JP2010041069A - Optical pulse signal regeneration method and optical pulse signal regeneration apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To stably achieve an entire optical 3R signal regeneration function even if a change in an external environment is generated such as the peripheral temperature fluctuation of a NOLM (Non-linear Optical Loop Mirror) functioning as an optical gate circuit. <P>SOLUTION: The optical pulse signal regeneration apparatus includes an initial stage regeneration optical pulse signal generator 10, an optical clock signal extracting device 20, a phase adjustment signal extracting device 30, an optical clock signal phase adjusting device 50, and the NOLM 60. The initial stage regeneration optical pulse signal generator performs 2R signal regeneration, and generates and outputs initial stage regeneration optical pulse signals 11. The optical clock signal extracting device receives the input of the initial stage regeneration optical pulse signals 15-2 and extracts and outputs optical clock signals 25. The phase adjustment signal extracting device receives the input of the regeneration optical pulse signals 57 and generates and outputs phase adjustment signals 43. The phase adjustment signals are input to the optical clock signal phase adjusting device and the phase of the optical clock signal is adjusted so as to match with that of the initial stage regeneration optical pulse signal. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention amplifies and shapes an optical pulse signal whose intensity is reduced during propagation through an optical fiber transmission line and distortion or phase variation occurs in the optical pulse waveform, and corrects the phase variation to correct the optical pulse. The present invention relates to an optical pulse signal regeneration method and an optical pulse signal regeneration apparatus for reproducing a signal.

  In optical fiber communication, communication is performed by propagating an optical pulse signal reflecting a binary digital signal obtained by modulating an optical pulse train in which optical pulses are arranged at regular and regular time intervals through an optical fiber as a transmission path. . The regular constant time interval is a time interval corresponding to the reciprocal of the frequency corresponding to the transmission density frequency. Hereinafter, the transmission density is sometimes referred to as a bit rate.

  Recently, transmission distances and capacities of optical fiber communication networks have been increased. As transmission becomes longer, optical loss in the optical transmission line, S / N ratio decrease due to the use of multiple optical amplifiers, and waveform distortion due to optical fiber group velocity dispersion and nonlinear optical effects in the optical fiber occur. In addition, there is a problem that the quality of the optical pulse signal is deteriorated due to a variation in the phase. That is, the occurrence of waveform distortion and phase variation in the optical pulse signal becomes more prominent as the transmission capacity increases.

  Therefore, a repeater is provided in the middle of the optical transmission line at intervals of several tens to several hundred kilometers, and in this repeater, the so-called optical pulse signal regeneration, in which the frequency waveform and time waveform of the optical pulse signal are restored to the original shape, is performed. Has been done. That is, in optical fiber communication, in order to increase the transmission distance, the function of amplifying the optical pulse signal (Re-amplifying), the function of shaping the waveform of the optical pulse constituting the optical pulse signal (Re-shaping), and There is a need for an optical pulse signal regeneration device that has the three functions of regenerating timing by controlling the time width and phase of the optical pulse to be reproduced.

  Hereinafter, for convenience of explanation, the function of amplifying the optical pulse signal (Re-amplifying) and the function of shaping the optical pulse waveform constituting the optical pulse signal (Re-shaping) may be collectively referred to as 2R signal reproduction. . In addition, 2R signal reproduction may include 3R signal reproduction including a function (Re-timing) for timing reproduction by controlling the time width and phase of an optical pulse.

  In order to regenerate the optical pulse signal to be reproduced whose intensity has decreased during propagation through the optical fiber transmission line and the optical pulse waveform has been distorted or the phase has varied, the optical pulse signal is converted into an electrical pulse signal once. There are a method of performing a reproduction process and a method of performing a signal reproduction process in the state of an optical signal without being converted into an electric signal. A method of performing 2R or 3R signal regeneration processing in the state of an optical signal without being converted into an electrical signal is sometimes referred to as all-optical 2R or all-optical 3R signal regeneration processing.

  In the method of temporarily converting an optical pulse signal into an electrical pulse signal and performing 2R or 3R signal regeneration processing, due to the limitation of the operating speed of the electronic device used for this processing, the optical pulse signal particularly with a bit rate exceeding 40 Gbit / s is used. It becomes difficult to respond to this.

  Therefore, as a technique for solving this, a technique for performing all-optical 2R signal regeneration processing using an optical fiber mode-locked laser, a highly nonlinear optical fiber, and an electroabsorption optical modulator is disclosed (for example, Non-Patent Document 1). reference). In addition, an all-optical 2R signal regeneration processing method by shifting the wavelength of the optical pulse signal to be reproduced by using a self-phase modulation in a highly nonlinear dispersion flat fiber and a spectrum slicing method using a wavelength filter is disclosed (for example, Non-patent document 2). Further, as an improved version of the all-optical 2R signal regeneration processing method using the spectrum slice method, a method of connecting spectrum slice type wavelength converters in multiple stages is disclosed (for example, see Non-Patent Document 3).

