JPH1075215A - Optical add / drop multiplexer and wavelength division multiplex submarine branching system - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To reduce insertion loss of a through optical signal in an optical add / drop multiplexer. SOLUTION: An optical wavelength multiplexed signal λ1 to λ4 incident through an input terminal (INPUT) is incident on a dielectric multilayer filter 1 having different transmission wavelengths according to an inclination angle, and for example, only an optical signal of a wavelength λ2. Is extracted (transmitted) and emitted through a drop light emission terminal (DROP). Further, the filter 1
The optical signal of the same wavelength λ2 as the optical signal extracted by the filter 1 is added to the add light incident terminal (ADD) so that it has the same optical axis as the optical signals of the wavelengths λ1, λ3, λ4 reflected by the filter 1.
Through the filter 1. And this wavelength λ2
Are combined with the optical signals of the wavelengths λ1, λ3, λ4 to form a through optical signal, which is emitted via an emission terminal (OUTPUT). Since the through optical signal is reflected only once by the filter 1, the insertion loss can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical add / drop multiplexer suitable for use in, for example, an optical communication system for transmitting and receiving optical wavelength multiplex signals, and a wavelength division multiplex submarine using the optical add / drop multiplexer. In particular, the present invention relates to a branching system, in which an optical signal transmitted through the optical add / drop multiplexing device (through optical signal) by using one dielectric multilayer filter and setting the number of times of reflection of an incident optical wavelength multiplex signal to one. 2) an optical add / drop multiplexer and a wavelength division multiplex submarine branching system for reducing the insertion loss.

[0002]

2. Description of the Related Art Conventionally, there has been known an optical add / drop multiplex device formed of two optical circulators and a fiber grating. The optical add / drop multiplexer extracts an optical signal of a predetermined wavelength from the input optical wavelength multiplex signal, and simultaneously multiplexes an optical signal of the same wavelength as the optical signal of the predetermined wavelength with the extracted optical signal. And is emitted.

[0003]

Here, the fiber grating used in the conventional optical add / drop multiplexer has a large insertion loss of the through optical signal formed by the multiplexing. For this reason, the present applicant has filed Japanese Patent Application No.
In the specification and drawings of JP-A-63684, an optical ADM apparatus using two dielectric multilayer filters is disclosed.

That is, this optical ADM apparatus is configured as shown in FIG. 5, and an optical wavelength multiplexed signal in which three optical signals of wavelengths λ1 to λ3 are optically multiplexed via an input terminal (INPUT). Supplied, first dielectric multilayer filter 5
1 is incident. This first dielectric multilayer filter 51
Is the wavelength λ of the three optical signals of the wavelengths λ1 to λ3.
2 has an optical property of transmitting an optical signal. For this reason, of the optical wavelength multiplexed signals incident on the first dielectric multilayer filter 51, only the optical signal of the wavelength λ2 passes through the first dielectric multilayer filter 51, and the wavelength λ1 and the wavelength λ3
Is reflected to the second dielectric multilayer filter 52.
Is incident on. The optical signal of the wavelength λ2 transmitted through the first dielectric multilayer filter 51 is emitted to the outside as a drop light signal via a drop light emission terminal (DROP).

[0005] The second dielectric multilayer filter 52 has an optical characteristic of transmitting an optical signal of wavelength λ2, like the first dielectric multilayer filter 51. Therefore, the wavelength λ reflected by the first dielectric multilayer filter 51
The optical signal having the wavelength 1 and the wavelength λ3 is reflected again by the second dielectric multilayer filter 52.

An optical signal of the wavelengths λ1 and λ3 reflected by the second dielectric multilayer filter 52 is supplied to the second dielectric multilayer filter 52 via an add light input terminal (ADD). An optical signal having a wavelength λ2 is incident so as to have the same optical axis as the optical signal. Therefore, the optical signals of the wavelengths λ1 and λ3 reflected by the second dielectric multilayer filter 52 are multiplexed with the optical signal of the wavelength λ2 from the add optical input terminal (ADD), and the incident terminal Is an optical wavelength multiplexed signal (optical wavelength multiplexed signal composed of wavelengths λ1 to λ3) having the same components as the optical wavelength multiplexed signal incident through the optical network. The optical wavelength multiplex signal formed by the multiplexing is output to the outside via an output terminal (OUTPUT) as a through optical signal.

