JPH0653586A - Optical fiber amplifier - Google Patents

Abstract

(57) [Summary] [Purpose] One unit can amplify multiple signal lights at once.
Provided is an optical fiber amplifier which can be easily attached to a multi-core optical fiber. In an optical fiber amplifier for amplifying signal light by a stimulated emission effect in a rare earth-doped fiber 10 on which pumping light from a pumping light source 5 enters, a plurality of optical fibers 6 and 7 are collectively provided in an input / output section Connectable connectors 2 and 3 are provided, and a plurality of main body circuits 4 including the rare earth-doped fiber 10 are provided between these input / output portions.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical fiber amplifier for guiding signal light and pumping light to a rare earth-doped fiber doped with a rare earth element such as erbium (Er) and amplifying the signal light by the stimulated emission effect. More specifically, the present invention relates to an optical fiber amplifier capable of collectively amplifying a plurality of signal lights from a multi-core optical fiber core wire.

[0002]

2. Description of the Related Art An optical fiber amplifier in which signal light and pumping light are introduced into a rare earth-doped fiber doped with a rare earth such as Er, and the signal light is amplified by the stimulated emission effect of the rare earth-doped fiber is known. , Usually Fig. 4
The configuration is as shown in FIG.

In FIG. 4, reference numeral 31 is a signal light incident connector, 32 is an optical isolator that blocks reflected light and allows light to pass in only one direction, 33 is an excitation light source such as a laser diode, and 34 is excitation light. Is an optical coupler, 35 is a rare-earth-doped fiber, and 36 is a signal light emitting connector.

From the incident connector 31 to the optical isolator 32
The signal light incident through is mixed with the excitation light by the optical coupler 34 and introduced into the rare earth-doped fiber 35, and is amplified in the rare earth-doped fiber 35 by the stimulated emission effect.

[0005]

Generally, one optical fiber amplifier as described above is provided for each communication optical fiber to which signal light is sent, and as shown in FIG.
For the tape core wire T of the core, four optical fiber amplifiers 37, ... Are provided for each optical fiber f. in this case,
In each optical fiber amplifier 37, the rare-earth-doped fiber 3
An input connector 31 and an output connector 36 for a single wire are attached to the input and output portions of a main body circuit 38 centered at 5, respectively. A single wire connector 39 is attached for each book.

Therefore, when an optical fiber amplifier is provided in a multi-core optical fiber, not only is the mounting work troublesome, but also a large number of optical fiber amplifiers are required, which occupies a large occupied space and is costly.

The present invention addresses such a conventional problem, and enables a single optical fiber amplifier to collectively amplify a plurality of signal lights input from a plurality of optical fibers. An object of the present invention is to reduce the number of optical fiber amplifiers to be attached to a multi-core optical fiber and to facilitate the attachment work.

[0008]

In order to achieve the above-mentioned object, the present invention provides an optical fiber amplifier for amplifying a signal light by a stimulated emission effect in a rare earth-doped fiber on which pumping light from a pumping light source is incident, The input / output section is provided with a connector to which a plurality of optical fibers can be collectively connected, and the main body circuit including the rare earth-doped fiber is provided between the input / output sections.

[0009]

In the optical fiber amplifier configured as described above, a plurality of signal lights incident through the connector are amplified by the stimulated emission effect of the rare earth-doped fiber and emitted from the other connector. When this optical fiber amplifier is attached to a multi-core optical fiber core, a single connector may be attached to the optical fiber core wire and connected to a single connector on the amplifier side.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The details of the present invention will be described based on the embodiments shown in FIGS. First, FIGS. 1 and 2 relate to a first embodiment of the present invention. FIG. 1 is a schematic configuration diagram of an entire optical fiber amplifier, and FIG. 2 is a configuration diagram of a main circuit which is a part thereof.

As shown in FIG. 1, the optical fiber amplifier 1 of this embodiment corresponds to a four-core tape core wire T.
Four-core input connector 2 and four-core output connector 3
And two body circuits 4 and a pumping light source 5 such as a single laser diode.

Both incident side and output side connectors 2, 3
Is capable of connecting four optical fibers at a time, and two optical fibers 6 and 7 on the incident side and the optical output side, which are connected to the connectors 2 and 3, are connected to the main body circuit 4 respectively. It Corresponding to these connectors 2 and 3, a 4-core connector 8 is also attached to the 4 optical fibers f of the tape core wire T.

As will be described later, each main body circuit 4 is mainly composed of a rare earth-doped fiber and collectively amplifies two input signal lights by the stimulated emission effect of the rare earth-doped fiber. In this example, The single pumping light source 5 is used as a common light source, and the pumping light is introduced to each of them through the optical coupler 9 as a light distributor.

As shown in FIG. 2, each main body circuit 4 has a single rare earth-doped fiber 10 and a pumping light for introducing the pumping light from the pumping light source 5 into the rare earth-doped fiber 10. The optical coupler 11 and the first and second optical elements provided at both ends of the rare earth-doped fiber 10, respectively.
And the signal light from the two incident side optical fibers 6 and 6 through the first and second signal light optical couplers 12 and 13, respectively. The light is incident on the rare earth-doped fiber 10 in both directions, and the amplified signal light in the rare earth-doped fiber 10 is extracted from the first and second signal light optical couplers 12 and 13 through the two emission side optical fibers 7 and 7. It is like this. Reference numeral 14 is an optical isolator provided in each of the two optical fibers 6 and 6 on the incident side.

