JPH05188230A - Waveguide type optical component with filter - Google Patents

Abstract

(57) [Summary] [Structure] At least two directional coupler type optical couplers 1, 2, 3 and 4 arranged in parallel to each other, and a plurality of incident side optical waveguides connected to the directional coupler type couplers. The waveguide P ₁ and the plurality of outgoing side optical waveguides P ₂ are both arranged on one substrate 5, and the plurality of incident side optical waveguides P ₁ are arranged.
And each of the plurality of emission side optical waveguides P ₂ are
The first incident side optical waveguide group G ₁ , the second incident side optical waveguide group G _2, the first outgoing side optical waveguide group G ₃ and the second outgoing side optical waveguide are arranged so that the optical waveguides in each group are adjacent to each other. Group G ₄
And each of the optical waveguide groups G ₁ , G ₂ , G ₃ ,
A waveguide type optical component with a filter in which any one of G ₄ is provided with one filter 7 across a plurality of optical waveguides constituting the optical waveguide group in common. [Effect] Since the composite functions are integrated on one substrate, the overall size is small. The extra length storage space of the optical fiber at the time of connecting each optical component can be made zero.

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 with a filter, and more particularly to a compact waveguide type optical component for multiplexing and demultiplexing light in an optical communication system.

[0002]

2. Description of the Related Art When light is guided through an optical fiber transmission line, a fiber type filter component as shown in FIG. 2 has already been developed for the purpose of changing the optical characteristics of the optical waveguide according to the wavelength of the guided light. ing. In this filter component, two optical fibers 8 and 8 are arranged in parallel on a substrate 5, and one slit groove 6 is formed by cutting each of these optical fibers 8 and 8. 6 has a structure in which one dielectric multilayer filter 7 having a thickness of, for example, about 20 μm is embedded and the filter 7 is optically connected to optical fibers 8 and 8.

Further, a waveguide optical component as shown in FIG. 3 has already been manufactured for the purpose of multiplexing / demultiplexing light. In this optical component, a plurality of (four in the figure) directional coupler type couplers 1, 2, 3 and 4 are arranged in parallel at a predetermined interval on a single substrate 5 to form an overall optical component. And optical ports 1a and 1b; optical ports 2a and 1b at one end of each of these directional coupler type couplers 1, 2, 3 and 4, respectively.
2b; optical ports 3a, 3b; optical ports 4a, 4b; are connected to form an incident side optical port of each directional coupler type coupler, and optical ports 1c, 1d; optical ports are provided at the other ends. 2c, 2d; optical port 3c, 3d; optical port 4
c, 4d; are connected to each other to form an emission side optical port of each directional coupler type coupler.

By the way, when the optical component shown in FIG. 2 and the optical component shown in FIG. 3 are combined to realize two functions of changing the transmission characteristic and multiplexing and demultiplexing of light, FIG. As described above, by using the multi-core optical tape fiber 13 for connecting the above-mentioned fiber bar type filter component 10 and the above-mentioned waveguide optical component 11 in the storage box 9 to, for example, the multi-core connectors 12 and 12, This fiber is fused part 1
At 4, it is necessary to make an optical connection by, for example, fusion splicing.

[0005]

However, in the above-mentioned connection, a large space is required for accommodating the extra length of the multi-core optical tape fiber 13 in the fusion splicing portion 14. Therefore, even if the optical waveguides are integrated to reduce the overall size of each optical component like the above-described waveguide optical component 11, it is not possible to take advantage of the miniaturization.

The present invention solves the above-mentioned problems, integrates the filter function and the optical multiplexing / demultiplexing function, and reduces the extra length storage space of the optical fiber in the connection of both optical components, which has been conventionally required, to zero. It is an object of the present invention to provide a single waveguide type optical component with a filter, which is extremely small and has multiple functions.

