, first, when the ferrule is formed of zirconia ceramics, a cylindrical or rectangular parallelepiped shaped body that becomes a ferrule is obtained in advance by a predetermined molding method such as injection molding, press molding, extrusion molding or the like. The molded body is fired at 1300 to 1500 ° C. and subjected to cutting or polishing to a predetermined dimension. Note that a predetermined shape may be formed in advance on the formed body by cutting or the like, and then fired.

  The front surface of the ferrule 2 has a curved surface with a radius of curvature of about 5 to 30 mm in order to reduce the connection loss with the plug, and the rear end surface reflects light emitted from an optical element such as an LD on the end surface of the optical fiber. In order to prevent reflected light returning to the optical element, mirror polishing is preferably performed on an inclined surface of about 4 to 10 °.

  The ferrule 2 in the optical receptacle X has a groove 2d formed on the outer peripheral surface. FIG. 2 is a partially enlarged cross-sectional view of the ferrule in which the groove 2d is formed. As shown in FIG. 2, the groove 2 d is formed so as to open toward the gap S between the first holder 4 and the second holder 5.

  Further, the depth of the groove 2d may be a depth at which metal scratches formed on the outer peripheral surface of the ferrule 2 due to the press-fitting of the first holder 4 are not formed on the bottom and side surfaces of the groove 2d. For example, it is preferable that the thickness is about 0.01 to 0.1 mm. On the other hand, the width of the groove 2d (the width in the longitudinal direction of the ferrule 2) is not particularly limited because it is sufficient that at least a part of the opening of the groove 2d is positioned in the gap S, but the optical receptacle is small. From the viewpoint of chemical conversion, 0.1 mm to 1 mm is preferable. In the optical receptacle X, the width of the groove 2d (the width in the longitudinal direction of the ferrule 2) is preferably smaller than the width of the gap S in the longitudinal direction of the ferrule 2. According to such a form, since the press-fit length of the 1st holder 4 and the 2nd holder 5 with respect to the ferrule 2 can be ensured long, it becomes possible to hold | maintain the ferrule 2 more strongly.

  The shape of the groove 2d is not particularly limited, and for example, when viewed in a cross section perpendicular to the longitudinal direction (axial direction) of the ferrule 2, the angle formed between the bottom surface and the side surface is approximately 90 °. A square shape, a semicircular shape in which the bottom surface and the side surface are connected by a curved surface, or the like can be selected. Here, as shown in FIG. 2, when the groove portion 2d is formed at an obtuse angle between the side surface of the groove portion 2d and the outer peripheral surface of the ferrule 2, it is possible to prevent the first holder 4 from being caught during press-fitting into the ferrule 2. Therefore, the generation of burrs in the first holder 4 can be reduced. Further, if marking is performed on the groove 2d with, for example, ink or the like, the assembly operator can easily grasp the position where the groove 2d is formed, so that the press-fitting operation of the second holder 5 is facilitated. Furthermore, if the groove portion 2 is formed along the circumferential direction of the outer peripheral surface of the ferrule 2, even if a metal flaw occurs on the surface of the ferrule 2 due to the press-fitting of the first holder, the first and second holders can be more reliably performed. The space can be electrically insulated.

  As a method of forming the groove portion 2d, for example, it can be formed by cutting with a conical tool or the like whose tip is coated with diamond abrasive grains. Moreover, you may provide a groove | channel at the time of shaping | molding of a ferrule, such as press molding.

  The sleeve 3 is formed of a cylindrical body having a through-hole into which the ferrule 2 and a plug (not shown) are inserted. The optical axis of the optical fiber 1 held by the ferrule 2, the optical axis of the optical fiber of the plug, and It is a member that bears the function of matching. The sleeve 3 is made of, for example, a ceramic material such as zirconia or alumina, or a metal material such as copper. In particular, from the viewpoint of wear resistance, the sleeve 3 is preferably made of a ceramic material such as alumina or zirconia. For example, when the sleeve 3 is formed of a zirconia ceramic material, a cylindrical or columnar molded body that becomes a split sleeve is obtained in advance by a predetermined molding method such as injection molding, press molding, or extrusion molding. The molded body is fired at 1300 to 1500 ° C. and subjected to cutting or polishing to a predetermined dimension. Note that a predetermined shape may be formed in advance on the formed body by cutting or the like, and then fired.

  The surface roughness of the inner peripheral surface of the sleeve 3 is preferably an arithmetic average roughness (Ra) of 0.2 μm or less in consideration of plug insertion. Further, the tolerance between the outer diameter of the ferrule 2 and the inner diameter of the sleeve 3 is preferably ± 1 μm or less in order to obtain a low connection loss. Further, it is desirable that the inner diameter of the sleeve 3 is designed so as to have an insertion force of 0.98 N or more in order to securely hold the ferrule 2.

