JP2003046441A - Optical packet transmitter and optical packet arrival detector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical packet transmitter that generates an optical pulse synchronously with an arrival time of an optical packet signal while keeping optical pulse intensity nearly constant for the input signal light. SOLUTION: The optical packet transmitter is provided with a means that uses an optical packet signal resulting from adding a prescribed number of consecutive optical pulse trains to the head of a data optical pulse train and outputs an optical pulse only at the head of the received continuous optical pulse train by applying the extracted continuous optical pulse train to an optical circuit whose semiconductor optical amplifiers are arranged at asymmetrical positions in a ring interferometer.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to reception and signal processing of an optical packet signal that arrives irregularly in time from a transmission line, and relates to an optical device in which a semiconductor optical amplifier is arranged at an asymmetric position in a ring interferometer. The present invention relates to a technique for optically extracting only the first optical pulse of an optical packet signal using a circuit and generating an optical pulse synchronized with the time when the optical packet signal arrives.

[0002]

2. Description of the Related Art As a technique for generating a single optical pulse for notifying the arrival of an optical packet signal without passing through an electric circuit, a semiconductor is placed at an asymmetric position in a ring interferometer as shown in FIG. A technique using the optical circuit 4 in which the optical amplifier 13 is arranged is known.

In such an optical circuit 4, the inputted optical packet signal is first branched by the directional coupler 14 into clockwise light and counterclockwise light. In the optical circuit 4, the semiconductor optical amplifier 13 which is a non-linear element is arranged at an asymmetrical position, and the time when the optical pulse forming the input optical packet signal passes through the semiconductor optical amplifier 13 is clockwise. The counterclockwise light pulse is slower than the light pulse.

Here, when the clockwise and counterclockwise light pulses arrive at the directional coupler 14 again around the ring interferometer, the clockwise and counterclockwise light pulses have the same magnitude. When a phase difference is given, the optical pulse is output to the input port 6 to which the optical packet signal is input, and when a clockwise and counterclockwise optical pulse is given a phase difference of about π, the input port is It is output to the output port 7 which is the opposite of the above.

In the technique of generating an optical pulse by using the optical circuit 4 as described above, a comparison is made with the data signal 30 at the head of the data optical pulse train forming the data signal 30 of the input optical packet signal as shown in FIG. Then, the optical packet signal 31 to which the optical pulse is added as the packet pointer 32 having a high light intensity is used. In this case, as the source of the packet pointer 32, another optical packet transmitter different from the optical packet transmitter of the data signal 30 is required.

By the clockwise packet pointer 32 that first passes through the semiconductor optical amplifier 13, the semiconductor optical amplifier 1 is
The gain of 3 is saturated. As a result, the counterclockwise packet pointer 32 passing through the semiconductor optical amplifier 13 with a delay.
Since the phase difference given by the clockwise packet pointer 32 that has passed through the semiconductor optical amplifier 13 differs by about π, the packet pointer 32 is output to the output port 7.

Data signal 3 other than the packet pointer 32
For 0, the gain saturation of the semiconductor optical amplifier 13 does not occur, and since the gain recovery time of the semiconductor optical amplifier 13 is sufficiently long, the phase difference given by the clockwise and counterclockwise data signals 30 is almost the same. It becomes equal and is output to the input port 6. As described above, the optical pulse generator that outputs only the head packet pointer 32 in response to the arrival of the optical packet signal is realized.

[0008]

As described above, in the technique of generating an optical pulse using the optical circuit 4 in which the semiconductor optical amplifier 13 is arranged at an asymmetrical position in the ring interferometer, the head of the optical packet signal 31 is used. A packet pointer 32, which is an optical pulse having a light intensity high enough for the semiconductor optical amplifier 13 to cause gain saturation, is transmitted to the data optical pulse train, and the data optical pulse train forming the data signal 30 is weak enough to prevent the semiconductor optical amplifier 13 from gain saturation. It must be signal light intensity.

