JP2001356228A - Optical waveguide device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a small size optical waveguide capable of being highly integrated. SOLUTION: The surface 11 of an element mounting area 4 and the surface 12 of a waveguide forming area 2 are adjacently provided on a substrate 1 by providing a difference in level in the boundary, and ends of cores 3a, 3b of an optical waveguide circuit which are formed in the waveguide forming area 2 are terminated in the end surface 13 of the difference in level of the boundary surface between the waveguide forming area 2 and the element mounting area 4 and are juxtaposed at an interval. A light receiving element 8 and a light emitting element 9 which are respectively and optically connected to the ends of these plural juxtaposed cores 3a, 3b are arranged on the element mounting area 4, and a parting part 30 which electrically and optically shields these light receiving element 8 and light emitting element 9 is provided. The parting part 30 is formed by a conductive metallic film 202 in a wall part 201 of a clad which forms the waveguide forming area 2 and surfaces which face the light receiving element 8 and the light emitting element 9.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical waveguide device for mounting an optically active element such as a light emitting / receiving element (light emitting element or light receiving element) or an electronic circuit element and performing optical communication or the like using these elements. The present invention relates to a waveguide device.

[0002]

2. Description of the Related Art Light-receiving and light-emitting elements and electronic circuit elements are used for optical communication. In recent years, the integration of these elements has been advanced, and accordingly, a device having these elements mounted on a substrate has been developed. Miniaturization is required.

As an example of the above-mentioned device, for example, as shown in FIG. 10A, a surface 11 of an element mounting area 4 (an element mounting surface) and a surface 1 of a waveguide forming area 2 (a surface) 1 are formed on a substrate 1.
There is an optical waveguide device in which an optical active element mounted in the element mounting area 4 and an optical waveguide circuit formed in the waveguide forming area 2 are integrated with each other so that a step is provided at the boundary between them. FIG. 2B shows a cross section taken along line KK ′ of FIG.

In the optical waveguide device shown in FIG.
A light receiving element (PD: photodiode) 8 and a light emitting element (L
D: laser diode) 9 is provided. The light receiving element 8 and the light emitting element 9 are arranged so as to be shifted from each other in the optical axis direction (the Z direction in the drawing), and a monitor PD 21 for monitoring the light emitting element 9 is provided near the light emitting element 9. Have been.

An insulating film 103a such as SiO ₂ is provided on the surface 11 of the element mounting area 4.
The electrode wiring patterns 5, 6, and 6 'are formed on the upper surface and the surface 12 of the waveguide forming region 2. One surface (lower surface) of the light receiving element 8, the light emitting element 9, and the monitor PD 21 is a solder 7 such as Sn / Au. Is connected to the electrode wiring pattern 5. Further, the opposite surfaces (upper surfaces) of the light receiving element 8, the light emitting element 9, and the monitor PD 21 are connected to the electrode wiring patterns 6, 6 'by a wire-shaped wiring member 10.

[0006] The waveguide forming region 2 has an insulating film 1 on a substrate 1.
The lower clad 104, the core 3, and the upper clad 105 are provided with a through hole 03 interposed therebetween. In the optical waveguide device shown in the figure, an optical waveguide circuit is formed having two cores 3 (3a, 3b), and one end face (left end face in the figure) of each of the cores 3a, 3b is an element. It is terminated at step end surfaces 13a and 13b at the boundary between the mounting region 4 and the waveguide forming region 2. The terminal surface of the core 3a faces the light receiving part of the light receiving element 8, and the terminal surface of the core 3b faces the light emitting part of the light emitting element 9.

In the above optical waveguide device, the core 3
The light propagating through a is received by the light receiving element 8, and the light emitted from the light emitting element 9 enters the core 3b and propagates.

In the above optical waveguide device, when the light receiving element 8 and the light emitting element 9 are arranged side by side without shifting the position in the optical axis direction, the light spreads in the gap between the elements 8, 9 and the waveguide forming region 2. The optical crosstalk gets worse,
In addition, electric crosstalk due to electric induction also worsens.
Therefore, in the conventional optical waveguide device, in order to prevent these problems, as described above, the light receiving element 8 and the light emitting element 9 are arranged so as to be shifted in the optical axis direction.

