JPH10282361A - Optical fiber holding member, waveguide type optical part and optical waveguide device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To avoid axial shift due to the expansion/contraction of extra resin and prevent ill effect including total loss by forming a groove extended from a joint end face to the axial direction of optical fibers on the outer face perpen dicular to the joint end face of an optical fiber holding member. SOLUTION: An optical fiber holding member 7 has a V-groove 3 to hold plural optical fibers 2 arranged on the surface of an aligned substrate 1 and a holddown plate 5 put on the optical fibers 2 arranged in the V-groove 3, the holddwon plate 5, the optical fibers 2 and the substrate 1 being fixed with a resin 6-1. On the outer face perpendicular to the joint end face 5-1 of the optical fiber holding member 7, or on the outer periphery surface of the holddwon plate 5, a groove 4 extended from the joint end face 5-1 to the axial direction of the optical fibers 2 is provided. The groove 4 is a path for resin 6 excessively deposited between the joint end faces, where the optical fiber holding member 7 is joined to waveguide type optical parts, to overflow so that the extra resin 6 can be removed from near the joint end faces.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a waveguide type optical component, an optical fiber holding member used for inputting / outputting signal light to / from the waveguide type optical component, and an optical waveguide device using the same. It is.

[0002]

2. Description of the Related Art With the development of optical communication technology, conventional light sources,
In addition to optical fibers and receivers, optical splitters, optical switches,
Various optical waveguide devices such as an optical multiplexer / demultiplexer are required. This type of optical waveguide device basically includes a waveguide type optical component on which a waveguide chip is mounted, and an optical fiber holding member for inputting and outputting signal light to and from the waveguide type optical component. A waveguide type optical component generally has a structure in which a reinforcing plate is fixed to a waveguide chip in which a waveguide is formed on a substrate such as silicon or glass, and an optical fiber holding member is formed on a substrate having a V-groove. The arranged optical fibers are fixed with an adhesive or the like.

Japanese Patent Application Laid-Open No. 4-73607 discloses an optical fiber holding member of this type, as shown in FIG. 9, in which an optical fiber 2 is arranged in a V-groove 3 and pressed down from above with a lid 5a for bonding. An optical fiber holding member having a structure fixed by an agent is shown. Japanese Patent Application Laid-Open No. Hei 7-151929 discloses a V-shaped groove 3 for holding an optical fiber 2 and a groove 4 perpendicular to the axial direction of the optical fiber 2 as shown in FIG.
An optical fiber holding member having a is shown.

[0004]

Problems to be Solved by the Invention Japanese Patent Laid-Open No. 4-73607
The conventional example shown in Japanese Patent Application Publication No.
There is a groove 3 and this and the lid 5a are fixed by an adhesive. Therefore, the optical fiber 2 and the adhesive layer or the V-groove 3
The adhesive layer has a structure in which peeling due to curing shrinkage of the adhesive easily occurs between the adhesive layer and the adhesive layer. When the separation occurs, the separation extends to the joint between the waveguide type optical component and the optical fiber, and there is a problem that the coupling loss or the return loss is deteriorated.

In the conventional example disclosed in Japanese Patent Application Laid-Open No. 7-151929, a groove 4a is provided at right angles to the V-groove 3 for holding the optical fiber 2, and this and the lid 5a are bonded with an adhesive. Fixed. For this reason, the structure is such that peeling does not easily occur between the optical fiber 2 and the adhesive layer or between the V-groove 3 and the adhesive layer. However, if an excessive amount of adhesive is adhered between the end face 6 of the optical fiber holding member and the end face of the waveguide type optical component, an axis shift occurs due to the curing shrinkage of the adhesive or the expansion and contraction due to temperature fluctuation, resulting in a coupling loss or a coupling loss. There is a problem that the return loss is deteriorated.

Accordingly, an object of the present invention is to provide an optical fiber holding member, a waveguide type optical component, and an optical waveguide device by solving such a problem.

[0007]

SUMMARY OF THE INVENTION An optical fiber holding member according to the present invention holds one or a plurality of optical fibers arranged in parallel and has an optical fiber at a joint end face to be joined to a waveguide type optical component. In the optical fiber holding member in which is exposed, a groove extending in the axial direction of the optical fiber from the joint end surface is formed on an outer surface orthogonal to the joint end surface of the optical fiber holding member.

