JPS60195506A - Optical fiber leading-in terminal - Google Patents

Abstract

PURPOSE:To obtain a stable fixation of an optical fiber by a soldering material by only a local heating, and also to execute and airtight sealing as necessary by providing a hollow part opened toward the opposite direction of a root part of a nozzle having a through-hole of a thin diameter which is a little larger than the outside diameter of an optical fiber to be inserted. CONSTITUTION:A metallized optical fiber 14 is inserted into a body 18, passes through a nozzle part 11 and it is led into an optical device vessel. In this state, a molten soldering material 16 is placed on the nozzle tip having an oblique section, and by heating the thinly constricted nozzle part 11, air in the optical fiber leading-in terminal body 18 is absorbed from an exhaust hole 13. The molten soldering material 16 permeates along the metallized optical fiber 14 in the inside of the nozzle part 11, and when heating is stopped, the solder coagulates. Also, at the same time when the optical fiber 14 is fixed, an airtight sealing of the part concerned in realized. Also, thereafter, when an adhesive agent 7 is injected to an optical fiber covered part 15, sucking air from the exhaust hole 13, the optical fiber covered part 15 is solidified stably in the optical fiber leading-in terminal.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an optical fiber introduction terminal, and more particularly to a structure for fixing and hermetically sealing an optical fiber introduction part of an optical fiber communication device.

Many technologies have been developed for optical fiber introduction terminals of optical devices for optical fiber communication. If hermetic sealing is not required, the jacket portion 1 of the optical fiber
c Mechanical fixing (crimping, etc.), or mechanical fixing of an optical fiber (tension reinforcing material (Kepler, etc.) in the covering part) is applied. In the case of hermetically sealing the optical fiber through the optical device container, fill the gap in the optical fiber introduction terminal with adhesive, or metalize the optical fiber core wire, insert it into a through hole drilled in the optical device container, and solder it. The method is applied.

On the other hand, as the application area of optical fiber communication expands 1 and the environmental conditions in which optical devices are used become more severe, hermetic sealing of optical devices is becoming an essential condition. It is believed that hermetic sealing of the optical fiber introduction part of optical devices will become an important technology in the future.

Conventionally, there are two methods for hermetically sealing the optical fiber introduction part: a method using adhesive as shown in FIG. 1, and a method using solder sealing as shown in FIG. Adhesive method Vi As shown in FIG. 1, the gap between the coated portion 3 of the optical fiber 2 inserted into the optical fiber introduction terminal of the optical device container 1 and the inside of the optical fiber introduction terminal is filled with adhesive 4, and then air is applied. Although it is used for sealing, sufficient airtightness cannot be ensured due to the hygroscopic nature of the adhesive itself and deterioration over time. On the other hand, hermetic sealing by soldering K ensures much better airtightness than using adhesive. However, as shown in FIG. 2, the entire optical device container must be heated to a temperature higher than the temperature at which the solder material melts. There is a risk of thermal damage to optical devices. In addition, if only the optical fiber introduction part is heated and soldered for a short period of time to avoid thermal damage, the solderability between the solder material and the optical fiber introduction part will be poor, and sufficient care must be taken. There was a problem that sealing could not be achieved.

SUMMARY OF THE INVENTION An object of the present invention is to provide an optical fiber introduction terminal for an optical device that can stably fix an optical fiber by soldering with only local heating and can be hermetically sealed if necessary. .

For this purpose, the present invention (such optical fiber introduction terminal) includes a nozzle having a through hole with a small diameter slightly larger than the outer diameter of the optical fiber to be inserted, and a base portion of the nozzle. An optical fiber introducing terminal main body having a central part connected to a small diameter through hole in the nozzle and opening in a direction opposite to the nozzle, and a circular flange part protruding outward from a side surface of the main body. It is an integrated structure.

In order to make it easier to receive the molten solder material, the tip of the nozzle is cut diagonally, or the fiber coating material is fixed mechanically or using an iJ coupling agent to the main body where the optical fiber is introduced. If it is maintained, it is effective in enhancing the -j- effect.