In such an optical ADM apparatus, since a dielectric multilayer filter is used instead of a fiber grating as a means for demultiplexing and multiplexing an optical wavelength multiplex signal, insertion of the through optical signal is performed. Loss can be reduced.

However, as a result of the research and development of the present applicant, in addition to this optical ADM device, an optical add / drop multiplex device and a wavelength division multiplex submarine branch device capable of reducing insertion loss of a through optical signal. This is disclosed here because the system was successfully developed.

[0009]

According to a first aspect of the present invention, there is provided an optical add / drop multiplexer according to the present invention, wherein a plurality of optical signals having different wavelengths are optically multiplexed. An input terminal into which the multiplexed signal is input, an output terminal from which an optical wavelength multiplexed signal having the same optical signal component as the optical wavelength multiplexed signal input through the input terminal is output, and input through the input terminal. A drop light emitting terminal from which a drop optical signal that is an optical signal of a predetermined wavelength extracted from the optical wavelength multiplex signal is emitted; and an add light incident that receives an add optical signal that is an optical signal having the same wavelength as the drop optical signal. And a terminal. Further, an optical signal of a predetermined wavelength among the optical wavelength multiplexed signals incident through the incident terminal is transmitted, and this is emitted through the drop light emitting terminal as a drop optical signal, and other than the drop optical signal. By reflecting the optical signal and multiplexing it with the add optical signal input through the add optical input terminal, the optical wavelength multiplexing of the same optical signal component as the optical wavelength multiplex signal input through the input terminal is performed. It has one dielectric multilayer filter for forming a signal and outputting the signal through the output terminal.

[0010] Such an optical add / drop multiplexing device includes:
Of the optical wavelength multiplexed signal incident through the incident terminal, an optical signal of a predetermined wavelength is reflected by the dielectric multilayer filter, and the reflected optical signal of the predetermined wavelength is incident through the add light incident terminal. Multiplexed with the added add optical signal to form an optical wavelength multiplexed signal (through optical signal) having the same optical signal component as the optical wavelength multiplexed signal incident via the incident terminal, which is connected to the output terminal. Emitted through

Since the through optical signal, which is an optical wavelength multiplexed signal emitted through the emission terminal, is reflected only once by the dielectric multilayer filter, the insertion loss of the through optical signal is greatly reduced. Can be reduced.

Next, in the optical add / drop multiplexer according to the present invention, the optical wavelength formed by the multiplexing at the output terminal provided at a position different from the installation position of the input terminal. The dielectric multilayer filter is provided with a predetermined inclination angle so that a multiplex signal is incident.

Specifically, it is desirable that the tilt angle of the dielectric multilayer filter is, for example, not less than 1 degree and not more than 10 degrees. This can prevent such an inconvenience that an optical signal other than the drop optical signal reflected by the dielectric multilayer filter returns to the light source via the incident terminal and adversely affects the light signal.

In the optical add / drop multiplexer according to the present invention, the optical wavelength multiplex signal from the input terminal is converged and incident on a dielectric multilayer filter, and the dielectric multilayer filter is provided. One collimator lens for collimating an optical wavelength-division multiplexed signal formed by combining the optical signal reflected by the film filter and the add optical signal incident through the add optical incident terminal and entering the output terminal Having. The dielectric multilayer filter transmits an optical signal of a predetermined wavelength out of the input optical wavelength multiplex signal, and receives the optical wavelength multiplex signal through the incident terminal and the collimator lens. An optical wavelength multiplexed signal formed by multiplexing the optical signal reflected by the film filter and the add optical signal is provided at an inclination angle such that the optical wavelength multiplexed signal enters the output terminal via the collimator lens.

Such an optical add / drop multiplexer has
An objective lens for converging an optical wavelength multiplexed signal from the input terminal and entering the dielectric multilayer filter, which has conventionally been separately required, and an optical signal reflected by the dielectric multilayer filter as a parallel light. A single collimator lens can be used in common with the collimator lens for making the light enter the output terminal, and the cost can be reduced through simplification of the configuration of the optical add / drop multiplexer.

In the optical add / drop multiplexer according to the present invention, a crosstalk removing dielectric multilayer film for removing a crosstalk component from a drop optical signal transmitted through the dielectric multilayer filter is provided. Has a filter.

