JPH05297228A - Coil of fiber for light amplification - Google Patents

Abstract

PURPOSE:To provide a coil of a fiber for light amplification which ensures minimization of the mounting space by forming flat the light amplification fiber. CONSTITUTION:A fiber 21 for light amplification is configured with a core in the central part containing rare earth element and a clad layer surrounding the core and formed in a flat coil having a specified length. Therein the coil width of flat winding is made below 20 times as large as the dia. of the fiber 21, and the resultant coil is adhered by a resin. The inner dia. (e) of this coil 20 may for example be 30 mm while the clad outer dia. of the fiber 21 be 125mum as standard dia., and the outer dia. including the resin covering be 250mum to contain the required length of winding as 50 m, which should result in an outer dia. of winding within 70 mm. In this condition, the coil width F is 1mm.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light amplification fiber winding body, and more particularly to obtaining a light amplification fiber winding body which can be mounted in a device or the like with a minimum mounting space.

In the long-distance signal transmission means, an optical fiber is used as a transmission line in recent years with an optical signal amplification device interposed therebetween, or the optical signal is transmitted without relay.

In this way, the amplification and relay of the optical signal attenuated in the middle of the optical transmission line is carried out by converting the optical signal into an optical / electrical signal, amplifying this electric signal, and then converting it into an electric / optical signal and re-lighting it. I was trying to send to the transmission line. Instead, recently, a fiber for optical amplification containing a rare earth element,
It has come to a practical stage to directly amplify the optical signal in the state of the optical signal. This is extremely efficient because it does not require a light / electricity or electricity / light conversion device.

Further, it is possible to perform long-distance non-relay communication by amplifying and transmitting the optical signal in the transmitting section. An outline of such an optical communication system will be described with reference to FIG. 8. Basically, an optical signal from an optical transmitter 1 including a semiconductor laser for a light source of signal light and a modulator is an optical transmission line. An optical repeater 3 installed at a point for amplifying the attenuated signal light transmitted to the fiber 2.
Is composed of a rare-earth-doped optical amplification fiber, an optical coupler connected to the optical fiber, and an optical coupler for optically coupling the optical amplification fiber with the optical fiber of the transmission line. ..

In the above optical amplification fiber, a core glass portion, which serves as an optical signal transmission line in the central portion of the optical fiber, is doped with a predetermined amount of a rare earth element, and the periphery thereof is formed as a clad glass layer, and the periphery thereof is protected. And a resin coating layer for use therein are formed.

The attenuated signal light is coupled to the optical amplification fiber, and stimulated emission of light occurs due to the excitation light of the semiconductor laser, and the signal light is amplified, so that it is transmitted to the optical fiber 4 of the next transmission line. Input to the optical receiver 5.
Of course, a plurality of optical repeaters 3 are installed at appropriate intervals according to the transmission distance.

The fiber for optical amplification is 10 to 100 m
The length is set to an optimum length depending on various conditions such as the doping amount of rare earth. The type of the rare earth element is selected according to the wavelength band of the optical signal. For example, Er (erbium ion) is doped in the 1.5 μm band.

Since this optical amplifying fiber has the above-mentioned length, it is bulky and if it is properly installed in the apparatus, it causes problems such as being bulky and easily damaged. It is necessary to shape it and attach it.

[0009]

2. Description of the Related Art An optical amplification fiber has a standard cladding outer diameter of 125 μm, and the outer diameter including the resin coating formed on the outside thereof is 250 μm. For example, if this optical amplification fiber is a wound body with a required length of 50 m,
Conventionally, it was formed into a shape as shown in FIG. That is, the optical amplification fiber winding body 10 includes a bobbin 1 for winding the fiber winding body 10.
1, the outer width B is 8 mm, the inner width b for winding the optical amplification fiber 12 is 6 mm, and the inner diameter d is 30 m.
The outer diameter D of the winding was 50 mm.

[0010]

The size of the above conventional structure is not so large, but in view of the mounting density of future devices, an efficient shape of the mounting space is required. The bobbin 11 also needs to have a thickness in consideration of rigidity and strength for winding the optical amplification fiber 12, but there is also a demand for compressing even the space for the bobbin.

An object of the present invention is to provide a fiber winding body for optical amplification which satisfies the above conventional requirements.

[0012]

Means for Solving the Problems The constituent means of the present invention for solving the above-mentioned problems of the prior art comprises a central core portion containing a rare earth element, and a cladding layer surrounding the core portion. In the optical amplification fiber, the optical amplification fiber winding is a flat winding with respect to the optical amplification fiber having a required length.

