JP2019219521A - Optical module and method for manufacturing the same - Google Patents

Abstract

To provide an optical module easily penetrated and welded between a ferrule and the diameter part of a sleeve while enhancing beam quality.SOLUTION: An inclined end surface optical fiber 1' and ferrule 2' having a 8° inclined end surface is inclined by 4°(=8°/2) to a sleeve 3", and the tilt angle of the inclined end surface to the sleeve 3" is 4°; an inclined open hole 31 for inserting the inclined end surface optical fiber 1' and the ferrule 2' in the sleeve 3" is also inclined by 4°; emission light from the inclined end surface of the inclined end surface optical fiber 1' is almost vertical in a large diameter part 33' of the sleeve 3"; flat surfaces 31"b and 31"c parallel to a surface (a surface including an inclined direction S) formed in the inclined direction of the inclined end surface optical fiber 1' are formed, and the tube thickness of a small diameter part 31" is partially thin; and the ferrule 2' is penetrated and welded at the places of the flat surfaces 31"b and 31"c facing the inclined open hole 31"a of the small diameter part 31".SELECTED DRAWING: Figure 1

Description

  The present invention relates to an optical module and a method for manufacturing the same.

  An optical module using an optical fiber is used as a light source module of a medical fundus camera, a laser processing device, and the like in a light emitting module, a light receiving module, a multiplexing module, a demultiplexing module, and the like in an optical communication system.

  6A and 6B show a first conventional optical module, wherein FIG. 6A is an upper perspective view, FIG. 6B is a lower perspective view, and FIG. 6C is a sectional view of a sleeve. 2).

  In FIG. 6, the optical module includes an optical fiber 1, a ferrule 2 for sealing and fixing one end of the optical fiber 1 to enhance the optical connectivity of the optical fiber 1, and a ferrule 2 for fixing the ferrule 2 by inserting the ferrule 2. And a lens holder 4 fixed to the sleeve 3 and having a built-in lens.

In FIG. 6, the optical fiber 1 and the ferrule 2 are inserted into the sleeve 3. At this time, in order to fix the optical axis of the optical fiber 1 and the optical axis of the lens of the lens holder 4 with high accuracy, the fixing is performed by spot welding using a YAG laser. For example, as shown in FIG. 6 (A), the ferrule 2 and the sleeve 3 is penetration welding in to and through the welding point P ₂ welded at the welding point P _1. On the other hand, as shown in (B) of FIG. 6, the sleeve 3 and the lens holder 4 are welded at a welding point P _3. In this case, in order to reduce the welding energy through the weld point P _2, the sleeve 3 small diameter portion 31, a three-stage structure of the medium diameter portion (flange portion) 32 and the large diameter portion (base portion) 33, through the welding point P ₂ is the thinnest as possible the small diameter portion 31 provided. For example, the tube thickness of the small diameter portion 31 is about 0.25 mm. As a result, penetration welding between the ferrule 2 and the small diameter portion 31 of the sleeve 3 can be easily performed. The ferrule 2 and the sleeve 3 are made of the same or the same kind of metal material for the penetration welding between the facing surfaces (contact surfaces).

  As shown in FIG. 6C, the sleeve 3 shown in FIG. 6 is formed by a drilling process for forming vertical through holes 31a, 32a, and 33a for penetrating the optical fiber 1 and the ferrule 2, and a small diameter portion 31, This is performed by a lathing process for forming the outer diameters of the middle diameter portion 32 and the large diameter portion 33. The manufacturing cost is low, and the thinnest small diameter portion 31, for example, a tube thickness of about 0.25 mm is relatively easy.

  On the other hand, in the optical fiber 1, the end face of the optical fiber is formed to have an inclined surface of, for example, 8 ° in order to suppress the reflected return light (see paragraph 0003 of Patent Document 3 and paragraph 0004 of Patent Document 4). The inclined end face optical fiber having an end face as an inclined face is particularly effective for a single mode optical fiber having a small core diameter, but may also be applied to a multimode optical fiber.

  7A and 7B show a second conventional optical module, in which FIG. 7A is a front view and FIG. 7B is a sectional view of a sleeve (see Patent Documents 3 and 5). The optical module of FIG. 7 employs an inclined end face optical fiber 1 '.