  The first holder 4 has an inner hole 4 a that holds the ferrule 2 and a case insertion groove 4 b into which a part of the sleeve case 6 is inserted, and has a function of holding the ferrule 2 and the sleeve case 6. The inner hole 4a is a through-hole penetrating from the one end surface 4c of the first holder 4 to the other end surface 4d, and a portion on the tip side where the sleeve 3 of the ferrule 2 is not inserted is press-fitted. The first holder 4 is similarly made of metal in consideration of joining with the sleeve case 6 made of metal. And as a material which comprises such a 1st holder 4, stainless steel, copper, iron, and nickel are mentioned, for example. Moreover, as a manufacturing method of the 1st holder 4, when forming with stainless steel, for example, it manufactures by cutting or press work.

  The second holder 5 has an inner hole 5a into which the rear end portion 2c of the ferrule 2 is inserted, and holds the rear end portion 2c of the ferrule 2 to thereby have a function of fixing the ferrule 2. The second holder 5 is preferably made of metal, considering that it is firmly fixed later by welding or the like to a metal case in which the optical element is accommodated. And as a material which comprises such a 2nd holder 5, it is preferable to select the material which can be welded, such as stainless steel, copper, iron, nickel, for example, and if it is stainless steel, it is suitable also from a viewpoint of corrosion resistance. It is. Moreover, as a manufacturing method of the 1st holder 4, when forming with stainless steel, for example, it manufactures by cutting or press work.

  The second holder 5 is arranged so as to provide a gap S between the one end surface 4 c of the first holder 4 and the one end surface 5 b facing the first holder 4. Thus, by providing the gap S between the first holder 4 and the second holder 5, contact between the first holder 4 and the second holder 5 can be prevented. The second holder 5 can be easily insulated. Furthermore, in the optical communication component and the optical receptacle according to the present invention, a groove 2d that opens toward the gap S is formed on the outer peripheral surface of the ferrule 2 in the gap S between the first holder 4 and the second holder 5. Therefore, even if the first holder 4 is press-fitted, no metal scratch is formed in the groove 2d. As a result, in the present invention, even if the metal scratch as described above occurs, the first holder 4 and the second holder 5 can be electrically insulated. For example, the optical element is accommodated in the second holder 5. Even when an optical module is configured by joining the conductive casings, the influence of electrical signal noise on the optical element can be reduced, and the reliability can be improved.

  The sleeve case 6 is a substantially cylindrical tubular member for accommodating the sleeve 3, and has an opening 6 a into which the plug is inserted and a joint 6 b to be inserted into the first holder 4. The diameter of the space for accommodating the sleeve 3 in the sleeve case 6 is configured to be slightly larger (for example, 60 μm) than the outer diameter of the sleeve 3. The opening 6a is a part for guiding the plug when the plug is inserted, and has a tapered shape. The opening end diameter of the opening 6a is slightly larger (for example, 0.2 mm) than the outer diameter of the plug.

  The material constituting the sleeve case 6 includes synthetic resin (thermoplastic resin, thermosetting resin, etc.), metal (stainless steel, copper, iron, nickel, etc.), ceramics (aluminum oxide (alumina), zirconium oxide (zirconia), etc.) ), Glass (such as quartz), and the like. Among these, it is preferable to use the same material as that of the first holder in consideration of fixing with the first holder and combining the thermal expansion coefficient to improve reliability.

  The joining method of the sleeve case 6 and the first holder 4 can be appropriately selected depending on the material. For example, if the first holder 4 is made of metal such as stainless steel and the sleeve case 6 is made of metal or ceramics, it is press-fitted. The joining by is suitable. On the other hand, when the sleeve case 6 is made of resin or glass, adhesion is preferable.

  Next, an embodiment of a method for manufacturing an optical communication component and an optical receptacle according to the present invention will be described with reference to the drawings.

  3A and 3B are cross-sectional views showing a method for manufacturing an optical communication component and an optical receptacle. FIGS. 3A and 3B show a manufacturing process of the optical communication component, and FIG. 3C shows an optical communication component. The manufacturing process which assembles an optical receptacle using it is shown.

  First, the ferrule 2 is prepared, and the groove 2d is formed along the circumferential direction of the outer peripheral surface. The groove 2d is cut with a conical tool or the like with a diamond applied to the tip. At this time, the outer periphery of the ferrule 2 is grasped and fixed, and the tool is brought into contact with the outer periphery of the ferrule while the ferrule 2 is rotated in the circumferential direction to form a groove.

  Next, as shown in FIG. 3A, the first holder 4 is press-fitted into the inner hole 4 a of the first holder 4 from the one end 2 c side of the ferrule 2. At this time, the first holder 4 is press-fitted until the groove 2 d of the ferrule 2 is exposed from the one end face 4 a of the first holder 4. Such press-fitting is performed by fixing the ferrule 2 to a jig and pressing the holder 4 with a press. At this time, small metal scratches are formed along the longitudinal direction of the ferrule 2 on the outer periphery of the ferrule 2 added by the first holder 4.

  Next, as shown in FIG. 3B, the second holder 5 is press-fitted into the inner hole 5 a of the second holder 5 from the one end 2 c side of the ferrule 2. At this time, the second holder 5 is press-fitted to the portion where the gap portion S is provided between the first holder 4 and the one end surface 4a of the first holder 4 and the groove portion 2d is opened to the gap portion S. Through the above-described steps, an optical communication component is manufactured.