  On the other hand, the time width and phase of the optical pulse of the optical pulse signal that has been subjected to the all-optical 2R signal regeneration processing are re-timed using a non-linear optical loop mirror (NOLM), so that There is a report example of performing optical 3R regeneration processing (for example, see Non-Patent Document 4).

  In this all-optical 3R signal regeneration process, the optical clock signal is extracted from the optical pulse signal to be reproduced, and AND processing (gating) of the optical pulse signal to be reproduced and the optical clock signal is performed using an optical gate circuit. By doing so, the optical pulse signal is reproduced. That is, in the NOLM functioning as an optical gate, only the energy component of the overlapping portion of the optical pulses of the optical pulse constituting the optical pulse signal to be reproduced and the optical pulse constituting the optical clock signal is output from the optical gate. Using this effect, a technique is adopted in which the optical pulse signal is regenerated by performing timing recovery (Re-timing) by matching the phase of the optical pulse signal to be reproduced with the phase of the optical clock signal. ing.

In the all-optical 3R signal regeneration process disclosed in Non-Patent Document 4, the NOLM used as an optical gate is a first having a function of bidirectionally coupling light propagating through the first and second optical paths. And a second optical coupler including a third optical path directionally coupled to the loop optical path, and a loop optical path connecting the two optical paths of the first and second optical paths. . That is, in the all-optical 3R signal regeneration process disclosed in Non-Patent Document 4, a logical product process (AND process) of the optical pulse signal and the optical clock signal is performed by this NOLM.
T. Her, et al., "Experimental Demonstration of A Fiber-based Optical 2R Regenerator in Front of an 80 Gbit / s Receiver," OFC 2003 TuH3 Masayuki Matsumoto, et al., "Wavelength-Shift-Free SPM-Based 2R Regeneration by Bidirectional Use of a Highly Nonlinear Fiver," OFC 2007 OME 5 Masayuki Matsumoto, “3R regeneration of DPSK signal using nonlinear effect of fiber” 2006 Proceedings of IEICE General Conference B-10-22 Hitoshi Murai et al., “Procedure for 160-Gb / s 3R signal regenerative repeater transmission using JGN2 optical test head” 2008 IEICE General Conference Proceedings B-10-75, p. 358

  However, in addition to the above-mentioned all-optical 2R signal regeneration processing, in the all-optical 3R signal regeneration processing by adding a re-timing function by NOLM that functions as an optical gate circuit, along with changes in the external environment such as ambient temperature fluctuations of NOLM It has been found that there is a problem that the all-optical 3R signal reproduction process is not sufficiently performed. In other words, when a change in the external environment such as ambient temperature fluctuation of the NOLM occurs, a phase shift occurs between the optical pulse signal regenerated by the all-optical 2R signal regeneration process and the optical clock signal, and this causes the all-optical 3R signal. It has been found that it is difficult to stably realize the playback processing function.

  Therefore, the present invention always sets the phase shift amount between the optical pulse signal regenerated by the all-optical 2R signal regeneration process and the optical clock signal to 0 even if the external environment changes such as the ambient temperature fluctuation of the NOLM occur. An object of the present invention is to provide an optical pulse signal regeneration method that can be maintained and an apparatus that implements the method.

  The inventor of the present invention has conducted research to observe the wavelength spectrum of a reproduced optical pulse signal generated by performing 3R signal reproduction processing on the inputted reproduced optical pulse signal, and obtained the following knowledge. If the wavelength spectrum of the reproduced optical pulse signal is symmetric with respect to the center wavelength of this wavelength spectrum band, there is no deviation between the phase of the first-stage reproduced optical pulse signal and the phase of the optical clock signal. That is, among the plurality of peaks generated in the wavelength spectrum band with respect to the center wavelength of the wavelength spectrum band of the reproduction optical pulse signal, the short wavelength side and the long wavelength side closest to the center wavelength of the wavelength spectrum band It has been found that if the intensity ratio of the wavelength components each having a peak is 1: 1, there is no deviation between the phase of the first-stage reproduced optical pulse signal and the phase of the optical clock signal.

  Therefore, if the operation of delaying the phase of the optical pulse signal of the first stage or the phase of the optical clock signal is performed so that the intensity ratio of the two wavelength components is always 1: 1, the all-optical 3R signal regeneration processing function is achieved. We reached the view that it would be possible to achieve it stably.

  According to the gist of the present invention based on the above philosophy, the following optical pulse signal regeneration method and an optical pulse signal regeneration device for realizing the method are provided.

  The optical pulse signal regeneration method according to claim 1 of the present invention includes a first stage regeneration optical pulse signal generation step, an optical clock signal extraction step, a regeneration optical pulse signal generation step, a phase adjustment signal extraction step, and a phase adjustment step. It is comprised including.