[0007]

In order to achieve the above object, in the present invention, at least two waveguide type optical functional elements and a plurality of incident sides connected to the waveguide type optical functional elements are provided. An optical port and a plurality of emission side optical ports are both arranged on a single substrate, and the plurality of incidence side optical ports and the plurality of emission side optical ports are respectively provided as a first incidence side optical port. Group and a second incident side optical port group, and a first emission side optical port group and a second emission side optical port group, and the optical port group is formed in any of the optical port groups. Provided is a waveguide type optical component with a filter, characterized in that one filter is arranged across a plurality of optical ports in common, and specifically, at least two optical components arranged in parallel with each other are provided. Directional coupler type optical coupler, and before A plurality of incident side optical waveguides and a plurality of emission side optical waveguides connected to the directional coupler type optical coupler are both disposed on a single substrate, and the plurality of incident side optical waveguides and the plurality of optical waveguides are disposed. Each of the output side optical waveguide of, so that the optical waveguide in each group is adjacent to each other,
The first incident-side optical waveguide group and the second incident-side optical waveguide group, and the first outgoing-side optical waveguide group and the second outgoing-side optical waveguide group are classified into one of the optical waveguide groups. Commonly traverses multiple optical waveguides that make up the optical waveguide group 1
There is provided a waveguide part with a filter, characterized in that a plurality of filters are arranged.

The optical component of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a schematic plan pattern diagram when the waveguide type optical functional element is a directional coupler type coupler.
In this optical component, first, directional coupler type couplers 1, 2, 3, 4 are arranged in parallel with each other on a substrate 5 made of Si. Here, it is assumed that one end 5a of the substrate 5 is the incident side and the other end 5b is the emitting side.

Optical ports 1a and 1b; optical ports 2a and 2b; optical ports 3a and 3b; optical ports 4a and 1b are respectively provided at one ends of the directional coupler type couplers 1, 2, 3 and 4.
4b; are connected to form an incident-side optical port P _{1 of} each directional coupler type coupler, and optical ports are provided at the other ends of the directional coupler type couplers 1, 2, 3, and 4, respectively. 1c, 1d; optical ports 2c, 2d; optical ports 3c, 3
d; optical ports 4c and 4d; are connected to each other to form an emission side optical port P _{2 of} each directional coupler type coupler.

In this case, at the incident side optical port P ₁ , optical ports 1a and 1b connected to the directional coupler type coupler 1 are provided.
Optical ports 2a, 2 connected to the directional coupler type coupler 2
b, Optical port 3 connected to directional coupler type coupler 3
a, 3b, and the optical ports 4a, 4b connected to the directional coupler type coupler 4, the first incident side optical port group G ₁ and the optical ports 1b, 2b, which are optical ports 1a, 2a, 3a, 4a.
The optical ports are classified into the second incident side optical port group G ₂ composed of 3b and 4b, and the optical ports in each of the optical port groups G ₁ and G ₂ are arranged on the substrate 5 in a pattern structure adjacent to each other.

Similarly, at the output side optical port P ₂ , optical ports 1c and 1d connected to the directional coupler type coupler 1, optical ports 2c and 2d connected to the directional coupler type coupler 2,
Optical ports 3c and 3 connected to the directional coupler type coupler 3
d, Optical port 4 connected to directional coupler type coupler 4
c and 4d are the first emission side optical port group G ₃ and the optical ports 1d, 2d and 3 which are composed of the optical ports 1c, 2c, 3c and 4c.
The optical ports are classified into the second emission side optical port group G ₄ composed of d and 4 d, and the optical ports in each of the optical port groups G ₃ and G ₄ are arranged on the substrate 5 in a pattern structure adjacent to each other.

Therefore, the optical ports 1a, 2a, 3a, 4a forming the optical port group G ₁ and the optical ports 1b, 2b, 3b, 4b forming the optical port group G ₂ cross each other, and Each optical port 1c constituting the port group G ₃
2c, 3c, 4c and the optical ports 1d, 2d, 3d, 4d forming the optical port group G ₄ cross each other.

Generally, when the optical ports are crossed,
Light leakage to other optical ports intersecting with the loss at the intersection occurs. In order to eliminate such an inconvenience, the above-mentioned crossing angle of each optical port is set to 10 ° or more in full angle. This is because with such an intersection angle, the loss and light leakage can be suppressed to a level at which there is no practical problem.

