WO2015046409A1

WO2015046409A1 - Optical element module

Info

Publication number: WO2015046409A1
Application number: PCT/JP2014/075578
Authority: WO
Inventors: 徳一宮崎; 加藤　圭
Original assignee: 住友大阪セメント株式会社
Priority date: 2013-09-30
Filing date: 2014-09-26
Publication date: 2015-04-02
Also published as: JP5825315B2; JP2015069130A

Abstract

The purpose of the present invention is to provide an optical element module, which is provided with a small and low-cost structure, and whereby operation efficiency of sealing operations is improved, and a thermal damage of a fiber coat is reduced. Disclosed is an optical element module wherein: a housing for housing an optical element is provided; the optical element is optically coupled to an optical fiber introduced into the housing through a through hole that is provided in a side wall of the housing; and outside of the housing, a protection member that protects the optical fiber led out from the through hole is disposed on a part of the optical fiber, and the optical fiber is held by means of a fiber fixing section integrally formed with the housing by having the protection member between the fiber fixing section and the optical fiber. The optical element module is characterized in that, in the through hole, a gap between the side wall and a bare fiber section having an optical fiber coat removed therefrom is sealed and fixed using a metal material.

Description

Optical element module

The present invention relates to an optical element module, and more particularly, to an optical element module in which an optical element is accommodated in a casing and an optical fiber introduced into the casing and the optical element are optically coupled.

Optical elements such as optical modulators are frequently used in the optical communication field and the optical measurement field. Many of these optical elements are used as an optical element module in which an optical element is accommodated in a metal casing. The optical element module is configured to introduce an optical fiber through a through hole provided in a side wall of the casing, optically couple the optical element inside the casing and the optical fiber, and seal the through hole. ing.

Patent Document 1 describes that a sealing structure of an optical fiber is sealed and fixed by using a through pipe without applying an excessive force to the optical fiber at an oblique incidence.

Patent Document 2 discloses a method of fixing an optical fiber when a fixing pipe is used to reduce the size of an optical element module.

Patent Document 3 discloses an optical element package having improved workability using an insertion pipe having a slit.

In the prior art disclosed in Patent Document 1 and Patent Document 2, there is a problem that the pipe portion is a separate body and the cost is increased. Moreover, in the structure like patent document 3, since the diameter of an insertion pipe is large, it is difficult for solder to flow between a pipe and an optical fiber, and sealing with a case wall part is difficult. Moreover, since the heating time required for the sealing operation becomes long, there is a problem that damage to the fiber coating and the protective member disposed outside the fiber coating increases.

Japanese Patent Laid-Open No. 7-199003 JP 2004-145253 A JP 2009-128677 A

The problem to be solved by the present invention is to solve the above-mentioned problems, have a small and low-cost structure, improve the working efficiency in the sealing work, and reduce the optical damage to the fiber coating and the like. An element module is provided.

In order to solve the above problems, the optical element module of the present invention has the following technical features.
(1) A housing for storing the optical element is provided, and the optical element is optically coupled to an optical fiber introduced into the housing through a through hole provided in a side wall of the housing. Outside the body, a protective member for protecting the optical fiber led out from the through hole is arranged in a part of the optical fiber, and the fiber fixing portion integrated with the housing is interposed through the protective member. In the optical element module that holds the optical fiber, a gap between the bare fiber part from which the optical fiber coating is removed and the side wall is sealed and fixed with a metal material inside the through hole. To do.

(2) In the optical element module according to (1), the inner diameter of the through hole is 0.3 mm to 0.9 mm.

(3) In the optical element module according to (1) or (2) above, the inner diameter of the through hole is larger than the outer diameter of the bare fiber portion from which the fiber coating is removed, and is equal to or smaller than the outer diameter of the protective member. It is characterized by being set.

(4) In the optical element module according to any one of (1) to (3), the optical fiber is butt-connected to the optical element, and the optical axis of the optical fiber at the connection portion passes through the optical element module. It is in the range of the inner diameter of the hole.

(5) The optical element module according to any one of (1) to (4), wherein the through hole is inclined with respect to the side wall.

According to the present invention, a housing for storing an optical element is provided, and the optical element is optically coupled to an optical fiber introduced into the housing through a through hole provided in a side wall of the housing. Outside the housing, a protective member that protects the optical fiber led out from the through hole is arranged in a part of the optical fiber, and the protective member is attached by a fiber fixing portion integrated with the housing. In the optical element module that holds the optical fiber via, the gap between the bare fiber portion from which the optical fiber coating is removed and the side wall is sealed and fixed with a metal material inside the through hole. The size of the through-hole formed in the first and second holes is small, and the fiber fixing part serves only to hold the optical fiber coated with the fiber, so that the structure can be simplified. In addition, the sealing operation is easy, and in particular, reliable sealing can be performed between the optical fiber and the side wall. When sealing, the time required for the soldering operation can be shortened, and thermal damage to the fiber coating is small.

