JP2003156653A - Optical parts - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide optical parts in a linear form having no increase in the insertion loss of light in which the center axis of the optical fiber in the light receiving side is coincident with the propagation direction of light. SOLUTION: In the optical parts, a dielectric multilayered film filter 12 is held between microlenses 11, a first optical fiber holder 15 and a second optical fiber holder 17 are joined to the faces of the microlenses 11 not joined with the dielectric multilayered film filter 12, and the center axis of the optical fiber 16 is disposed as inclined with respect to the center axis of the microlens 11 according to the thickness d of the dielectric multilayered film filter 12. The optical fiber 16 is disposed in such manner that the center axis of the fiber is coincident with the path of the light exiting from the microlens 11 to enter the optical fiber 16. The center axes of the first optical fiber holder 15 and of the second optical fiber holder 17 are coincident with the center axis of the microlens 11.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical component such as a micro-optics type wavelength division multiplexing transmission component used in the field of optical fiber communication, and more particularly to an optical component having a small insertion loss.

[0002]

2. Description of the Related Art As an optical component, a micro-optics type wavelength division multiplex transmission (Wavelength Division Multiplexing) for multiplex transmission of a plurality of optical signals having different wavelengths bidirectionally or unidirectionally
Multiplexing, hereinafter abbreviated as "WDM". ) Parts and the like. Figure 3 shows the conventional micro-optics type WD.
It is a figure which shows M parts, FIG.3 (a) is a top view, FIG.
(B) is a front view. This micro optics type W
In the DM component, a dielectric multilayer filter 2 is sandwiched between two cylindrical microlenses 1 and 1, and these are fixed with an adhesive or the like.

Further, the fiber strands 3 and 4 on the light incident side are provided.
Has two V grooves 5a, 5a in which the bare optical fiber portions 3a, 4a exposed by removing the coating layer at the tip thereof are formed in parallel to the central axis direction of the first optical fiber holder 5 having a rectangular parallelepiped shape. It is stored in and is joined with an adhesive.
Then, the first optical fiber holder 5 is joined to the microlens 1 with an adhesive or the like. Similarly, the optical fiber strand 6 on the light receiving side is similarly housed in a V groove 7a formed parallel to the central axis direction of the second optical fiber holder 7 and fixed by an adhesive or the like. The optical fiber holder 7 is bonded to the microlens 1 with an adhesive or the like.

[0004]

By the way, FIG. 3 (b)
When the thickness t of the dielectric multilayer filter 2 shown in FIG. 3 increases, the central axis of the bare optical fiber portion 6a on the light receiving side forms an angle θ with the path of light as shown in FIG. Occurs. The larger this angle deviation, the more microlens 1
There is a problem that the insertion loss of the light that is incident on the bare optical fiber portion 6a increases. In order to reduce such insertion loss of light, an external force is applied to the second optical fiber holder 7 so that the entire second optical fiber holder 7 is moved along the central axis of the optical fiber element wire 6 and the path of light. There is a way to tilt so that and match. However, according to this method, the micro-optics type WDM component shown in FIG. 3 has a problem that mechanical strength, temperature characteristics, etc. are deteriorated.

In addition, the two optical fiber wires 3 on the incident side,
There has been a problem that the larger the interval of 4, the larger the insertion loss of light from the microlens 1 into the bare optical fiber portion 6a.

The present invention has been made in view of the above circumstances, in which the center axis of the optical fiber on the light receiving side coincides with the path of light,
An object of the present invention is to provide an optical component having a linear shape that does not increase the insertion loss of light.

[0007]

