JP2000162469A - Optical coupling method for coupling optical fiber array with optical waveguide, and optical component - Google Patents

Abstract

PROBLEM TO BE SOLVED: To shorten the aligning time required for optical coupling between an optical fiber array and an optical waveguide. SOLUTION: This optical coupling method for coupling an optical fiber array 2 with an optical waveguide 1 includes a temporary aligning process for measuring respective core positions 2a, 1a of the fiber array 2 and the waveguide 1 while observing the core positions 2a, 1a of the array 2 and the waveguide 1 with a television monitor in a condition where an end face of a module 12 of the fiber array 2 and an end face of a module 11 of the waveguide 1 are approached to move and approach the modules 11, 12 on a position-adjusting table by a distance measured therein so as to correct the posion shifting distance, and the fine aligning process for correcting the position of the respective cores 2a, 1a of the fiber array 2 and the waveguide 1 to make a received light quantity maximum while detecting with a light receiver the quantity of light incident from either of the fiber array 2 or the waveguide 1 to be emitted from another one, when the optical fiber array 2 and the optical waveguide 1 are coupled optically.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for optically coupling an optical fiber array composed of optical fibers arranged on a substrate and an optical waveguide formed on the substrate, and more particularly to an optical coupling for performing alignment in a short time. The present invention relates to a method and an optical component comprising an optical fiber array and an optical waveguide.

[0002]

2. Description of the Related Art Conventionally, in order to optically couple an optical fiber array and an optical waveguide, according to Japanese Patent Application Laid-Open No. 4-161907, first, an optical waveguide formed on a substrate as shown in FIG. An optical fiber array module 12 including an optical fiber array 2 composed of optical fibers arranged in parallel on a substrate is mounted on a fixed base (not shown) on which an optical waveguide module 11 including the optical waveguide module 11 is mounted. The optical waveguide module 11
The end face of the optical fiber array module 12 is abutted against the end face on the light-incident side.

[0005] Next, an NFP (near field pattern) device is connected to the output side end face of the optical waveguide module 11, and a field pattern of the output light that enters from the optical fiber array 2 of the optical fiber array module 12 and exits from the optical waveguide 1 is displayed. The position of the optical fiber array 2 is finely adjusted while observing in the step (1), and the provisional alignment is performed so that the optical axes of the corresponding optical waveguides 1 are substantially coincident with each other.

[0004] Thereafter, the NFP device is removed from the end face on the emission side of the optical waveguide module 11, and the tip end face of the optical fiber array module 13 having an optical power meter connected to the rear end is connected to each optical waveguide 1. The optical fiber array module 12 and the optical fiber array module 1 are fine-adjusted by the position adjusting table while monitoring the emitted light with the optical power meter and at the position where the coupling loss is minimized.
The precision centering is performed to precisely align the optical axis by alternately positioning 3.

As described in JP-A-4-343304 and JP-A-5-11135, a positioning marker is formed on an optical fiber array module or an optical waveguide module, and the positioning marker is used as a mark. An optical coupling method of aligning the optical axes of the optical fiber array and the optical waveguide by simply positioning the modules so that the positioning markers of both modules coincide with each other while observing with a television monitor device has also been proposed.

[0006]

However, in the method of using the NFP described in the above-mentioned publication to detect the field pattern of the outgoing light passing through the optical fiber array and the optical waveguide, and to align the two, the light Work cannot be performed while visually grasping the positions of the fiber array and the optical waveguide, and considerable time is required because the positions of the fiber array and the optical waveguide are adjusted in a groping state only by changing the field pattern of the emitted light.

In particular, when the processing dimensional error of the optical fiber array module or the optical waveguide module is large, or when the optical fiber array module and the optical waveguide module are set on an adjustment table or the like, the positional deviation between the optical fiber array and the optical waveguide is reduced. When it is large, it takes more time.

In addition, a positioning marker is attached to the optical fiber array module or the optical waveguide module described in the above-mentioned publications, and the positioning marker is positioned only by matching the positioning markers of the two modules while observing the marker with a television monitor. In the method of achieving optical coupling, an extra step of forming a positioning marker is required in the manufacturing process of both modules, and the number of chips that can be obtained from one wafer is reduced, thereby increasing the manufacturing cost.

In the method using the positioning marker, it is necessary to match the positioning marker with an accuracy of sub-micron or more in order to achieve optical coupling such that the connection loss is sufficiently small, but this is not always easy. In addition, the cost of equipment such as an optical system and a positioning mechanism increases, and it is necessary to match environmental temperatures with high accuracy.