However, in practice, it is technically difficult to generate optical pulses having different signal intensities in an optical packet signal transmitted at high speed. For example, in order to generate optical pulses having different signal intensities, the optical packet transmitters need two different systems of optical packet transmitters, and the two systems of optical packet transmitters are synchronized with each other to form one optical packet transmitter. Since optical pulses having different signal intensities are generated in the optical packet signal, the hardware configuration becomes complicated and the hardware cost becomes expensive. Further, when transmitting an optical packet signal in which optical pulses having different intensities are mixed, a high intensity optical pulse is greatly affected by the nonlinear effect of the fiber, and a low intensity optical pulse is significantly affected by the signal attenuation. Therefore, there is a problem that it is difficult to perform long-distance transmission.

The present invention has been made against such a background, and it is possible to generate an optical pulse synchronized with the arrival time of an optical packet signal while keeping the optical pulse intensity of the input signal light substantially constant. An object of the present invention is to provide an optical packet transmission device and an optical packet arrival detection device that can be used.

[0011]

The present invention uses an optical packet signal in which a fixed number of continuous optical pulse trains are added to the beginning of a data optical pulse train, and transmits or blocks light in accordance with a control signal input from the outside. An optical gate means for switching and an optical circuit in which a semiconductor optical amplifier is arranged at an asymmetrical position in a ring interferometer are provided, and only a continuous optical pulse train added at the beginning by a control signal input from the outside by the optical gate means is provided. By inputting the continuous optical pulse train having means for extracting, and extracting the continuous optical pulse example only by the means for extracting the continuous optical pulse, to an optical circuit in which a semiconductor optical amplifier is arranged at an asymmetric position in the ring interferometer. By outputting only the leading optical pulse of the input continuous optical pulse train,
An optical pulse synchronized with the arrival time of the head of the optical packet signal is generated.

The optical gate means comprises an optical branching means in front of the optical gate means, a part of the optical packet signal is branched by the optical branching means, and an optical signal is output according to the reception timing of the part of the optical packet signal. The optical packet signal is transmitted for a time including the head of the continuous optical pulse train forming the packet arrival detection signal and not including the data optical pulse train forming the data signal, or an optical branching unit is provided in front of the optical gate unit. Then, a part of the optical packet signal is branched by the optical branching means, and a data signal is formed without including the head of the continuous optical pulse train forming the optical packet arrival detection signal according to the reception timing of a part of the optical packet signal The optical packet signal is blocked or the semiconductor photomultiplier is placed at an asymmetric position in the ring interferometer for the time including all of the data optical pulse trains. Optical branching means is provided after the optical circuit in which the optical circuit is arranged, and the optical branching means branches a part of the output optical pulse of the optical circuit in which the semiconductor optical amplifier is arranged at an asymmetrical position in the ring interferometer. By using the control signal of the optical gate means, the optical packet signal is driven for a time period including all the data optical pulse trains forming the data signal according to the reception timing of a part of the output optical pulse.

Further, by providing an optical isolator between the optical gate means and an optical circuit in which a semiconductor optical amplifier is arranged at an asymmetrical position in the ring interferometer, the characteristics can be improved.

Further, the characteristics can be improved by providing a polarization controller in the optical circuit in which the semiconductor amplifier is arranged at an asymmetrical position in the ring interferometer.

It is also applicable to construct an optical circuit in which semiconductor optical amplifiers are arranged at asymmetrical positions in the optical gate and the ring interferometer on the same optical circuit board.

The conventional technique is that a continuous optical pulse train forming an optical packet arrival detection signal added to an optical packet signal can be obtained from the same optical packet transmitter as the data optical pulse train forming the data signal. The difference is that an optical pulse synchronized with the time when the head of the packet signal arrives can be accurately obtained.

That is, a first aspect of the present invention is to generate an optical packet signal including an optical packet arrival detection signal arranged at the head and a data signal arranged subsequent to this optical packet arrival detection signal. It is an optical packet transmitter equipped with a means for doing so.

