JP3458347B2 - Optical amplifier module - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical amplifier module in the field of optical communication. 2. Description of the Related Art An optical amplifier module is an apparatus for amplifying signal light as it is in an optical communication network, and an optical amplifier module using an erbium-doped optical fiber (EDF) as an amplification medium has been put to practical use. In such an optical amplifier module, to obtain a high gain, the EDF is 20 to 30 m.
Since the above-mentioned length is required, it is wound around a drum or wound along a case and fixed with metal fittings for storage. [0003] However, optical fibers such as EDF cannot be bent to a radius of R30 or less in general because of loss and long-term strength reliability. In this case, the diameter of the drum must be at least 60 mm, which is not suitable for high-density mounting. [0004] In addition, since the EDF is coated with a UV-curing resin (UV) having a diameter of 0.25 and has a small diameter, there is a problem that the EDF is likely to be damaged when fixed with metal fittings. Otherwise, vibration may damage the EDF. In an optical amplifier module, if the optical fiber is cut at any one point, the entire device stops, and preventing damage to the EDF is important in terms of reliability. [0005] In order to solve the above-mentioned problems, the present invention provides a long EDF wound in a loop.
Is covered with a hot-melt adhesive sheet.
The heat-fusible adhesive sheet with heat
And the adhesive and EDF melted with the heat-shrinkable sheet are removed.
The EDF is fixed to the case by pressing.
You. FIG. 1 is a perspective view showing an optical amplifier module according to a first embodiment of the present invention, FIG. 2 is an explanatory view of a main part of FIG. 1, and FIG. FIG. 2B is a plan view, and FIG.
It is an AA sectional view of (a). In the figure, 1 is an EDF (erbium-doped optical fiber) as an amplification medium, 2 and 3 are high-power laser diodes for exciting the EDF 1,
Reference numerals 4 and 5 denote multiplexers for multiplexing the pump light into the signal light path. 6 and 7 are optical isolators for suppressing return light due to reflection in order to prevent an oscillation phenomenon at the time of optical amplification, and 8 and 9 are optical branching couplers for monitoring and controlling signal light.
Numerals 0 and 11 are light receiving element modules for monitoring and controlling the signal light. Reference numeral 12 denotes an input connector for inputting an optical signal, and reference numeral 13 denotes an output connector for outputting an amplified optical signal. The components are connected by fusing optical fibers drawn from the components. Reference numerals 14 to 23 denote a fusion reinforcing material for reinforcing the fusion portion of the optical fiber, and the above components are mounted in a case 25 mounted on the circuit board 24 of the optical communication device. FIG. 3 is a block diagram showing a connection relationship between components of the above-described optical amplifier module. Here, as shown in FIG. 2, the EDF 1 is fixed in a planar shape by using a material wound in a loop shape, such as UV or silicon, which is the same material as the fiber coating. As a fixing method, for example, a method in which the EDF 1 wound in a loop is immersed in a liquid resin and cured, or a resin coating sheet 2 containing the loop-shaped EDF 1 is used by laminating or the like.
Create 6. Further, since the ends of the EDF 1 need to be exposed to the outside of the resin coating sheet 26 in order to connect with other optical components, the ends of the EDF 1 are previously attached to both ends of the EDF 1.
It is passed through a vinyl tube 27 of about 1 mm, and the resin is fixed so that only the EDF 1 protected by the tube 27 comes out of the resin coating sheet 26. For mounting on the optical amplifier module, an optical component other than the EDF1 is fixed to the case 25, fusion-splicing of the drawn optical fibers is performed, and the extra length of the optical fiber is stored, and then the EDF1 covered with the resin coating sheet 26 is covered. Is connected to a predetermined optical fiber, and is fixed above the optical component mounting space in the case 25 by a screw or an adhesive. As described above, according to the optical amplifier module of the first embodiment, since the EDF 1 is completely covered and covered with the resin, there is no fear of cutting.
Since it is resistant to vibration and shock, long-term reliability can be obtained. In addition, since the EDF 1 that is easy to handle and protrudes from the resin coating sheet 26 is protected by the tube 27, cutting due to a work error or the like can be prevented, and the number of assembly steps and the yield can be reduced. Further, in order to obtain the long-term reliability without using a drum and to fix the EDF 1 above the mounting space,
The size of the optical amplifier module in the width and depth directions can be reduced, and the size can be reduced. FIG. 4 is a perspective view showing a second embodiment of the optical amplifier module of the present invention, FIG. 5 is an explanatory view of a main part of FIG. 4, FIG. 5 (a) is a plan view, and FIG. 5
It is BB sectional drawing of (a). In the EDF 1 according to the second embodiment, the EDF 1 wound in a loop is fixed in a loop using a resin such as UV or silicon which is the same material as the fiber coating.
