JP3309541B2 - Optical fiber array - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention
The present invention relates to an improvement in the structure of an optical fiber array in which optical fibers are arranged with high precision, which is coupled to an optical module including a D array or a PD array.

[0002]

2. Description of the Related Art For example, there is known an optical fiber array having a structure in which an optical fiber is sandwiched and positioned by a V-groove formed by etching silicon (hereinafter, simply referred to as Si) (issued in October, 1985, Journal of Lighw
ave Technology vol. LT-3 No. 5, p. 1159). Also,
Japanese Patent Laying-Open No. 4-86802 discloses an optical fiber array having a structure in which two L-shaped magnets are opposed to each other to sandwich an optical fiber. However, when coupling the optical fiber array to an optical module composed of an LD array, a PD array, and the like, the two are aligned while monitoring light loss and the like, and are aligned and fixed by soldering or YAG laser welding. Is common.

[0003]

In the case where such an optical fiber array is aligned with an optical module, conventionally, X,
Alignment with respect to the three axes of Y and Z and the rotation direction of each axis was required.

[0004]

As a result of various studies on the above problems, the present inventor has found that (a) by simultaneously polishing the metal sleeve end face so as to be flush with the optical fiber array end face, X Y direction requires only rotation only alignment in the XY plane, and (b) as shown in FIG. 5 (b),
Metal sleeve covers the entire circumference of the optical fiber array
Metal sleeve and optical fiber array
Now solder turns to enough in the gap between the stomach, (c) the non-light-
The fiber positioning member is exposed on the polished surface of the optical fiber array.
It is in a position retracted from the end face so that it does not come out
The solder is shown in FIG. 6 inside the metal sleeve at the tip.
Filled to complete hermetic seal
It has been found that the present invention becomes easier , and the present invention has been completed.

According to the present invention, in an optical fiber array for positioning and holding an optical fiber, the optical fiber is positioned by an optical fiber positioning member, and a metal sleeve is provided on an outer peripheral portion thereof. in the array end surface is polished so that the optical fiber surface and flush over the entire circumference, and the inner (b) a metal sleeve, an optical fiber at the end face, are sealed fixed by soldering with the positioning member, (c) Light fa
The positioning member is exposed on the polished surface of the optical fiber array.
An optical fiber array, wherein the optical fiber array is located at a position retracted from the end face so as not to be disturbed . I will provide a. Also,
The polished end surface of the metal sleeve is also characterized in that it serves as an abutting surface when positioning and fixing the optical fiber array surface. The metal sleeve is also characterized in that it also serves as a welding or solder fixing flange for hermetically sealing the optical fiber array. Further, the optical fiber positioning member is two array plates having V-grooves on at least one side, and the optical fibers are characterized in that they are clamped in a sandwich manner between the two array plates. The optical fiber positioning member has at least one of V
This is a member in which a guide hole is formed by joining two array plates each having a groove, and is also characterized in that an optical fiber is positioned by being inserted into the guide hole. The optical fiber positioning member is silicon, glass,
Another feature is that any one of ceramics or a combination thereof is used as a material. Also,

Another feature is that the metal sleeve is provided with a window that can press the built-in optical fiber positioning member. Press the optical fiber positioning member
Another feature is that the fixing member is a leaf spring. Further, the present invention is characterized in that the window portion also serves as an inlet for an optical fiber, a solder for sealing the optical fiber positioning member, and a heat-resistant adhesive. (10) The optical fiber positioning member is also characterized in that the drawing amount is 1 mm or less. In (11) to (10), the case end of the module array and the optical fiber array are joined by soldering or YAG laser welding so that the case end and the optical fiber array end form a reference plane. It is also unique.

Hereinafter, the present invention will be described in more detail with reference to the drawings and the like. FIG. 1 is a schematic diagram showing a basic structure of a sandwich type optical fiber array of the present invention. Figure 1
FIG. 1A is a plan view thereof, and FIG.
FIG. 1 is a longitudinal sectional view showing one embodiment, and FIG. 1- (C) is a longitudinal sectional view showing another embodiment. In FIG. 1, reference numeral 1 denotes an optical fiber, 1 'denotes an optical fiber group, and 2 denotes an optical fiber positioning member, which is composed of two upper and lower plates for clamping the optical fiber 1 in a sandwich shape. 3
Is a metal sleeve surrounding the optical fiber positioning member,
The inside of the metal sleeve is sealed and fixed with solder at the end face together with the optical fiber 1 and the positioning member 2.