Here, a feature of the present invention is that the generating means generates the optical packet arrival detection signal as an optical pulse train of at least one pulse having substantially the same light intensity and the same bit rate as the data signal. There is a means to do so.

A second aspect of the present invention is to receive an optical packet signal including an optical packet arrival detection signal arranged at the head and a data signal arranged subsequently to the optical packet arrival detection signal, and to receive the optical packet signal. It is an optical pulse arrival detection device provided with means for detecting arrival of an optical packet signal based on a packet arrival detection signal.

Here, a feature of the present invention is that the optical packet signal is an optical packet signal transmitted from the optical packet transmitter of the present invention, and the optical packet signal is used to detect the optical packet arrival detection signal. And a means for outputting an optical pulse synchronized with the optical pulse train included in the optical packet arrival detection signal extracted by the extracting means. As a result, only the head optical pulse can be extracted and output from a part of the optical packet arrival detection signal.

Therefore, it is possible to generate an optical pulse synchronized with the arrival time of the optical packet signal while keeping the optical pulse intensity of the input signal light constant.

The extracting means comprises an optical branching means, an optical gate means for transmitting or blocking light according to a control signal, and a control means of the optical gate means for generating the control signal. One of the optical packet signals shunted by is input to the optical gate means and the other is input to the control means, and the control means includes means for generating the control signal in accordance with the reception timing of the optical packet signal. Is desirable.

In this case, the means for generating the control signal includes the head of the optical packet arrival detection signal according to the reception timing of the head pulse of the optical packet signal and does not include all the data signals. In addition, the optical gate means may be configured to include a means for generating a control signal for making the optical gate means in a transmissive state, or the means for generating the control signal may be arranged such that the optical packet arrives at the reception timing of the first pulse of the optical packet signal. It is preferable to include a means for generating a control signal for turning off the optical gate means in synchronization with a time including all of the data signals without including the head of the detection signal.

Alternatively, means for outputting an optical pulse synchronized with the optical pulse train included in the optical packet signal, and a time including all of the data signals according to the head pulse detection time of the optical pulse train output from the outputting means The optical gate means for interrupting the optical pulse train may be provided.

An optical isolator may be provided between the optical gate means and the output means. According to this, since it is possible to block the optical pulse output toward the optical gate unit from the output unit that is unnecessary for detecting the arrival of an optical packet, for example, the unit that generates the control signal is The characteristics of the device can be improved by avoiding erroneous detection when detecting the reception timing of the head pulse.

The output means can be realized by an optical circuit in which a semiconductor optical amplifier is arranged at an asymmetrical position in the ring interferometer. Further, this optical circuit may be provided with means for making the polarization direction a predetermined direction. According to this, for example, when the polarization direction of the clockwise optical pulse is limited by the semiconductor optical amplifier, the polarization direction of the counterclockwise optical pulse is changed to the polarization direction of the clockwise optical pulse. This can be matched with the wave direction, the coupling efficiency between the clockwise light pulse and the counterclockwise light pulse can be improved, and the characteristics of the output means can be improved. Further, the phase difference between the clockwise optical pulse and the counterclockwise optical pulse can be adjusted by the rotation of the plane of polarization, and the characteristics of the outputting means can be improved.

Further, at least the optical gate means and the output means can be formed on the same optical circuit board. As a result, the device configuration can be downsized and simplified. On the same optical circuit board, in addition to the optical gate means and the output means, the optical isolator, the means for setting the polarization direction to a predetermined direction, the optical branching means, etc. may be formed. .

The semiconductor optical amplifier in the optical circuit may be a multi-electrode semiconductor optical amplifier having two or more current injection electrodes. Alternatively, the optical circuit may be provided with a variable optical attenuator. Alternatively, the optical circuit may be provided with a linear amplifier. This makes it possible to compensate for the loss difference between the two paths connecting the semiconductor optical amplifier and the output port of the directional coupler, and improve the characteristics of the optical circuit.