Further, the flat winding width is set to 20 times or less of the fiber diameter for optical amplification. Further, it is an optical amplification fiber winding body in which the optical amplification fiber winding body is joined by a resin.

[0014]

According to the above-mentioned construction means of the present invention, since the optical amplification fiber winding body is flat, it can be mounted in any space inside the device, and the space is so large as to affect the size of the device. Therefore, the mounting structure of the device can be made efficient.

The outer diameter of the optical amplification fiber is the standard diameter 1
By setting the maximum value of 25 μm to 20 times or less, there is no adverse effect on mounting, and miniaturization and thinning are not hindered.

Furthermore, since these optical amplification fiber rolls are joined and integrated with a resin, they do not lose their shape, so that they are easy to handle as a single unit. It is stable even after installation.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The optical fiber winding body of the present invention will be described in detail with reference to the drawings based on a specific embodiment based on the structure.

FIG. 1 is a perspective view of an embodiment of a fiber winding body for optical amplification of the present invention. In the figure, reference numeral 22 is the starting end of the winding start of the optical amplification fiber 21, and 23 is the ending end of the winding. Fiber amplifier for optical amplification 20
The inner diameter e of the fiber is, for example, 30 mm. When the cladding outer diameter of this optical amplification fiber is 125 μm, which is the standard diameter, and the outer diameter including the resin coating is 250 μm and the required length is 50 m, the winding outer diameter E falls within 70 mm. .. Incidentally, the winding width F could be set to 1 mm in this state.

The product of the present invention thus obtained is a thinned fiber amplifier for optical amplification, which has only a conventional optical fiber for amplification without a bobbin. A method of manufacturing the optical amplification fiber winding body 20 will be described with reference to FIG. 2. Reference numeral 30 in the drawing is a winding frame, 31 and 32 are a pair of winding frame halves, and 35 is a resin coating device.

The winding frame 30 has a pair of symmetrically separable winding frame halves 31 and 32 which are opposed to each other and brought into close contact with each other. And then
It is attached to a winding device (not shown) so that it can rotate in the direction of arrow H. The opposing width G of the optical amplification fiber winding portion 33 of this winding frame is set to 1 mm, and the diameter of its bottom portion is 30 mm.

In the resin coating device 35, a lower roller 36 and an upper roller 37 are in contact with each other and can rotate in the directions of arrows I and J. A resin supply tank 38 is arranged on the lower roller 36 and the upper roller 37.
A required amount of resin 39 can flow out to the upper surface of 7.

The fiber amplification body for optical amplification having the above structure is manufactured as follows. That is, the winding frame 30 is rotated in the direction of the arrow H, the optical amplification fiber 25 is pulled out from the drum (not shown) as shown by the arrow K, and is passed between the rollers 36 and 37 facing each other.
It is wound around the bottom of the wound portion 33 of 0 for an appropriate number of times and the tip thereof is pulled out.

When the winding frame 30 is rotated while allowing the resin 39 to flow out from the tank 38, the resin 39 is applied to the optical amplification fiber 25 along the surface of the roller 37 as the roller 37 rotates, and this is applied to the inside of the winding portion 33. To be wound up. Since the optical amplification fiber winding body 26 is formed in this manner, it is confirmed that the required length is obtained in the wound state, and the resin is cured to separate the winding frame 30 to separate the optical amplification fiber. The winding body 20 (FIG. 1) is taken out.

The above resin may be a synthetic resin adhesive or a molding resin, but if it is an ultraviolet (UV) curable resin, it can be shortened by irradiating ultraviolet rays from the holes 34 on the side surface of the reel 30. Can be cured in time.

In the above manufacturing method, the resin is supplied at the same time, but it is also possible to manufacture without using the resin coating device 35. The optical amplification fiber 25 is simply wound around the winding frame 30, and in a state in which the optical amplification fiber 25 is wound for a required length, resin is supplied from the hole 34 on the side surface of the winding frame 30 to impregnate the inside thereof and the optical amplification fiber winding body 26 is integrally joined. Then, the winding frame 30 is separated to take out the optical amplification fiber winding body 20 (FIG. 1).