  In FIG. 7, the end face of the inclined end face optical fiber 1 'is an inclined face of, for example, 8 [deg.]. Therefore, the light emitted from the inclined end face (not shown) of the inclined end face optical fiber 1 ′ is inclined about 4 ° (= 8 ° / 2) and travels inside the large diameter portion 33 of the sleeve 3. In this case, in order to make the optical axis of the inclined end face optical fiber 1 'coincide with the optical axis of the lens of the lens holder 4 with high accuracy, the center of the inclined end face optical fiber 1' and the center of the lens of the lens holder 4 are shifted. , The beam position is adjusted.

  The sleeve 3 in FIG. 7 is formed in the same manner as the sleeve 3 in FIG. 6 by a drilling process and a large diameter for forming the vertical through holes 31a, 32a, and 33a for penetrating the inclined end face optical fiber 1 'and the ferrule 2. This is performed by a lathing process for forming the outer diameter of the portion 31, the middle diameter portion 32, and the small diameter portion 31, and the manufacturing cost is low, and the thinnest of the small diameter portion 31 is relatively easy. For example, the tube thickness of the small diameter portion 31 is about 0.25 mm. As a result, penetration welding between the ferrule 2 and the small diameter portion 31 of the sleeve 3 can be easily performed. Also in this case, the ferrule 2 and the sleeve 3 are made of the same or the same kind of metal material for the penetration welding between the opposing surfaces (contact surfaces).

  8A and 8B show a third conventional optical module, wherein FIG. 8A is an overall perspective view, FIG. 8B is an overall front view, and FIG. 8C is a sectional view of a sleeve (see Patent Documents 4 and 6).

  In FIG. 8, the inclined end face optical fiber 1 'having an 8 ° inclined end face and the ferrule 2' are inclined by 4 ° (= 8 ° / 2) with respect to the sleeve 3 ', and the inclination angle of the inclined end face with respect to the sleeve 3' is changed. 4 °. In this case, the inclined through holes 31'a and 32'a for inserting the inclined end face optical fiber 1 'and the ferrule 2' in the sleeve 3 'are also inclined by 4 degrees. Accordingly, the light emitted from the inclined end face of the inclined end face optical fiber 1 'is substantially vertical in the large diameter portion 33' of the sleeve 3 '. As a result, the optical axis of the inclined end face optical fiber 1 'and the lens holder (not shown) can be adjusted without adjusting the deviation between the center of the inclined end face optical fiber 1' and the center of the lens (not shown) of the lens holder 4. ) Can be made to coincide with the optical axis of the lens with high accuracy. Therefore, the beam quality can be increased. Also in this case, the ferrule 2 'and the sleeve 3' are made of the same or the same kind of metal material for the penetration welding between the opposing surfaces (contact surfaces).

  The sleeve 3 in FIG. 8 is formed similarly to the sleeve 3 in FIG. 7, with the inclined through holes 31′a, 32′a and the vertical through hole 33′a for penetrating the inclined end face optical fiber 1 ′ and the ferrule 2 ′. And a lathing process for forming the outer diameters of the small diameter portion 31 ', the medium diameter portion 32', and the large diameter portion 33 ', and the manufacturing cost is low.

Japanese Utility Model Publication No. 6-76908 JP-A-2003-344698 JP 2002-196180 A JP-A-7-151934 JP 2004-219756 A JP-A-9-1371

  However, the optical modules shown in FIGS. 7 and 8 using the inclined end face optical fiber 1 'have the following problems.

  That is, in the second conventional optical module shown in FIG. 7, it is still not easy to adjust the beam position due to the deviation between the center of the optical fiber 1 'and the center of the lens holder 4, and as a result, the beam quality is low. There is a problem that.

Further, in the third conventional optical module shown in FIG. 8, the inclined through holes 31'a and 32'a for the inclined end face optical fiber 1 'and the ferrule 2' are inclined in the sleeve 3 '. , the wall thickness d 'of the small diameter portion 31' of the sleeve 3 is varied in the range of _d 1 to d _2. Therefore, it is difficult to specify the thinnest portion of the small diameter portion 31 ', and as a result, there is a problem that it is difficult to perform penetration welding between the ferrule 2' and the small diameter portion 31 'of the sleeve 3'.