[0029]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An optical packet transmitter and an optical packet arrival detector according to an embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a block diagram of the optical packet arrival detection apparatus of the first embodiment. FIG. 2 is a block diagram of the optical packet arrival detection device of the second embodiment. FIG. 3 is a block diagram of the packet arrival detection device of the third embodiment. FIG. 4 is a block diagram of the essential parts of the optical packet transmitter of this embodiment. FIG. 5 is a diagram showing an optical pulse train of an optical packet signal of this embodiment. FIG. 6 is a diagram showing a first configuration example of the optical circuit of this embodiment. FIG. 7 is a diagram showing an operation example of the multi-electrode semiconductor optical amplifier of this embodiment. FIG. 8 is a diagram showing a second configuration example of the optical circuit of this embodiment. FIG. 9 is a diagram showing a third configuration example of the optical circuit of this embodiment.

A first aspect of the present invention is to provide an optical packet arrival detection signal 8 placed at the head, as shown in FIG.
The optical packet transmission device is provided with means for generating an optical packet signal 21 including the data signal 20 arranged following the optical packet arrival detection signal 8.

Here, as a characteristic of the present invention, as shown in FIG. 4, the means for generating the optical packet arrival detection signal 8 has the same optical intensity and the same bit rate as the data signal 20. It is provided with an optical packet arrival detection signal adding unit 1 and an optical modulator 2 which are generated as an optical pulse train of pulses or more.

A second aspect of the present invention is to provide an optical packet signal 21 including an optical packet arrival detection signal 8 arranged at the head and a data signal 20 arranged subsequent to the optical packet arrival detection signal 8. Received packet arrival detection signal 8
The optical pulse arrival detection device is provided with means for detecting the arrival of the optical packet signal 21 based on the above.

Here, the feature of the present invention is that the optical packet signal 21 is an optical packet signal transmitted from the optical packet transmitter of the present invention, and as shown in FIG. An optical packet arrival detection signal extraction unit 3 for extracting the head portion including the packet arrival detection signal 8 and an optical pulse train included in the optical packet arrival detection signal 8 extracted by the optical packet arrival detection signal extraction unit 3. And an optical circuit 4 for outputting an optical pulse synchronized with. This makes it possible to extract and output only the leading optical pulse from a part of the optical packet arrival detection signal 8.

The optical packet arrival detection signal extraction unit 3 includes an optical branching unit 10, an optical gate 11 that transmits or blocks light according to a control signal, and an optical gate drive circuit 12 of the optical gate 11 that generates this control signal. And the optical branching unit 10
One of the optical packet signals 21 divided by is input to the optical gate 11 and the other is input to the optical gate drive circuit 12, and the optical gate drive circuit 12 generates the control signal according to the reception timing of the optical packet signal 21. .

In the first embodiment, the optical gate drive circuit 12
Generates a control signal that causes the optical gate 11 to be in a transmission state at a time that includes the head of the optical packet arrival detection signal 8 according to the reception timing of the head pulse of the optical packet signal 21 and does not include all of the data signal 20. To do.

In the second embodiment, as shown in FIG. 2, the optical gate drive circuit 12 does not include the head of the optical packet arrival detection signal 8 according to the reception timing of the head pulse of the optical packet signal 21 and does not include the data signal. A control signal for turning off the optical gate 11 is generated in accordance with a time including all of 20.

In the third embodiment, as shown in FIG. 3, according to the head pulse detection time of the optical pulse train output from the optical circuit 4, the optical pulse train is interrupted in time including all the data signals 20. A gate 11 is provided.

An optical isolator 5 is provided between the optical gate 11 and the optical circuit 4. Further, a polarization controller 9 having a predetermined polarization direction is inserted in the optical circuit 4.

Further, the semiconductor optical amplifier in the optical circuit 4 is
As shown in FIG. 6, a multi-electrode semiconductor optical amplifier 15 having two or more current injection electrodes can be used. Further, a variable optical attenuator 17 as shown in FIG. 8 or a linear optical amplifier 18 as shown in FIG. 9 may be inserted in the optical circuit 4.