By providing the crosstalk removing dielectric multilayer filter, it is possible to remove the crosstalk component of the drop optical signal passing through the dielectric multilayer filter, thereby extracting a high-quality drop optical signal. Can be possible.

Next, in a wavelength division multiplexing submarine branching system according to the present invention, a plurality of optical signals having different wavelengths are subjected to optical wavelength division multiplexing from an optical submarine cable from a transmission device. The optical add / drop multiplexing device extracts an optical signal of a predetermined wavelength from the optical wavelength multiplexed signal, transmits the extracted signal to the repeater via the optical submarine cable, and transmits the predetermined wavelength from the repeater. Is a wavelength division multiplexing submarine branching system for multiplexing the optical signal of (1) with an optical signal obtained by extracting the optical signal of the predetermined wavelength, and transmitting the optical wavelength multiplexing signal to a receiving device via an optical submarine cable. As the optical add / drop multiplexer, an optical add / drop multiplexer having the same configuration as that of the above-described optical add / drop multiplexer is provided.

That is, the optical add / drop multiplexing device includes an input terminal to which an optical wavelength multiplex signal from the transmission device is input, and an optical signal component of the same optical wavelength component as the optical wavelength multiplex signal input through the input terminal. An output terminal for transmitting an optical wavelength multiplex signal to the receiving device side, and a drop optical signal, which is an optical signal of a predetermined wavelength extracted from the optical wavelength multiplex signal incident via the incident terminal, to the relay device side. And an add light incident terminal to which an add optical signal from the repeater, which is an optical signal having the same wavelength as the drop optical signal, enters. Also, an optical signal of a predetermined wavelength among the optical wavelength multiplexed signals incident from the transmission device side via the incident terminal is transmitted and transmitted as a drop optical signal to the relay device side via the drop light emission terminal. In addition, by reflecting an optical signal other than the drop optical signal and multiplexing the add optical signal transmitted from the repeater side through the add optical incident terminal, the optical signal is incident through the incident terminal. It has one dielectric multilayer filter for forming an optical wavelength multiplexed signal having the same optical signal component as the optical wavelength multiplexed signal and transmitting the optical wavelength multiplexed signal to the receiving device side via the emission terminal.

In such a wavelength division multiplexing submarine branching system, a through optical signal, which is an optical wavelength multiplexing signal transmitted to the receiver via the emission terminal, is reflected only once by the dielectric multilayer filter. Therefore, the insertion loss of the through optical signal can be significantly reduced.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of an optical add / drop multiplexer and a wavelength division multiplex submarine branching system according to the present invention will be described below in detail with reference to the drawings.

First, an optical add / drop multiplexer according to a first embodiment of the present invention has a wavelength λ1 as shown in FIG.
An input terminal (INPUT) to which an optical wavelength multiplexed signal formed by optical wavelength multiplexing of optical signals of .lambda.4 is input, and an add light input terminal (ADD) to which an add optical signal which is an optical signal of wavelength .lambda.2 is input. And an output terminal (OUTPUT) from which an optical wavelength multiplexed signal of the same optical signal component (optical signal of wavelengths λ1 to λ4) as the optical wavelength multiplexed signal input via the input terminal is output. A drop light output terminal (DROP) from which a drop light signal, which is a light signal of wavelength λ2 extracted from the light wavelength multiplexed signal that has been incident, is output, one dielectric multilayer filter 1, and 1 shown in FIG. Two collimator lenses 2
It is composed of

The dielectric multilayer filter has the characteristic that the center wavelength of the transmitted optical signal shifts to the shorter wavelength side according to the tilt angle. For this reason, the dielectric multilayer filter 1
Is that the input terminal and the output terminal are separated from each other in position, the optical signal having the wavelength λ2 can be transmitted, and the wavelength λ2
In order to prevent an optical signal having a wavelength other than the optical signal described above from returning to the laser light source side and adversely affecting the laser signal, the inclination angle is fixed to a predetermined angle (θ).

More specifically, the tilt angle θ is determined by the characteristics of the dielectric multilayer filter 1, but is desirably at least 1 degree in order to separate the input terminal and the output terminal from each other.
In addition, in the overall design of the optical add / drop multiplexer, 1
It is desirably 0 degrees or less.

In the dielectric multilayer filter 1 according to the present embodiment, the angle of inclination formed by a straight line orthogonal to the optical axis of the optical wavelength multiplexed signal incident through the incident terminal is 1 degree. (Θ = 1
Every time).