Reference numeral 5 denotes a window provided at an appropriate position on the metal sleeve 3 as shown in FIG.
This is advantageous in that the positioning member 2 is pressed by a clamp member (not shown) such as a leaf spring. Metal sleeve 3
Is, as shown in FIGS. 1- (a), (b) and (c),
It is important that the end surface of the optical fiber array is polished so as to be flush with the optical fiber surface over the entire circumference. In the present invention, by adopting such a configuration, the polished end surface of the metal sleeve 3 is used for positioning and fixing the optical fiber array to other components of the optical parallel transmission optical module, for example, an LD array, a lens array, and the like. An abutment surface can be formed.

When the optical fiber positioning member 2 is drawn in from the polished surface, the inside of the metal sleeve 3 at the tip is filled with solder 17 as shown in FIG. 6, and there is an effect that the hermetic seal is easily completed. . FIG. 6 is a schematic diagram for explaining a situation where the end face and the optical fiber and the optical fiber positioning member are hermetically sealed with solder when the optical fiber positioning member is drawn in from the polished surface and fixed. In this case, as shown in FIG. 6, hermetic sealing is performed between the polished surface and the optical fiber positioning member by a hermetic seal portion 8 made of solder, low melting point glass or the like, and at the same time, the solder 17 is placed in the optical fiber positioning member. The gap between the upper and lower plates 2 ′, 2 ″ of the member 2 and the metal sleeve 3 is also sealed. The drawing amount of the optical fiber positioning member from the polishing surface only needs to have a gap enough to be filled with solder or adhesive. In order not to impair the alignment accuracy of the optical fiber on the surface, it is desirable that the distance does not exceed 1 mm.

As shown in FIGS. 1 and 2, the optical fiber positioning member 2 is an array plate having two V-grooves on at least one side, and comprises an upper plate 2 'and a lower plate 2 ". The optical fiber 1 is clamped in a sandwich manner between two array plates, and the optical fiber positioning member 2 on the upper surface may be made of a transparent member, thereby facilitating observation of the solder filling inside. 3 (a), the position of the optical fiber 15 can be easily confirmed, and the optical fiber positioning member 2 is formed by joining two array plates having the V-grooves to guide holes (shown in FIG. 3). Is not formed), and the optical fiber 1 is positioned by being inserted into the guide hole.

As the structure of the V-groove, the bottom of the V-groove of the array plate preferably has an R surface. The R surface of the V-groove can be easily formed by grinding with a diamond blade, and in particular, can have an R portion of 5 μm or more. In the case of the present invention, the outer periphery thereof may be configured to be pressed by a leaf spring made of an invar alloy or the like through the window 5 provided in the metal sleeve, so that the assembly of the optical fiber array is further facilitated. Become. As an invar alloy suitable for forming the metal sleeve, a Ni-Fe alloy is preferable. This has the advantage that the coefficient of thermal expansion is low and deformation is small even when heat is applied when fixing the optical fiber array to the optical module.

FIG. 5 is a schematic view for explaining a method of fixing and hermetically sealing an optical fiber in an optical fiber positioning member by soldering. When this solder comes into contact with the optical fiber coating portion, the coating dissolves and a large amount of gas is generated. Therefore, it is preferable to fix only the optical fiber glass portion. FIG.
As shown in (c), the solder is preferably fed from the tip of the optical fiber 1 while applying ultrasonic vibration. Specifically, the temperature suitable for sealing (that is, the optical fiber 1,
The solder in the solder bath heated to a temperature at which the viscosity of the solder liquid rises in the gap between the optical fiber positioning members 2) is given an ultrasonic vibration by an appropriate ultrasonic vibrator. It is desirable that the tip of the optical fiber array 2 be put into the solder bath so that the solder flows around these gaps.

Furthermore, when the solder joint between the optical fiber array and the metallic sleeve 3, for complete hermetic seal, as shown in FIG. 5 (b), a metal ground
In this structure, the probe 3 covers the outer peripheral portion of the optical fiber array.
In addition, it is desirable that a gap is formed between the metal sleeve 3 and the optical fiber array so that the solder is sufficiently rotated. Further, in order to prevent crack growth or breakage on the surface of the optical fiber, it is preferable to apply a carbon coat or the like to the optical fiber in advance.