It is sectional drawing which shows a part of optical element module of this invention. It is a figure which shows an example of the fiber fixing | fixed part used for the optical element module of this invention.

Hereinafter, the present invention will be described in detail using preferred examples.
FIG. 1 shows an embodiment of the optical element module of the present invention.
The present invention includes a housing for storing an optical element, and the optical element is optically coupled to an optical fiber introduced into the housing through a through hole provided in a side wall of the housing. Outside the housing, a protective member that protects the optical fiber led out from the through hole is arranged in a part of the optical fiber, and the protective member is attached by a fiber fixing portion integrated with the housing. In the optical element module that holds the optical fiber via, a gap between the bare fiber portion from which the optical fiber coating is removed and the side wall is sealed and fixed with a metal material inside the through hole. And

The “bare fiber part” in the present invention means an optical fiber composed only of a core and a clad, and “optical fiber strand” in which a thin protective film (primary coating) such as UV coating is applied to the bare fiber part. It is distinguished from an “optical fiber core wire” in which a protective film made of a resin such as nylon is used for a coating layer (secondary coating) covering the optical fiber. The coated state of the optical fiber other than the sealing portion of the housing may have a coating as long as it does not greatly affect the metallization process or the sealing process. However, the covering state of the optical fiber in the portion inserted into the housing depends on the size of the through hole in the housing side wall, but at least the secondary coating is preferably removed from the viewpoint of work efficiency. .

Further, “optical fiber coating (fiber coating)” in the present invention mainly means the above “primary coating”. Further, the “protective member” in the present invention corresponds to the “secondary coating” and “loose tube” as described later.

In the optical element module of the present invention, a through hole is provided on the side wall of the housing, and the fiber fixing portion is integrally processed on the side wall or joined by welding or soldering so as to be connected to the through hole. As will be described later, since the optical fiber (bare fiber portion) is sealed and fixed in a through hole provided in the side wall, many parts are integrated with the housing, and as shown in Patent Documents 1 to 3, the side wall This eliminates the need for parts such as a pipe penetrating through, thereby reducing the size and reducing the number of parts.

Fig. 2 shows the shape of the fiber fixing part bonded to the side wall of the casing. FIG. 2A is a view seen from above, and FIG. 2B is a cross-sectional view taken along the dotted line AA in FIG. The fiber fixing part is a cylindrical body such as a cylinder, and a slit is formed in a part of the outer periphery so that the optical fiber can be easily inserted.

The side of the fiber fixing portion to be joined to the housing has a tapered inner diameter as shown in FIG. 1, and an opening connected to the through hole in the side wall is formed. When inserting a bare fiber part (the part inserted into the housing may have a coating remaining within a range not hindering sealing) by providing a taper-shaped slope. In addition, the optical fiber can be smoothly inserted from the fiber fixing part into the through hole in the side wall, and further inside the housing, and not only the workability is improved, but also the push-in condition and the amount of bending of the optical fiber can be easily adjusted. Become.

The width w of the slit may be set to be wider than the width of the coated or protected optical fiber (including the primary coating, the secondary coating, or the loose tube). This is a series of operations from inserting the bare fiber part from which the fiber coating has been removed into the through hole, positioning the optical fiber, then performing the sealing operation, and finally fixing the optical fiber to the fiber fixing part. It is set so that it is easy to perform.

Next, the procedure for fixing the optical fiber will be described. The bare fiber part from which the fiber coating has been removed is inserted from the fiber fixing part, and the tip of the optical fiber is connected to the optical element by butt connection (butt joint) or the like. In FIG. 1, an optical element in which an optical waveguide such as an optical modulator is formed is illustrated as the optical element, but the optical element of the present invention is not limited to this.

The optical fiber is sealed and fixed in the through hole provided in the side wall of the housing. In the vicinity of the sealing fixing portion, the fiber coating is removed, and in order to maintain sealing performance, a metal film, for example, Au or the like is formed on the glass portion of the optical fiber by vapor deposition or plating through a base metal such as Cr ( Metallization process). In addition to the metal film, it may be pre-soldered with a special metal solder for glass. As for the coating state of the optical fiber other than the sealing portion of the casing, there may be a coating as long as it does not greatly affect the metallization process or the sealing process. However, the covering state of the optical fiber in the portion inserted into the housing depends on the size of the through hole in the housing side wall, but at least the secondary coating is preferably removed from the viewpoint of work efficiency. .

Solder paste or the like is injected into the sealing portion from the work hole or slit provided in the fiber fixing portion, and a soldering iron or the like is brought into contact with the concave portion formed on the housing side of the fiber fixing portion to locally heat, or induction Solder paste or the like is melted by a heating means or the like and hermetically sealed between a case (through hole inner wall) plated with a metal such as Au and the optical fiber.