The collimator lens 2, as shown in FIG. 2, converges an optical wavelength multiplex signal incident through the incident terminal (INPUT) and impinges it on the dielectric multilayer filter 1, which will be described later. The optical wavelength-division multiplexed signal from the dielectric multilayer filter 1 formed by the multiplexing is converted into a parallel light and is incident on an output terminal (OUTPUT). That is, an objective lens for converging an optical wavelength multiplex signal from the input terminal (INPUT) and the dielectric multilayer filter 1
And a collimator lens for collimating an optical wavelength multiplexed signal formed by an optical signal or the like reflected by the optical collimator lens 2 (one collimator lens 2 is used in common). I have.

Next, the operation of the optical add / drop multiplexer according to the first embodiment having such a configuration will be described.

This optical add / drop multiplexer has a wavelength λ.
An optical wavelength multiplexed signal obtained by multiplexing four optical signals of 1 to λ4 is input via an input terminal (INPUT), and is input to the dielectric multilayer filter 1 via the collimator lens 2. As described above, this dielectric multilayer filter 1
Has an optical characteristic of transmitting only the optical signal of the wavelength λ2 among the optical signals of the wavelengths λ1 to λ4. For this reason,
Only the optical signal having the wavelength λ2 of the optical wavelength multiplexed signal incident on the dielectric multilayer filter 1 is transmitted through the dielectric multilayer filter 1 and externally transmitted as a drop optical signal via the drop light emitting terminal (DROP). Is emitted.

Further, as described above, the dielectric multilayer filter 1 is provided with an inclination angle of 1 degree. For this reason, among the optical wavelength multiplexed signals incident on the dielectric multilayer filter 1, the optical signals of the wavelengths λ1, λ3 and λ4 are reflected according to the inclination angle θ of the dielectric multilayer filter 1, It is reflected at an angle of 2 degrees (2θ) formed by the optical axis of the optical wavelength multiplexed signal and the optical axes of the optical signals of wavelengths λ1, λ3 and λ4 reflected by the dielectric multilayer filter 1. You.

Here, an add optical signal, which is an optical signal having the same wavelength as the wavelength λ2 extracted from the optical wavelength multiplex signal by the dielectric multilayer filter 1, is reflected by the dielectric multilayer filter 1. Optical input terminal (ADD) so that it has the same optical axis as the optical signals of the wavelengths λ1, λ3 and λ4.
Is incident through. Therefore, the optical signals of the wavelengths λ1, λ3 and λ4 reflected by the dielectric multilayer filter 1 are multiplexed with the add optical signal of the wavelength λ2 incident via the add optical input terminal (ADD). It will be. Then, due to this multiplexing, the same optical signal component (wavelength λ1) as the optical wavelength multiplexed signal incident via the incident terminal (INPUT).
Λ4) is formed. The optical wavelength multiplex signal formed by the multiplexing is emitted to the outside through an emission terminal (OUTPUT) as a through optical signal via the collimator lens 2.

In the optical add / drop multiplexer according to the first embodiment, the optical wavelength multiplex signal formed by the reflection only once by the dielectric multilayer filter is output as the through optical signal. Since the light is emitted through the terminal (OUTPUT), the insertion loss of the through optical signal can be significantly reduced.

When a fiber grating is used in place of the dielectric multilayer filter 1, the fiber grating has a thickness of 0.01 nm / .degree.
Although the temperature characteristic error occurs, the dielectric multilayer filter 1 has 0.0025n each time the temperature changes once.
Only a very small temperature characteristic error of m / ° C. occurs. For this reason, it is possible to provide a highly reliable optical add / drop multiplex device with stable operation.

An objective lens for converging an optical wavelength multiplexed signal from the input terminal (INPUT), which has conventionally been separately required, and an optical signal reflected by a dielectric multilayer filter are converted into parallel light. The collimator lens for entering the output terminal (OUTPUT) can be shared by the one collimator lens 2, and the cost can be reduced through simplification of the configuration of the optical add / drop multiplexer. .

Next, an optical add / drop multiplexer according to a second embodiment of the present invention will be described. Note that this second
In the description of the optical add / drop multiplexing device according to the embodiment, the same reference numerals are given to portions showing the same operations as those of the optical add / drop multiplexing device according to the above-described first embodiment,
A detailed description thereof will be omitted.