The above-mentioned problems of optical crosstalk and electric crosstalk can occur in the case where light-receiving elements are arranged side by side and in the case where light-emitting elements are arranged side by side. Also, when the light emitting elements are arranged side by side, as described above, the elements are arranged while being shifted in the optical axis direction.

[0010]

However, in the above-described optical waveguide device, the light emitting and receiving elements are arranged with the positions of the light emitting and receiving elements shifted in the optical axis direction. However, the length of the optical waveguide device becomes longer in the optical axis direction, making it difficult to reduce the size of the optical waveguide device, and it is also difficult to achieve high integration of the optical active element and the optical waveguide circuit. Further, the optical waveguide device has a problem that the optical crosstalk is deteriorated as described above, and the electric crosstalk due to the electric induction is also deteriorated.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned conventional problems, and an object of the present invention is to provide a compact, optical, and electrical device capable of highly integrating an optically active element or an optical waveguide circuit. It is to provide an optical waveguide device with good crosstalk.

[0012]

In order to achieve the above-mentioned object, the present invention has the following structure to solve the problem. That is, in the first invention, the surface of the element mounting region and the surface of the waveguide forming region are adjacent to each other with a step formed on the boundary between the substrate and the interface between the waveguide forming region and the element mounting region. A plurality of ends of the optical waveguide circuit formed in the waveguide forming region are terminated and arranged side by side at intervals on the step end surface of Each of the optically active elements to be optically connected is disposed on the element mounting area via a partition for electrically and optically shielding the optically active elements from each other.

According to a second aspect of the present invention, in addition to the configuration of the first aspect, the waveguide forming region has a clad and a core, and the core forms an optical waveguide circuit. It is a means for solving the problem with a configuration in which a conductive material is provided on a surface facing the optically active element in the partition portion, which is formed integrally with the clad.

Further, a third aspect of the present invention, in addition to the configuration of the second aspect, has a problem in that the partition has a core integrally formed with an optical waveguide circuit in a waveguide forming region. It is a means to solve.

In the present invention having the above-described structure, a plurality of end faces of the optical waveguide circuit terminated on the stepped end face at the boundary between the waveguide forming area and the element mounting area are arranged side by side with an interval therebetween. Because the optically active elements that are optically connected to the optical waveguide circuit ends arranged side by side are arranged on the element mounting area via the partition portion that electrically and optically shields the optically active elements, Unlike the related art, it is not necessary to displace the optical active elements in the optical axis direction. For example, the optical active elements can be arranged side by side so as to face the boundary surface.

Therefore, in the present invention, the length of the optical waveguide device in the direction of the optical axis of the optical active device can be made shorter than that of the conventional optical waveguide device, and the optical active device and the optical waveguide circuit are compact and highly integrated. It is possible to provide an optical waveguide device that can be manufactured.

[0017]

Embodiments of the present invention will be described below with reference to the drawings. In the description of the present embodiment, the same reference numerals are given to the same parts as those in the conventional example, and the overlapping description will be omitted. FIG. 1A is a perspective view showing a first embodiment of an optical waveguide device according to the present invention. Also, (b) of FIG.
-K 'sectional view is shown.

As shown in these figures, the present embodiment is configured substantially in the same manner as the conventional example, and the present embodiment is different from the conventional example in that the waveguide forming region 2 and the element The stepped end surface 13 at the boundary surface with the mounting area 4 is a straight surface having no step, and the stepped end surface 13 has cores 3a and 3b.
Of the cores 3
The light receiving element 8 and the light emitting element 9 which are optically connected to the ends of the elements a and 3b, respectively, are arranged on the element mounting area 4 via a partition 30 for electrically and optically shielding the elements 8 and 9 from each other. It is.

In the present embodiment, the partition portion 30 communicates with the waveguide forming region 2, and by providing the partition portion 30, the light receiving element 8 and the light emitting element 9 can be electrically and optically shielded. These light receiving element 8 and light emitting element 9 are Z
They are arranged side by side without shifting the position in the direction.