According to the above object, a dielectric multilayer filter or another optical element is sandwiched between two microlenses, and the dielectric multilayer in the longitudinal direction of the two microlenses. An optical component in which a first optical fiber holder or a second optical fiber holder is joined to each of the surfaces that are not joined to the filter or other optical element, and the first optical fiber holder is on the incident side. An optical fiber is held, the second optical fiber holder holds the optical fiber on the light receiving side, and the central axis of the optical fiber on the light receiving side depends on the thickness of the dielectric multilayer filter or other optical element. Therefore, the problem can be solved by an optical component obliquely arranged with respect to the central axis of the microlens. It is preferable that the longitudinal central axes of the first optical fiber holder and the second optical fiber holder coincide with the central axis of the microlens. It is preferable that the longitudinal central axes of the first optical fiber holder and the second optical fiber holder are parallel to the central axis of the microlens. It is preferable that a holding portion that holds the optical fiber on the light receiving side is formed on the second optical fiber holder. It is preferable that the holding portion is formed obliquely with respect to the central axis of the microlens.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention is described in detail below.
1A and 1B are views showing a micro-optics type WDM component as an example of the optical component of the present invention. FIG. 1A is a plan view and FIG. 1B is a front view. In the optical component of this example, a disk-shaped dielectric multilayer filter 12 is sandwiched between two cylindrical microlenses 11 and fixed with an adhesive or the like. Further, the bare optical fiber portions 13a and 14a of the optical fiber wires 13 and 14 on the light incident side are exposed by removing the coating layer at the tip thereof.
Are housed in two holding portions 15a, 15a formed in parallel with the central axis of the first optical fiber holder 15 in the longitudinal direction, and are fixed by an adhesive or the like. The first optical fiber holder 15 is joined to the microlens 11 with an adhesive or the like. Further, in the optical fiber element 16 on the light receiving side, the bare optical fiber portion 16a exposed by removing the coating layer at the tip of the optical fiber element 16 has a rectangular parallelepiped second optical fiber holder as shown in FIG. A holding portion 17 formed at an angle α with respect to the central axis of the longitudinal direction of 17
It is stored in a and is fixed with an adhesive or the like. And
This second optical fiber holder 17 is used for the microlens 1
It is joined to 1 with an adhesive or the like.

Also, in the optical component of this example, the central axes of the respective constituent members are aligned. Specifically, the microlens 1
The central axes of 1 and 11 and the central axis of the dielectric multilayer filter 12 coincide with each other. Further, the first optical fiber holder 15
The central axis of the second optical fiber holder 16 in the longitudinal direction coincides with the central axes of the microlenses 11 and 11 and the dielectric multilayer filter 12.

In the optical component of this example, the central axis of the optical fiber element wire 16 coincides with the central axis of the microlens 11 according to the thickness d of the dielectric multilayer filter 12 shown in FIG. 1 (b). It is arranged diagonally. At this time, the central axis of the optical fiber element wire 16 is aligned with the path of the light emitted from the microlens 11 and incident on the optical fiber element wire 16, as shown by the broken line in FIG. A holding portion 17a formed on the second optical fiber holder 17
Form an angle α with the longitudinal central axes of the microlens 11 and the second optical fiber holder 17.

Microlens 11 used in this example
Is composed of a rod lens made of alkali glass or the like, a grin lens, etc., and its refractive index continuously changes in the radial direction and the axial direction. The microlens 11 has an outer diameter of 1.0 to 3.0 mm and a length of 2.0 to 6.0 m.
m, which is appropriately set according to the refractive index distribution and the material.

The dielectric multilayer filter 12 is formed by laminating thin films having different refractive indexes such as silica (SiO ₂ ), titania (TiO ₂ ), and tantalum pentoxide (TaO ₅ ) on a substrate such as quartz glass. The material and thickness are appropriately selected according to the wavelength of light. In this example, a dielectric multilayer filter in which thin films of silica and titania are alternately laminated on a quartz glass substrate and has a total thickness of about 2 mm is used.

As the optical fiber strands 13, 14 and 16, a single mode optical fiber having an outer diameter of 250 to 900 μm or a polarization maintaining optical fiber is used. The single mode optical fiber has a structure in which a coating layer made of an ultraviolet curable resin or the like is provided on a bare optical fiber made of quartz glass or the like. A polarization-maintaining optical fiber includes a core made of quartz glass doped with germanium oxide (GeO ₂ ), a clad provided around the core with the same central axis as the core, and made of quartz glass. It is composed of two stress-applying portions each having a circular section and made of glass having a coefficient of thermal expansion larger than that of the silica glass forming the clad and arranged substantially symmetrically with respect to the core.

The first optical fiber holder 15 has a length of 5 to 5.
20 mm, width 1.0-3.0 mm, thickness 0.5-3.0
It has a rectangular parallelepiped shape of about mm, and is made of quartz, glass, ceramics, resin, metal, or the like. In addition, the first optical fiber holder 15 includes the optical fiber strands 13 and 14
The two holding portions 15a, 15a for accommodating the bare optical fiber portions 13a, 14a of the first optical fiber holder 1
It is formed in parallel with the central axis of the longitudinal direction of 5 over the entire length in the longitudinal direction. The shape of the groove of the holding portion 15a is
It may have any shape such as a V groove, a circular shape, a rectangular shape, or a trapezoidal shape. Further, the size of the holding portion 15a has an opening diameter of 1
It is about 25 to 500 μm.

