JP2001264574A - V grooved substrate for optical fiber - Google Patents

Abstract

PROBLEM TO BE SOLVED: To miniaturize an optical waveguide element by reducing the number of connecting processes and connecting optical waveguide cores situated within different flat surfaces to optical fibers by one part with high density. SOLUTION: Plural V grooves 11, 12, 13 for setting up optical fibers 21, 22, 23 are provided in positions of plural different heights in a V grooved substrate 1 for optical fibers.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a simple and compact optical integrated circuit or various optical devices and optical fibers used in the fields of general optics and micro-optics, and in the fields of optical communication and optical information processing. V for optical fiber to connect
It relates to a groove substrate.

[0002]

2. Description of the Related Art In the field of optical waveguides used in the fields of optical communication and optical information processing, studies for integration, miniaturization, high functionality, and low cost have been actively conducted in recent years. Actually, silica-based optical waveguide devices have been put to practical use in a part of the optical communication field.

[0003] Such an optical waveguide device generally comprises, like an optical fiber, a core portion through which light is optically guided and a clad portion covering the core portion.

[0004] Until now, in many cases, an optical waveguide element has an optical waveguide core formed on the same plane parallel to the substrate surface. Some have also proposed optical waveguide devices with higher-density optical wiring. Among such proposals, there is an attempt to form an optical waveguide core on a different plane parallel to the substrate surface and to couple the upper and lower optical paths with a directional coupler or the like.

Since an optical waveguide element alone cannot be connected to an optical fiber or other optical components, an optical waveguide element usually has
Only when the optical fiber is connected via the connecting component and the optical fiber connector is connected to the tip of the optical fiber,
Can be connected to other optical components and optical fibers. Therefore, the connection between the optical waveguide element and the optical fiber is important.

[0006] Since the light has a strong linearity, the core of the optical waveguide element and the core of the optical fiber are connected to the optical fiber by one.
It is necessary to perform alignment with an accuracy of about ~ several microns. The use of a V-groove substrate having a V-groove having a V-shaped cross section enables this highly accurate alignment. Usually, a V-groove is formed on the same plane, and an optical fiber is arranged in the V-groove, thereby enabling high-accuracy alignment.

However, when a plurality of optical waveguide cores are arranged on different planes in the thickness direction of the substrate, a V-groove substrate on which optical fibers are arranged is prepared for each height and connected. It was necessary.

The problems of the prior art will be outlined using the optical waveguide type position detecting optical sensor shown in FIG. FIG. 7A is a schematic view of the entire optical waveguide type position detection optical sensor, and FIG. 7B is an enlarged front view of a portion A in FIG.

Reference numeral 72 denotes an optical waveguide core, 73 denotes an optical waveguide clad, 71 denotes a substrate, 70 denotes an optical waveguide element, 74 denotes an optical fiber connected to the optical waveguide core 72, and 75 denotes a connection provided at the tip of the optical fiber 74. An optical connector 66 is an optical waveguide connecting part for aligning and connecting the optical waveguide core 72 and the optical fiber 74 with high precision.

There are five optical waveguides 72, and an optical waveguide composed of the optical waveguide core 72 and the optical waveguide clad 73 is formed on a substrate 71. Optical waveguide core 72
Are arranged in two different planes in three different planes parallel to the substrate 71, respectively. As shown in FIG. 7B, a total of five optical waveguide cores 72 are arranged close to each other on the light detection side. Further, in order to independently detect the light incident on each optical waveguide core 72, each optical waveguide core 72 needs to be connected to five different optical fibers 74. Therefore, on the side connected to the optical fiber 74, the optical waveguide core 72
Are arranged at appropriate intervals apart from each other as compared to the light detection side. Therefore, the optical waveguide cores 72 other than the central optical waveguide core 72 have a curved portion as shown in FIG.

In the connection between the optical waveguide core 72 and the optical fiber 74, the center of the optical waveguide core 72 and the center of the core of the optical fiber 74 are aligned with a single mode optical fiber with an accuracy of 1 micron or less and a core diameter of 50 microns. Even in a multi-mode optical waveguide, it is necessary to perform alignment with high accuracy of 5 microns or less. Therefore, the optical waveguide connecting component 66
It is necessary to fix the optical fiber 74 with high accuracy, and a substrate on which a V-groove is formed is usually used as the substrate of the optical waveguide connecting component 66.