  The first stage reproduction optical pulse signal generation step is a step in which the time waveform shaping of the optical pulse of the inputted optical pulse signal to be reproduced and the amplification of the optical pulse are performed to generate and output the first stage reproduction optical pulse signal. The optical clock signal extraction step is a step of extracting the optical clock signal from the first stage reproduction optical pulse signal. The reproduction optical pulse signal generation step is a step of generating and outputting a reproduction optical pulse signal that is a logical product of the first-stage reproduction optical pulse signal and the optical clock signal. The phase adjustment signal extraction step is the shortest wavelength side closest to the center wavelength of the wavelength spectrum band among a plurality of peaks generated in the wavelength spectrum band with respect to the center wavelength of the wavelength spectrum band of the reproduction optical pulse signal. And a phase adjustment signal that is a power component having a magnitude proportional to the intensity ratio of both wavelength components, each of which has a wavelength component having a peak on the long wavelength side and a wavelength component having a long wavelength side. The phase adjustment step is a step of matching the phase of the optical clock signal with the phase of the first stage reproduction optical pulse signal based on the phase adjustment signal.

  The optical pulse signal regeneration method described above is realized by the optical pulse signal regeneration device according to claim 4. That is, the optical pulse signal regeneration device of the present invention comprises a first-stage regeneration optical pulse signal generator, an optical clock signal extraction device, a NOLM, a phase adjustment signal extraction device, and an optical clock signal phase adjuster. The

  The first-stage reproduced optical pulse signal generator receives the reproduced optical pulse signal, performs time waveform shaping of the optical pulse and amplifies the optical pulse, and generates and outputs the first-stage reproduced optical pulse signal. The optical clock signal extraction device receives the first stage reproduction optical pulse signal, extracts the optical clock signal from the first stage reproduction optical pulse signal, and outputs it. The NOLM receives the first stage reproduction optical pulse signal and the optical clock signal, and generates and outputs a reproduction optical pulse signal.

  The phase adjustment signal extraction device receives a reproduction optical pulse signal, and from the reproduction optical pulse signal, among the plurality of peaks generated in the wavelength spectrum band with respect to the center wavelength of the wavelength spectrum band of the reproduction optical pulse signal, A phase adjustment signal which is a wavelength component having a short wavelength side peak and a long wavelength side peak closest to the center wavelength of the wavelength spectrum band, and is a power signal having a magnitude proportional to the intensity ratio of both wavelength components. Generate and output.

  The optical clock signal phase adjuster receives the optical clock signal, generates a phase adjusted optical clock signal based on the phase adjustment signal, and generates and outputs a phase adjusted optical clock signal in accordance with the phase of the first stage reproduction optical pulse signal.

  As described in claim 5, the optical pulse signal regenerator according to the present invention may comprise a first-stage regenerated optical pulse signal phase adjuster instead of the optical clock signal phase adjuster described above. The first stage regenerated optical pulse signal phase adjuster receives the first stage regenerated optical pulse signal and adjusts the phase of the first stage regenerated optical pulse signal to the phase of the optical clock signal based on the phase adjustment signal. Generate and output.

  In the optical pulse signal regeneration method according to the present invention, the optical clock signal extraction step includes the step of extracting the electrical clock signal from the first stage regeneration optical pulse signal and the mode-locked semiconductor laser by the electrical clock signal, as described in claim 2. It is preferable to include a step of controlling and generating an optical clock signal by the mode-locked semiconductor laser.

  This optical clock signal extraction step is realized by the optical clock signal extraction device according to claim 6. That is, the optical clock signal extraction device generates an optical clock signal by performing mode-synchronized operation with the electric clock signal extractor that extracts and outputs the electric clock signal when the first-stage reproduction optical pulse signal is input. And a mode-locked semiconductor laser that outputs the output.

  In the optical pulse signal regeneration method of the present invention, the phase adjustment signal extraction step includes a reproduction optical pulse signal branching step, a first phase adjustment signal generation step, and a second phase adjustment signal, as described in claim 3. It is preferable to include a generation step and a phase adjustment signal generation step.

  The reproduction light pulse signal branching step is a step of branching the reproduction light pulse signal into a first reproduction light pulse signal and a second reproduction light pulse signal.

  The first phase adjustment signal generation step is closest to the center wavelength of the wavelength spectrum band among a plurality of peaks generated in the wavelength spectrum band with respect to the center wavelength of the wavelength spectrum band of the first reproduction optical pulse signal. Generating and outputting a first phase adjustment signal that is a power signal proportional to the intensity of the wavelength component having a peak on the short wavelength side.

  The second phase adjustment signal generation step is closest to the center wavelength of the wavelength spectrum band among a plurality of peaks generated in the wavelength spectrum band with respect to the center wavelength of the wavelength spectrum band of the second reproduction optical pulse signal. Generating and outputting a second phase adjustment signal that is a power signal proportional to the intensity of the wavelength component having a peak on the long wavelength side.