The second optical fiber holder 17 has a length of 5 to 20 mm, a width of 1.0 to 3.0 mm, and a thickness of 0.5 to.
It has a rectangular parallelepiped shape of about 3.0 mm and is made of quartz, glass, ceramics, resin, metal or the like. Also,
As shown in FIG. 2 (a), the second optical fiber holder 17 has a holding portion 17 a for accommodating the bare optical fiber portion 16 a of the optical fiber strand 16 and a lengthwise direction of the second optical fiber holder 17. The second optical fiber holder 17 is formed at an angle α with the central axis of the direction from one end to the other end in the longitudinal direction of the second optical fiber holder 17. Also, this holding portion 17a
The shape of the groove is not limited to the V groove as shown in FIG.
It may have any shape such as a circular shape, a rectangular shape, or a trapezoidal shape. Further, the size of the holding portion 17a is such that the opening diameter 125 to
It is about 500 μm.

A holding portion 15a for holding the optical fiber strands 13 and 14
An adhesive, a low melting point glass, a solder, or the like is used for fixing the optical fiber strand 16 to the holding portion 17a. Further, in order to protect the optical fiber strands 13, 14, 16, the first optical fiber holder 15 and the second optical fiber holder 17 are made of quartz, glass, ceramics, resin, metal or the like, not shown. A lid may be provided. Such a lid is used for the optical fiber strands 13, 14, 16
After being stored in the holding portion 15a or the holding portion 17a, they are joined so as to cover the holding portion 15a or the holding portion 17a.

In the optical component of this example, the central axis of the optical fiber wire 16 is emitted from the microlens 11,
Since it coincides with the path of the light incident on the optical fiber strand 16, the angle of misalignment between the path of the light and the central axis of the optical fiber strand 16 causes the light from the microlens 11 to reach the optical fiber strand 16. Insertion loss does not increase. Therefore, even if the thickness d of the dielectric multilayer filter 12 is increased, the holding portion 17a is correspondingly moved to the microlens 1 by the thickness d.
By adjusting the angle α formed between the central axes of the first and second optical fiber holders 17 in the longitudinal direction, the dielectric multilayer filter 12 having a large thickness d can be used without increasing the insertion loss of light. . That is, there is no limitation on the thickness d of the dielectric multilayer filter 12 used. Further, according to the path of the light incident on the optical fiber strand 16, the holding portion 17
By adjusting the angle α formed by a with the longitudinal central axis of the microlens 11 and the second optical fiber holder 17, even if the distance between the two optical fiber strands 13 and 14 on the incident side becomes large, Insertion loss does not increase. Therefore, there is no limitation on the distance between the two optical fiber strands 13 and 14 on the incident side. Also, in the optical component of this example,
In order to reduce the light insertion loss, external force is applied,
Since it is not necessary to incline the entire second optical fiber holder 17 according to the path of light, mechanical strength and temperature characteristics do not deteriorate. In addition, the optical fiber strand 16 on the light receiving side is attached to the holding portion 17a formed on the second optical fiber holder 17.
Since it is stored, the central axis of the optical fiber element wire 16 and the light path can be easily matched. Also, the second
The holding portion 17a formed on the optical fiber holder 17 of
Since it is formed obliquely with respect to the central axis of the microlens 11, it is not necessary to apply a force from the outside to tilt the entire second optical fiber holder 17 in accordance with the path of light.

Hereinafter, the effects of the present invention will be clarified by showing concrete examples with reference to FIGS. 1, 2 and 3. (Embodiment) In the optical component as shown in FIG. 1, the thickness d of the dielectric multilayer filter 12 is changed, and the holding part 17a and the central axis of the second optical fiber holder 17 in the longitudinal direction are correspondingly changed. The second optical fiber holder 17 was manufactured by changing the angle α formed by and, and several kinds of optical components were manufactured.
At this time, the central axis of the optical fiber strand 16 was made to coincide with the path of the light emitted from the microlens 11 and entering the optical fiber strand 16. The optical insertion loss of the obtained optical component was measured. The results are shown in Table 1.

(Comparative Example) As a comparative example, in the micro-optics type WDM component as shown in FIG.
An optical component was manufactured in which the optical fiber 6 was housed in the V groove 7a formed in parallel with the central axis direction of the optical fiber holder 7. The optical insertion loss of the obtained optical component was measured. The results are shown in Table 1.

[0020]

[Table 1]

From the results shown in Table 1, it is arranged that the center axis of the optical fiber element wire 16 on the light receiving side is aligned with the path of the light emitted from the microlens 11 and incident on the optical fiber element wire 16. It was confirmed that the optical insertion loss did not increase.