[0010]

SUMMARY OF THE INVENTION In order to overcome the above-mentioned problems, the present invention provides an end face on the incident side of an optical waveguide module including an optical waveguide and an end face of a first optical fiber array module including a first optical fiber array. In a state in which the optical fiber core of the first optical fiber array and the optical waveguide core at the end face on the incident side are corrected using a television monitor device, and the output side of the optical waveguide module is corrected. In a state where the end face of the second optical fiber array and the end face of the second optical fiber array module including the second optical fiber array are close to each other, an optical fiber core of the second optical fiber array and A provisional alignment step for correcting the displacement of the optical waveguide core on the end face, and receiving the amount of light incident from the first or second optical fiber array and emitted from the other optical fiber array An optical fiber array and the optical waveguide of the optical coupling method characterized by comprising a fine aligning step of modifying the monitor the optical fiber core with a positional deviation of the optical waveguide core by.

In the present invention, a module including an optical fiber array is called an optical fiber array module, and a module including an optical waveguide is called an optical waveguide module. The optical fiber array module connected to the incident side of the optical waveguide module is also referred to as a first optical fiber array module, and the optical fiber array module connected to the output side is also referred to as a second optical fiber array module.

Further, in the present invention, in the temporary alignment step, a CCD is used as a television camera of the television monitor device.
It is characterized by using a camera. Further, the present invention provides the optical fiber core of the optical fiber array or the width direction (X direction) orthogonal to each optical waveguide core of the optical waveguide.
Measuring the distance of the displacement, and correcting the displacement by moving the optical fiber array module or the optical waveguide module in the X direction by this distance.

According to the present invention, in the pre-alignment step, the conventional NF
Using the P device, the field pattern of the outgoing light passing through them without observing the positions of the optical fiber array and the optical waveguide was detected, and the misalignment between the two was corrected by groping. Using a television monitor instead of the NFP device, with the end face of the optical fiber array module and the end face of the optical waveguide module including the optical waveguide close to each other, the optical fiber core of the optical fiber array and the optical waveguide Since the displacement of the optical waveguide core is corrected, the adjustment time required for the temporary alignment can be significantly reduced. As a result, the time required for full alignment can be significantly reduced.

Further, since high positioning accuracy is not required in the temporary alignment step, a positioning marker is not required, and an increase in module manufacturing cost can be avoided.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. Note that the same parts are assigned the same numbers, and duplicate descriptions are omitted.

(Optical Fiber Array Module, Optical Waveguide Module) An embodiment of the present invention will be described using the same optical fiber array modules 12, 13 and optical waveguide module 11 as those in the conventional example shown in FIG. However, in the conventional example, the optical fiber array module 1 shown in FIG.
In the embodiment of the present invention, reference numeral 2b denotes a so-called V-groove having a V-shaped cross section, and an optical fiber is placed in the V-groove. Have been.

Reference numeral 11 denotes an optical waveguide module, in which 16 optical waveguides 1 are formed on a substrate, and at both ends thereof are arranged at equal intervals and in the width direction on the plane of the substrate. Each optical waveguide 1 is composed of a core portion having a high refractive index at a central portion and a cladding portion having a low refractive index at a peripheral portion. FIG.
In the figure, the intermediate portion of the optical waveguide module 11 is omitted.

Reference numeral 12 denotes a first optical fiber array module connected to the incident end of the optical waveguide module 11,
Eight optical fiber ribbons are arranged on the substrate in parallel in the width direction, and 16 optical fibers are mounted on the V-grooves 2b arranged in parallel with the optical waveguide 1 at the same pitch. To form an optical fiber array 2. Each optical fiber constituting the optical fiber array 2 is a two-layered concentric linear body made of silica glass having different refractive indices, and has a high refractive index core in the center and a low refractive index in the periphery. Of cladding. 13 is an optical waveguide module 1
This is a second optical fiber array module connected to one output end, and has the same structure as the first optical fiber array module connected to the input end.

(Aligning Device) FIG. 2 shows an aligning device used in the temporary alignment process and the fine alignment process according to the embodiment of the present invention.
An example is shown below. Reference numeral 100 denotes a television monitor device, which is a television camera 101, an image processing device 102, and a display device 1
It consists of 03. The television camera 101 is a charge coupled device (CCD) as a fixed imaging device.
e) CCD camera equipped with an element whose resolution is ±
Those having a high performance of 30 μm or less, particularly preferably ± 3 μm or less, are suitable.