FIG. 6 is a sectional view showing a conventional optical waveguide connecting component using a V-groove substrate for connecting an optical waveguide core and an optical fiber.

Reference numeral 62 denotes a V-shaped V-shaped cross section, 61 denotes a V-groove substrate having the V-shaped groove 62 formed thereon, 63 denotes an optical fiber having a circular cross-section disposed in the V-groove 62, 67 denotes an upper cover, and 66 denotes a light guide. Wave path connecting parts.

That is, an optical fiber 63 is provided in each V-groove 62.
And fixed with the upper lid 67 using an adhesive or the like. This end face is flattened by polishing, and connected to the end face of the optical waveguide with an adhesive or the like. The V-groove 62 is usually formed at a constant depth in order to maintain positional accuracy in the height direction.

Therefore, conventionally, a large number of optical fibers 6
When connecting a plurality of V-grooves 62 at an arbitrary position in the same plane parallel to the surface of the V-groove substrate 61,
A plurality of V grooves 62 may be formed in one V groove substrate 61.

[0016]

However, as shown in FIG. 7, when the optical waveguide cores 72 are present in different planes in the thickness direction of the substrate 71, the V-groove substrates shown in FIG. It was necessary to produce an optical waveguide connecting component 66 having 61.

That is, in the optical waveguide type position detecting optical sensor of FIG. 7, since the optical waveguide core 72 exists in three planes different from the surface of the substrate 71, three optical waveguide connecting parts 66 are provided.
Is required.

Also, if the optical waveguide core 72 having a small curvature radius is provided in the optical waveguide, the optical waveguide loss of the light due to the bend increases, and thus the optical waveguide core 72 having the bend. Then, it is necessary to increase the radius of curvature to some extent. Therefore, if the optical waveguide core 72 on the optical fiber connection side is disposed apart, not only the width of the optical waveguide element 70 but also the length of the optical waveguide element 70 needs to be increased. Wave loss also increases. A typical example is 2cm long
The optical waveguide element 70 of the order is obtained.

Further, as described above, when three optical waveguide connecting parts 66 are required, not only the number of parts increases, but also the individual optical waveguide connecting parts 66 with the optical fibers 74 attached to the optical waveguide core 72. In order to make the connection, the distance between the optical fibers 74 between the different optical waveguide connecting parts 66 must be increased to some extent, which makes it difficult to mount the optical fibers at high density.

A first problem to be solved by the present invention is as follows.
An object of the present invention is to reduce the number of connection steps by connecting a plurality of optical waveguide cores in different planes with a single optical waveguide connecting component.

A second problem to be solved by the present invention is as follows.
An object of the present invention is to reduce the size of an optical waveguide element by connecting an optical waveguide core and an optical fiber of an optical waveguide connecting component in different planes at a high density.

[0022]

In order to solve the above-mentioned problems, the present invention relates to an optical fiber V-groove substrate provided with an optical fiber installation V-groove, wherein a plurality of different heights in a thickness direction of the substrate are provided. The V-groove is provided at the position of the V-shape.

Further, the present invention is characterized in that a plurality of V-grooves having different depths are provided on an optical fiber V-groove substrate provided with V-grooves for installing optical fibers.

The V-groove is a groove having a V-shaped cross section.

By forming an optical waveguide connecting component using the above-described optical fiber V-groove substrate, a single optical waveguide connecting component can be used to form an optical waveguide core and an optical waveguide core in different planes of an optical waveguide element. It is possible to connect the optical fiber as a waveguide connecting component with high precision and high density.

[0026]

Embodiments of the present invention will be described below in detail with reference to the drawings. In the drawings described below, those having the same functions are denoted by the same reference numerals, and the repeated description thereof will be omitted.

Embodiment 1 FIG. 1A is a cross-sectional view of an optical waveguide connecting component having an optical fiber V-groove substrate according to Embodiment 1 of the present invention.

Reference numerals 11, 12, and 13 denote V-shaped cross sections.
Grooves 1 are V-groove substrates on which V-grooves 11, 12, and 13 are machined on steps, and 21, 22, and 23 are V-grooves 11, 12, and 13.
Is an optical fiber having a circular cross section, 7 is an upper cover made of a stepped block for holding the optical fibers 21, 22, 23, and 6 is an optical waveguide connecting part.