  The phase adjustment signal generation step is a step of generating and outputting a phase adjustment signal that is a power signal having a magnitude proportional to the intensity ratio between the first phase adjustment signal and the second phase adjustment signal.

In the optical pulse signal reproduction method of the present invention, the phase adjustment signal extraction step is realized by the phase adjustment signal extraction device according to claim 7. That is, it is preferable that the phase adjustment signal extraction device includes a reproduction optical pulse signal branching device, a first phase adjustment signal generator, a second phase adjustment signal generator, and an intensity comparator.

  The reproduction optical pulse signal branching unit receives the reproduction optical pulse signal, branches the first reproduction optical pulse signal and the second reproduction optical pulse signal, and outputs them.

  The first phase adjustment signal generator receives the first reproduction optical pulse signal and sets the center wavelength of the wavelength spectrum band to the center wavelength of the wavelength spectrum band among the plurality of peaks generated in the wavelength spectrum band with respect to the center wavelength of the wavelength spectrum band. A first phase adjustment signal, which is a power signal proportional to the intensity of the wavelength component having the shortest peak on the shortest side, is generated and output.

  The second phase adjustment signal generator receives the second reproduction optical pulse signal and sets the center wavelength of the wavelength spectrum band to the center wavelength of the wavelength spectrum band among the plurality of peaks generated in the wavelength spectrum band with respect to the center wavelength of the wavelength spectrum band. A second phase adjustment signal that is a power signal proportional to the intensity of the wavelength component having the peak on the long wavelength side that is closest is generated and output.

  The intensity comparator receives the first phase adjustment signal and the second phase adjustment signal, and is a phase adjustment signal that is a power signal having a magnitude proportional to the intensity ratio between the first phase adjustment signal and the second phase adjustment signal. Is generated and output.

  According to the optical pulse signal regeneration device of the present invention as set forth in claim 4 or 5, the phase adjustment signal is supplied to the optical clock signal phase adjuster or the first stage regenerated optical pulse signal phase adjuster, whereby the optical clock signal A phase adjustment step is performed in which the phase of the first stage and the phase of the first stage reproduction optical pulse signal are matched. Therefore, according to the optical pulse signal regeneration device of the present invention, based on the phase adjustment signal, the optical clock signal phase adjuster or the first-stage regeneration optical pulse signal phase adjuster always sets the intensity ratio of both wavelength components to one pair. An operation for adjusting the phase of the first-stage reproduction optical pulse signal or the phase of the optical clock signal is executed so as to be 1.

  Therefore, even if a change occurs in the external environment such as the ambient temperature fluctuation of the NOLM, the phase shift amount between the first stage reproduction optical pulse signal and the optical clock signal can always be kept at zero. This makes it possible to stably realize the all-optical 3R signal reproduction processing function.

  The optical clock signal extraction step is realized by the optical clock signal extraction device including the mode-locked semiconductor laser according to claim 6, so that the wavelength of the optical clock signal can be freely selected, and the optical clock signal is configured. It becomes possible to arrange the time waveform of the optical pulse into a shape free from waveform distortion having excellent symmetry with respect to the time axis. The wavelength of the optical clock signal can be easily changed by changing the oscillation wavelength of the mode-locked semiconductor laser to be used. This has the advantage that the wavelength of the optical clock signal to be extracted can be appropriately selected in accordance with the wavelength of the optical pulse signal in an optical repeater using the optical pulse signal regeneration device of the present invention.

  8. The phase according to claim 7, wherein the phase adjustment signal extraction step comprises a reproduction optical pulse signal branching unit, a first phase adjustment signal generator, a second phase adjustment signal generator, and an intensity comparator. By realizing it with the adjustment signal extraction device, the phase adjustment signal can be easily obtained.

  The first phase adjustment signal generator and the second phase adjustment signal generator provided by the above-described phase adjustment signal extraction device, while observing the first phase adjustment signal and the second phase adjustment signal, the intensity ratio of both signals The object of the present invention can be achieved by manually adjusting the phase of the first-stage regenerative optical pulse signal or the phase of the optical clock signal so that is always one-to-one. That is, the phase adjustment signal extraction step and the phase adjustment step can be performed manually.

  On the other hand, in order to automate the phase adjustment signal extraction step and the phase adjustment step, a configuration including the above-described intensity comparator may be used. That is, the above-described intensity comparator generates a phase adjustment signal indicating the intensity ratio between the first phase adjustment signal and the second phase adjustment signal, and based on the phase adjustment signal, the phase of the first-stage reproduced optical pulse signal or the optical clock The means for autonomously adjusting the phase of the signal can be implemented based on an existing feedback control technique.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Each drawing used to describe the configuration of the apparatus is merely an example of the configuration according to the present invention, and only schematically shows the arrangement relationship of each component to the extent that the present invention can be understood. However, the present invention is not limited to the illustrated example. Moreover, in each figure, the same component is shown with the same number, and the overlapping description may be omitted. In the schematic configuration diagram shown below, the path of an optical signal such as an optical fiber is indicated by a thick line, and the path of an electrical signal is indicated by a thin line.