In the optical add / drop multiplexer according to the second embodiment, as shown in FIG. 3, the optical add / drop multiplexer has a wavelength λ2 transmitted through the dielectric multilayer filter 1 after the dielectric multilayer filter 1. A crosstalk removing dielectric multilayer filter 3 for removing a crosstalk component from a drop optical signal, which is an optical signal, is provided.

That is, the dielectric multilayer filter 1
Extracts an optical signal (drop optical signal) having a wavelength of λ2 from an optical wavelength multiplexed signal incident through an input terminal (INPUT). The optical signal is extracted due to an error in the installation inclination angle of the dielectric multilayer filter 1. , The wavelength λ2 of the extracted drop optical signal.
An optical signal having a wavelength other than the above may appear as a crosstalk component.

Therefore, like the optical add / drop multiplexer according to the second embodiment, a crosstalk removing dielectric that transmits only an optical signal of wavelength λ2 is provided downstream of the dielectric multilayer filter 1. By providing the body multilayer filter 3, a high-quality drop optical signal from which a crosstalk component has been removed can be formed. Therefore, it is not necessary to adjust the inclination angle of the dielectric multilayer filter 1 so strictly, and it is possible to improve the degree of freedom of design.
Assembly accuracy can be reduced.

Next, the optical add / decode according to each of the above-described embodiments will be described.
The drop multiplexer can be applied to a wavelength division multiplex submarine branching system as shown in FIG.

The wavelength division multiplexing submarine branching system according to the third embodiment of the present invention transmits and receives optical wavelength division multiplexing signals of wavelengths λ1 to λ4, the first and second WDM terminal devices 30 and 36. And the first and second WDM terminal devices 30 and 3
WDM submarine branching device 33 provided at the relay position between 6
And a terminal device 41 that receives an optical signal of a predetermined wavelength branched by the WDM submarine branching device 33 and returns the optical signal to the WDM submarine branching device 33.

Specifically, the first WDM terminal device 3
0 is connected to the WDM submarine branching device 33 by an optical submarine cable 31 via an optical amplification repeater 32. Similarly, the second WDM terminal device 36
5 and an optical submarine cable 34 connected to the WDM submarine branching device 33. In addition, the WDM submarine branching device 33 is connected to the terminal station device 41 by a non-repeater optical submarine cable 37.

The WDM submarine branching device 33 has the same configuration as the optical add / drop multiplexing device according to each of the above embodiments, and is used for the first WDM terminal device 30 and the second WDM terminal device 36. For each optical add / drop multiplexing unit 43. Each optical add / drop multiplexing unit 43
Is designed to add / drop an optical signal of wavelength λ2.

The terminal unit 41 takes in the optical signal of the wavelength λ2 and transmits the add optical signal of the wavelength λ2 to each optical add / drop multiplexing unit 43 via the high-output terminal optical amplifier 42. In the vicinity thereof, an optical amplifier 38 to which the drop optical signal is transmitted, a WDM coupler 39 and a laser light source 40 for exciting the optical amplifier 38, and an add optical signal having a wavelength λ2 are amplified. A high-power terminal optical amplifier 42 for transmitting to the WDM submarine branching device 33 is provided.

Next, the operation of the wavelength division multiplex submarine branching system according to the third embodiment having such a configuration will be described. In this wavelength division multiplex submarine branching system, the first WDM terminal device 30 transmits
When transmitting an optical wavelength multiplex signal to the DM terminal device 36,
Conversely, the second WDM terminal device 36 sends the first WDM
Regardless of the case where the optical wavelength multiplexed signal is transmitted to the DM terminal station device 30, the system performs the same operation in any case.
Only the system operation when transmitting an optical wavelength multiplex signal to the terminal device 36 will be described, and the system operation when transmitting an optical wavelength multiplex signal from the second WDM terminal device 36 to the first WDM terminal device 30 will be described. Will be omitted.

That is, in this case, the first WDM terminal device 30 transmits the wavelength λ 1 transmitted to the second WDM terminal device 36.
An optical wavelength multiplexed signal in which the optical signals of .lambda.4 to .mu.4 are multiplexed is formed and transmitted to the optical add / drop multiplexing unit 43 in the WDM submarine branching unit 33 via the optical amplification repeater 32.