The image processing device 102 is a television camera 101
Is a device for converting and processing the information recorded by the computer, and the display device 103 is a device for displaying such information as an image. Specifically, the display device 103
The video recorded by the television camera 101 is reproduced as an image, and the position information of the position clicked by the mouse on the image is displayed.

The aligning stage 50 includes position adjusting tables 53 and 55 for an optical fiber array and a position adjusting table 54 for an optical waveguide.
Consists of Each of these position adjustment tables has a function of moving to a desired position in a three-dimensional space by inputting and setting position parameters X, Y, Z, θx, θy, θz to control devices (not shown). . In addition, these adjustment stands can display the position parameters and the related data between the positions designated by linking to the television monitor device 100 on an image.

In the present invention, for the sake of convenience, the origin of the coordinate axis is set to one of the core positions to be aligned with the end face of the optical waveguide, and the X-axis is set to the optical waveguide module as indicated by the coordinate symbol in FIG. 11, the rotation angles θx, θy, θz in the width direction of 11 and in the direction perpendicular to the optical waveguide core, the Y axis in the direction orthogonal to the surface of each optical waveguide module 11, the Z axis in the optical axis direction of the optical waveguide. The direction is assumed to be a rotation about these axes as central axes.

The distances between the origin and the core positions of the corresponding end faces of the optical fiber array are represented by △ X, △ Y, △ Z, and the angular deviations in the rotational direction of the optical fiber array are represented by △ θx, △ θy,
It is represented by Δθz.

Reference numeral 51 denotes a light source for generating a light beam used for monitoring the optical coupling state, and 52 measures the light amount of the light beam passing through the optical fiber array and the optical waveguide to determine the optical coupling state. It is a light receiver for detecting.

(Temporary alignment step) First, the position adjusting table 53
With the mounting surfaces of the position adjusting table 54 set horizontally, the optical fiber array module 12 and the optical waveguide module 1
1 are placed respectively. First, the position adjusting table 53 is moved in the direction of the optical waveguide module 11 located in the Z direction, and the end face of the optical fiber array module 12 is brought as close as possible to the incident side end face of the optical waveguide module 11.

While observing each core of the optical fiber array 2 and the core of the optical waveguide 1 with the display device 103 of the television monitor 100, as shown in FIG. 1A, it is close to one of both side surfaces of the optical waveguide module 11. The positional deviation ΔX in the X direction between the optical waveguide core 1a of the optical waveguide 1 and the corresponding optical fiber core 2a of the optical fiber array 2 is displayed on the screen of the display device 103 and read.

Specifically, each position of the optical waveguide core 1a on the screen of the display device 103 and the corresponding position of the optical fiber core 2a of the optical fiber array 2 are clicked with a mouse, and the relation between these positions is determined. The position information is displayed on the screen, and the value of ΔX is read therefrom. By inputting and setting this distance △ X as the distance to be moved to the control device of the position adjusting table 53, the position is moved,
On the screen of the display device 103, the positions of the cores in the X direction are matched as illustrated in FIG. 1B.

In this case, the actual positioning accuracy of the optical waveguide core 1a and the corresponding optical fiber core 2a is C
Although it is determined by the resolution of the CD camera, the displacement of the cores in the X direction is about ± 30 μm or less, particularly preferably ± 3 μm.
It is preferable that the thickness can be reduced to about μm or less. In the temporary alignment process, alignment of each core in the X direction is performed particularly from the side of each module.
Or, when manufacturing the module, the distance in the X direction up to the position where the optical waveguide 1 is formed, or the position adjusting table 53,
This is for compensating for variations at the time of setting to 54 and 55.

After the provisional alignment of the input end of the optical waveguide module 11 is completed, the optical fiber array module 1
3 are opposed to each other, and optical axis alignment by provisional alignment is performed in the same procedure as in the case of the incident end. In this case, the positioning of the optical fiber array module 13 is performed by using the position adjusting table 5.
Use a position adjusting table 55 having the same function as that of No. 3.

The provisional alignment step is for roughly positioning the cores of the optical fiber array 2 and the optical waveguide 1 for the purpose of efficiently performing the precise alignment. With respect to the positional deviation and the angular deviation of the position parameters that are easily performed, only the following adjustments by the well-known conventional technique are performed.