The partitioning section 30 has a wall 201 integrally formed with the cladding (upper cladding 105 and lower cladding 104) forming the waveguide forming region 2, and the thickness of the wall 201 is 5 μm. And A conductive metal film 202 as a conductive material is provided on a side of the partition 30 facing the light receiving element 8 and the light emitting element 9.
The conductive metal film 202 is formed of Ti / Ni / Au and has a thickness of 0.1 / 0.1 / 0.5 (each unit is μm).

The present embodiment is configured as described above. Hereinafter, a method of manufacturing the optical waveguide device of the present embodiment will be described. First, as shown in FIG.
A substrate 1 made of silicon or the like is prepared, and a step 102 is formed by processing the front side of the substrate 1 as shown in FIG.
Next, as shown in FIG. 1C, an insulating film 103 is formed on the surface side of the substrate 1 by a known flame hydrolysis deposition method.
It is made into a transparent glass, and then, as shown in FIG.
The surface of the insulating film 103 is polished so as to be flat to the extent that the surface of the substrate 1 is exposed (not necessarily exposed).

Next, as shown in FIG. 1E, a film of the lower clad 104 is formed on the upper side of the insulating film 103 by a flame hydrolysis deposition method, and vitrified. The lower clad 104 can be optically coupled by aligning the light receiving / emitting portion of the light receiving element 8 or the light emitting element 9 mounted on the element mounting area 4 with the core 3 of the waveguide forming area 2 in the height direction. It is formed to an appropriate thickness. Next, a core film 106 is formed on the upper side of the lower clad 104 by a flame hydrolysis deposition method, as shown in FIG.

Next, as shown in FIG. 3A, the core is formed by well-known photolithography and RIE (reactive ion etching) so that a target optical waveguide circuit is formed by the core film 106. The core 3 is formed by patterning and vitrification. (B) of the same figure shows a cross-sectional view taken along the line KK 'of (a) of the same figure, and (c) of the same figure shows a side view.

Next, as shown in FIGS. 3 (d), 3 (e) and 3 (f), a film of the upper clad 105 is formed on the upper side of the core 3 by a flame hydrolysis deposition method, and the vitrification is performed. I do.
FIG. 3E shows a cross-sectional view taken along the line KK ′ in FIG. 3D, and FIG. 3F shows a side view.

Next, as shown in FIGS. 4A and 4B, an unnecessary glass film is removed by dry etching such as RIE to form an element mounting region 4. FIG. 2B is a sectional view taken along line KK ′ of FIG. At the time of this dry etching, the wall portion 2 for forming the partition portion 30 is formed.
01 (formed by the lower cladding 104 and the upper cladding 105) is left without being removed, so that in this embodiment, the wall 201 of the partition 30 is integrated with the cladding of the waveguide forming region 2. Is formed.

Next, as shown in (c) and (d) of the drawing, the light-emitting element 9 and the like or the electrode wiring pattern 5 on the surface 11 of the element mounting area 4 are to be insulated from the substrate 1. Forms an insulating film 103a such as SiO _{2 as} necessary. The method of forming the insulating film 103a is based on well-known photolithography, sputtering film formation, and the like. (D) of the figure is a side view.

Next, as shown in FIGS. 5A and 5B, a conductive metal film 202 is formed on the surface of the wall 201 facing the light receiving element 9 and the light emitting element 8 by Ti / Ni. / Au to form the partition portion 30, and the electrode wiring patterns 5, 6, 6 'and the marker 205 are formed by well-known photolithography and vapor deposition. The marker 205 is a mark for position recognition when mounting a light receiving element 8, a light emitting element 9, a monitoring PD 21, and an optical element such as an optical fiber or an optical filter.
Ti / Ni / Au can be applied as the material of 6 ′ and the marker 205. 5B is a sectional view taken along line KK ′ of FIG. 5A, and the insulating film 103a is omitted in FIG.

Next, as shown in FIGS. 3C and 3D, the light receiving element 8, the light emitting element 9, and the monitor PD 21 are fixed by the solder 7 provided on the electrode pattern 5.
The electrode wiring patterns 5 and 6 are formed by the wiring material 10 of the u wire.
And the light receiving element 8, the light emitting element 9, and the monitoring PD 21 are connected. FIG. 4D is a sectional view taken along line KK ′ of FIG. 4C, and the solder 7 is formed by well-known photolithography and vapor deposition.