As the solder material, a material obtained by adding additives such as Zn, Sb, Al, Ti, Si, and Cu to a normal Pb-Sn alloy is preferable. As the heat-resistant adhesive,
Preferably, an adhesive having a gas generation amount of not more than% by weight at 260 ° C. for 10 seconds, for example, an epoxy-based adhesive is desirable. Further, the optical fiber positioning member is silicon,
Desirably, the material is glass or ceramic, or a combination thereof.

FIG. 2 is a schematic diagram for explaining a method of forming a joint surface with another optical module on the end surface between the metal sleeve surface and the optical fiber array surface. In FIG. 2, FIG.
As shown in (a), a swelling portion 7 is provided by applying a solder or an adhesive 7 '. Thereafter, as shown in FIG. 2B, the end faces are polished so that the end face of the metal sleeve and the end face of the optical fiber are coplanar. As a result, the end face is polished to expose the solder or the adhesive 7 ', thereby forming an airtight structure.

FIG. 3 is a schematic view showing an example of the method of the present invention which does not require Z alignment when joining an optical fiber array and an optical parallel transmission optical module. FIG. 4 is a schematic diagram showing an example where conventional XYZ alignment is required when joining an optical fiber array and an optical parallel transmission optical module. In FIG. 3, the optical fiber array must always be bonded to the optical parallel transmission optical module at a constant interval (Z). In this case, a case 11 is provided on the exterior of the optical module and bonded by this. Specifically, the end face of the case 11 of the module array and the optical fiber array are fixed by soldering or YA.
Joint 16 by G laser welding is preferred. In that case,
In FIG. 3, the operation is performed so that the case end face and the optical fiber array end face constitute a reference plane. On the other hand, FIG. 4 shows a conventional method performed in a state where an optical fiber array is inserted inside a case end face of a module array. In this case, XYZ alignment is required. The metal sleeve material is preferably made of an Invar alloy.

[0017]

The present invention will be described in more detail with reference to the following examples, which do not limit the scope of the present invention. V-groove processing was performed on the silicon wafer with a diamond blade to form a sandwich type array plate. The eccentricity of the V-groove was processed at ± 0.3 μm. Also, as shown in FIG. 1, a metal sleeve is formed using an invar alloy, and the optical fiber is fixed to a tip of about 4 mm with a solder containing Zn, Sb, Al, Ti, etc. in an Sb-Pb alloy, The other portion was injected and fixed through the window 5 of the metal sleeve with an epoxy-based heat-resistant adhesive (gas generation amount under heating at 260 ° C. × 10 seconds is 0.1%). The optical fiber was a carbon-coated 18-core optical fiber having a pitch of 250 μm. The optical fiber outer diameter is 125 ± 0.3μ
m, and the core eccentricity was all within 0.3 μm. After assembly, the eccentricity of the other optical fibers was measured with reference to the 1st and 18th cores. 0.8 μm, which was all within 1.0 μm.

Next, as shown in FIG. 2, the above-mentioned soldering agent is applied to the end face of the optical fiber array to form a raised portion, and then the end face of the optical fiber array and the end face of the metal sleeve are connected to each other as shown in FIG.
-As shown in (b), it is polished so as to be on the same plane,
The optical module was joined to an optical component. Further, the case protecting the optical module and the metal sleeve covering the optical fiber array were welded and integrated by a YAG laser. In this case, a constant gap Z (200 μm) is formed between the optical module and an optical component such as a lens array.
And joined.

[0019]

As described above, the metal sleeve (flange) is used.
By polishing and configuring the end face so as to be flush with the end face of the optical fiber array, parallel movement in the longitudinal direction at the time of alignment and rotation in the rotation direction around two axes orthogonal to the longitudinal direction are performed. Alignment is not required, and there is an advantage that alignment is required only in the X and Y directions and the XY plane. Also, it is easy to seal both end faces with solder. In addition, the metal sleeve is optical fiber
Since the structure covers the outer periphery of the array,
Solder spins in the gap between the probe and the optical fiber array
Swell. The optical fiber positioning member is an optical fiber positioning member.
Pull more than the end face so that it is not
In the metal sleeve at the tip.
Filled, easy to complete hermetic seal
It becomes .

[Brief description of the drawings]

FIG. 1 is a schematic view showing a basic structure of a sandwich type optical fiber array of the present invention. FIG. 1- (A) is a plan view, FIG. 1- (B) is a longitudinal sectional view showing one embodiment of the present invention, and FIG. 1- (C) is a longitudinal sectional view showing another embodiment. FIG.