According to the structure of the present invention, the optical fiber holding member joined to the waveguide type optical component by the polymer resin is:
A groove extending in the axial direction of the optical fiber from the joint end surface is formed on an outer surface orthogonal to the joint end surface. This groove is configured such that when the end face of the waveguide type optical component and the end face of the optical fiber holding member are joined, the joining end face and the outer surface of the optical fiber holding member communicate with each other via the groove. The excess resin overflows to the outer peripheral portion through this groove even if the excess resin adheres to the surface. Therefore, no extra resin is left near the joining end face, so that relative position movement due to expansion and contraction of the resin is suppressed, and axial deviation can be minimized.

Further, the waveguide type optical component according to the present invention comprises:
An outer surface of a waveguide-type optical component in which an optical waveguide including a core and a clad is formed on a substrate, and the optical waveguide is exposed at a bonding end surface to be bonded to the optical fiber holding member. Is characterized in that a groove is formed extending from the joint end face in the axial direction of the optical waveguide.

According to the structure of the present invention, the waveguide type optical component joined to the optical fiber holding member by the polymer resin is:
A groove extending in the axial direction of the optical fiber from the joint end surface is formed on an outer surface orthogonal to the joint end surface. This groove is configured such that when the end face of the waveguide type optical component and the end face of the optical fiber holding member are bonded, the bonded end face and the outer surface of the waveguide type optical component communicate with each other through the groove. Even if excess resin adheres to the end face, the excess resin overflows to the outer peripheral portion through this groove. Therefore, no extra resin is left near the joining end face, so that relative position movement due to expansion and contraction of the resin is suppressed, and axial deviation can be minimized.

Further, the optical waveguide device according to the present invention is characterized in that an optical waveguide is formed on a substrate, and the optical waveguide device is one or parallel with a waveguide type optical component in which the optical waveguide is exposed at a joint end face to be joined to an optical fiber holding member. An optical fiber holding member that holds a plurality of optical fibers arranged in the optical fiber and that exposes the optical fiber at a joint end face that joins with the waveguide type optical component, wherein the waveguide type optical component and the optical fiber holding member face each other. In the optical waveguide device which is arranged and fixed via a polymer resin, at least one of the outer surfaces of the waveguide type optical component or the optical fiber holding member orthogonal to the joint end face is provided in the axial direction of the optical fiber from the joint end face. A groove extending in the groove is formed.

According to the structure of the present invention, the waveguide type optical component and the optical fiber holding member are joined by the polymer resin,
A groove extending in the axial direction of the optical fiber from the joint end surface is formed on at least one of the outer surfaces of the waveguide type optical component and the optical fiber holding member orthogonal to the joint end surface. Therefore,
Even if excess resin adheres to the joint end face, the excess resin overflows to the outer periphery through this groove, so that excess resin does not accumulate on the joint end face, minimizing axial misalignment due to resin expansion and contraction. Thus, the coupling loss or the return loss can be prevented from deteriorating.

[0013]

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. In the description of the drawings, the same elements will be denoted by the same reference symbols, without redundant description.

First, an optical fiber holding member according to the present invention will be described. FIG. 1 is a perspective view illustrating a configuration of an optical fiber holding member according to an embodiment of the present invention. The optical fiber holding member 7 includes one or a plurality of optical fibers arranged in parallel on the surface of an alignment substrate 1. A V-groove 3 for holding the fiber 2 is provided. The holding plate 5 is placed on the optical fiber 2 arranged in the V-groove 3, and the holding plate 5, the optical fiber 2 and the substrate 1 are connected to the resin 6. 1 to fix.
Reference numeral 4 denotes an outer surface orthogonal to the bonding end surface 5-1 of the optical fiber holding member 7, that is, a bonding end surface 5
1 is a groove formed in the axial direction of the optical fiber 2.

The groove 4 is a passage through which the excessively adhered resin 6 can overflow between the joining end faces for joining the optical fiber holding member 7 and the waveguide type optical component 8 shown in FIG. By providing the groove 4, the excess resin 6 can be removed from the vicinity of the joint end face.

FIG. 2 is a perspective view showing the structure of an optical fiber holding member having a plurality of optical fibers. As shown in FIG. 2, the optical fiber holding member 7-1 holds the eight-core ribbon type optical fiber 2-0 in each of the eight V grooves 3 formed in the alignment substrate 1, and presses the holding plate from above. 5 and fixed with resin 6-1. Three grooves 4 having a rectangular cross section are formed on the lower surface of the substrate 1 to the end face 1-1, and three rectangular grooves 4 are also formed on the upper face of the holding plate 5.
-1.

