JPH0475007A - Optical fiber terminal - Google Patents

Abstract

PURPOSE:To obtain an LD module which is less fluctuated in the coupling efficiency of an LD and an optical fiber even against a severe thermal stress and has high reliability by using AuSi solder for fixing and air-tight sealing of the optical fiber into a metallic sleeve. CONSTITUTION:This terminal consists of the optical fiber 1, an optical fiber jacket 2, a pipe 3 for protecting the optical fiber, the metallic sleeve 6, and the AuSi solder 21. Namely, the AuSi solder 21 is used for fixing and air-tight sealing of the optical fiber 1 into the metallic sleeve 6 at the optical fiber terminal for the laser diode (LD) module. The LD module which lessens the creeping of the solder 21 and is eventually less fluctuated in the light output at the fiber end even when subjected to the severe thermal stress is obtd. in this way.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an optical fiber, an optical fiber, and a terminal of a laser diode module used in a communication system.

[Conventional technology]

FIG. 4 is a cross-sectional view showing the optical fiber and terminal of a conventional laser diode module. In FIG. 3) is an optical fiber, a protection pipe, (4) is Pb5n solder, (5) is a polymer adhesive 7, (6) is a metal sleeve, and (6a) is a flange attached to the metal sleeve.

FIG. 5 is a sectional view of an example of a DTP type laser diode module that is actually used for the optical fiber and terminal shown in FIG. 4. In the figure, (7) is the package, (8
) is a cover, (9) is a thermo module that controls the temperature of the laser diode (hereinafter simply referred to as LD),
(10) is the LD heat sink, (11) is the LD,
(12) is a monitor photodiode (hereinafter simply PD
). (13) is the stem, (14) is the stem (13)
) is the thermistor for temperature detection, and (16) is the thermistor (15) that holds and fixes the thermistor (15).
) and a holding material for fixing the mount (14), (17) is a rod lens (square gradient index lens) for condensing the light from LD (11), and (18) is a The lens holder (19) is for holding and fixing the rod lens (17), and the sleeve holder (19) is for holding and fixing the metal sleeve (6).
20) is solder for airtightness. Note that internal wiring is omitted.

Next, the operation will be explained. First, the basic optical parts are Al L.
D (11), rod lenses (1, 7), optical fibers, and wires (1) are used to adjust and fix the optical axis outside the package (7), and then inside the package (7). Incorporate into. One assembly method will be briefly explained below. The stem (13) is connected to the LD (11) and PD (12) through the heat sink (10).
) and fix the mount (14) around it by welding or the like.

Next, insert the rod lens (17) into the lens holder [18].
Attach the LD (11) and rod lens (17)
Align the axes of the mount l-(14) and lens holder (
18) Weld. Next, in order to hold the metal sleeve (6) on which the optical fiber and wire (1) are attached, put the metal sleeve (6) into the hole of the sleeve holder (19), and first align and fix the metal sleeve (6). Perform axis alignment with the LD (11) and rod lens (17). Note that the tip of the metal sleeve holder (6) is usually polished obliquely to prevent reflection from the optical fiber or wire. Once the position of the optical fiber and wire (1) is determined, fix the optical axis direction by using a metal sleeve (6) and sleeve holder (19) with a pad, etc.
Further, the lens holder (18) and the sleeve holder (19) are fixed in the vertical direction of the optical axis by welding or the like. This completes the production of the internal module. Here, in advance, pankaen (
7) contains a thermo module (9) and a thermistor (15).
) to which the holding material (16) is attached is fixed by soldering. Next, put the internal module into the package (7),
The package (7) and the flange (6a) provided on the metal sleeve (6) are soldered. Furthermore, internal wiring is performed and finally the cover (8) is seam welded to the package (7). With this module, even if the ambient temperature changes, the L D
The holding material (16) is
) The current supplied to the thermo module (9) is adjusted by detecting and feeding back the resistance value of the thermistor (15) fixed to the thermostat. In general, ATC (
Automatic Temperature Con
trol) circuit is attached externally to perform automatic temperature control.

[Invention or problem to be solved]

LD using optical fiber and terminal configured as above
By leaving the module at high or low temperatures for a long period of time or applying thermal stress such as thermal cycling, the Pb5n solder used for fixing the end of the optical fiber and wire (1) and for airtightness inside the metal sleeve may cause a creep phenomenon. ,the result,
There was a problem in that the relative position of the optical fiber and wire (1) with respect to the L D (11) and the rod lens (17) changed, and the output at the end of the fiber varied greatly.

This invention was made in order to solve the above-mentioned problems, and it is possible to create an LD module with a small solder creep phenomenon even when exposed to severe thermal stress, and as a result, with a small fluctuation in the fiber optical output of the LD module. The purpose is to obtain.