  Next, as shown in FIG. 3C, the sleeve 3 is inserted and fixed to the tip 2b of the ferrule 2 included in the above-described optical communication component. Finally, a part of the sleeve case 6 is press-fitted into the case insertion groove 4b of the first holder 4 to produce an optical receptacle.

  Thus, according to the optical communication component and the optical receptacle manufacturing method of the present invention, since the first holder 4 and the second holder 5 are press-fitted from the rear end face side of the ferrule 2, for example, the rear end face of the ferrule 2 Even when the ferrule 2 is polished obliquely, the front end surface of the ferrule 2 is fixed to the bottom surface of the ferrule fixing jig in the vertically downward direction, and each holder can be press-fitted with high accuracy along the axial direction of the ferrule 2.

  FIG. 4 is a cross-sectional view showing an embodiment of an optical module provided with an optical receptacle according to the present invention. The optical module Y includes an optical receptacle X and an optical element unit 10. The optical element unit 10 includes an optical element 11, a lens 12, a housing 13, and a bonding ring 14.

  The optical element 11 is a light emitting element for emitting light toward the optical fiber 1 inserted in the through hole 2 a of the ferrule 2 or a light receiving element for receiving light derived through the optical fiber 1. is there. Examples of the light emitting element include a semiconductor laser diode (LD) and a light emitting diode (LED), and examples of the light receiving element include a receiving PD (photodiode).

  When the optical element 11 is a light emitting element, the lens 12 has a function of condensing the light emitted from the light emitting element and introducing it into the optical fiber 1. When the optical element 11 is a light receiving element, the lens 12 emits from the optical fiber 1. It is a member having a function of collecting the collected light and introducing it into the light receiving element. As such a lens, for example, a spherical quartz lens can be used.

  The housing 13 is a cylindrical member for housing the optical element 11 and the lens 12, and is joined to the second holder 5 of the optical receptacle X via a joining ring, for example, by welding. Examples of the material constituting the housing 13 include weldable materials such as stainless steel, copper, iron, and nickel. Among these, stainless steel is preferable from the viewpoint of corrosion resistance and weldability.

  The joining ring 14 is a member for joining the second holder 5 and the housing 13. Examples of the material constituting the joining ring include weldable materials such as stainless steel, copper, iron, and nickel, and stainless steel is preferable from the viewpoint of corrosion resistance and weldability.

  Although specific embodiments of the present invention have been described above, these are merely examples, and the present invention is not limited thereto, and various modifications can be made without departing from the spirit of the invention. It is. In addition, in each figure, about the common part, the same code | symbol is attached | subjected and the overlapping description is abbreviate | omitted. The number of arrangement of each component, the arrangement position, and the like are not limited, and can be appropriately set depending on the purpose of use, application, desired performance, and the like of the optical receptacle and the optical module.

It is sectional drawing which shows embodiment of the optical receptacle which concerns on this invention. It is a partial expanded sectional view of the groove part vicinity in embodiment of the optical receptacle which concerns on this invention. It is explanatory drawing which shows the manufacturing process of the components for optical communications which concern on this invention, and an optical receptacle. It is sectional drawing which shows embodiment of the optical module which concerns on this invention. It is sectional drawing showing the conventional optical receptacle.

Explanation of symbols

X: optical receptacle Y: optical module 1: optical fiber 2: ferrule 2a: through-hole 2b: front end 2c: rear end 2d: groove 3: sleeve 4: first holder 4a: inner hole 4b: one end surface 5: first 2 Holder 5a: Inner hole 6: Sleeve case gap: S
10: Optical element unit 11: Optical element 12: Lens 13: Housing 14: Ring for bonding

Claims (6)

A ferrule having electrical insulation,
A cylindrical metal first holder having an inner hole into which a part of the ferrule is press-fitted,
A portion of the ferrule excluding the part has a press-fitted inner hole, and the first holder and a cylindrical second holder disposed via a gap,
The ferrule has a groove on the outer peripheral surface that opens toward the gap.   The optical communication component according to claim 1, wherein a width of the groove portion in the longitudinal direction of the ferrule is smaller than a width of the gap portion in the longitudinal direction of the ferrule.   The optical communication component according to claim 1, wherein an angle formed between a side surface of the groove and the outer peripheral surface of the ferrule is an obtuse angle. A method for manufacturing an optical communication component according to any one of claims 1 to 3,
Forming the groove in the ferrule;
Press-fitting the first holder from one end side of the ferrule into the inner hole of the first holder, and exposing the groove of the ferrule from one end surface of the first holder;
The second holder is press-fitted into the inner hole of the second holder from one end side of the ferrule, a gap is provided between the one end surface of the first holder, and the groove opens to the gap. And a step of press-fitting to a part. The optical communication component according to any one of claims 1 to 3,
An optical fiber disposed within the ferrule penetration;
And a sleeve into which the other end of the ferrule is inserted. An optical receptacle according to claim 5;
An optical element for emitting light toward the optical fiber or receiving light through the optical fiber;
An optical module comprising: a housing connected to the second holder of the optical receptacle and accommodating the optical element.

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