FIG. 3 is a perspective view showing the structure of an optical fiber holding member provided with a single-core optical fiber. As shown in FIG. 3, the optical fiber holding member 7-2 is a single optical fiber 2
Are held in a V-groove 3 formed in the alignment substrate 1, pressed from above by a holding plate 5, and fixed with a resin 6-1. A groove 4 having a semicircular cross section is formed on the upper surface of the holding plate 5 up to the end surface 5-1.

As described above, the cross-sectional shape of the groove 4 may be any of a V shape, a semicircle, a square, and the like, and there is no limitation on the shape or the number of grooves. By forming the groove 4 in this manner, the excess resin 6 applied between the joining end faces of the optical fiber holding member 7 and the waveguide type optical component 8 overflows to the surface of the holding member 7 through the groove 4. be able to. Therefore, since no extra resin 6 remains in the vicinity of the joint end face, the resin does not expand or contract due to temperature fluctuation, and stable connection characteristics can be obtained. On the other hand, if the excess resin 6 overflows and adheres to the vicinity of the joining end face without providing the groove 4, when a temperature change or the like occurs, it causes peeling of the joining end face or misalignment of the axis.

In order to form the V-groove 3 or the groove 4, cutting with a blade saw is used for simplicity. Further, it can be formed by anisotropic etching. Specifically, after forming windows for V-grooves having different lengths and widths on a Si substrate having a {100} plane orientation by using a lithography technique used in a normal semiconductor IC manufacturing process, It can be formed using an anisotropic etching method in which the 111 ° plane is hardly dissolved, in particular, an anisotropic wet etching method. The Si anisotropic wet etching utilizes the characteristic that the etching rate for the {111} plane having a high atomic density is much lower than the etching rate for the other {100} and {110} planes, and is determined by the crystal structure. V-grooves having different angles are formed. Therefore, V grooves having different depths can be formed by changing the width to be etched.

Optical fiber alignment substrate 1 and holding plate 5
For silicon, quartz glass, ceramic, or the like is used. As the polymer resins 6 and 6-1, epoxy-based, acrylic-based, urethane-based, and silicone-based resins are used, and from the viewpoint of stability during or after manufacture, an ultraviolet-curable resin or a visible-light-curable resin is used. It is suitable.

The optical fiber 2 includes a core having an outer diameter of several tens of μm and a multi-mode optical fiber made of silica glass having a cladding having an outer diameter of 125 μm provided around the core, or a core having an outer diameter of several μm. A quartz glass single mode optical fiber having a cladding with an outer diameter of 125 μm provided around the core is used.

Next, a waveguide type optical component according to the present invention will be described. FIG. 4 is a plan view of a waveguide type optical component having an eight-branch function formed on a quartz glass substrate, and FIG. 5 is a perspective view of the waveguide type optical component. In FIG. 4, the light incident from the input end facet 8-1 of the waveguide type optical component 8 is divided into eight by the optical waveguide 9, and the output end facet 8-2 is output.
Is emitted from. On the other hand, as shown in FIG. 5, the waveguide type optical component 8 has a groove 4 extending in the axial direction of the optical fiber 2 from the joint end face on the outer surface orthogonal to the joint end faces 8-1 and 8-2 on the input / output side. Is formed. These grooves 4 are for overflowing the excessively attached resin when the waveguide type optical component 8 and the optical fiber holding members 7-1 and 7-2 are fixed by a polymer resin. There is no particular limitation on the cross-sectional shape or the number of grooves.

Next, an optical waveguide device according to the present invention will be described. FIG. 6 is a perspective view showing a configuration of an optical waveguide device according to an embodiment of the present invention, in which one or a plurality of waveguide-type optical components 8 having an optical waveguide formed on a substrate are arranged in parallel. The optical fiber holding members 7-1 and 7-2 holding the optical fiber of
A groove 4 extending in the axial direction of the optical fiber 2 from the joint end surface is formed on the outer surface orthogonal to the joint end surface.

The optical fiber holding members 7-1 and 7-2 are optical fiber holding members having the structures shown in FIGS. 2 and 3, respectively. A groove 4 is provided in the axial direction.