  In order to solve the above-described problems, an optical module according to the present invention includes an inclined end face optical fiber, a ferrule to which one end of the inclined end face optical fiber is mounted, and a diameter part and a diameter part to insert and fix the ferrule by being inclined. An optical module including a sleeve having a base portion for holding, wherein a flat surface parallel to a surface formed by the axis of the diameter portion and the ferrule is provided on the diameter portion, and a space between the ferrule and the flat surface facing the ferrule is provided. Are fixed by penetration welding.

  Further, the method for manufacturing an optical module according to the present invention includes a first step for inserting and mounting the inclined end face optical fiber into the ferrule, and a step of forming the outer diameter of the sleeve and the base made of the same or similar metal material as the ferrule. And a third step of forming an inclined through hole in the radial portion with respect to the axial direction of the sleeve and forming a vertical through hole in the axial direction of the sleeve in the base portion. And a fourth step for forming a flat surface parallel to a plane formed by the axis of the diameter portion and the inclined through hole in the diameter portion, and an inclination after the first, second, third, and fourth steps. A fifth step for inserting the ferrule having the end face optical fiber into the sleeve, and a sixth step for performing a penetration welding between the ferrule and a flat surface facing the ferrule after the fifth step. Is provided.

  For the penetration welding, the ferrule and the sleeve may be made of the same or the same type of resin material instead of the same or the same type of metal material. In this case, in the above-described method for manufacturing an optical module, instead of the second and third steps, a sleeve including a diameter portion having an inclined through hole and a base portion having a vertical through hole is formed by a mold. Process is provided.

  ADVANTAGE OF THE INVENTION According to this invention, penetration welding between a ferrule and the diameter part of a sleeve can be facilitated, improving beam quality.

1 shows an embodiment of an optical module according to the present invention, wherein (A) is an overall perspective view and (B) is an overall front view. 1A shows a top view, FIG. 1B shows a right side view, FIG. 1C shows a front view, FIG. 2C shows a front view for explaining through welding, and FIG. FIG. 4 is a sectional view taken along line DD of FIG. 2 is a flowchart for explaining a method for manufacturing the optical module of FIG. FIG. 3 shows an optical module as a first comparative example, where (A) is an overall perspective view and (B) is an overall front view. FIG. 6 shows an optical module as a second comparative example, in which (A) is an overall perspective view, (B) is a top view of a sleeve, and (C) is a front view of the sleeve. 1A shows a first conventional optical module, wherein FIG. 1A is an overall upper perspective view, FIG. 1B is an overall lower perspective view, and FIG. 1C is a sectional view of a sleeve. FIG. 6 shows a second conventional optical module, in which (A) is an overall front view and (B) is a cross-sectional view of a sleeve. 3A and 3B show a third conventional optical module, in which FIG. 3A is an overall perspective view, FIG. 2B is an overall front view, and FIG. 1C is a sectional view of a sleeve.

  1A and 1B show an embodiment of an optical module according to the present invention, wherein FIG. 1A is an overall perspective view, and FIG. 1B is an overall front view.

  In FIG. 1, a sleeve 3 "is provided instead of the sleeve 3 'of FIG. 8, and the sleeve 3" has a small-diameter portion 31 "instead of the small-diameter portion 31' of FIG. In the components shown in FIG. 1, only the small diameter portion 31 "of the sleeve 3" is different from the components shown in FIG. 8. Therefore, similarly to the optical module shown in FIG. It is not necessary to adjust the deviation of the holder 4 from the center of the lens (not shown), and the beam quality can be improved.

In the small diameter portion 31 "of FIG. 1, an I-cut surface, that is, a sleeve 3" (small diameter) parallel to a plane formed by the inclined direction of the inclined end face optical fiber 1 ', that is, a plane including the inclined direction S (see FIG. 2A). part 31 ") axis _{a x} and the ferrule 2 '(inclined through holes 31 of" a) a flat surface 31 parallel to the plane formed by the "b, 31" c formed, portions wall thickness of the small diameter portion 31 " In this case, the flat surfaces 31 "b and 31" c are present over the entire small-diameter portion 31 "in the axial direction to reduce the manufacturing cost.