In this embodiment, the V-groove 1 is located at a plurality of different heights (in different planes) in the thickness direction of the V-groove substrate 1.
1, 12, and 13 are provided.

FIG. 1B is a front view of an optical waveguide connected to an optical fiber by the optical waveguide connecting part 6 of FIG. 1A.

Reference numerals 31, 32, and 33 denote optical waveguide cores, and reference numeral 3 denotes an optical waveguide clad. (Note that a, b, and c in the figure correspond to FIG. 3A described later.)

The optical waveguide cores 31, 32, and 33 have two, one, and two optical waveguides arranged in three different planes parallel to the substrate from the left side of the figure. In conjunction with this, the V-grooves 11, 12, and 13 in FIG.
From the left side of the drawing, two, one, and two are respectively formed at three different height positions (in different planes) in the thickness direction of the groove substrate 1, and the respective V grooves 11 and 12 are formed. , 1
Optical fibers 21, 22, and 23 are arranged in 3, and are fixed with an upper lid 7 using an adhesive or the like.

The optical fiber 2 mounted on the V-groove substrate 1
The core centers 1, 22, and 23 are the core centers of the optical waveguides 31, 32, and 33 in FIG. 1B, within ± 1 μm for a single mode optical waveguide, and ± 5 μm for a multimode optical waveguide having a core diameter of 50 μm. It is necessary to match within the accuracy. Conventional V-groove substrates require high-precision positional accuracy only in the direction parallel to the substrate.
In this embodiment shown in (a), high-precision processing is required not only in a direction parallel to the substrate but also in a direction perpendicular thereto.

Embodiment 2 FIG. 2 is a cross-sectional view of an optical waveguide connecting component having a V-groove substrate for an optical fiber according to Embodiment 2 of the present invention.

Reference numerals 41, 42 and 43 denote V grooves having different depths,
Is a V-groove substrate on which V-grooves 41, 42, 43 having different depths are processed, 21, 22, 23 are optical fibers, 7 is an upper lid made of a stepped block for holding the optical fibers 21, 22, 23, 26 is an optical waveguide connecting component.

In this embodiment, the V-groove substrate 2 is provided with a plurality of V-grooves 41, 42 and 43 having different depths.

That is, in this embodiment, each V groove 4
By setting the relative depth between 1, 42, and 43 to a desired value with a desired accuracy, the height of the optical waveguide device shown in FIG. A plurality of optical waveguide cores 31, 32, and 33 having different lengths can be connected to the centers of the optical fibers so as to coincide with each other.

In the first and second embodiments, the typical length of the conventional optical waveguide element is 2 cm,
It is sufficiently possible to make it as short as about 1.5 cm. When PMMA (polymethyl methacrylate) is used as the optical waveguide material, the optical waveguide loss is 1.55 μm of light wavelength.
Since m is 0.5 dB / cm, the loss can be reduced by 0.25 dB in the optical waveguide element shorter by 0.5 mm. As described above, the first and second embodiments have an effect that the loss can be reduced as compared with the conventional device.

[0039]

Embodiment 1 FIG. 3A is a sectional view of a V-groove substrate for an optical fiber according to Embodiment 1 of the present invention, FIG. 3B is an enlarged view of a V-groove portion, and FIG. is there.

In the present embodiment, the V-grooves 11 and the V-grooves 11 are located at a plurality of different heights (in different planes) in the thickness direction of the V-groove substrate 1.
12 and 13 are provided.

That is, as shown in FIG. 3A, in order to manufacture an optical waveguide connecting component having an optical fiber V-groove substrate 1 in accordance with an existing optical waveguide, first, an optical fiber V-groove substrate 1 A glass block made of Pyrex (registered trademark) glass having a V groove was formed by cutting.

Here, a = 30 μm, b = 250 μm,
c = 750 μm, thickness t = 1 mm, width w = 4 mm, length 3 mm of glass block (V-groove substrate 1 for optical fiber)
It is.

The angle x of the V-grooves 11, 12, 13 (see FIG. 3)
(B)) is 70 degrees. It is cut so that the V-groove depth f becomes 603 μm. Actually, the tip of the V-groove is rounded.
The depth g was set to 450 μm.

As shown in FIG. 3C, a Pyrex glass block serving as the upper lid 7 was machined by cutting. Specifically, cutting was performed so that h = 30 μm, i = 750 μm, thickness j = 1.5 mm, width k = 4 mm, and length 3 mm.