At least the optical gate 11 and the optical circuit 4 are formed on the same optical circuit board. Further, all the optical circuits including the optical isolator 5, the polarization controller 9, and the optical branching section 10 can be formed on the same optical circuit board.

Next, an outline of the operation of the optical packet arrival detection apparatus according to the embodiment of the present invention will be described. The optical circuit 4 is designed so that the clockwise and counterclockwise optical pulses branched by the directional coupler 14 are alternately input to the semiconductor optical amplifier 13 in accordance with the bit rate of the input optical pulse.

On the other hand, the above-mentioned optical gate 11 and optical gate 1
By the action of the optical gate drive circuit 12 which gives a switching signal to 1, the input to the optical circuit 4 in which the semiconductor optical amplifier 13 is arranged at an asymmetrical position in the ring interferometer includes the head of the optical packet arrival detection signal 8. Limited to continuous light pulse trains only.

Therefore, clockwise and counterclockwise light pulses are alternately and continuously input to the semiconductor optical amplifier 13 in the optical circuit 4. At this time, only the optical pulse first input to the semiconductor optical amplifier 13 is input to the semiconductor optical amplifier 13 in the non-signal state, and the second and subsequent semiconductor optical amplifiers 1
The optical pulse input to the optical amplifier 3 is input to the semiconductor optical amplifier 13 in the gain recovery process which is saturated by the previous optical pulse.

As a result, the second and subsequent semiconductor optical amplifiers 1
All the optical pulses input to the optical fiber 3 are given the same phase delay, and the amount of phase delay can be shifted by about π from the amount of the phase delay given to the optical pulse first input to the semiconductor optical amplifier 13. is there.

Therefore, when the directional coupler 14 is coupled around the ring interferometer, the first optical pulse of the continuous optical pulses has a phase delay that is different from the clockwise and counterclockwise optical pulses by about π. Since it is given, it is output from the output port 7 on the side opposite to the input side, and the second and subsequent optical pulses of the continuous optical pulse are given the same phase delay as the clockwise and counterclockwise optical pulses. 6
It becomes possible to output to the side, and the optical pulse output synchronized with the arrival time of the optical packet signal, which is the object of the present invention, can be obtained.

The embodiments of the present invention will be described in more detail below.

(First Embodiment) A first embodiment of the present invention will be described with reference to FIG. The optical packet signal 21 is transmitted to the optical branching unit 1
It is branched by 0, one is input to the optical gate 11, and the other is input to the optical gate drive circuit 12.

The optical gate drive circuit 12 outputs a control signal in response to the arrival of the input optical packet signal 21, and makes the optical gate 11 transmit the input optical packet for a certain period of time. The time required for the optical gate 11 to pass an input optical packet is
It is set to start earlier than the arrival of the optical packet signal 21 input to the gate and end while the continuous optical pulse train forming the optical packet arrival detection signal 8 added to the head of the optical packet signal 21 passes. The optical gate 11 and the optical gate drive circuit 12 cause the optical gate 11 to output a part of the optical packet arrival detection signal 8 added to the head of the optical packet signal 21.

The optical pulse train output from the optical gate 11 is input from the input port 6 of the optical circuit 4. From the optical circuit 4, only the head optical pulse corresponding to the optical packet arrival detection signal 8 in the input optical pulse train is output from the output port 7. Since the output optical pulse is the head optical pulse of the continuous pulse train corresponding to the optical packet arrival detection signal 8, the optical pulse synchronized with the arrival time of the optical packet signal 21 can be obtained.

An optical isolator 5 for blocking the return light from the optical circuit 4 between the optical gate 11 and the optical circuit 4.
Is arranged, the malfunction of the optical packet arrival detection signal extraction unit 3 due to the return light can be avoided, and therefore the characteristics are improved.