In any of the above cases, it is preferable that the winding frame 30 is subjected to a resin non-sticking treatment, for example, a film treatment of a tetrafluoroethylene chloride resin (trade name: Teflon) on its surface. A second embodiment of the optical amplifier fiber winding body of the present invention will be described below with reference to FIG. This optical amplification fiber winding body 50, as shown in FIG.
Frame plates 54 and 55 are laminated on both sides of a disc-shaped core member 51 at the center and resin thin plates (or films) 52 and 53 on both sides (upper and lower sides in the figure). A space between the thin plates 52 and 53 facing each other serves as a fiber-amplifying fiber winding portion 56.
The facing interval is about 1 mm.

The optical amplification fiber 59 is wound around the winding frame 58 thus formed for a required length, and after confirming that the required length is obtained, the frame plates 54 and 55 on both sides are removed,
(B) As shown in the figure, the thin plates 52 and 53 are closely adhered to each other around the wound optical amplification fiber 59 and resin-sealed.
At this time, if the inside is vacuumed, the shape is fixed by the action of atmospheric pressure after sealing. Further, as shown in FIG. 2, a resin may be applied to the optical amplification fiber 59 and cured to be resin-sealed, but in this case, it is not particularly necessary to make a vacuum state.

One of the optical amplification fibers 59, 59 led out to the left and right sides of the illustrated optical amplification fiber assembly 50 is the starting end of the winding start, and the other is the ending end of the winding.

In each of the above embodiments, the starting end of the winding start of the optical amplification fiber is the center side, and the ending end of the winding is the outermost circumference. In such a case, drawing out the end of the fiber for optical amplification at the beginning of winding to the outer circumference affects the thickness of the fiber winding for spectral amplification. A fiber winding body for optical amplification which does not have such a structure is shown in FIG. 4 in the third embodiment of the present invention.
Will be described below.

In the present embodiment, for ease of understanding, the winding frame and the like are not shown for the sake of convenience. First, in FIG. 4A, the optical amplification fiber 62 is provided around the core material 61.
And both ends 63 and 64 are simultaneously wound in the opposite directions of the arrows M and N.

The optical amplification fiber winding body 60 thus obtained does not have a winding start start end of the optical amplification fiber, as shown in FIG. Since both end portions 65 and 66 can be pulled out in the tangential direction of the outer periphery as shown in the drawing, or in any direction such as the parallel direction, depending on the requirements of the device, it may be convenient for mounting. Becomes

It goes without saying that this embodiment can be applied to the above-mentioned embodiments and also to the below-mentioned embodiments. Next, an example of an apparatus to which the fiber winding body for optical amplification of the present invention is applied and mounted will be described with reference to FIG.
The perspective view of FIG. In FIG. 5, a printed board unit 70 is used as an optical amplifier, a front board 72 is attached to the front side of the printed board 71, and a plug-in connector 73 is attached to the back side. With such a configuration, the printed board unit 70 is plugged in and connected to the housing of the optical amplification unit device (not shown).

A modularized optical component 74 such as a thin semiconductor laser device, an isolator, an optical multiplexer / demultiplexer is mounted on one surface of the printed board 71, and a mounting area 75 where circuit components are mounted is provided around the module. Has been formed. The optical amplification fiber winding body 76 of the present invention is attached near the mounting area of the optical component 74. This printed board unit 7
0 is extremely thin as a whole and is mounted in a device at a high density. Therefore, the packaging efficiency due to the thinned fiber amplifier for optical amplification is extremely advantageous.

FIG. 6 shows another example of an apparatus to which the fiber winding body for optical amplification of the present invention is applied and mounted. This will be described below. In FIG. 6, the optical amplification device is a modularized unit 80, and an optical component 81 such as a semiconductor laser device that is miniaturized and thinned is housed in a thin casing 82 together with a circuit board and the like. The optical amplification fiber winding body 85 of the present invention is attached to the inner surface side of the cover 83 that covers the upper opening of the housing 82.

The optical amplification fiber winding body 85 may be constructed by attaching the above-mentioned ones or by forming the winding frame 86 on the cover 83 and winding the optical amplification fiber 87 around the winding frame 86. That's right. A connector for electrical connection, a connector for optical fiber connection, and the like are provided so as to penetrate the housing 82.

Even when the optical amplification fiber winding body 85 is mounted so as to overlap the optical component 81 as described above, the optical amplification fiber assembly 85 is made thin, so that the unit 80 is made to have the entire thickness. A thin and miniaturized state is maintained.

The housing 82 is rectangular in plan view. The fiber amplification body for optical amplification applied to such a case has the shape shown in FIG. 7 rather than the circular shape as in the above-described embodiment, so that the entire surface can be utilized, and it is thinner. It can be shaped.