Specifically, the terminal structure of the present invention has a cylindrical body with a flange and a through hole through which an optical fiber passes, and is attached to an optical device container via the flange. The part that enters the optical device container when installed is shaped like a shoe nozzle. When the optical fiber is actually completely fixed and hermetically sealed, the metallized optical fiber is inserted into the optical fiber introduction terminal body and protruded from the nozzle tip. In this state, place the molten solder material on the diagonal cut part of the nozzle,
If the nozzle tip is heated and at the same time the air inside the optical fiber introduction terminal body is exhausted using the through hole drilled on the opposite side of the nozzle through the flan'), the narrow and constricted nozzle part will heat efficiently. The molten solder material penetrates into the through-hole in the nozzle along the optical fiber and solidifies when heating is stopped, thereby simultaneously achieving fixation of the optical fiber and airtight sealing of the nozzle.

Next, an embodiment of the invention will be described in terms of measurement with reference to the output l.

FIG. 3 is a partially cutaway view of an optical fiber introduction terminal according to the present invention. FIG. 4 shows its sectional view. The terminal body 18 is
Through the flange 12 1. This is pre-brazed to the optical device container (not shown), and the air quality between the container and the main body at this portion is ensured. Metallized optical fiber 14 is inserted into body 18 and nozzle portion 11
(- Guided into the optical device container. In this state, the molten solder material 16 is passed through the nozzle tip 14 with an oblique cut.
When the air inside the optical fiber introduction terminal main body 18 is sucked through the exhaust hole 13 while heating the narrow constricted nozzle portion 11, the molten solder material 16 penetrates inside the nozzle portion 11 along the metalized optical fiber 14. However, when the heating is stopped, the solder solidifies 17, and the optical fiber 14 is fixed and the area is hermetically sealed at the same time. Furthermore, after this, the adhesive 17 is injected into the optical fiber coated portion 15 while being suctioned through the exhaust hole 13, and the optical fiber to-be-pupiled portion 15 is stably fixed within the optical fiber introduction terminal. Also, the same effect can be obtained even if the optical fiber 14 is not metalized.

As described above, the optical fiber introducing terminal with a nozzle of the present invention can fix and hermetically seal the optical fiber in a short period of time without causing thermal damage to the optical components mounted in the optical device container. The solder can be fixed by heating, and at the same time, the solder material and the optical fiber are soldered over a sufficient length by suction from the exhaust hole, making it possible to achieve a safe hermetic seal.

[Brief explanation of drawings]

Figure 1 is a cross-sectional view showing the state of fixing and hermetically sealing an optical fiber in an optical fiber introduction terminal using an adhesive according to the prior art, and Figure 2 shows a terminal structure in which the optical fiber is fixed and hermetically sealed using a conventional solder material. 3 is a partial cutaway view showing one embodiment of the present invention, and FIG. 4 is an enlarged sectional view of FIG. 3. 11 Nozzle 1 lil 1 minute, 12...Flange, 1
3. Exhaust gas, 14. Metallized optical fiber. 15... Optical fiber coating portion, 16... Solder material. 17... Adhesive, 18... Terminal body. Agent Patent Attorney Rikichi Somekawa

Claims (1)

[Scope of Claims] (1) A nozzle having a through hole with an inner diameter slightly larger than the outer diameter of the optical fiber to be inserted, and a through hole of the nozzle that is integrally formed at the root portion of the nozzle. A terminal body having a hollow portion communicating with the nozzle and opening in a direction opposite to the nozzle, and two 7-run parts integrally formed on the outer surface of the terminal body and protruding outward. Optical fiber introduction terminal 1-a. (2) The optical fiber introduction terminal according to claim 1, wherein the tip of the nozzle is cut obliquely with respect to the nozzle axis. (31. The optical fiber introduction terminal according to claim 1, wherein the terminal main body has the hollow portion (the communicating through hole) formed on the side opposite to the nozzle from the 7-run 2 portion. (4) The terminal body is characterized in that a fixed holding portion of an optical fiber coating material or a tension reinforcing material is formed at the optical fiber inlet portion on the opposite side from the nozzle. Optical fiber introduction terminal in item 1.