The details of the sleeve 3 ″ in FIG. 1 will be described in detail with reference to FIG. 2. In FIG. 2, (A) is a top view, (B) is a right side view, (C) -1 is a front view, (C) -2 is a front view showing the penetration welding point _{P 2,} a D-D line cross-sectional view of (D) is (a).

As shown in FIG. 2D, in order to incline the inserted 8 ° inclined end face optical fiber 1 ′ by 4 °, the inclined through holes 31 ″ a, 32′a of the small diameter portion 31 ″ and the medium diameter portion 32 ′. Is inclined by 4 ° with respect to the vertical direction. As shown in FIGS. 2 (A), (B) and (C) -1, the flat surfaces 31 "b and 31" c are surfaces (inclined) formed by the small-diameter portion 31 "and the medium-diameter portion 32 'in the inclination direction S. is parallel to the plane) including the direction S. that is, in the FIG. 1 (B), the flat surface 31 "b, 31" c sleeve 3 axes _{a x} and the ferrule 2 for "(the small diameter portion 31") '(gradient It is parallel to the plane formed by the through holes 31 ″ a). Therefore, as shown in FIG. 2B, the thickness of the inclined through-hole 31 "a of the small-diameter portion 31" can be minimized, for example, 0.25 mm. As a result, as shown in the (C) -2 2, when the small-diameter portion 31 flat surface 31 facing the a "tilt through hole 31 of the""b,31" location c to provide a full penetration weld point _{P 2,} Easy penetration welding.

1 and 2, the ferrule 2 'and the sleeve 3 "are made of the same or similar metal material for the penetration welding between the opposed surfaces (contact surfaces).
・ Austenitic stainless steel (SUS304, SUS303, etc.)
・ Martensitic stainless steel (SUS403, etc.)
・ Mild steel (SPCC, SS400C, etc.)
·cast iron
・ Aluminum alloy (A5052, etc.)
Etc. Select one or two of these metals. SUS304 and / or SUS403 are used as optimal metals.

  A method for manufacturing the optical module of FIG. 1 will be described with reference to FIG.

  First, in the inclined end facet optical fiber attaching step 301, the 8 ° inclined end facet optical fiber 1 'is inserted and attached to the ferrule 2'.

  Next, in a sleeve small diameter portion, middle diameter portion, and large diameter portion forming step 302, the outer diameters of the small diameter portion 31 ″, the middle diameter portion 32 ′, and the large diameter portion 33 ′ of the sleeve 3 ″ are formed in a lathe processing step. .

Next, in a sleeve through hole forming step 303, the small diameter portion 31 "of the sleeve 3", the inclined through holes 31 "a, 32'a of the middle diameter portion 32 ', and the vertical through hole 33'a of the large diameter portion 33'. to form the drilling process. in this case, the inclined through-hole 31 is "a, 32'a sleeve 3" is 4 ° inclined relative to the axis _{a x} direction, the vertical through hole 33'a sleeve 3 " Axis _Ax direction.

Next, in a sleeve flat surface forming step 304, the flat surfaces 31 "b, 31" c of the small diameter portion 31 "of the sleeve 3" are subjected to a general end milling step. In this case, since the flat surfaces 31 "b and 31" c extend over the entire axis _Ax direction of the small-diameter portion 31 ", it is not necessary to form a groove in accordance with each product, and the flat surface 31" is formed by one round-trip general end milling process. The faces 31 "b and 31" c can be machined.

  Next, in a ferrule insertion step 305, the ferrule 2 'on which the inclined end face optical fiber 1' is mounted is connected to the inclined through hole 31 "a of the small diameter portion 31" of the sleeve 3 "and the inclined through hole 32 'of the medium diameter portion 32'. 1a and the vertical through hole 33'a of the large-diameter portion 33'.In this case, the distal end portions of the inclined end face optical fiber 1 'and the ferrule 2' have a large diameter as shown by a dotted line in FIG. It is inserted to the vicinity of the center of the portion 33 '(base portion).

Finally, the more of the same type in the through-hole 31 "a, the flat surface 31 facing the 32'a" b, 31 "location c _{P 2} (see (C) -2 2) at penetration welding step 306 performing penetration welding by YAG laser respect between the ferrule 2 'and the "small-diameter portion 31 of the" sleeve 3. in this case, the welding of the welding point P _1, P ₃ of other welding for example FIG. 6 as necessary Also do.