To assemble these components to produce an optical waveguide connecting component, first, as shown in FIG. 1A, an outer diameter 2 is formed on a V-groove substrate 1 made of a V-grooved glass block.
A single 50 μm single-mode optical fiber 22 and four multi-mode optical fibers 21 and 23 are
2 and 13, a few drops of the ultraviolet curable resin were dropped, and then the upper part was pressed down with the upper lid 7, and the ultraviolet curable resin was cured by irradiating ultraviolet rays to fix the optical fibers 21, 22 and 23. The end face was polished in order to remove the protruding ultraviolet curable resin portion and the like.

FIG. 4A is a front view of an optical waveguide device connected to the optical fiber V-groove substrate 1 of the present embodiment shown in FIG.

In (a), 51 is a substrate, 52, 54
Is an optical waveguide core, 53 is an optical waveguide clad, 44 is an optical waveguide, 45 is an upper lid, and 46 is an optical waveguide element.

An optical waveguide 44 is formed on a silicon substrate 51 having a thickness of 1 mm to constitute an optical waveguide element 46. In the polymer optical waveguide, the optical waveguide cores 52 and 54 are made of PMMA (polymethyl methacrylate) and the optical waveguide clad 53 is made of an ultraviolet curing epoxy resin on a silicon substrate 51 having a thickness of 1 mm. The size of the center single-mode optical waveguide core 52 is 6 μm × 6 μm, and the size of the surrounding multi-mode optical waveguide core 54 is 30 μm ×
30 μm, and the total length is 1.5 cm.

The center of the single-mode optical waveguide core 52 and the center of the multi-mode optical waveguide core 54 are each separated by 30 μm in the height direction. This optical waveguide 44
Using an adhesive, the upper surface was fixed with an upper lid 45 made of Pyrex glass block, and the end surface was polished.

The end face of the polymer optical waveguide 44, the upper face of which is fixed by the upper lid 45, and the end face of the optical fiber V-groove substrate 1 of FIG. 3 according to the present embodiment were connected and fixed with an ultraviolet curing adhesive.

FIG. 4B shows the optical fiber V of this embodiment.
It is a side view which shows the mode that the optical waveguide connection component which has a grooved substrate and the optical waveguide were bonded and fixed.

Reference numeral 47 denotes an optical waveguide connecting component using the V-groove substrate for an optical fiber according to the present embodiment; 48, an optical fiber;
Is an optical connector for connection provided at the tip of the optical fiber 48.

There are a total of five optical fibers 48. The breakdown is one single mode optical fiber and four multimode optical fibers.

Further, an optical connector 49 was connected to the tip of the optical fiber 48 opposite to the optical waveguide connecting component 47.

Each optical waveguide core 5 shown in FIG.
In order to evaluate the connection loss of the optical waveguide connecting component 47 using the V-groove substrate for optical fibers 2 and 54 and the optical fiber of this embodiment, a laser beam having a wavelength of 1.55 μm is incident from the optical connector 49 side.
Output light was measured using a photodiode at the end face on the optical waveguide side.

FIG. 5 is a diagram showing a measuring system at this time.

Reference numeral 54 denotes a semiconductor laser having a wavelength of 1.55 μm,
55 is an optical fiber for extracting the output from the semiconductor laser 54, 56 is an optical connector provided on the end face of the optical fiber 55, 47 is an optical waveguide connecting component using the optical fiber V-groove substrate of this embodiment, 48 is An optical fiber of the optical waveguide connecting component 47, an optical connector 49 of the optical fiber 48, an optical waveguide element 46, and a photodiode 57 for detecting an optical output.

In the measurement by the photodiode 57, first, an optical output is detected by using the photodiode 57 at the optical connector 56, and then the optical connector 56 and the optical connector 49 are connected as shown in FIG. Then, the light output was detected by the photodiode 57 and the difference was defined as the light loss.

The measured loss results are 2.0 dB for the single mode optical waveguide core 52 (FIG. 4A) and 1.0 dB for the multimode optical waveguide core 54, respectively.
The values were 0.9 dB, 1.1 dB, and 1.0 dB. PMM
The loss of the A optical waveguide is 0.5 dB / at a wavelength of 1.55 μm.
cm, when the optical waveguide length is 1.5 cm, the optical waveguide itself has a loss of 0.75 dB. Also, since an optical fiber having a mode field diameter of 9.5 μm was used as the single mode optical fiber 22 (see FIG. 1A),
When light enters the 6 μm square single mode optical waveguide core 52, a coupling loss of about 1 dB occurs. It is considered that the loss of the single mode optical waveguide core 52 is larger than that of the multimode optical waveguide core 54 by about 1 dB.