<Optical pulse signal regeneration device>
With reference to FIG. 1, the configuration and operation of an optical pulse signal regeneration device according to an embodiment of the present invention will be described. FIG. 1 is a schematic configuration diagram of an optical pulse signal regeneration device according to an embodiment of the present invention.

  The optical pulse signal regeneration device of the present invention comprises a first-stage regeneration optical pulse signal generator 10, an optical clock signal extraction device 20, a phase adjustment signal extraction device 30, an optical clock signal phase adjuster 50, and a NOLM 60. Composed.

  The NOLM 60 is a Sagnac type optical interferometer including an optical fiber 64, an optical coupler 66, and a bidirectional optical coupler 62. The optical coupler 66 is supplied with a first-stage reproduction optical pulse signal 15-1 or a phase adjustment first-stage reproduction optical pulse signal 53, which will be described later. An optical clock signal 51 is input to the bidirectional optical coupler 62, and a reproduction optical pulse signal 63 and a reproduction optical pulse signal 65 are output from the bidirectional optical coupler 62.

  As will be described later, the optical clock signal 51 is an optical clock signal output by adjusting the phase of the optical clock signal 25 output from the optical clock signal extraction device 20 by the optical clock signal phase adjuster 50. This is an adjusted optical clock signal. Hereinafter, the phase-adjusted optical clock signal output from the optical clock signal phase adjuster 50 is simply referred to as an optical clock signal 51 for the sake of simplicity.

The first stage reproduction optical pulse signal generator 10 receives the reproduced optical pulse signal 9, performs time waveform shaping of the optical pulse and amplification of the optical pulse, and generates and outputs the first stage reproduction optical pulse signal 11. That is, the regenerated optical pulse signal 9 having a wavelength of λ _s is input to the first-stage reproduced optical pulse signal generator 10, and the first-stage reproduced optical pulse signal 11 having a wavelength of λ _p is generated and output.

  The first stage reproduction optical pulse signal 11 can be generated by a method of connecting the spectrum slice type wavelength converters disclosed in Non-Patent Document 4 described above in multiple stages. The spectrum slice type wavelength converter is configured by combining a highly nonlinear dispersion flattened fiber (HN-DFF) and an optical bandpass filter. When the optical pulse signal to be reproduced is input to the HN-DFF, the spectral bandwidth of the optical pulse signal to be reproduced widens due to the self-phase modulation effect.

  The self-phase modulation effect is a phenomenon that occurs when an optical pulse propagates through an optical fiber. At the center of the optical pulse, the refractive index of the optical fiber increases due to the optical Kerr effect. For this reason, the speed of light is delayed near the center of the optical pulse. As a result, the wavelength of the first half of the pulse becomes longer and the second half becomes shorter. That is, the spectrum bandwidth of the optical pulse signal to be reproduced is widened by the self-phase modulation effect. A highly nonlinear dispersion flat fiber has a characteristic in which the self-phase modulation effect appears remarkably.

  With reference to FIG. 2, the configuration of the first-stage reproduction optical pulse signal generator 10 configured by connecting the spectrum slice type wavelength converters in two stages will be described. FIG. 2 is a schematic block diagram of the first stage reproduction optical pulse signal generator 10. As shown in FIG. The first-stage regenerative optical pulse signal generator 10 includes a first optical amplifier 100 constituting the first stage, a first HN-DFF 102, and a (10-1) band-pass filter 104. A second optical amplifier 106 constituting the second stage, a second HN-DFF 108, and a (10-2) -th bandpass filter 110 are provided.

  In the first stage reproduction optical pulse signal generator 10 shown in FIG. 2, in the first stage, the optical pulse signal 9 to be reproduced is inputted to the first optical amplifier 100 and amplified, and then inputted to the first HN-DFF 102. Thus, the spectral bandwidth of the optical pulse signal 9 to be reproduced is widened. The first reconstructed optical pulse signal 103 output from the first HN-DFF 102 with the spectral bandwidth expanded is supplied to the (10-1) bandpass filter by the (10-1) bandpass filter 104. It is converted to a wavelength of 104 transmission band.

  In the second stage, the first regenerated optical pulse signal 105 whose wavelength has been converted is input to the second optical amplifier 106 and amplified, and then input to the second HN-DFF 108 to reduce the spectral bandwidth. Can be spread. The second reproduced optical pulse signal 109 output from the second HN-DFF 108 with the spectral bandwidth expanded is converted into the wavelength of the transmission band of the (10-2) -th bandpass filter 110. The output light from the (10-2) -th bandpass filter 110 is the first stage reproduction optical pulse signal 11.