[0022]

As described above, in the optical component of the present invention, the dielectric multilayer filter or other optical element is sandwiched between two microlenses, and the two microlenses have the above-mentioned structure in the longitudinal direction. An optical component in which a first optical fiber holder or a second optical fiber holder is bonded to each of the surfaces that are not bonded to the dielectric multilayer filter or other optical element, the first optical fiber holder Holds the optical fiber on the incident side, the second optical fiber holder holds the optical fiber on the light receiving side, and the central axis of the optical fiber on the light receiving side is the dielectric multilayer film filter or another optical element. According to the thickness, since the microlenses are arranged obliquely with respect to the central axis, the insertion loss of light does not increase even if the thickness of the dielectric multilayer filter increases. . Further, depending on the path of the light incident on the optical fiber on the light receiving side, the central axis of the optical fiber on the light receiving side can be adjusted by adjusting the angle formed by the central axis of the microlens.
Even if the distance between the two optical fibers on the incident side becomes large, the insertion loss of light does not increase.

If the central axis of the optical fiber on the light receiving side is arranged so as to coincide with the path of the light emitted from the microlens and incident on the optical fiber on the light receiving side, the path of the light and the light receiving There is no increase in insertion loss of light from the microlens to the optical fiber on the light receiving side due to the angular deviation from the central axis of the optical fiber on the light receiving side. If the central axes of the first optical fiber holder and the second optical fiber holder in the longitudinal direction coincide with the central axis of the microlens, an external force is applied in order to reduce the insertion loss of light. In addition, since it is not necessary to tilt the entire second optical fiber holder according to the path of light, mechanical strength and temperature characteristics do not deteriorate. If the second optical fiber holder has a holding portion for holding the light-receiving side optical fiber, if the light-receiving side optical fiber is housed in this holding portion, the light-receiving side optical fiber can be easily stored. It is possible to match the path of light with the central axis of. If the holding portion is formed obliquely with respect to the central axis of the microlens, it is not necessary to apply a force from the outside to tilt the entire second optical fiber holder 17 according to the path of light.

[Brief description of drawings]

FIG. 1 is a diagram showing an example of an optical component of the present invention.
1A is a plan view, and FIG. 1B is a front view.

2 shows an example of an optical fiber holder used in the optical component of the present invention, FIG. 2 (a) is a plan view, and FIG.
2B is a front view, and FIG. 2C is a left side view.

3 is a diagram showing a conventional micro-optics type wavelength division multiplexing transmission component, FIG. 3 (a) is a plan view, and FIG.
(B) is a front view.

FIG. 4 is an enlarged view of the inside of the circle of FIG.

[Explanation of symbols]

11 ... Microlens, 12 ... Dielectric multilayer filter, 13, 14, 16 ... Optical fiber element wire, 13a, 1
4a, 16a ... Naked optical fiber part, 15 ... First optical fiber holder, 15a, 17a ... Holding part, 17 ... Second optical fiber holder

Continued front page    (72) Inventor Yoshihiro Momitsu             Fuji Co., Ltd. 1440 Rokuzaki, Sakura City, Chiba Prefecture             Kura Sakura Office (72) Inventor Kenji Nishiwaki             Fuji Co., Ltd. 1440 Rokuzaki, Sakura City, Chiba Prefecture             Kura Sakura Office (72) Inventor Takuhiro Nakamura             Fuji Co., Ltd. 1440 Rokuzaki, Sakura City, Chiba Prefecture             Kura Sakura Office F-term (reference) 2H037 AA01 BA32 CA03 CA04 CA10                       CA16 DA04 DA12

Claims (5)

[Claims] 1. A dielectric multilayer filter or another optical element is sandwiched between two microlenses, and is bonded to the dielectric multilayer filter or another optical element in the longitudinal direction of the two microlenses. An optical component in which the first optical fiber holder or the second optical fiber holder is joined to each of the surfaces not formed, the first optical fiber holder holding the optical fiber on the incident side, The second optical fiber holder holds the optical fiber on the light receiving side, and the central axis of the optical fiber on the light receiving side corresponds to the central axis of the microlens depending on the thickness of the dielectric multilayer filter or other optical element. An optical component characterized by being arranged obliquely with respect to. 2. A center axis of the optical fiber on the light receiving side is arranged so as to coincide with a path of light emitted from the microlens and incident on the optical fiber on the light receiving side. The optical component according to claim 1. 3. The central axis in the longitudinal direction of the first optical fiber holder and the second optical fiber holder coincides with the central axis of the microlens. Optical parts. 4. The optical component according to claim 1, wherein the second optical fiber holder is provided with a holding portion for holding the optical fiber on the light receiving side. 5. The optical component according to claim 1, wherein the holding portion is formed obliquely with respect to the central axis of the microlens.