In consideration of these points, the excess loss due to the connection with the five optical waveguide cores 52 and 54 in different planes is about 0.2 to 0.3 dB, and a low-loss connection has been achieved. Became clear.

Embodiment 2 In this embodiment, the V-groove substrate 2 is provided with a plurality of V-grooves 41, 42 and 43 having different depths.

That is, in accordance with the existing optical waveguide, FIG.
Waveguide connecting component 2 using optical fiber V-groove substrate 2
In order to produce No. 6, a glass block made of Pyrex glass with a V-groove serving as the optical fiber V-groove substrate 2 was prepared by cutting.

The angle x of the V-grooves 41, 42, 43 is 70 degrees. The V-groove 41 is cut so as to have a depth of 603 μm, the groove 42 has a depth of 573 μm, and the groove 43 has a depth of 543 μm. Actually, the tip of the V-groove is rounded (see FIG. 3B). The actual depths are 450 μm, 420 μm, respectively.
It was 390 μm. Glass block (V for optical fiber
The thickness of the groove substrate 2) is 1 mm, the width is 4 mm, and the length is 3 mm
It is.

Next, the Pyrex glass block serving as the upper lid 7 was machined by cutting. The upper lid 7 has the same dimensions as those in FIG. Specifically, as shown in FIG. 3C, h = 30 μm, i = 750 μm, and thickness j = 1.5 m
Cutting was performed so that m, width k = 4 mm, and length = 3 mm.

Thereafter, the device was manufactured by the same steps as in the first embodiment.

That is, first, the V-grooves 41, 42, 4 of the optical fiber V-groove substrate 2 composed of a V-grooved glass block.
3, one single-mode optical fiber 22 having an outer diameter of 250 μm and four multi-mode optical fibers 21 and 23 are respectively arranged, a few drops of an ultraviolet curable resin are dripped, and then the upper lid 7 presses the upper part thereof. Ultraviolet rays were applied to cure the ultraviolet curing resin, and the optical fibers 21, 22, and 23 were fixed. The end face was polished in order to remove the protruding ultraviolet curable resin portion and the like.

The optical fiber V-groove substrate 2 of this embodiment is connected to the same one as the optical waveguide element 46 shown in FIG. Specifically, on a silicon substrate 51 having a thickness of 1 mm,
The optical waveguide 44 is formed to form an optical waveguide element 46. In the polymer optical waveguide, the optical waveguide cores 52 and 54 are made of PMMA (polymethyl methacrylate) and the optical waveguide clad 53 is made of an ultraviolet curing epoxy resin on a silicon substrate 51 having a thickness of 1 mm. The size of the center single-mode optical waveguide core 52 is 6 μm × 6 μm, and the size of the surrounding multi-mode optical waveguide core 54 is 30 μm ×
30 μm, and the total length is 1.5 cm.

The center of the single-mode optical waveguide core 52 and the center of the multi-mode optical waveguide core 54 are separated by 30 μm in the height direction. The optical waveguide 44 is attached to the upper cover 4 made of a Pyrex glass block by using an adhesive.
5, the upper surface was fixed, and the end surface was polished.

The end face of the polymer optical waveguide 44, the upper face of which is fixed by the upper lid 45, and the end face of the optical fiber V-groove substrate 2 of FIG. 2 according to the present embodiment were connected and fixed with an ultraviolet curing adhesive.

Next, as shown in FIG. 4B, an optical connector 49 was connected to the end of an optical fiber 48 opposite to the optical waveguide connecting component 47.

The respective optical waveguide cores 52 and 54 (FIG. 4)
(A)) In order to evaluate the connection loss of the optical waveguide connecting component 47 using the optical fiber V-groove substrate 2 of the present embodiment, a laser beam having a wavelength of 1.55 μm was incident from the optical connector 49 side. As in Example 1, as shown in FIG. 5, output light was measured using the photodiode 57 at the end face on the optical waveguide side.