The reason for using the first-stage reconstructed optical pulse signal generator configured by connecting the spectrum slice type wavelength converter in two stages instead of one is to increase the wavelength shift amount that is the wavelength conversion amount. That is, this is because the difference between the wavelength λ _s of the reproduced optical pulse signal 9 and the wavelength λ _p of the first-stage reproduced optical pulse signal 11 is made large.

This is to ensure a timing recovery function (re-timing) of an optical pulse by the NOLM 60 described later. In order to ensure the timing regeneration function of NOLM 60, the difference between λ _s and λ _p is required to be 8 nm or more. On the other hand, it is difficult to shift the wavelength of a high-bit-rate optical pulse signal with a bit rate exceeding 40 Gbit / s by 8 nm or more in a one-stage spectrum slice wavelength converter.

  The first-stage regenerative optical pulse signal generator 10 includes a first optical amplifier 100 and a second optical amplifier 106 at the preceding stage of each of the first HN-DFF 102 and the second HN-DFF 108. Re-amplifying is executed by the first optical amplifier 100 and the second optical amplifier 106. Also realized by the combination of the first HN-DFF 102 and the (10-1) bandpass filter 104, and the combination of the second HN-DFF 108 and the (10-2) bandpass filter 110. Re-shaping for shaping the waveform of an optical pulse along with wavelength conversion is executed by the spectrum slicing method. In other words, the optical pulse signal 9 to be reproduced is input to the first-stage reproduction optical pulse signal generator 10, 2R signal reproduction is performed simultaneously with wavelength conversion, and the first-stage reproduction optical pulse signal 11 is generated and output.

  The first-stage reproduction optical pulse signal 11 is input to the optical branching device 14, branched into the first-stage reproduction optical pulse signal 15-1 and the first-stage reproduction optical pulse signal 15-2, and output.

  The optical clock signal extraction device 20 receives the first-stage regenerated optical pulse signal 15-2, extracts the electrical clock signal 23, and outputs the electrical clock signal 23. A mode-locked semiconductor laser (MLLD) 24 that generates and outputs the signal 25 is provided. That is, the optical clock signal extraction device 20 receives the first-stage reproduction optical pulse signal 15-2, extracts the optical clock signal 25 from the first-stage reproduction optical pulse signal 15-2, and outputs it.

  The electric clock signal extractor 22 can be configured by appropriately using, for example, a known phase-locked loop (PLL). When using a PLL, first, the first-stage regenerative optical pulse signal 15-2 is converted into an electrical pulse signal by a photodiode or the like, and the electrical pulse signal is converted into a phase comparator and a voltage-controlled oscillator (VCO). It is possible to extract the electric clock signal 23 by a method of detecting the edge timing of the electric pulse signal with a phase comparator and adjusting the oscillation frequency and phase of the VCO.

  The optical clock signal extraction device 20 is not limited to the configuration including the electric clock signal extractor 22 and the mode-locked semiconductor laser 24 as described above. It is also possible to use an all-optical clock signal extraction device that performs all processing as an optical signal without performing electrical processing using the electrical clock signal extractor 22. For example, the optical clock signal extraction method disclosed in Japanese Patent Application Laid-Open No. 2007-221198 or Japanese Patent Application Laid-Open No. 2007-124026 is realized by appropriately using the optical clock signal extraction device 20 as the optical clock signal extraction device 20. It is possible.

  The phase adjustment signal extraction device 30 includes a reproduction optical pulse signal branching unit 32, a first phase adjustment signal generator 44, a second phase adjustment signal generator 46, and an intensity comparator 42. As will be described later, the reproduction light pulse signal 57 is input to the reproduction light pulse signal splitter 32. The first phase adjustment signal generator 44 includes a first optical bandpass filter 34 and a first photoelectric converter 38. The second phase adjustment signal generator 46 includes a second optical bandpass filter 36 and a second photoelectric converter 40.

The reproduction light pulse signal 57 is a signal that is output from the reproduction light pulse signal 63 output from the NOLM 60 after being input to the optical bandpass filter 56 via the optical circulator 54 and filtered. Reproduced optical pulse signal 63 is input to the optical band-pass filter 56, the wavelength lambda _c component is a wavelength of the optical clock signal is cut, the wavelength lambda _p component is the wavelength of the reproducing light pulse signal is reproduced optical pulse signal 57 Is transmitted and output. That is, the reproduction optical pulse signal 63 output from the NOLM 60 via the optical circulator 54 includes a wavelength λ _c component that is the wavelength of the optical clock signal. , The wavelength λ _c component is removed, and the reproduced optical pulse signal 57 having the wavelength λ _p is transmitted and output.

  On the other hand, the first stage reproduction optical pulse signal 15-1 is input to the NOLM 60. The optical clock signal 51 output from the optical clock signal phase adjuster 50 is input to the NOLM 60 via the optical circulator 54. In the NOLM 60, timing regeneration (Re-timing) is performed to match the phase of the first stage reproduction optical pulse signal 15-1 with the phase of the optical clock signal 51, and a reproduction optical pulse signal 65 is generated and output. .