A slit groove 6 is formed in the optical port group G ₁ so as to commonly traverse the respective optical ports 1a, 2a, 3a, 4a constituting the optical port group G ₁ , and a predetermined filter 7 is inserted and fixed in the slit groove 6. And is connected to the optical ports 1a, 2a, 3a, 4a. Therefore, one filter 7 functions as a common filter for each optical port 1a, 2a, 3a, 4a.

The location of the filter 7 is not limited to the above-mentioned optical port group G ₁ , but the optical port group G ₂ ,
It may be either G ₃ or G ₄ . Also, filter 7
For example, in addition to the commonly used dielectric multilayer filter, a metal film, an optical crystal or the like can be used. The parallel arrangement of the directional coupler-type couplers, the pattern structure of the optical port, and the slit groove are, for example, a quartz slab having a cladding and a core formed by a conventional flame deposition method, and a photolithography technique and an etching technique. It can be formed by applying.

[0016]

EXAMPLE The optical component shown in FIG. 1 was manufactured as follows. First, a Si substrate 5 having a thickness of 1000 μm is doped with SiO ₂ (lower clad) having a thickness of 25 μm and TiO ₂ having a thickness of 8 μm by a flame deposition method so that its refractive index is higher by 0.3% than that of the lower clad. A SiO ₂ layer (core layer) was sequentially laminated to obtain a substrate having a two-layer structure.

Then, the optical port pattern shown in FIG. 1 is transferred to the above-mentioned two-layer structure substrate by photolithography, and is further etched using α-Si as a mask so that the side surface of the substrate 5 perpendicular to the horizontal plane is exposed. The formed core was formed into a ridge shape. The cross-sectional shape of this core was a square having a width of 8 μm and a height of 8 μm, and the lower clad other than the part where the core was formed was completely exposed.

Thereafter, an upper clad made of the same SiO ₂ as the lower clad and having a thickness of 25 μm was formed by the same flame deposition method. As described above, in the structure in which the core is embedded in the clad, the connection loss can be suppressed to a small value when the single mode optical fiber is connected to the core which is the waveguide.

Next, the filter groove pattern is transferred again by photolithography to the upper clad where the optical port group G ₁ consisting of the cores 1a, 2a, 3a, 4a is buried, and α-Si is masked. As a result of dry etching, length 1800μm, width 30μ
A vertical filter groove 6 having a depth of 50 μm was formed. After that, a dielectric multilayer film with a thickness of 2 on a 1.5 mm square quartz substrate.
The filter 7 was prepared by vapor deposition of 8 μm, and the transmittance of light having a wavelength of 1.55 μm was 0%, and the transmittance was 100% at a wavelength of 1.3 μm. The filter 7 was inserted and connected to each core with an optical adhesive. ..

In forming the filter groove 6, the four cores 1a, 2a, 3a, which have already been formed,
In order to match the position and the angle to 4a with a certain degree of accuracy, alignment was performed by aligning with the filter groove pattern on the basis of the alignment pattern formed simultaneously with the cores 1a, 2a, 3a and 4a. Further, in order to suppress return light due to minute reflection at the filter insertion portion, the filter groove 6 is formed so that the crossing angle between each core 1a, 2a, 3a, 4a and the filter 7 is 9 °.

This optical component has a function of controlling the transmission characteristics depending on the wavelength of light realized by the filter 7 and a function of multiplexing and demultiplexing light realized by the directional coupler type couplers 1, 2, 3, and 4. Since it is integrated on one substrate 5,
An extra length storage space required for connecting an optical component having a single function with an optical fiber as in the conventional art is unnecessary, and the size is reduced as a whole.

The optical component of the present invention is not limited to the structure shown in FIG. 1, and for example, a Mach-Zehnder interferometer to which a directional coupler is applied or a plurality of Y branch waveguides are connected in series. It can also be applied to optical splitters and the like. Further, the optical port is not limited to the one in which the scene-gle mode propagates, but may be of the type in which multi-mode propagates.