The measured loss results are 1.9 dB for the single mode optical waveguide core 52 and 1.1 dB and 0.9 dB for the multimode optical waveguide core 54, respectively.
They were 1.0 dB and 0.9 dB. Since the loss of the PMMA optical waveguide is 0.5 dB / cm at a wavelength of 1.55 μm, when the optical waveguide length is 1.5 cm, the loss of the optical waveguide itself is 0.7 dB.
There is a 5 dB loss. In addition, since the single mode optical fiber used was an optical fiber having a mode field diameter of 9.5 μm, the single mode optical waveguide core 52 of 6 μm square was used.
When light is incident on the device, a coupling loss of about 1 dB occurs.
It is considered that the loss of the single mode optical waveguide core 52 is larger than that of the multimode optical waveguide core 54 by about 1 dB.

Considering these points, the excess loss due to the connection with the five optical waveguide cores 52 and 54 in different planes is about 0.2 to 0.3 dB, and a low-loss connection has been achieved. Became clear.

Although the present invention has been specifically described based on the embodiments, the present invention is not limited to the above-described embodiments, and it is needless to say that various modifications can be made without departing from the gist of the present invention. It is.

[0075]

As described above, according to the present invention,
An optical waveguide core and an optical fiber in different planes,
Simple, compact, high-density and low-loss connections can be made at once with a single component. Therefore, the number of connection steps can be reduced, and the element can be downsized.

[Brief description of the drawings]

1A is a cross-sectional view of an optical waveguide connecting component having an optical fiber V-groove substrate according to a first embodiment of the present invention, and FIG. 1B is an optical fiber connected by the optical waveguide connecting component of FIG. It is sectional drawing of an optical waveguide.

FIG. 2 is a cross-sectional view of an optical waveguide connecting component having an optical fiber V-groove substrate according to a second embodiment of the present invention.

3A is a cross-sectional view of a V-groove substrate for an optical fiber according to a first embodiment of the present invention, FIG. 3B is an enlarged view of a V-groove portion, and FIG. 3C is a cross-sectional view of an upper lid.

FIG. 4A is a front view of an optical waveguide connected to the optical fiber V-groove substrate according to the first and second embodiments of the present invention.

FIG. 5 is a diagram showing a measurement system of Examples 1 and 2 of the present invention.

FIG. 6 is a cross-sectional view of a conventional connection component using a V-groove substrate for connecting an optical waveguide and an optical fiber.

7A is a schematic view of the entire optical waveguide type position detecting optical sensor, and FIG. 7B is an enlarged front view of a portion A in FIG.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... V-groove board, 6 ... Optical waveguide connection part, 7 ... Top lid, 1
1, 12, 13: V-groove, 21, 22, 23: optical fiber, 31, 32, 33: optical waveguide core, 3: optical waveguide clad, 2: V-groove substrate, 26: optical waveguide connecting part, 4,
1, 42, 43 ... V groove, 40 ... substrate, 44 ... optical waveguide,
51, 53: optical waveguide core, 52: optical waveguide clad,
45 top cover, 46 optical waveguide element, 47 optical waveguide connecting part, 48 optical fiber, 49 optical connector, 54 semiconductor laser, 55 optical fiber, 56 optical connector, 5
7 ... photodiode, 61 ... V-groove substrate, 62 ... V-groove,
Reference numeral 63 denotes an optical fiber, 66 denotes an optical waveguide connecting part, 67 denotes an upper lid, 70 denotes an optical waveguide element, 71 denotes a substrate, 72 denotes an optical waveguide core, 73 denotes an optical waveguide clad, and 74 denotes an optical fiber.
5. Optical connector.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Akira Tomaru 2-3-1, Otemachi, Chiyoda-ku, Tokyo Within Nippon Telegraph and Telephone Corporation (72) Inventor Yujiro Kato 2-chome, Otemachi, Chiyoda-ku, Tokyo No. 1 Nippon Telegraph and Telephone Corporation (72) Inventor Toru Maruno 2-3-1 Otemachi, Chiyoda-ku, Tokyo F-Term within Nippon Telegraph and Telephone Corporation (reference) 2H037 AA01 BA02 BA11 BA24 DA04 DA12

Claims (2)

[Claims] 1. An optical fiber V-groove substrate provided with optical fiber installation V-grooves, wherein the V-grooves are provided at a plurality of different heights in the thickness direction of the substrate. V-groove substrate for optical fiber. 2. An optical fiber V-groove substrate having an optical fiber installation V-groove provided with a plurality of V-grooves having different depths.