[Means to solve the problem]

The optical fiber and terminal according to the present invention use AuSi solder for fixing the terminal of the optical fiber and wire and for airtightness.

[Effect]

Since the optical fiber and the terminal in this invention use AuSi solder, the solder creep phenomenon is less than that of Pb5n solder, so the optical fiber and terminal are resistant to thermal stress.
The movement of the wire can be suppressed.

〔Example〕

FIG. 1 is a sectional view showing an embodiment of the present invention. In FIG. 1, (1) is an optical fiber, a bare wire, (2) is an optical fiber, a jacket, (3) is an optical fiber, a protective pipe,
(6) is a metal sleeve, (21) is an optical fiber, AuSi solder used for fixing the end of the wire (1) and airtightly.

In the optical fiber terminal for the LD module configured as described above, AuSi solder (21) is used for fixing the optical fiber and wire (1) in the metal sleeve (6) and making it airtight. Compared to Pb5n-based solder, the solder creep phenomenon is small and stable against thermal stress. For this purpose, for example, if the above-mentioned optical fiber and terminal are used in the conventional DIP type LD module described above, stable fiber optical output can be obtained even when subjected to severe thermal stress, and the amount of fluctuation thereof is small.

FIG. 2 is a sectional view showing another embodiment of the invention,
(1') (2) (3) (5) (6) (21
) are the same as in the previous embodiment. (22) has a hole a few microns larger than the outer diameter of the optical fiber or strand at its center, and the tip is tapered. (23) has a metal sleeve (6) and a ceramic ( 22) is the brazing material that fixes it.

In this example, a fine hole is machined, and the tip is
By using the ceramic (22) processed into a ) shape, the amount of AuSi solder (21) can be reduced, making it possible to solder with a laser processing machine, making it possible to create optical fibers,
It is possible to improve the workability of terminal processing. Of course, in this case as well, the ceramic (22) of the optical fiber and wire (1)
Since AuSi solder (21) is used for fixation and airtightness, even under severe thermal stress, stable fiber optical output can be obtained and its fluctuation is small.

FIG. 3 is a sectional view showing another embodiment of the invention,
It is the same as in Fig. 2 except that a counterbore (24b) is machined at the tip of the ceramic (22).

〔Effect of the invention〕

As explained above, this invention uses AuSn-based solder for fixing optical fibers and wires in metal sleeves and for airtightness in optical fiber end terminals for LD modules, which can withstand severe thermal stress. Since the variation in coupling efficiency between the LD and the optical fiber is small, it is possible to provide a highly reliable LD module.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing one embodiment of the present invention, FIGS. 2 and 3 are sectional views showing other embodiments, FIG. 4 is a sectional view of a conventional optical fiber and a terminal, and FIG. is conventional optical fiber,
FIG. 2 is a cross-sectional view of a DIP type LD module in which a terminal is incorporated. In the figure, (1) is an optical fiber, strand, (2) is an optical fiber, jacket, (3) is an optical fiber, protection pipe, (4) is Pb5n solder, (5) is a polymer adhesive,
(6) is metal sleeve, (7) is package, (8) is cover, (9) is thermo module, (10) is heat sink, (11,) is LD, (12) is PD
, (1,3) is the stem, (1,4) is the mount, (15) is the thermistor, (16) is the retainer,
(17) is a rondo lens, (18) is a lens holder, (19) is a sleeve holder, (20) is an airtight solder (21) is AuSi solder, and (22) is a ceramic. Note that the same reference numerals in Figure 9 indicate the same or corresponding parts.

Claims (3)

[Claims] (1) An optical fiber whose tip is gold-plated, a protective pipe for protecting the optical fiber, a metal sleeve to which the optical fiber and the protective pipe are attached, and a metal sleeve for fixing the optical fiber and the metal sleeve. In optical fiber terminals using solder for airtightness, A
An optical fiber terminal characterized by using nSi solder. (2) An optical fiber whose tip is gold-plated, a protective pipe that protects the optical fiber, a metal sleeve to which the optical fiber and the protective pipe are attached, and a metal sleeve with a diameter slightly larger than the outer diameter of the optical fiber in the center. There is a hole, and
The tip of the hole is tapered, and at the same time, the outer periphery of the gold-plated ceramic is brazed to the metal sleeve, and AnSi solder is used for the tapered portion of the optical fiber and the ceramic. optical fiber terminal. (3) An optical fiber whose tip is gold-plated, a protective pipe that protects the optical fiber, a metal sleeve to which the optical fiber and the protective pipe are attached, and a metal sleeve with a diameter slightly larger than the outer diameter of the optical fiber in the center. There is a hole, and
The tip of the hole is counterbored, and at the same time, the outer periphery of the gold-plated ceramic is brazed to the metal sleeve, and AnSi solder is used for the optical fiber and the counterbore part of the ceramic. optical fiber terminal.