Further, by providing the polarization controller 9 in the optical circuit 4, the semiconductor optical amplifier 13 does not limit the same polarization direction as the clockwise optical pulse whose polarization direction is fixed to a certain extent. It can also be applied to a clockwise optical pulse, and the characteristics can be improved by increasing the coupling efficiency when the clockwise optical pulse and the counterclockwise optical pulse are coupled in the directional coupler 14. You can Also,
By rotating the plane of polarization, the phase difference between the clockwise optical pulse and the counterclockwise optical pulse can be adjusted, and the characteristics of the optical circuit 4 can be improved.

Further, as shown in the first configuration example of the optical circuit 4 in FIG. 6, the semiconductor optical amplifier 13 in the optical circuit 4 is a multi-electrode semiconductor optical amplifier 15 having two or more current injection electrodes. As a result, the loss difference between the two paths connecting the semiconductor optical amplifier 15 and the output ports a and b of the directional coupler 14 can be compensated, and the characteristics of the optical circuit 4 can be improved.

FIG. 7 shows an operation example of the multi-electrode semiconductor optical amplifier. In FIG. 7, excessive attenuation is provided between the output port a of the directional coupler 14 and the multi-electrode semiconductor optical amplifier 15 as compared with the output port b of the directional coupler 14 and the multi-electrode semiconductor optical amplifier 15. The case where the factor 16 exists is shown. The attenuation factor may be a junction loss at the junction of various optical waveguides or an insertion loss of each component in the optical circuit 4, and its size and distribution are not limited.

At this time, the current injected into the multi-electrode semiconductor optical amplifier 15 is adjusted to give a spatial distribution to the gain and the nonlinear effect obtained in the semiconductor optical amplifier, thereby canceling the existence of the excessive attenuation factor 16. be able to. For example, as shown in FIG. 7, when the number of electrodes is two, it is possible to cancel the excessive attenuation factor 16 by dividing into a region that gives a linear amplification effect and a region that gives a nonlinear effect. However, this does not limit other current injection methods or the number of electrodes of the semiconductor optical amplifier.

Further, as shown in the second configuration example of the optical circuit 4 in FIG. 8, the variable optical attenuator 17 is arranged in the optical circuit 4 between the directional coupler 14 and the semiconductor optical amplifier 13. As a result, the loss difference between the two paths connecting the semiconductor optical amplifier 13 and the output ports a and b of the directional coupler 14 can be eliminated, and the characteristics of the optical circuit 4 can be improved.

Further, as shown in the third configuration example of the optical circuit 4 of FIG. 9, a linear optical amplifier 18 is arranged in the optical circuit 4 between the directional coupler 14 and the semiconductor optical amplifier 13. As a result, the loss difference between the two paths connecting the semiconductor optical amplifier 13 and the output ports a and b of the directional coupler 14 can be eliminated, and the characteristics of the optical circuit 4 can be improved.

Further, a configuration in which the optical gate 11 and the optical circuit 4 are formed on the same optical circuit board is also applicable. Further, the optical isolator 5 and the optical branching section 10 can also be formed on the same optical circuit board.

(Second Embodiment) A second embodiment of the present invention will be described with reference to FIG. In the second embodiment, the optical gate drive circuit 12 outputs a control signal in response to the arrival of the input optical packet signal 21, and makes the optical gate 11 block the input optical packet for a certain period of time. The time when the optical gate 11 cuts off the input optical packet for a certain time starts while the continuous optical pulse train forming the optical packet arrival detection signal 8 added to the head of the optical packet signal 21 input to the gate passes, and The data optical pulse train constituting the signal 20 is terminated after passing through it.

The optical gate 11 and the optical gate drive circuit 12 cause the optical gate 11 to output a part of the continuous optical pulse train constituting the optical packet arrival detection signal 8 added to the head of the optical packet signal 21.

The optical pulse train output from the optical gate 11 is input to the optical circuit 4 from the input port 6. From the optical circuit 4, only the head optical pulse of the input optical pulse train is output from the output port 7. Since the output optical pulse is the leading optical pulse of the input continuous optical pulse, the optical pulse synchronized with the arrival time of the input optical packet signal 21 can be obtained. Others are the same as the first embodiment.