In the present embodiment, the partition is formed between the light receiving element 8 and the light emitting element 9 by electrically and optically shielding the elements 8 and 9 from each other as described above. By providing the portion 30, both electrical crosstalk and optical crosstalk between the light receiving element 8 and the light emitting element 9 can be suppressed. Further, the light receiving element 8 and the light emitting element 9 can be arranged side by side without shifting the position in the Z direction. Therefore, the length in the Z direction can be shortened as compared with the conventional optical waveguide device, and the optical waveguide device can be reduced in size, and both electrical crosstalk and optical crosstalk can be suppressed.

Further, according to the present embodiment, the partition 3
Numeral 0 is formed integrally with the cladding of the waveguide forming region 2, and the partitioning portion 30 forms a wall portion 201 in an operation of removing an unnecessary portion of the waveguide forming region 2 by RIE or the like, and forms the wall portion 201 on the surface thereof. It can be easily formed by forming the conductive metal film 202. Therefore, the optical waveguide device of the present embodiment can be an optical waveguide device that is easy to manufacture.

FIG. 6 is a perspective view showing a second embodiment of the optical waveguide device according to the present invention. Book second
The second embodiment is substantially the same as the first embodiment. The second embodiment is different from the first embodiment in that the partition 30 is integrated with the optical waveguide circuit. Has the core 3 (3c) formed on the substrate.
In the second embodiment, the conductive metal film 202 provided on the partition portion 30 is made of a material (Cr / Ti / Pt / Au) having a high reflectance with respect to the wavelength of light propagating through the core 3c.
Etc.).

The second embodiment is manufactured in the same manner as the first embodiment. However, in the second embodiment, when the optical waveguide circuit is formed, as shown in FIG. ,
The cores 3a, 3b, and 3c are formed, and the wall 201 is formed such that the wall 201 of the partition 30 has the core 3c when the glass is removed by RIE, as shown in FIG.

The present embodiment is configured as described above, and the second embodiment can also provide the same effects as those of the first embodiment.

According to the second embodiment, on the side of the partition 30 facing the light receiving element 8 and the light emitting element 9, the conductive material having a high reflectance with respect to the wavelength of the light propagating through the core 3c is provided. Since the metal film 202 is provided, the core 3c formed in the partition portion 30 is optically and electrically shielded, so that optical crosstalk between the light receiving element 8 and the light emitting element 9 is deteriorated and the electric In addition to suppressing the deterioration of the talk, the deterioration of the optical crosstalk of the core 3c with the cores 3a and 3b can be suppressed, and the optical waveguide device has a higher degree of freedom (higher integration degree of the optical waveguide circuit). It can be.

The present invention is not limited to the above-described embodiment, but can adopt various embodiments. For example, in each of the above-described embodiments, the partition portion 30 includes the cladding or the wall portion 201 having the cladding and the core 3 c and the conductive metal film 20.
2, but as shown in FIG.
Other optical components such as the optical filter 14 may be provided on the optical disk. In the drawing, reference numeral 15 denotes an optical filter insertion groove.

The material for forming the conductive metal film 202 provided in the partition portion 30 is not particularly limited, and is appropriately set. The conductive material such as the conductive metal film 202 transmits light. The worse the performance, the more the optical crosstalk of the optically active elements such as the light receiving element 8 and the light emitting element 9 can be suppressed.

Further, in each of the above embodiments, the partition 3
0 is formed integrally with the cladding of the waveguide forming region 2 or integrally with the core and the cladding of the waveguide forming region 2. For example, as shown in FIG.
Is formed separately from the waveguide forming region 2 by forming a clad or a clad and a core on a substrate 19 for a partition, and forming the partition 30 by fusion bonding of an adhesive or glass, soldering of metal, or the like. And may be integrated with the waveguide forming region 2.

When the partition 30 is integrated with the waveguide forming region 2 by metal soldering, for example, a line-shaped metal film 17 is formed at the junction with the partition 30 on the waveguide forming region 2 side. Then, a line-shaped metal film 18 is also formed on the partition 30 side, and when the partition 30 and the waveguide forming region 2 are joined so that the metal films 17 and 18 are aligned with each other, the partition 30 and the waveguide forming region 2 are connected. The positioning of the wave path forming region 2 can be performed easily and well.

