JP2002111584A - Optical routing method and device thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a new optical routing method and a device, capable of performing header recognition and the transfer of signals required for optical routing in optical communication at a ultra-high speed. SOLUTION: Packet signals are divided into signal light (2) and header recognition signals (3) and the spectral distribution (7) of the header recognition signals (3) is acquired. The obtained spectral distribution (7) is made incident on a space filter for reproducing the spectral distribution of a single super-short pulse beam, only when the spectral distribution provided with the same amplitude and phase as the header signal part of the packet signals to be a transfer object in an optical router is made incident; and the spectral distribution of the single super-short pulse beam is reproduced, only when the amplitude and phase of the incident spectral distribution are the same as the header signal part. The signal super-short pulse beam of the reproduced spectral distribution is outputted as control light (11). Then, by making the control light (11) and the signal light (2) to be incident simultaneously on a nonlinear medium (15) to cause reaction, only when both of the light are made incident, will the packet signals be the transfer object in the optical router be pulled out.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical routing method and apparatus. More specifically, the invention of this application relates to a new optical routing method which is useful for optical routing for controlling the destination of packet signals in an all-optical network for optical communication, and which can perform header recognition and signal transfer at an extremely high speed. The present invention relates to an optical routing device.

[0002]

2. Description of the Related Art In the field of optical communication, with the spread of the Internet, the transmission capacity has been increased by time multiplexing or wavelength multiplexing, and its signal form is basically an ultra-high-speed time-series optical signal. Signal. Also, with the increase in transmission capacity, it is necessary to perform various processes on transmission information at an extremely high speed. The current ultra-high-speed processing system basically converts an ultra-high-speed optical signal into an electric signal (optical / electrical conversion), performs various processes using the converted electric signal, and converts the obtained electric signal into an optical signal. Converted to a signal (electrical / optical conversion).

In optical routing for relaying an optical signal transmitted by optical communication and transferring the signal to a next destination, it is necessary to recognize a header signal included in a transmitted packet signal at an extremely high speed. . However, conventionally, the header recognition is performed after the optical / electrical conversion, and there is a problem that the mismatch in the band in the conversion between the optical signal and the electric signal lowers the overall processing capability.

Accordingly, the invention of this application has been made in view of the above circumstances, and solves the problems of the prior art, and realizes header recognition and signal transfer necessary for optical routing in optical communication. It is an object of the present invention to provide a new optical routing method and its device that can be performed at high speed.

[0005]

The present invention solves the above problems by dividing a packet signal into a signal light and a header recognition signal, obtaining a spectrum distribution of the header recognition signal, and obtaining the obtained spectrum distribution. Is input to a spatial filter that reproduces the spectral distribution of a single ultrashort pulse light only when a spectral distribution having the same amplitude and phase as the header signal portion of the packet signal to be transferred by the optical router is incident, Only when the amplitude and phase of the incident spectrum distribution are the same as the header signal portion, reproduce the spectrum distribution of the single ultrashort pulse light, and output the single ultrashort pulse light of the reproduced spectrum distribution as control light. And
By simultaneously inputting the control light and the signal light to a nonlinear medium in which a reaction occurs only when the two lights are incident, the optical router extracts only the packet signal to be transferred. An optical routing method (Claim 1) is provided.

Further, the invention of this application is directed to the above-mentioned optical routing method, wherein the nonlinear medium has a reaction caused by a self-diffraction phenomenon due to four-wave mixing formed between the control light and the signal light, and the Kerr effect. Alternatively, the use of an optical shutter in which a reaction occurs due to the photochromic effect (claim 2) and (claim 3) is provided as the mode.

Still further, the invention of this application provides an optical routing device (claim 4) for executing the above optical routing method, in which the packet signal is divided into a signal light and a header recognition signal. An optical unit, an optical unit for acquiring a spectrum distribution of a header recognition signal, and a single ultrashort only when a spectrum distribution having the same amplitude and phase as the header signal portion of the packet signal to be transferred by the optical router is incident. A spatial filter that reproduces the spectral distribution of the pulsed light, an optical unit that outputs a single ultrashort pulsed light of the reproduced spectral distribution as control light, and a reaction occurs only when the control light and the signal light enter. A nonlinear medium, and the control light and the signal light are simultaneously incident on the nonlinear medium, so that the packet signal to be transferred by the optical router is The withdrawal of the is adapted to be performed (claim 5) provides as its aspects.

[0008]

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0009]

FIG. 1 is a flow chart for explaining an optical routing method according to the present invention, and FIG. 2 exemplifies a main configuration of an optical routing apparatus for executing the optical routing method. Hereinafter, FIGS. 1 and 2
The invention of this application will be described with reference to FIG.

<Step S1> First, a packet signal is divided into a signal light (2) and a header recognition signal (3). This is performed by an optical means such as a translucent mirror (4) capable of reflecting the signal light (2) contained in the packet signal and transmitting the header recognition signal (3), or vice versa. The packet signal is composed of, for example, ultrashort pulse light for ultrahigh-speed optical communication.

<Step S2> Subsequently, the header recognition signal (3) is input to the header recognition system (1). In the header recognition system (1), first, a spectrum distribution (7) of the header recognition signal (3) is obtained. This is performed, for example, by dispersing the header recognition signal (3) by the diffraction grating (5) and performing Fourier transform by the cylindrical lens (6).