As a fixing method, for example, a method in which the EDF 1 wound in a loop is immersed in a liquid resin and cured, or a lamination process is used, and a resin coating tube 28 containing the EDF 1 in a loop is created. Further, since the end of the EDF 1 needs to be put out of the resin coating tube 28 in order to connect with another optical component, the end of the EDF 1 is passed through a vinyl tube 27 of about φ1 mm in advance, and The resin is fixed so that only the EDF 1 protected by 27 comes out of the resin coating tube 28. The other configuration is the same as that described with reference to FIG. 1, and the description thereof is omitted here. For mounting on the optical amplifier module, the EDF 1 covered with the resin coating tube 28 is first fixed to the extra-length cable storage portion in the case 25, and thereafter, the optical component is fixed to the case 25. The drawn optical fibers are fusion-spliced to each other and the EDF 1, and the excess optical fiber 29 is covered with a resin coating tube 28.
Store around DF1. As described above, according to the optical amplifier module of the second embodiment, since the EDF 1 is completely covered and covered with the resin, there is no fear of cutting.
Since it is resistant to vibration and shock, long-term reliability can be obtained. In addition, the resin coating tube 28 is easy to handle.
Since the EDF 1 protruding from the tube is also protected by the tube 27, it can be prevented from being cut due to a work error or the like, and the number of assembly steps and the yield can be reduced. Further, since the EDF 1 is fixed to the extra-length cable storage portion with long-term reliability, the width, the depth direction, and the height direction of the optical amplifier module can be reduced, and the optical amplifier module can be downsized. FIG. 6 is a perspective view showing a main part of an optical amplifier module according to a third embodiment of the present invention. In the figure, reference numeral 30 denotes a heat-shrinkable sheet, 31 denotes a hot-melt adhesive sheet, and the fixing portion of the EDF 1 is first covered with the hot-melt adhesive sheet 31, then the heat-shrinkable sheet 30 is covered and the metal fitting 32 is mounted. It is fixed to the case 25 with screws 33 and heated in a constant temperature layer. Although not shown, other configurations are the same as those described with reference to FIG. FIG. 7 is a cross-sectional view taken along the line CC in FIG. 6 and shows the operation of the third embodiment. After the EDF 1 is housed in a loop along the outer periphery of the case 25, the fixing portion of the EDF 1 is first covered with a hot-melt adhesive sheet 31 as shown in FIG. And the metal fitting 32 with the screw 33 in the case 2
5 and heated in a constant temperature layer, the hot-melt adhesive sheet 31 is melted as shown in FIG. 7B, and the EDF 1 and the EDF 1 and the case 25 and the heat-shrinkable sheet 3 are melted.
Since the zero interval is adhered and the heat-shrinkable sheet 30 further contracts, the EDF 1 is fixed by the case 25 and the heat-shrinkable sheet 30 via an adhesive. As described above, according to the optical amplifier module of the third embodiment, since the EDF 1 is fixed via the adhesive, the cutting can be prevented without directly touching the edge of the bracket. Moreover, since it is fixed with an adhesive and further pressed down by the heat shrinkable sheet 30,
It does not move at the time of vibration or impact, so that cutting can be prevented and long-term reliability can be obtained. Since the EDF 1 and the extra optical fiber can be fixed together, the size of the optical amplifier module can be further reduced. As described above, according to the present invention, since a long EDF is wound in a loop and coated with a resin and stored and fixed in a case, cutting of the EDF is prevented, and vibration and impact are prevented. , So long-term reliability can be obtained. In addition, since the handling becomes easy, the assembling work becomes easy, and the number of assembling steps and the yield can be reduced. Further, since the EDF can be stored without using a drum, the size of the optical amplifier module can be reduced.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view showing a first embodiment of an optical amplifier module according to the present invention. FIG. 2 is an explanatory view of a main part of FIG. 1 FIG. 3 is a block diagram of the optical amplifier module FIG. 4 is a perspective view showing a second embodiment of the optical amplifier module of the present invention. FIG. 5 is an explanatory view of a main part of FIG. 4. FIG. 6 shows a third embodiment of the optical amplifier module of the present invention. [FIG. 7] CC sectional view of FIG. 6 [Description of reference numerals] 1 EDF 26 resin coating sheet 27 vinyl tube

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Claims (1)

(57) [Claims] [Claim 1] A long erbium-doped optical fiber (ED
F) is wrapped in a loop, and then heated with a hot-melt adhesive sheet.
Cover, cover the heat-shrinkable sheet from above,
The hot-melt adhesive sheet is melted, and
Hold the melted adhesive and EDF and put the EDF in the case
An optical amplifier module fixed to the optical amplifier module.