Referring to FIG. 7, the fiber winding body 90 for optical amplification is basically rectangular. Then, the radii r of the four inner corners are the minimum bendable dimensions of the optical amplification fiber. The portion around which the optical amplification fiber is actually wound is formed in an arc 92 having a large radius R with respect to a straight line (indicated by a chain double-dashed line) 91 connecting the quarter arcs.

The core part of the winding frame is formed in such a shape. Therefore, the outer peripheral contour 93 of the optical amplification fiber winding body 90 wound and formed by this is similar to the core portion. Since the optical amplifying fiber end portions 94, 94 of the present embodiment are formed by the winding method shown in the embodiment of FIG. 4, both are extended to the outer peripheral end.

As in the present embodiment, the straight line portion has a large arc 9
The reason for setting 2 is as follows. In other words, if a straight line is formed between the quarter arcs formed by the radius r, the linear portion will not be in a linear state due to other reasons such as centrifugal force when the optical amplification fiber is wound. It is curved and wound.

As the winding progresses, this is crushed by the optical amplifying fiber wound upward, which causes an abnormal shape. Therefore, we try to prevent such a situation from occurring.

As described above, it is sufficiently possible for the optical fiber winding body of the present invention to be deformed into an elliptical shape or an applied shape. Next, considering the winding width, that is, the thickness, the above-described embodiment has a thickness of 1 mm, but is not limited to this. Since the width (thickness) of the circuit components to be mounted is about 3 mm or less, if the diameter of the standard optical amplification fiber is 125 μm, the thickness of the resin coating can be arbitrarily set.
It is difficult to set a diameter of m as a reference value.

Therefore, the outer diameter of the cladding of the optical amplification fiber is 125 μm, which is 20 times the outer diameter, that is, 2.5 mm is the upper limit. The above numerical value is appropriate in consideration of adding the thickness of a thin plate, a resin for bonding, etc. to this. As a matter of course, the setting below this can be set in accordance with the relationship between the winding diameter and the area, if necessary.

A known epoxy resin, urethane resin, or the like can be applied as the bonding resin. However, by applying a relatively flexible resin after curing, the optical amplification fiber roll is mounted on the mounting surface. It is also possible to mount it by bending it along.

[0045]

As described in detail above, according to the fiber amplifier for optical amplification of the present invention, the completed product has no winding frame, bobbin, etc. Is effective in improving the implementation efficiency of
It is extremely effective to contribute to downsizing and thinning of the device. By making it thinner, it also has flexibility and can be made to fit the mounting surface. By bonding with a resin, practical effects such as easy handling are remarkable.

[Brief description of drawings]

FIG. 1 is a perspective view of an embodiment of a fiber winding body for optical amplification of the present invention.

FIG. 2 is an explanatory view of a method for manufacturing a fiber winding body for optical amplification in FIG.

FIG. 3 is a second embodiment of a fiber winding body for optical amplification of the present invention.

FIG. 4 is a third embodiment of a fiber winding body for optical amplification of the present invention.

FIG. 5 is an example of an apparatus to which the fiber winding body for optical amplification of the present invention is applied and mounted.

FIG. 6 is another example of an apparatus to which the fiber winding body for optical amplification of the present invention is applied and mounted.

FIG. 7 is a fourth embodiment of a fiber winding body for optical amplification of the present invention.

FIG. 8 is a schematic diagram of an optical communication system.

FIG. 9: Conventional fiber amplification fiber winding body

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Optical transmitter 2, 4 Optical fiber 3 Optical repeater 5 Optical receiver 20 Optical amplification fiber roll 21 Optical amplification fiber 22, 23 Optical fiber amplification start and end 30 Winding frame 35 Resin coating device 39 Resin 50 Optical amplification fiber roll 51 Core material 52,53 Thin plate 58 Reel 60 Optical amplification fiber roll 70 Printed board unit 76 Optical amplification fiber roll 80 Optical amplification module unit 85 Optical amplification fiber roll

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location H01S 3/02 3/07 8934-4M

Claims (3)

[Claims] 1. An optical amplification fiber (21) comprising a central core portion containing a rare earth element and a clad layer surrounding the core portion, wherein the optical amplification fiber (21) has a required length. Regarding the wound body, a fiber wound body for optical amplification, wherein the wound body is a flat wound body (20). 2. The optical amplification fiber winding body according to claim 1, wherein the flat winding width (F) is 20 times or less the optical amplification fiber diameter. 3. A winding body (20) of the fiber for optical amplification.
The optical fiber winding body according to claim 1 or 2, wherein the resin is bonded by a resin (39).