According to the structure of the present invention, the waveguide type optical component 8
The optical fiber holding member 7 and the optical fiber holding member 7 are joined by the polymer resin 6, and the groove 4 extending in the axial direction of the optical fiber from the joint end surface is formed on at least one of the outer surfaces of the waveguide type optical component 8 and the optical fiber holding member 7. As a result, even if an excessive amount of resin adheres to the joint end surface, the excess resin can overflow through the groove 4 to the outer peripheral portion of the waveguide type optical component 8 or the optical fiber holding member 7. Therefore, no extra resin is accumulated in the vicinity of the joining end face, and no axial displacement occurs due to contraction of the resin.

[Embodiment] An optical fiber holding member and an optical waveguide device according to the present invention will be specifically described in accordance with a manufacturing process.

First step: First, the optical fiber holding member 7-1 shown in FIG. 2 will be described. First, square grooves 4 having a width of 500 μm, a depth of 250 μm, and a length of 5 mm are formed in the optical axis direction on the outer surfaces of the alignment substrate 1 and the holding member 5 made of quartz glass.
This was formed. The square grooves were formed by a diamond cutter having a square tooth tip.

Next, eight V grooves 3 for holding the ribbon type optical fiber 2-0 were formed on the inner surface of the alignment substrate 1. The V-groove was formed by a V-shaped disk-shaped diamond cutter. The interval between the V grooves 3 was formed in accordance with the interval between the optical waveguide arrays 8-0 of the waveguide type optical component. Next, an optical fiber is arranged in each of the eight V grooves 3,
An ultraviolet curable resin was applied while being pressed by the holding plate 5 from above, and was fixed by irradiation with ultraviolet light. Finally, the bonded end face of the optical fiber 2-0 was polished to form an optical fiber holding member 7-1 having eight optical fibers. The polished end face was finished at an angle of about 8 ° to prevent light from reflecting off this end face and returning back through the same path.

Second Step: Next, the optical fiber holding member 7-2 shown in FIG. 3 will be described. The semicircular groove 4 was formed on the outer surface of the holding member 5 made of quartz glass by a diamond cutter in the same manner as in the first step. Also, one V-groove 3 for holding the optical fiber 2 was formed on the inner surface of the alignment substrate 1 made of quartz glass. The optical fiber 2 was placed in the V-groove 3, and an ultraviolet-curable resin was applied while being pressed by the holding plate 5 from above, fixed by irradiating ultraviolet rays, and the bonded end face of the optical fiber 2 was polished and finished.

Third step: waveguide type optical component 8 shown in FIG.
Will be described with reference to the process chart of FIG. First, a flame burner 20 is placed on a quartz glass substrate 10.
Lower cladding layer 11 of glass fine particles mainly composed of SiO2
−0 is formed (FIG. 7A).

Next, after a high refractive index layer 12-0 made of glass fine particles added with GeO2 is formed on the lower cladding layer 11-0 by the flame burner 20 (FIG. 7).
(B)), lower cladding layer 11-0 and high refractive index layer 1
The substrate 10 on which 2-0 was deposited was heated to obtain a lower cladding layer 11 and a high refractive index layer 12 of a transparent glass body (FIG. 7).
(C)).

Next, a resist film is provided on the high refractive index layer 12, the core pattern of the waveguide type optical component 8 shown in FIG. 4 is transferred by lithography, and the core peripheral portion is etched to form the core 13. It was formed (FIG. 7D).

On the core 13, a flame burner 20
After forming an upper cladding layer 14-0 composed of glass fine particles containing O2 as a main component (FIG. 7E), the substrate 10 on which the upper cladding layer 14-0 is deposited is heated to form an upper cladding layer of a transparent glass body. The layer 14 was formed to form the waveguide-type optical component 8 (FIG. 7F).

Finally, two grooves 4 were formed in the optical axis direction from the joint end face of the waveguide type optical component 8. Groove processing is performed using a diamond cutter with a square tooth tip.
Formed on top.

Fourth Step: A method for manufacturing the optical waveguide device shown in FIG. 6 will be described. The end face 8-1 on the input side of the waveguide type optical component 8 manufactured in the third step is joined to the holding end face of the holding member 7-2 holding one optical fiber manufactured in the second step, and the third step. The bonding end face of the holding member 7-1 holding the eight optical fibers manufactured in the first step is bonded to the output side end face 8-2 of the waveguide type optical component 8 manufactured in
An ultraviolet-curing resin 6 was applied between these end faces, and was irradiated and irradiated with ultraviolet rays to be adhered and fixed.