  Thus, even if the flat surfaces 31 "b and 31" c are added in FIGS. 1 and 2, there is no increase in the number of difficult manufacturing steps, and therefore there is no increase in manufacturing cost.

  The order of the sleeve through-hole forming step 303 and the sleeve flat surface forming step 304 in FIG. 3 is not limited to this order, and any of the steps may be performed first.

Further, in the above-described embodiment, the ferrule 2 ′ made of the same or the same kind of metal material and the small diameter portion 31 ″ of the sleeve 3 ″ are through-welded, but the ferrule 2 ′ and the sleeve 3 ″ are the same. Alternatively, through-welding is possible even if it is made of the same type of resin material.
・ Polycarbonate (PC)
・ Polypropylene (PP)
・ Polyvinyl chloride (PVC)
・ Acrylic resin (PMMA)
・ Polyphenylene sulfide (PPS)
・ Polyether ether ketone (PEEK)
・ Polyolefin resin (POM)
・ Polyvinylidene fluoride (PVDF)
・ Ethylene tetrafluoride resin (Teflon (registered trademark)) (PTFE)
Etc. One or two of these resins are selected. PPS is used as the optimal resin. In this case, a small diameter portion, a medium diameter portion, a large diameter portion forming step (lathe processing step) 302, a sleeve through hole forming step (drilling step) 303, and a sleeve flat surface forming step (general end milling step) of FIG. ) 304, instead of the small diameter portion 31 ″, the middle diameter portion 32 ′, the outer diameter of the large diameter portion 33 ′, the inclined through holes 31 ″ a, 32′a, the vertical through hole 33′a, and the flat surface 31 ″ b, 31 "c is formed by an injection molding method using a mold. At this time, the thickness of the small-diameter portion 31 "is relatively large (see FIG. 2D), so that the molten material is applied to the inside of the flat surfaces 31" b and 31 "c of the small-diameter portion 31" of the mold. Can be rotated evenly, and is therefore easy to manufacture.

  4A and 4B show an optical module as a first comparative example, where FIG. 4A is an overall perspective view and FIG. 4B is an overall front view.

  In the optical module of FIG. 4, a window 31'd is formed in the small diameter portion 31 'of the sleeve 3' of the optical module of FIG. As a result, the window portion 31'd of the small diameter portion 31 'corresponds to the flat surfaces 31 "b, 31" c in FIGS. Therefore, similarly to the present invention, the location of the window 31'd and the ferrule 2 'can be welded.

However, in the optical module of FIG. 4, the window portion 31'd is not only formed in a part of the axial A _x-direction of the small diameter portion 31 '. As a result, a groove is required to form the window 31'd, so that a general-purpose end milling process cannot be applied, and the manufacturing cost increases as compared with the present invention.

  5A and 5B show an optical module as a second comparative example, wherein FIG. 5A is an overall perspective view, FIG. 5B is a top view of a sleeve, and FIG. 5C is a front view of the sleeve.

  In FIG. 5, the small diameter portion 31 'in FIG. 8 is also inclined by 4 [deg.], And the small diameter portion 31' is evenly thinned, for example, to a tube thickness of about 0.25 mm. Thereby, similarly to the present invention, penetration welding between the ferrule 2 'and the small-diameter portion 31' of the sleeve 3 'can be easily performed.

  However, in the optical module of FIG. 5, the outer diameter axis of the small diameter portion 31 'is inclined with respect to the outer diameter axes of the middle diameter portion 32' and the large diameter portion 33 ', so that the entire sleeve 3' NC end milling is difficult, and therefore, the manufacturing cost of the sleeve 3 'of the optical module is increased as compared with the present invention. In this case, the sleeve 3 'may be made of the same or the same kind of resin material together with the ferrule 2', and the sleeve 3 'may be formed by an injection molding method using a metal mold. Since it is as small as 25 μm, the molten material does not evenly reach the small-diameter portion 31 ′ of the mold, making the production itself difficult.