As described above, the optical add / drop multiplexing section 43 has the configuration shown in FIGS. 1 and 2, and the optical wavelength multiplexing signal is applied to the dielectric multilayer through the input terminal (INPUT). The light enters the membrane filter 1. The dielectric multilayer filter 1 extracts an optical signal having the wavelength λ2 from the input optical wavelength multiplex signal, and transmits the extracted optical signal to the terminal device 41 via the drop light output terminal (DROP) as a drop light signal. At this time, the optical amplifier 38 is excited by the WDM coupler 39 and the laser light source 40, and the wavelength λ2
Of the drop optical signal is amplified by a predetermined gain and
Sent to. For this reason, even if the non-repeated optical submarine cable 37 is extended, a drop optical signal always maintained at a predetermined level can be transmitted to the terminal device 41.

Next, when the drop optical signal is transmitted, the terminal device 41 captures the drop optical signal, and an optical signal of the same wavelength λ2 as the drop optical signal is added as an add optical signal via the high-output terminal optical amplifier 42. To the optical add / drop multiplexer 43.

This add light signal is input to the dielectric multilayer filter 1 via the add light input terminal (ADD) shown in FIG. Then, it is multiplexed with the optical signals of wavelengths λ1, λ3, λ4 reflected by the dielectric multilayer filter 1, and
The optical wavelength multiplexed signals (wavelengths λ1 to λ4) having the same optical signal components as the optical wavelength multiplexed signals input from the WDM terminal device 30 via the input terminal (INPUT).

The through optical signal, which is an optical wavelength multiplexed signal, is supplied to the optical amplification repeater 32 through the output terminal (OUTPUT).
Is transmitted to Then, the signal is amplified by the optical amplification repeater 32 with a predetermined gain and transmitted to the second WDM terminal device 36.

In the wavelength division multiplex submarine branching system according to the third embodiment,
Since the optical add / drop multiplexer 43 having the same configuration as the optical add / drop multiplexer according to each of the above-described embodiments is provided, the first or second WDM is performed via the optical add / drop multiplexer 43. It is possible to reduce insertion loss of through optical signals (optical wavelength multiplexed signals of λ1 to λ4) transmitted to the terminal devices 30 and 36, and to enable submarine cable communication of high quality optical wavelength multiplexed signals. Can be.

In the wavelength division multiplex submarine branching system according to the third embodiment, when it is desired to remove the crosstalk component of the through optical signal, as described with reference to FIG. The crosstalk removing dielectric multilayer filter 3 may be provided at a stage subsequent to the membrane filter 1. Thus, the same effect as the optical add / drop multiplexer according to each of the above-described embodiments can be obtained, such as obtaining a higher quality signal as the through optical signal.

Finally, in each of the above embodiments, specific numerical values such as the inclination angle of the dielectric multilayer filter 1 being about 1 degree have been described, but this is only an example. Of course, various changes can be made according to the wavelength and design of the optical signal to be transmitted.

[0052]

The optical add / drop multiplexer and the wavelength division multiplex submarine branching system according to the present invention can greatly reduce the insertion loss of through light.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a configuration of an optical add / drop multiplexer according to a first embodiment of the present invention.

FIG. 2 shows an objective lens required for an input terminal and an output terminal by adjusting an inclination angle of a dielectric multilayer filter provided in the optical add / drop multiplexer according to the first embodiment. FIG. 4 is a diagram for explaining how a collimator lens can be reduced by one collimator lens.

FIG. 3 is a diagram illustrating a configuration of an optical add / drop multiplexer according to a second embodiment of the present invention.

FIG. 4 is a block diagram of a wavelength division multiplexing submarine branching system according to a third embodiment of the present invention.

FIG. 5 is a diagram showing a configuration of an optical add / drop multiplexing device using two dielectric multilayer filters.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 dielectric multilayer filter 2 collimator lens 3 dielectric multilayer filter for removing crosstalk component INPUT input terminal OUTPUT output terminal ADD add light input terminal DROP drop light output terminal

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code Agency reference number FI Technical indication H04J 1/10 (72) Inventor Hidenori Taga 2-3-2 Nishishinjuku, Shinjuku-ku, Tokyo Kokusai Telegraph Telephone Co., Ltd. (72) Inventor Shu Yamamoto 2-3-2 Nishi-Shinjuku, Shinjuku-ku, Tokyo International Telegraph and Telephone Co., Ltd. (72) Inventor Shigeyuki Akiha 2-3-2 Nishi-Shinjuku, Shinjuku-ku, Tokyo International Telegraph Telephone Co., Ltd.