That is, the displacement ΔY in the Y direction is the height from the bottom of each module to the position where the optical fiber core 2a of the optical fiber array 2 or the optical waveguide core 1a of the optical waveguide 1 is formed. Therefore, the position in the Y direction of the position adjusting table 53 can be adjusted to be sufficiently small by setting the position in the Y direction of the position adjustment table 53 in advance in consideration of these design values.

In general, the end position of each module is not perpendicular to the Z direction. In this case, however, the end surface of the optical fiber array module 12 should be as close as possible to the end surface of the optical waveguide module 11 on the incident side. By moving the position adjustment table so as to be located at a close position, the adjustment can be made sufficiently small. When the end face of each module is orthogonal to the Z axis, ΔZ can be adjusted to zero by bringing the end faces into contact.

Further, the angular deviations Δθx, Δθz of the rotational angles θx, θz in the axial direction are made sufficiently small by adjusting the planes of the mounting tables of the position adjustment tables 53, 54 so as to form the same plane. be able to. Angle deviation of rotation angle θy △ θ
y, abutment portions having an abutment plane orthogonal to this plane are respectively formed on the planes of the mounting tables of the position adjustment tables 53 and 54, and the position adjustment tables 5 are formed so that the respective planes form the same plane.
By adjusting the side surfaces of the respective modules to the abutting plane after adjusting 3, 54, the size can be reduced sufficiently.

(Precision Alignment Step) After the positions of the cores of the optical fiber array 2 and the optical waveguide 1 are approximately brought close to each other by provisional alignment, the amount of light transmitted through these is monitored to perform precise alignment. Do.

That is, in this precise alignment step, an optical power meter unit including a light source 51 and a light receiver 52 is used in place of the image information by the television monitor device 100 in the temporary alignment, and the transmitted light amount is used as a clue. Perform alignment. Light source 5
Reference numeral 1 denotes a light emitting element such as a photodiode for generating light of a predetermined wavelength, and the light receiver 52 includes an optical power meter. The centering stage 50 including the position adjusting tables 53, 54, and 55 illustrated in FIG. 2 used in the temporary centering step is also used in the precision centering step.

In the precision alignment process, as shown in FIG. 3, first, the light source 51 is connected to the incident ends of the optical fibers at both ends of the optical fiber array module 12, while the corresponding light is transmitted through the optical waveguide module 11. The light beam emitted from the emission end of the fiber array module 13 is received by the light receiver 52, and the position parameter △ is adjusted so that the light amount becomes maximum.
By inputting and setting X, △ Y, △ Z, △ θx, に θy, △ θz to the control device of the position adjustment tables 53, 54, 55, the positions thereof are finely adjusted, and the optical fiber array module 12, 13 is positioned.

At the stage when the amount of light is almost maximum, the optical fiber array modules 12 and 13 and the optical waveguide module 11
Adhesive is added between each end face of. Thereafter, the smaller search units △ X, △ Y, △ Z, △ θx, △ θy, △ θz
Is selected and the positions of the optical fiber array modules 12 and 13 are adjusted so as to aim at the position where the light amount becomes maximum, the optical axes are aligned, and finally the positioning is performed. Finally, ultraviolet rays are applied to bond between the end face of the optical fiber array module 12 and the incident end of the optical waveguide module 11 and between the emission end of the optical waveguide module 11 and the end face of the optical fiber array module 13. The agent is fixed by curing.

In the embodiment of the present invention, the television monitor 100 is used in the temporary alignment step. In addition to this step, as shown in FIG. 4, a light source 51 and a large-diameter The optical fiber chip is connected, and the rear end is connected to an optical power meter. Using the optical receiver 52 composed of an optical fiber, provisional alignment for monitoring the amount of light transmitted through each module is performed, and positioning in the provisional alignment step is performed. It is also possible to further improve the accuracy.

In the temporary alignment step of the embodiment of the present invention, the positional deviation ΔX in the X direction is measured using the optical waveguide core 1a and the corresponding optical fiber core 2a of the optical fiber array 2 as a mark. However, with respect to the optical waveguide core 1a, all the portions in the optical fiber array module formed in parallel with the optical fiber core 2a, including the side portions of the optical fibers constituting the optical fiber array module and the edges of the V-grooves, As a mark, the distance ΔX between the optical waveguide core 1a and these marks can be measured to correct the displacement.