  In the above-described embodiment, two flat surfaces 31 "b and 31" c are provided on the small diameter portion 31 "of the sleeve 3", but only one of them may be provided. Further, the sleeve 3 ″ has a three-stage structure of a small diameter portion, a middle diameter portion (flange portion), and a large diameter portion (base portion), but may have a two-stage structure of a small diameter portion and a large diameter portion (base portion). Furthermore, the large-diameter portion (base portion) may not be cylindrical but may be rectangular having a cavity.

  In addition, the present invention can be applied to any change in the obvious scope of the above embodiment.

1: optical fiber 1 ': inclined end face optical fiber 2, 2': ferrule 3, 3 ', 3 ": sleeve 31, 31', 31": small diameter portion 32, 32 ': medium diameter portion (flange portion)
33, 33 ': large diameter part (base part)
31a, 32a, 33a: vertical through holes 31'a, 31 "a, 32'a: inclined through holes 33'a: vertical through holes 4: lens holder

Claims (10)

An optical module comprising a slanted end face optical fiber, a ferrule to which one end of the slanted end face optical fiber is mounted, a sleeve having a diameter part for inserting and fixing the ferrule by being inclined, and a base part for holding the diameter part. ,
A flat surface parallel to a surface formed by the shaft of the diameter portion and the ferrule is provided on the diameter portion, and a portion between the ferrule and the flat surface facing the ferrule is fixed by penetration welding. Optical module.   The optical module according to claim 1, wherein the flat surface exists over the entire diameter of the radial portion.   The sleeve further has a flange portion having a diameter larger than the diameter of the diameter portion and smaller than the diameter of the base portion between the diameter portion and the base portion, and the flange portion is inserted with the ferrule inclined. Item 3. The optical module according to item 1 or 2. A lens holder fixed to the base;
The optical module according to any one of claims 1 to 3, wherein a center of the inclined end face optical fiber and a center of a lens of the lens holder coincide with each other in the base portion of the sleeve. A first step for inserting and attaching the inclined end face optical fiber to a ferrule made of a metal material;
A second step for forming the outer diameter of the sleeve and the outer diameter of the base made of the same or the same type of metal material as the ferrule,
A third step of forming an inclined through hole inclined with respect to the axial direction of the sleeve in the radial portion and forming a vertical through hole in the axial direction of the sleeve in the base portion;
A fourth step of forming a flat surface parallel to a surface formed by the axis of the diameter portion and the inclined through hole in the diameter portion;
A fifth step of inserting the ferrule with the inclined end face optical fiber into the sleeve after the first, second, third, and fourth steps;
A sixth step of performing a through-welding between the ferrule and the location of the flat surface facing the ferrule after the fifth step. The second step further forms an outer diameter of the flange portion larger than the diameter of the diameter portion and smaller than the base portion between the diameter portion and the base portion,
6. The method of manufacturing an optical module according to claim 5, wherein the third step forms an inclined through hole in the flange portion, which communicates with the inclined through hole of the diameter portion and is inclined in the axial direction of the sleeve. A first step for inserting and attaching the inclined end face optical fiber to a ferrule made of a resin material;
A sleeve having a diameter portion and a base portion, wherein the diameter portion has an inclined through hole inclined with respect to an axial direction of the sleeve, and the base portion has a vertical through hole in an axial direction of the sleeve. A second step for molding a sleeve made of the same or the same type of resin material as the ferrule with a mold,
A third step of forming a flat surface parallel to a surface formed by the axis of the diameter portion and the inclined through hole in the diameter portion;
A fourth step of inserting the ferrule with the inclined end face optical fiber into the sleeve after the first, second, and third steps;
A fifth step of performing through welding between the ferrule and the location of the flat surface facing the ferrule after the fourth step.   In the second step, an outer diameter of a flange portion larger than the diameter of the diameter portion and smaller than the base portion is further formed between the diameter portion and the base portion. The method for manufacturing an optical module according to claim 7, wherein an inclined through hole which is communicated with the hole and is inclined in an axial direction of the sleeve is formed.   The method for manufacturing an optical module according to any one of claims 5 to 8, wherein the flat surface exists over an entirety of the radial portion in the axial direction. The optical module further includes a lens holder fixed to the base portion,
The method for manufacturing an optical module according to any one of claims 5 to 9, wherein a center of the inclined end face optical fiber and a center of a lens of the lens holder coincide with each other in a vertical through hole of the base portion of the sleeve. .

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