(Third Embodiment) A third embodiment of the present invention will be described with reference to FIG. In the third embodiment, the optical packet signal 21
Is input to the optical gate 11 in a state of being transmitted. Light gate 1
The optical pulse train output from 1 is input to the optical circuit 4 from the input port 6. From the optical circuit 4, only the head optical pulse of the input optical pulse train is output from the output port 7.

The output optical pulse is branched by the optical branching unit 10, one of which is used as an output and the other is input to the optical gate drive circuit 12. Optical gate drive circuit 12
Outputs a control signal in response to the arrival of the input optical pulse, and puts the optical gate 11 in a state of blocking the input optical packet for a certain period of time.

The time when the optical gate 11 cuts off the input optical packet for a certain period of time is the input of the continuous optical pulse train forming the optical packet arrival detection signal 8 added to the head of the optical packet signal 21 input to the optical gate 11. It starts inside and ends after the data optical pulse train forming the data signal 20 has passed.

The signal input to the optical circuit 4 by the optical gate 11 and the optical gate drive circuit 12 is the optical packet signal 21.
It is limited to a part of the continuous optical pulse train forming the optical packet arrival detection signal 8 added to the head of the.

Since the output optical pulse is the leading optical pulse of the continuous optical pulse forming the optical packet arrival detection signal 8, an optical pulse synchronized with the arrival time of the input optical packet signal 21 can be obtained. . Others are the same as the first embodiment.

[0066]

As described above, according to the present invention,
An optical pulse synchronized with the arrival time of the optical packet signal can be generated while keeping the optical pulse intensity of the input signal light constant.

[Brief description of drawings]

FIG. 1 is a block configuration diagram of an optical packet arrival detection device according to a first embodiment of the present invention.

FIG. 2 is a block configuration diagram of an optical packet arrival detection device according to a second embodiment of the present invention.

FIG. 3 is a block configuration diagram of an optical packet arrival detection device of a third embodiment of the present invention.

FIG. 4 is a block diagram of a main part of an optical packet transmitter according to an embodiment of the present invention.

FIG. 5 is a configuration diagram of an optical packet signal according to an embodiment of the present invention.

FIG. 6 is a diagram showing a first configuration example of an optical circuit.

FIG. 7 is a diagram showing an operation example of a multi-electrode semiconductor optical amplifier.

FIG. 8 is a diagram showing a second configuration example of an optical circuit.

FIG. 9 is a diagram showing a third configuration example of an optical circuit.

FIG. 10 is a configuration diagram of an optical circuit.

FIG. 11 is a configuration diagram of a conventional optical packet signal.

[Explanation of symbols]

1 Optical packet arrival detection signal addition unit 2 Optical modulator 3 Optical packet arrival detection signal extraction unit 4 Optical circuit 5 Optical isolator 6 input ports 7 output ports 8 Optical packet arrival detection signal 9 Polarization controller 10 Optical branch 11 optical gate 12 Optical gate drive circuit 13 Semiconductor Optical Amplifier (SOA) 14 Directional coupler 15 Multi-electrode semiconductor optical amplifier 16 Attenuation factor 17 Variable optical attenuator 18 Linear amplifier 20, 30 data signal 21, 31 Optical packet signal 32 packet pointer

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) H04B 10/26 10/28 (72) Inventor Yasuo Shibata 2-3-1 Otemachi, Chiyoda-ku, Tokyo Date Inside the Telegraph and Telephone Corporation (72) Inventor Takashi Sakamoto 2-3-1, Otemachi, Chiyoda-ku, Tokyo Japan Telegraph and Telephone Corporation (72) Inventor Yoshihisa Kai 2-3-1, Otemachi, Chiyoda-ku, Tokyo No. Japan Telegraph and Telephone Corporation (72) Inventor Noguchi alone 3-3-1 Otemachi, Chiyoda-ku, Tokyo Japan Telegraph and Telephone Corporation (72) Inventor Shigeto Matsuoka 2-3-3 Otemachi, Chiyoda-ku, Tokyo No. 1 Nihon Telegraph and Telephone Corporation F-term (reference) 2H079 AA05 AA13 BA01 CA05 CA24 DA16 EA04 EA05 EA07 EB15 FA02 FA03 FA04 5K102 AA10 AA11 AA63 MA01 MA02 MB11