Fifth Step: The temperature cycle test will be described. Regarding the optical waveguide device manufactured in the fourth step,
As shown in FIG. 8A, a temperature cycle (8 hours / cycle) test that periodically changes in the range of −40 ° C. to 85 ° C. was performed. During the addition of the temperature cycle, 1.3 μm light was input from the input side of the optical waveguide device, and the output power output from each optical fiber on the output side was measured. The output power fluctuated according to the temperature cycle as shown in FIG. When this fluctuation measurement was performed for eight output ports of the optical waveguide device, all of them were 0.12.
The variation was within dB.

Incidentally, in the optical fiber holding members 7-1 and 7-2 and the waveguide type optical component 8 shown in FIG.
An optical waveguide branching device without the device was fabricated and subjected to the same temperature cycle test. The variation of each output port during the test increased to 0.2 dB on average. This is probably because extra resin 6 remained between the joining surfaces of the optical fiber holding members 7-1 and 7-2 and the waveguide type optical component 8, and the resin caused temperature expansion and contraction.

[0038]

The present invention is embodied in the form described above and has the following effects.

Since the optical fiber holding member of the present invention has a groove formed on the outer surface thereof along the optical axis, excess resin adheres between the joining end faces of the optical fiber holding member and the waveguide type optical component. Nothing. Therefore, there is no axis deviation due to the expansion and contraction of the extra resin, and it is possible to prevent the coupling loss or the return loss from deteriorating.

In the optical waveguide device of the present invention, at least one of the outer surfaces of the waveguide type optical component and the optical fiber holding member is formed with a groove extending in the optical axis direction from the joint end face, so that an excessive amount of the joint end face is formed. Even if the resin adheres, it overflows to the outer peripheral portion through this groove. Therefore, no extra resin is accumulated in the vicinity of the joining end face, and it is possible to minimize the axial deviation due to the expansion and contraction of the resin.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a configuration of an optical fiber holding member according to the present embodiment.

FIG. 2 is a perspective view showing another configuration of the optical fiber holding member according to the embodiment.

FIG. 3 is a perspective view showing another configuration of the optical fiber holding member according to the embodiment.

FIG. 4 is a plan view of the waveguide-type optical component according to the embodiment.

FIG. 5 is a perspective view of a waveguide type optical component according to the present embodiment.

FIG. 6 is a perspective view showing a configuration of an optical waveguide device according to the present embodiment.

FIG. 7 is a view illustrating a manufacturing process of the waveguide-type optical component illustrated in FIG. 4;

FIG. 8 shows a temperature condition (a) and a change in output power (b) when a temperature cycle test is added to an optical waveguide device.
FIG.

FIG. 9 is a diagram showing a configuration of a conventional optical fiber holding member.

FIG. 10 is a diagram showing a configuration of a conventional optical fiber holding member.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Board, 1-1 ... Joining end surface, 2 ... Optical fiber, 2
−0: ribbon-type optical fiber, 3: V-groove, 4: groove, 5.
..Pressing plate, 5-1: joining end face, 6, 6-1: polymer resin, 7, 7-1, 7-2: optical fiber holding member, 8 ...
Waveguide type optical component, 8-1...
..Connection end face on output side, 9 ... optical waveguide, 9-0 ... optical waveguide array

Claims (3)

[Claims] 1. An optical fiber holding member for holding one or a plurality of optical fibers arranged in parallel and exposing said optical fiber at a joint end face to be joined to a waveguide type optical component. An optical fiber holding member, wherein a groove extending in the axial direction of the optical fiber from the joint end surface is formed on an outer surface orthogonal to the joint end surface of the member. 2. A waveguide-type optical component in which an optical waveguide including a core and a clad is formed on a substrate, and the optical waveguide is exposed at a joint end face to be joined to an optical fiber holding member. A waveguide type optical component, wherein a groove extending in the axial direction of the optical waveguide from the joint end face is formed on an outer surface orthogonal to the joint end face. 3. A waveguide type optical component in which an optical waveguide is formed on a substrate and the optical waveguide is exposed at a joint end face to be joined to an optical fiber holding member, and one or a plurality of lights arranged in parallel. An optical fiber holding member that holds the fiber and exposes the optical fiber at a joint end face that joins with the waveguide type optical component, and arranges the waveguide type optical component and the optical fiber holding member so as to face each other. In an optical waveguide device fixed via a molecular resin, an outer surface of at least one of the waveguide-type optical component and the optical fiber holding member orthogonal to the bonding end surface has an axis of the optical fiber from the bonding end surface. An optical waveguide device, wherein a groove extending in a direction is formed.