<Step S3> The obtained spectral distribution (7) is incident on a spatial filter. This spatial filter is used only when a spectral distribution having the same amplitude and phase as the header signal portion included in the packet signal to be transferred by the optical router prepared in advance is incident. It is designed to reproduce the distribution, and the spectral distribution of the single ultrashort pulse light is reproduced only when the amplitude and phase of the incident spectrum distribution (7) are the same as the header signal portion.

In the embodiment of FIG. 2, as an example of such a spatial filter, a simple filter having the same amplitude and phase as the amplitude and phase of the spectrum distribution of the header signal portion included in the packet signal to be transferred by the optical router is used. When the spectral distribution of one ultrashort pulse light is recorded as the reference light, and the spectral distribution (7) of the header recognition signal (3) and the spectral distribution of the single ultrashort pulse light as the reference light are the same, Only the hologram (8) for reproducing the spectral distribution of a single ultrashort pulse light is used. In addition to the hologram (8), a computer generated hologram or a synthetic identification function filter (SDF
A multi-signal discriminating correlation filter referred to as such) can be used.

<Step S4> Next, a single ultra-short pulse light having the reproduced spectral distribution is output as control light. Specifically, for example, a single ultrashort pulsed light is obtained by performing an inverse Fourier transform on the reproduced spectral distribution with a cylindrical lens (9) and compensating for the dispersion with a diffraction grating (10). Output as control light (11).

<Step S5> The output control light (1
1) is incident on the nonlinear medium (15) simultaneously with the signal light (2). The nonlinear medium (15) reacts only when the signal light (2) and the control light (11) enter, and for example, is formed between the control light (11) and the signal light (2). For example, an optical shutter in which a reaction occurs due to a self-diffraction phenomenon caused by four-wave mixing or an optical shutter in which a reaction occurs due to a Kerr effect or a photochromic effect can be used. Simultaneous incidence of both lights can be performed, for example, by using a mirror (1
This can be realized by adjusting the optical path length of the signal light (2) by an optical path difference adjusting system composed of 2), a right-angle prism (13), a mirror (14) and the like.

Then, by the incidence of the two lights on the nonlinear medium (15), only the packet signal to be transferred by the optical router is selectively extracted. That is, for the packet signal to be transferred by the optical router, as described above, the control light (11) is output from the header recognition system (1) and is incident on the nonlinear medium (15). ) Responds, forwarding by the optical router occurs,
On the other hand, for a packet signal that is not to be forwarded by the optical router, the control light (11) is not output, and only the signal light (2) enters the nonlinear medium (15).
5) does not react and passes as it is.

As described above, according to the invention of this application, the header recognition and the signal transfer required for optical routing in optical communication can be performed at an extremely high speed without performing the conventional electrical processing. is there.

Of course, the present invention is not limited to the above example, and various embodiments are possible in detail.

[0019]

As described above in detail, according to the invention of this application, a new optical routing method and a new optical routing method capable of performing header recognition and signal transfer required for optical routing in optical communication at an extremely high speed are provided. You.

[Brief description of the drawings]

FIG. 1 is a flowchart illustrating an optical routing method according to the present invention.

FIG. 2 is a main part configuration diagram illustrating an optical routing device that executes the optical routing method of the present invention;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Header recognition system 2 Signal light 3 Header recognition signal 4 Translucent mirror 5 Diffraction grating 6 Cylindrical lens 7 Spectrum distribution 8 Hologram 9 Cylindrical lens 10 Diffraction grating 11 Control light 12 Mirror 13 Right angle prism 14 Mirror 15 Non-linear medium

Continued on the front page F term (reference) 2K002 AA02 AB04 AB40 BA02 HA27 HA31 5K002 BA02 BA06 DA05 DA13 5K030 HA08 HB11 HD03 JL03 KX20 LB05 5K069 DB33 DB41 EA27

Claims (5)

[Claims] 1. A packet signal is divided into a signal light and a header recognition signal, a spectrum distribution of the header recognition signal is obtained, and the obtained spectrum distribution is the same as a header signal portion of a packet signal to be transferred by an optical router. When a spatial distribution having the amplitude and phase of the incident light is applied to a spatial filter that reproduces the spectral distribution of a single ultrashort pulse light only when the amplitude and the phase of the incident spectral distribution are the same as the header signal portion And reproduces the spectral distribution of the single ultra-short pulse light only as the control light, and outputs the single ultra-short pulse light having the reproduced spectral distribution as control light. By simultaneously injecting into a nonlinear medium in which a reaction occurs only when incident, it is possible to extract only the packet signal to be forwarded by the optical router. Optical routing method comprising. 2. The optical routing method according to claim 1, wherein a nonlinear medium that reacts by a self-diffraction phenomenon by four-wave mixing formed between the control light and the signal light is used. 3. The optical routing method according to claim 1, wherein an optical shutter that reacts by a Kerr effect or a photochromic effect is used as the nonlinear medium. 4. An optical routing device that executes the optical routing method according to claim 1. 5. An optical routing apparatus according to claim 4, wherein: an optical unit for dividing the packet signal into a signal light and a header recognition signal; an optical unit for acquiring a spectrum distribution of the header recognition signal; A spatial filter that reproduces the spectrum distribution of a single ultrashort pulse light only when a spectrum distribution having the same amplitude and phase as the header signal portion of the packet signal enters, and a single ultrashort pulse light with the reproduced spectrum distribution An optical means for outputting the control light as control light, and a nonlinear medium in which a reaction occurs only when the control light and the signal light enter. An optical routing device in which only a packet signal to be transferred is extracted by a router.