When the configuration of the present invention is applied to the former Mach-Zehnder interferometer, two directional couplers are connected in series and the length of two waveguides connecting them is changed by, for example, about 0.6 μm. By configuring a single Mach-Zehnder interferometer by controlling the difference between the coupling ratio of the directional coupler and the length of the waveguide connecting the two, for example, a branching ratio at a wavelength of 1.2 to 1.6 μm is 80: A two-input / two-output optical coupler such as 20 is constructed, and the directional coupler coupler 1 in FIG.
A structure in which 2, 3 and 4 are replaced by the 2-input / 2-output optical coupler may be used.

[0024]

As is apparent from the above description, the optical component with a filter according to the present invention has the function of controlling the transmission characteristics according to the wavelength of light realized by the filter and the light realized by the directional coupler type coupler. Since the multiplexing and demultiplexing function of is integrated on one board, the extra length storage space required when connecting optical components with a single function with an optical fiber is no longer required. , Downsizing as a whole.

[Brief description of drawings]

FIG. 1 is a schematic view showing a plane pattern of an optical component of the present invention.

FIG. 2 is a schematic plan view showing a conventional fiber type filter component.

FIG. 3 is a schematic plan view showing a conventional integrated waveguide.

FIG. 4 is a schematic view showing a plane pattern of a conventional structure in the case where optical components are connected to each other by optical fibers.

[Explanation of symbols]

1 directional coupler type coupler 1a, 1b, 1c, 1d optical port of directional coupler type coupler 1 2 directional coupler type coupler 2a, 2b, 2c, 2d optical port of directional coupler type coupler 2 3 direction Directional coupler type couplers 3a, 3b, 3c, 3d optical port 4 of directional coupler type coupler 3 directional coupler type couplers 4a, 4b, 4c, 4d optical port of directional coupler type coupler 4 substrate 5a, 5b End part of substrate 6 Slit groove 7 Filter 8 Optical fiber 9 Storage box 10 Fiber type filter component 11 Waveguide optical component 12 Multi-core connector 13 Multi-core optical tape fiber 14 Fusion part G ₁ First incident side optical port group G ₂ Second incident side optical port group G ₃ 1st outgoing side optical port group G ₄ 2nd outgoing side optical port group P ₁ Incident side optical port P ₂ Output side optical port

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Kuji Yanagawa 2-6-1, Marunouchi, Chiyoda-ku, Tokyo Furukawa Electric Co., Ltd. (72) Innovator Nobuo Tomita 1-6, Uchisaiwaicho, Chiyoda-ku, Tokyo Nihon Telegraph and Telephone Corporation (72) Inventor, Miyazaki, 5-23-8 Nishigotanda, Shinagawa-ku, Tokyo

Claims (2)

[Claims] 1. At least two waveguide type optical functional elements,
And a plurality of incident side optical ports and a plurality of emitting side optical ports connected to the waveguide type optical functional element are all arranged on one substrate, and the plurality of incident side optical ports and the plurality of incident side optical ports are arranged. The output side optical ports of the book are classified into a first input side optical port group and a second input side optical port group, and a first output side optical port group and a second output side optical port group, respectively, and
In one of the optical port groups, a single filter is arranged so as to commonly traverse a plurality of optical ports forming the optical port group. parts. 2. At least two directional coupler type optical couplers arranged in parallel to each other, and a plurality of incident side optical waveguides and a plurality of output side optical waveguides connected to the directional coupler type optical couplers. Both are arranged on a single substrate, and the plurality of incident side optical waveguides and the plurality of outgoing side optical waveguides are respectively arranged so that the optical waveguides in each group are adjacent to each other. Side optical waveguide group and a second incident side optical waveguide group, and a first emission side optical waveguide group and a second emission side optical waveguide group, and any one of the optical waveguide groups, the optical waveguide group 1. A waveguide component with a filter, wherein one filter is arranged so as to commonly traverse a plurality of optical waveguides constituting the above.