  The NO-LM 60 re-timing operation outputs from the optical gate only the energy components of the overlapping portions of the optical pulses of the optical pulses constituting the first stage optical pulse signal 15-1 and optical clock signal 51. It is realized by using the effect of being.

Since the reproduction optical pulse signal 65 includes an optical clock signal component having a wavelength λ _c and a reproduction optical pulse signal component having a wavelength λ _p , the reproduction optical pulse signal 65 is converted into an optical bandpass filter 70. , The optical clock signal component having the wavelength λ _c is removed, and the reproduction optical pulse signal 71 having the wavelength λ _p is output.

  In the optical pulse signal regeneration device according to the embodiment of the present invention described above, the optical clock signal arranged at the subsequent stage of the optical clock signal extraction device 20 in order to match the phases of the first-stage regeneration optical pulse signal and the optical clock signal. The phase adjuster 50 adjusts the phase of the optical clock signal 25. However, in order to match the phases of the first-stage reproduced optical pulse signal and the optical clock signal, it is also realized by adjusting the phase of the first-stage reproduced optical pulse signal 15-1 instead of adjusting the phase of the optical clock signal 25. The

  FIG. 1 also illustrates a configuration in which the phases of the first-stage reproduction optical pulse signal 15-1 and the optical clock signal are adjusted by adjusting the phase of the first-stage reproduction optical pulse signal 15-1. However, in order to adjust the phase of the first-stage reproduction optical pulse signal 15-1, the first-stage reproduction optical pulse signal phase adjuster 52 (shown by a broken-line rectangle) is connected to the optical splitter 14 and the optical coupler 66. The first-stage reproduction optical pulse signal 15-1 is input to the first-stage reproduction optical pulse signal phase adjuster 52 and output from the first-stage reproduction optical pulse signal phase adjuster 52. May be input to the optical coupler 66 of the NOLM 60.

  As described above, the reproduction optical pulse signal 57 is input to the reproduction optical pulse signal splitter 32 of the phase adjustment signal extraction device 30. The reproduction light pulse signal branching device 32 branches the reproduction light pulse signal 57 into a first reproduction light pulse signal 33-1 and a second reproduction light pulse signal 33-2 and outputs them.

The first phase adjustment signal generator 44 receives the first reproduction optical pulse signal 33-1, and has a wavelength spectrum band out of a plurality of peaks generated in the wavelength spectrum band with respect to the center wavelength of the wavelength spectrum band. A first phase adjustment signal 39, which is a power signal proportional to the intensity of a wavelength component having a short wavelength peak closest to the center wavelength, is generated and output. That is, the first reproduction light pulse signal 33-1, the first phase adjustment signal 35 is input an optical clock signal component having a wavelength of lambda _c is removed in the first optical band pass filter 34 is generated and output The The first phase adjustment signal 35 is input to the first photoelectric converter 38, and the first phase adjustment signal 39 is generated and output.

On the other hand, the second phase adjustment signal generator 46 receives the second reproduction optical pulse signal 33-2 and outputs the wavelength of the plurality of peaks generated in the wavelength spectrum band with respect to the center wavelength of the wavelength spectrum band. A second phase adjustment signal 41, which is a power signal proportional to the intensity of the wavelength component having a peak on the long wavelength side closest to the center wavelength of the spectrum band, is generated and output. That is, the second reproduction light pulse signal 33-2, a second phase adjustment signal 37 is input an optical clock signal component having a wavelength of lambda _c is removed in the second optical band pass filter 36 is generated and output The The second phase adjustment signal 37 is input to the second photoelectric converter 40, and a second phase adjustment signal 41 is generated and output.

  The intensity comparator 42 receives the first phase adjustment signal 39 and the second phase adjustment signal 41, and has a power that is proportional to the intensity ratio between the first phase adjustment signal 39 and the second phase adjustment signal 41. A phase adjustment signal 43 as a signal is generated and output.

  For the optical clock signal phase adjuster 50 and the first stage reproduction optical pulse signal phase adjuster 52, for example, a motor control variable delay line (manufactured by General Photonics, model number MLD-001) supplied from iWave Inc. is appropriately used. It is possible to use. If the optical clock signal phase adjuster 50 is realized by a motor control variable delay line, the length of the delay line is adjusted by controlling the built-in motor corresponding to the phase adjustment signal 43, so that the input is made. The phase of the optical clock signal 25 is adjusted. Similarly, if the first-stage reproduction optical pulse signal phase adjuster 52 is realized by a motor-controlled variable delay line, the phase of the input first-stage reproduction optical pulse signal 15-1 corresponding to the phase adjustment signal 43 is similarly changed. Adjusted.