In the above structure, the signal light transmitted through each optical fiber f of the tape core wire T is the connector 8,2.
It is input to the optical fiber amplifier 1 through the optical fiber amplifier 1 and is amplified by each main circuit 4 by 2 inputs and output from the connector 3 on the output side.

In each body circuit 4, the two input signal lights are incident on the rare earth-doped fiber 10 in opposite directions through the corresponding signal light optical couplers 12 and 13, respectively. Then, each signal light passes through the rare-earth-doped fiber 10 pumped by the pumping light, is amplified by bidirectional amplification, and does not interfere with each other.

In this way, the signal light from each optical fiber f of the tape core wire T is collectively amplified by one optical fiber amplifier 1. This optical fiber amplifier 1 is a tape core T
In the case where the tape core T is provided, a single connector 8 may be attached to the tape core wire T and connected to the connector 2 on the amplifier side.

In the first embodiment described above, the main body circuit 4 for amplifying the signal light for two inputs by the bidirectional amplification in the single rare earth-doped fiber 10 was used, but the main body circuit is not necessarily limited to this. The present invention is not limited to this, and as shown in FIG. 3, a body circuit having another configuration may be used.

FIG. 3 is a schematic configuration diagram of the entire optical fiber amplifier according to the second embodiment of the present invention. In this example,
Inside one optical fiber amplifier 21, four main body circuits 24 for amplifying one input signal light by unidirectional amplification with a rare earth doped fiber are provided.
Then, the signal light from each optical fiber f of the four-core tape core wire T is individually amplified. A single pumping light source 25 is provided, and the pumping light is distributed by the optical couplers 29a and 29b provided in two stages and supplied to each body circuit 24.

On the incident side and the outgoing side of the signal light, there are provided connectors 2 and 3 to which four optical fibers can be connected all at once. Correspondingly, the external tape core T also has four cores. The point that the connector 8 is attached is the same as in the first embodiment. The optical fibers 6 and 7 connected to the connectors 2 and 3 on the incident side and the emission side are respectively connected to the main body circuit 24.

The main body circuit 24 includes an optical isolator on the signal light incident side, a single rare earth-doped fiber, and an excitation light optical coupler for introducing the excitation light from the excitation light source 25 into the rare earth-doped fiber. Since it is provided, it is almost the same as the main body circuit 38 of the related art shown in FIG.

In each of the above embodiments, a single pumping light source 5 (25) is provided for the plurality of main body circuits 4 (24), and the pumping light from the pumping light source 5 (25) is supplied to each main body circuit. 4 (24)
It was distributed to each main circuit, but of course each main circuit 4
A dedicated excitation light source may be provided for each (24).

[0023]

The optical fiber amplifier according to the present invention collectively amplifies a plurality of signal lights, and it is sufficient to connect one optical fiber amplifier to a multi-core optical fiber core wire. It is possible to reduce the number of amplifiers to be attached to the optical fiber core wire, and to easily perform the attaching work.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of an entire optical fiber amplifier according to a first embodiment of the present invention.

FIG. 2 is a configuration diagram of a main circuit of the optical fiber amplifier.

FIG. 3 is a schematic configuration diagram of an entire optical fiber amplifier according to a second embodiment of the present invention.

FIG. 4 is a block diagram of a conventional optical fiber amplifier.

FIG. 5 is a connection diagram showing a usage state of a conventional optical fiber amplifier.

[Explanation of symbols]

 1,21 Optical fiber amplifier 2 Incident side connector 3 Emission side connector 4,24 Main circuit 5,25 Pumping light source 10 Rare earth doped fiber

Front Page Continuation (72) Inventor Haruo Oizumi 4-3 Ikejiri, Itami City, Hyogo Prefecture Mitsubishi Cable Industries, Ltd. Itami Works (72) Inventor Hisa Sawada 4-3 Ikejiri, Itami City, Hyogo Mitsubishi Cable Industries Itami Co., Ltd. (72) Inventor Masataka Nakazawa 1-1-6 Uchisaiwaicho, Chiyoda-ku, Tokyo Nihon Telegraph Telephone Co., Ltd. (72) Inventor Yasuro Kimura 1-1-6 Uchiyukicho, Chiyoda-ku, Tokyo Nihon Telegraph Telephone Stock In the company

Claims (1)

[Claims] 1. An optical fiber amplifier for amplifying signal light by a stimulated emission effect in a rare earth-doped fiber (10) on which pumping light from a pumping light source (5) is incident, wherein a plurality of optical fibers are provided at each input / output section. The connectors (2, 3) that can connect (6, 7) together are provided, and the rare earth-doped fiber is provided between these input and output parts.
An optical fiber amplifier, characterized in that a main body circuit (4) including (10) is provided.