If the diameter of the bare fiber part from which the fiber coating is removed is a single mode fiber, it is about 0.125 mm. Therefore, by setting the inner diameter of the through hole to about 0.3 mm to 0.9 mm, a capillary phenomenon occurs when the solder is melted. Thus, the solder can be fixed to the inside of the side wall of the housing uniformly and efficiently.

Also, by setting the inner diameter of the through hole to be larger than the outer diameter of the bare fiber part from which the fiber coating has been removed and less than the outer diameter of the protective member (secondary coating, loose tube, etc.) that protects the optical fiber, When the optical fiber is passed through the through hole, the insertion of the protective member into the housing is suppressed, and the working efficiency is increased.

Further, the position of the through hole and the size of the inner diameter are determined by inserting the optical fiber into the through hole and connecting the optical fiber to the optical element so that the optical axis of the optical fiber at the connection portion is the through hole. By setting so as to be within the range of the inner diameter, it is possible to further improve the working efficiency. That is, the through hole is provided on the extension line of the optical axis connected to the optical element so that the optical fiber is in contact with the through hole and the optical fiber is not damaged at the time of alignment and fixing with the optical element. By setting the position so that the extension of the optical axis is in the range of the diameter of the through hole, workability is good, and it is possible to prevent abnormal stress and bending from occurring in the optical fiber even after sealing and fixing Can do.

Furthermore, the through hole is inclined with respect to the side wall, so that the optical element and the optical fiber can be connected to each other while maintaining the Snell angle. In addition, when the optical element and the optical fiber are not in a straight line, it is possible to suppress an excessive stress from being applied to the connection portion between the optical element and the optical fiber.

After sealing, an optical fiber having a fiber coating or a protective member is placed inside the fiber fixing portion, and the opening end of the fiber fixing portion is closed with a fiber fixing auxiliary member. Then, an adhesive is poured from the slit or the working hole to fix at least the optical fiber coated with the fiber and the fiber fixing portion. The amount of the adhesive poured into the slit or the working hole of the fiber fixing portion may be such that both the bare fiber portion from which the fiber coating is removed and the optical fiber covered with the fiber are fixed.

For the fiber-coated optical fiber housed inside the fiber fixing part, there may be a protective member such as a loose tube. When there is a protective member such as a loose tube, it is desirable that these are also fixed to the fiber fixing portion with an adhesive.

The inner diameter of the fiber fixing part is desirably about 0.3 to 2 mm larger than the outer diameter of the fiber-coated optical fiber housed in the fiber fixing part (or the outer diameter of the protective member). If the inner diameter of the fiber fixing part is too small, it will interfere with the inflow of the adhesive when a highly viscous adhesive is used, and this will affect the bond strength between the fiber-coated optical fiber (or protective member) and the fiber fixing part. . If the inner diameter of the fiber fixing part is too large, a large amount of adhesive is required for fixing.

In FIG. 1, the fiber fixing portion is connected in an oblique direction (not vertical) to the side wall of the housing, but can also be connected to the side wall vertically. In that case, by forming the through hole perpendicular to the side wall and extending the optical axis of the optical element and the fiber connection part within the diameter of the through hole, an excessive force is applied to the optical fiber, increasing the loss and stress. Damage due to can be prevented.

The shape of the fiber fixing portion is not limited to a cylindrical shape, and may be a square shape or the like. In addition, the housing-side portion of the fiber fixing portion can have a thin structure to improve heat conduction to the solder and shorten the heating time. Thereby, damage to the fiber coating can also be suppressed.

As described above, according to the optical element module of the present invention, there is provided an optical element module having a small and low-cost structure, improving the working efficiency in the sealing operation, and reducing the heat damage to the fiber coating. It becomes possible to do.

Claims

A housing for storing optical elements is provided.
The optical element is optically coupled to an optical fiber introduced into the housing through a through hole provided in a side wall of the housing;
Outside the casing, a protective member for protecting the optical fiber led out from the through hole is disposed in a part of the optical fiber, and the protective member is provided by a fiber fixing portion integrated with the casing. In an optical element module that holds the optical fiber via
Inside the through hole, a gap between the bare fiber part from which the optical fiber coating is removed and the side wall is sealed and fixed with a metal material.
2. The optical element module according to claim 1, wherein the through hole has an inner diameter of 0.3 mm to 0.9 mm.
3. The optical element module according to claim 1, wherein an inner diameter of the through hole is set to be larger than an outer diameter of the bare fiber portion from which the fiber coating is removed and equal to or smaller than the outer diameter of the protective member. An optical element module.
4. The optical element module according to claim 1, wherein the optical fiber is butt-connected to the optical element, and the optical axis of the optical fiber at the connection portion is within the range of the inner diameter of the through hole. And an optical element module.
5. The optical element module according to claim 1, wherein the through hole is inclined with respect to the side wall.