FIG. 2 is a schematic diagram illustrating a method of forming a bonding surface with another optical module on an end surface between a metal sleeve surface and an optical fiber array surface. FIG. 2- (a) is a schematic view showing a state in which swelling portions of solder or an organic adhesive are formed on the both end faces, and FIG. 2- (b) is a state in which both end faces are polished so as to be on the same plane. FIG. 2C is a schematic diagram when the optical fiber positioning member is in a state of being pulled in from the end face.

FIG. 3 is a schematic view showing an example of the method of the present invention in which Z alignment is unnecessary when joining an optical fiber array and an optical parallel transmission optical module.

FIG. 4 is a schematic diagram showing an example where conventional XYZ alignment is required when joining an optical fiber array and an optical parallel transmission optical module.

FIG. 5 is a schematic diagram illustrating a method of fixing and hermetically sealing an optical fiber in an optical fiber positioning member using solder. Fig. 5- (a) is the cross section,
FIG. 5- (B) is an end view thereof, and FIG. 5- (C) is a schematic diagram showing a state in which solder is fed from the tip of the optical fiber array while applying ultrasonic vibration.

FIG. 6 is a schematic diagram for explaining a situation of a joining end face of an optical fiber array in which an optical fiber is arranged so as to protrude from a drawing end face, and a situation where the end face and the optical fiber and the optical fiber positioning member are hermetically sealed with solder.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Optical fiber 1 'Optical fiber group 2 Optical fiber positioning member 2' Upper plate 2 "Lower plate 3 Metal sleeve (flange) 5 Window 7 Rise 11 Case 12 LD array 13 Lens array 14 Optical fiber 15 Optical parallel transmission module 16 Joining by Laser Welding or Soldering 17 Solder or Adhesive 18 (Heat Resistant) Adhesive 19 Boundary 20 Solder Filling Z Z Gap

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-63-221307 (JP, A) JP-A-7-168056 (JP, A) JP-A-5-264868 (JP, A) JP-A-5-264868 127044 (JP, A) JP-A-4-98207 (JP, A) JP-A-1-125409 (JP, U) JP-A-1-94905 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) G02B 6/42 G02B 6/36

Claims (11)

(57) [Claims] In an optical fiber array for positioning and holding an optical fiber, the optical fiber is positioned by an optical fiber positioning member, and a metal sleeve is provided on an outer peripheral portion thereof. Is polished so as to be flush with the optical fiber surface over the entire circumference, and (b) the inside of the metal sleeve is sealed and fixed with solder at the end face together with the optical fiber and the positioning member, ( c ) the optical fiber Positioning
The members are not exposed to the polished surface of the optical fiber array.
An optical fiber array, wherein the optical fiber array is located at a position retracted from an end face . 2. The optical fiber array according to claim 1, wherein the polished end surface of the metal sleeve serves as an abutting surface when positioning and fixing the optical fiber array surface. 3. The optical fiber array according to claim 1, wherein the metal sleeve also serves as a welding or solder fixing flange for hermetically sealing the optical fiber array. 4. The optical fiber positioning member according to claim 1, wherein the optical fiber positioning members are two array plates having at least one V-groove, and the optical fibers are sandwiched between the two array plates. Optical fiber array. 5. The optical fiber positioning member is a member in which a guide hole is formed by joining two array plates having at least one V-groove, and the optical fiber is positioned by being inserted into the guide hole. The optical fiber array according to claim 1, wherein: 6. The optical fiber array according to claim 1, wherein the optical fiber positioning member is made of any one of silicon, glass, ceramic and a combination thereof. 7. The optical fiber array according to claim 1, wherein the metal sleeve is provided with a window capable of pressing the built-in optical fiber positioning member. 8. The optical fiber array according to claim 7, wherein the member for pressing and fixing the optical fiber positioning member is a leaf spring. 9. The optical fiber array according to claim 1, wherein the window portion serves as an optical fiber, a solder for sealing the optical fiber positioning member, and a heat-resistant adhesive injection port. 10., wherein the pressed amount of the optical fiber positioning member is 1mm or less, the optical fiber array of claim 1, wherein. 11. The method according to claim 11, wherein the case end face of the module array and the optical fiber array are joined by soldering or YAG laser welding so that the case end face and the optical fiber array end face constitute a reference plane. The optical fiber array according to any one of claims 1 to 10 .