Further, in each of the above embodiments, the glass film of the clad layer and the core layer is formed by the flame hydrolysis deposition method. However, the film formation method of these glasses is not particularly limited, and may be appropriately set. For example, CVD
The glass may be formed by a (Chemical Vapor Deposition) method, a sputtering method, or the like.

[0040]

According to the present invention, a plurality of end faces of an optical waveguide circuit terminated on a stepped end face at a boundary between a waveguide forming area and an element mounting area are juxtaposed with an interval therebetween. Conventionally, the optically active elements that are optically connected to the end portions of the optical waveguide circuits arranged side by side are provided on the element mounting substrate via partitions that electrically and optically shield the optically active elements. It is not necessary to displace the optical active elements in the optical axis direction as in the above, for example, the optical active elements can be arranged side by side so as to face the boundary surface, and the length of the optical waveguide device in the optical axis direction of the optical active element can be increased. Therefore, an optical waveguide device which is shorter than the conventional example and which is compact and capable of highly integrating an optical waveguide circuit can be obtained.

According to the second aspect of the present invention, the partition can be easily formed by forming the partition integrally with the clad of the waveguide forming region, and the conductive portion is provided on the surface facing the optically active element. By providing the material, the optically active elements can be accurately and electrically shielded from each other by the partition portion, and can be optically shielded.

Further, according to the third aspect of the present invention, since the partition portion has a core, the degree of freedom of the optical waveguide circuit in the waveguide forming region is improved, and the integration of the optical waveguide circuit is further increased. Can be performed.

[Brief description of the drawings]

FIG. 1 is a perspective view of a configuration of a first embodiment of an optical waveguide device according to the present invention, and FIG. 1A is a sectional view taken along line KK ′ of FIG.

FIG. 2 is an explanatory view showing a manufacturing process of the embodiment by a side view.

FIG. 3 is an explanatory view showing a manufacturing process subsequent to FIG. 2 of the above-described embodiment by perspective views (a), (d), cross-sectional views (b), (e), side views (c), and (f). It is.

4A to 4C are explanatory views showing a manufacturing process subsequent to FIG. 3 of the above embodiment with a perspective view (a), (c), a sectional view (b), and a side view (d).

FIG. 5 is an explanatory view showing a manufacturing process subsequent to FIG. 4 of the above-described embodiment by perspective views (a), (c), sectional views (b), and (d).

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

FIGS. 7A to 7C are explanatory views each showing one step in the manufacture of the second embodiment example in a perspective view.

FIG. 8 is an explanatory diagram showing a configuration near a partition in another embodiment of the optical waveguide device according to the present invention.

FIG. 9 is an explanatory view showing a manufacturing process example of still another embodiment of the optical waveguide device according to the present invention.

FIG. 10 is a perspective view of a conventional optical waveguide device,
It is explanatory drawing shown by KK 'sectional drawing of (a).

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Substrate 2 Waveguide formation area 3, 3a, 3b, 3c Core 4 Element mounting area 8 Light receiving element 9 Light emitting element 11 Surface (element mounting surface) 12 surface (surface) 13 Step end surface 30 Partition part 201 Wall part 202 Conductive metal film

Claims (3)

[Claims] An end face of a boundary surface between the waveguide formation region and the element mounting region is provided so that a surface of the element mounting region and a surface of the waveguide formation region are adjacent to each other with a step provided on a boundary thereof. A plurality of ends of the optical waveguide circuit formed in the waveguide forming region are terminated and arranged side by side with an interval therebetween, and an optical connection is made to each of the plurality of arranged optical waveguide circuit ends. An optical waveguide device, wherein the optically active element to be formed is disposed on the element mounting area via a partition part for electrically and optically shielding the optically active elements. 2. The waveguide forming region has a clad and a core, an optical waveguide circuit is formed by the core, and a partition is formed integrally with the clad. The optical waveguide device according to claim 1, wherein a conductive material is provided on a surface facing the active element. 3. The optical waveguide device according to claim 2, wherein the partition has a core formed integrally with the optical waveguide circuit in the waveguide forming region.