Claims (13)

[Claims] 1. An optical packet transmission device comprising means for generating an optical packet signal including an optical packet arrival detection signal arranged at the head and a data signal arranged subsequently to this optical packet arrival detection signal. In the optical packet transmission, the generating means includes means for generating the optical packet arrival detection signal as an optical pulse train of one or more pulses having substantially the same light intensity and the same bit rate as the data signal. apparatus. 2. An optical packet signal including an optical packet arrival detection signal arranged at the head and a data signal arranged subsequently to the optical packet arrival detection signal is received and based on the packet arrival detection signal. An optical pulse arrival detection apparatus comprising means for detecting the arrival of an optical packet signal, wherein the optical packet signal is the optical packet signal transmitted from the optical packet transmission apparatus according to claim 1, and the optical packet signal is converted into the optical packet signal. And a means for extracting a head portion including the packet arrival detection signal, and means for outputting an optical pulse synchronized with the optical pulse train included in the optical packet arrival detection signal extracted by the extraction means. A characteristic optical packet arrival detection device. 3. The extracting means comprises an optical branching means, an optical gate means for transmitting or blocking light according to a control signal, and a driving means of the optical gate means for generating the control signal, One of the optical packet signals branched by the branching unit is input to the optical gate unit and the other is input to the driving unit, and the driving unit generates the control signal in accordance with the reception timing of the optical packet signal. The optical packet arrival detection device according to claim 2, further comprising: 4. The means for generating the control signal includes a head of the optical packet arrival detection signal according to a reception timing of a head pulse of the optical packet signal, and adjusts to a time not including all of the data signals. 4. The optical packet arrival detection device according to claim 3, further comprising means for generating a control signal for bringing the optical gate means into a transmission state. 5. The means for generating the control signal, according to the reception timing of the head pulse of the optical packet signal, does not include the head of the optical packet arrival detection signal but adjusts to a time including all of the data signals. 4. The optical packet arrival detection device according to claim 3, further comprising means for generating a control signal for turning off the optical gate means. 6. An optical packet arrival detection signal is received by receiving an optical packet signal including an optical packet arrival detection signal arranged at the head and a data signal arranged subsequently to this optical packet arrival detection signal. An optical packet arrival detection device comprising means for notifying arrival of an optical packet signal based on the optical packet signal, wherein the optical packet signal is the optical packet signal transmitted from the optical packet transmission device according to claim 1, and is included in the optical packet signal. Means for outputting an optical pulse synchronized with the optical pulse train, and an optical gate for interrupting the optical pulse train in time including all of the data signals in accordance with the head pulse detection time of the optical pulse train output from the outputting means. An optical packet arrival detection device comprising: 7. The optical packet arrival detection device according to claim 3, further comprising an optical isolator provided between said optical gate means and said output means. 8. The optical packet arrival detection device according to claim 2, wherein the output means includes an optical circuit in which a semiconductor optical amplifier is arranged at an asymmetrical position in a ring interferometer. 9. The optical packet arrival detection device according to claim 8, wherein the optical circuit is provided with means for setting a polarization direction to a predetermined direction. 10. The optical packet arrival detection device according to claim 3, wherein at least the optical gate means and the output means are formed on the same optical circuit board. 11. The optical packet arrival detection device according to claim 8, wherein the semiconductor optical amplifier in the optical circuit is a multi-electrode semiconductor optical amplifier having two or more current injection electrodes. 12. The optical packet arrival detection device according to claim 8, wherein the optical circuit is provided with a variable optical attenuator. 13. The optical packet arrival detection device according to claim 8, wherein the optical circuit is provided with a linear amplifier.