In this case, since the measured value ΔX and the distance of the displacement of each core do not coincide with each other and include an error, the measured value ΔX is different between the mark and the optical fiber core 2a. The distance between the optical fiber core 2a and the optical waveguide core 1a is estimated by adding or subtracting a distance, and the optical fiber array module or the optical waveguide module is moved in the X direction by this distance. Correct the displacement by moving it.

[0041]

According to the present invention, the field pattern of the outgoing light passing therethrough is detected by using a conventional NFP device without visually recognizing the positions of the optical fiber array and the optical waveguide. Improving the optical coupling method to correct the positional deviation, using a television monitor instead of the NFP device, observing each core of the optical fiber array and the optical waveguide on a display device and measuring the positional deviation between the two,
By adopting a temporary alignment process of moving and correcting the position adjusting table by this distance, the time required for alignment is significantly reduced.

Further, according to the present invention, since no positioning marker is required for each of the optical fiber array module and the optical waveguide module, it is possible to avoid an increase in the manufacturing cost of these modules.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram illustrating an optical coupling method between an optical fiber array and an optical waveguide according to the present invention. FIG. 1 (a) shows the position shift ΔX measured in the provisional alignment step, and FIG. 1 (b) shows the image of the optical fiber array and the core of the optical waveguide after correcting the position shift ΔX. Show.

FIG. 2 is a conceptual diagram showing a centering device provided for carrying out the present invention.

FIG. 3 is a perspective view illustrating an optical coupling method by precision alignment according to the present invention.

FIG. 4 is a perspective view for explaining another optical coupling method using temporary alignment according to the present invention.

FIG. 5 is a perspective view showing an optical component in which an optical fiber array and an optical waveguide module are combined.

[Explanation of symbols]

 1: Optical waveguide 1a: Optical waveguide core 2: Fiber array 2a: Optical fiber array core 2b: V groove 11: Optical waveguide module 12, 13: Optical fiber array module 50: Alignment stage 51: Light source 52: Light receiver 53, 54, 55: Position adjustment table 100: Television monitor device 101: Television camera 102: Image processing device 103: Display device

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Tomomi Moriya 1-chome, Taya-cho, Sakae-ku, Yokohama-shi, Kanagawa F-term (reference) in Yokohama Works, Sumitomo Electric Industries, Ltd. 2H036 JA04 LA07 NA12 NA17 2H037 BA35 DA12 DA18 DA22

Claims (5)

[Claims] 1. An optical waveguide module including an optical waveguide module, wherein an incident side end face of the optical waveguide module and an end face of a first optical fiber array module including a first optical fiber array are brought close to each other.
A television monitor is used to correct the displacement between the optical fiber core of the first optical fiber array and the optical waveguide core at the end face on the incident side, and the output end face of the optical waveguide module and the second optical fiber. In a state where the end face of the second optical fiber array module including the array is brought close to the optical fiber core, the position of the optical fiber core of the second optical fiber array and the position of the optical waveguide core at the end face on the emission side are determined using a television monitor. And a misalignment step of correcting the positional deviation between the optical fiber core and the optical waveguide core while monitoring the amount of light incident from the first or second optical fiber array and emitted from the other optical fiber array with a light receiver. And a precision centering step of correcting the optical fiber. 2. The optical coupling method according to claim 1, wherein a CCD camera is used as the television camera of the television monitor device in the temporary alignment step. 3. In the temporary alignment step, the displacement in a width direction (X direction) orthogonal to each optical fiber core of the optical fiber array or each optical waveguide core of the optical waveguide is measured, and the displacement is measured. 3. The optical coupling method according to claim 1, wherein the displacement is corrected by moving the optical fiber array module or the optical waveguide module in the X direction. . 4. In the temporary alignment step, a side surface of an optical fiber constituting the optical fiber array or a V-groove of a substrate on which the optical fiber is mounted is used as a mark, and the mark and the core of the optical waveguide are formed. Measure the distance in the X direction between
By estimating the distance of the displacement between the optical fiber core and the optical waveguide core based on this distance, and moving the optical fiber array module or the optical waveguide module in the X direction by the distance of the displacement, the 4. The optical coupling method between an optical fiber array and an optical waveguide according to claim 1, wherein the displacement is corrected. 5. An optical fiber array and an optical waveguide manufactured by optically coupling the optical fiber array and the optical waveguide according to any one of claims 1 to 4. Optical components consisting of