Claims (5)

[Claims] 1. An input terminal into which an optical wavelength multiplexed signal obtained by multiplexing a plurality of optical signals having different wavelengths is input, and light having the same optical signal component as the optical wavelength multiplex signal input through the input terminal. An emission terminal from which a wavelength multiplexed signal is emitted; a drop light emission terminal from which a drop optical signal, which is an optical signal of a predetermined wavelength, extracted from the optical wavelength multiplexed signal incident via the incident terminal; An add light incident terminal on which an add optical signal that is an optical signal having the same wavelength as the optical signal is incident, and an optical signal having a predetermined wavelength among optical wavelength multiplexed signals incident through the incident terminal is transmitted. By emitting through the drop light emission terminal as a drop light signal, and by reflecting an optical signal other than the drop light signal, by multiplexing with the add light signal incident through the add light incidence terminal, Before An optical add / drop device having a single dielectric multilayer filter for forming an optical wavelength multiplexed signal having the same optical signal component as the optical wavelength multiplexed signal incident through the incident terminal and emitting the signal through the output terminal. Multiplexer. 2. The dielectric multilayer filter according to claim 1, wherein the optical wavelength multiplexed signal formed by the multiplexing is incident on an output terminal provided at a position different from the installation position of the incident terminal. The optical add / drop multiplexer according to claim 1, wherein the optical add / drop multiplexer is provided with an inclination angle of: 3. The optical wavelength multiplexed signal from the incident terminal is converged and incident on the dielectric multilayer filter, and the optical signal reflected by the dielectric multilayer filter and incident via the add light incident terminal. A collimator lens for collimating an optical wavelength multiplexed signal formed by multiplexing the added add optical signal and entering the output terminal; and the dielectric multilayer film filter comprises: While transmitting an optical signal of a predetermined wavelength among the signals, an optical wavelength multiplexed signal is incident through the incident terminal and the collimator lens, and the optical signal reflected by the dielectric multilayer filter and the add optical signal are multiplexed. The light according to claim 1 or 2, wherein the formed optical wavelength multiplexed signal is provided at an inclination angle such that the optical wavelength multiplexed signal is incident on an output terminal via the collimator lens. De / drop multiplexing apparatus. 4. A crosstalk removing dielectric multilayer filter for removing a crosstalk component from a drop optical signal transmitted through said dielectric multilayer filter. 3. The optical add / drop multiplexer according to claim 3. 5. An optical wavelength-division multiplexed signal in which a plurality of optical signals having different wavelengths are optically wavelength-multiplexed is transmitted from a transmission device via an optical submarine cable. The optical signal having the predetermined wavelength is extracted and transmitted to the repeater via the optical submarine cable, and the optical signal having the predetermined wavelength is multiplexed from the repeater with the optical signal obtained by extracting the optical signal having the predetermined wavelength. In a wavelength division multiplexing submarine branching system for transmitting a wavelength multiplexing signal to a receiving device via an optical submarine cable, the optical add / drop multiplexing device includes: an input terminal to which an optical wavelength multiplexing signal from the transmission device is incident; An emission terminal for transmitting an optical wavelength multiplex signal having the same optical signal component as the optical wavelength multiplex signal incident via the incident terminal to the receiving device side; and an optical wavelength incident via the incident terminal. A drop light emitting terminal for transmitting a drop optical signal, which is an optical signal of a predetermined wavelength extracted from the double signal, to the relay device side; and an adder from the relay device, which is an optical signal having the same wavelength as the drop optical signal. An add light incident terminal to which an optical signal is incident; and an optical signal having a predetermined wavelength among optical wavelength multiplexed signals incident from the transmission apparatus side via the incident terminal, and transmitting the drop light as a drop optical signal, Transmitting the signal to the repeater via the output terminal, reflecting an optical signal other than the drop optical signal, and multiplexing with the add optical signal transmitted from the repeater via the add light incident terminal. Thereby forming an optical wavelength multiplexed signal having the same optical signal component as the optical wavelength multiplexed signal incident via the incident terminal, and transmitting the signal to the receiving device side via the output terminal. Wavelength division multiplexing submarine branching system; and a filter.