  For the intensity comparator 42, a commercially available differential amplifier can be appropriately selected and used. A method for appropriately converting the output signal output from the differential amplifier into a state that can be used as a control signal for a variable delay line or the like used in the optical clock signal phase adjuster 50 and the first stage reproduction optical pulse signal phase adjuster 52 Belongs to the design items to be determined from the relationship with the differential amplifier and variable delay line used. For example, the control voltage of the variable delay line can be adjusted by using an amplifier that amplifies the output signal output from the differential amplifier as necessary.

  The phase adjustment signal 43 is supplied to the optical clock signal phase adjuster 50. The optical clock signal phase adjuster 50 receives the optical clock signal 25 output from the mode-locked semiconductor laser 24, and adjusts the phase of the optical clock signal 25 to the phase of the first-stage reproduced optical pulse signal based on the phase adjustment signal 43. The optical clock signal 51 is generated and output.

  If the phase of the first-stage reproduction optical pulse signal and the optical clock signal are adjusted by adjusting the phase of the first-stage reproduction optical pulse signal 15-1, the phase adjustment signal 43 is adjusted to the first-stage reproduction optical pulse signal phase adjustment. Is supplied to the vessel 52. The first-stage reproduction optical pulse signal phase adjuster 52 receives the first-stage reproduction optical pulse signal 15-1 and adjusts the phase of the first-stage reproduction optical pulse signal 15-1 to the phase of the optical clock signal based on the phase adjustment signal 43. The phase adjustment first stage reproduction optical pulse signal 53 is generated and output.

  That is, even if the phase adjustment signal 43 is supplied to either the optical clock signal phase adjuster 50 or the first stage reproduction optical pulse signal phase adjuster 52, the first phase adjustment signal 39 and the second phase adjustment signal 39 are based on the phase adjustment signal 43. An operation of delaying the phase of the optical clock signal 25 or the phase of the first stage reproduction optical pulse signal 15-1 is executed so that the intensity ratio with the phase adjustment signal 41 is always 1: 1.

  The intensity comparator 42 generates a phase adjustment signal 43 indicating the intensity ratio between the first phase adjustment signal 39 and the second phase adjustment signal 41. Based on the phase adjustment signal 43, the first stage reproduction optical pulse signal 15-1 The means for autonomously adjusting the phase or the phase of the optical clock signal 25 can be implemented using an existing feedback control technique.

  According to the optical pulse signal regeneration device of the embodiment of the present invention, either the direct detection (IM-DD: Intensity Modulation-Direct Detection) method or the balanced detection (Balanced detection) method is assumed as the format of the optical pulse signal. The format can also be supported. That is, it is possible to correspond to an optical pulse signal coded by the ASK (Amplitude Shift Keying) method which is a direct detection method, and also to an optical pulse signal coded by the DPSK method which is a balanced detection method. Is possible.

  In the above-described optical pulse signal regeneration device according to the embodiment of the present invention, a mode-locked semiconductor laser is used to generate an optical clock signal. However, a fiber laser mode-locked laser can be used as appropriate. It is. Further, it is possible to extract the optical clock signal by using, for example, an electro-absorption optical modulator other than the mode-locked semiconductor laser.

<Verification experiment>
Referring to FIG. 3, if the intensity of the first phase adjustment signal and the intensity of the second phase adjustment signal are equal, there is no deviation between the phase of the first stage reproduction optical pulse signal and the phase of the optical clock signal. A fact verification experiment will be described. FIG. 3 is a schematic block diagram of an experimental apparatus for verifying the relationship between the wavelength spectrum of the reproduced optical pulse signal and the amount of deviation between the phase of the first-stage reproduced optical pulse signal and the phase of the optical clock signal. is there.

  The optical pulse signal regenerator according to the embodiment of the present invention described with reference to FIG. 1 is introduced with an optical branching device 80 that branches the regenerated optical pulse signal 57 in order to monitor the regenerated optical pulse signal 57. Went. The reproduction optical pulse signal 57 input to the optical splitter 80 includes a reproduction optical pulse signal 57-1 input to the phase adjustment signal extraction device 30 to generate the phase adjustment signal 43, and a reproduction optical pulse signal for monitoring. Branch to 57-2.

  The reproduction optical pulse signal 57-1 is input to the reproduction optical pulse signal divider 32 of the phase adjustment signal extraction device 30, and is branched into the first reproduction optical pulse signal 33-1 and the second reproduction optical pulse signal 33-2. The

First reproduction light pulse signal 33-1, the first phase adjustment signal 35 is input an optical clock signal component having a wavelength of lambda _c is removed in the first optical band pass filter 34 is generated and output. The first phase adjustment signal 35 is input to the optical power meter 84 and the intensity thereof is measured.

Second reproduction light pulse signal 33-2, a second phase adjustment signal 37 is input an optical clock signal component having a wavelength of lambda _c is removed in the second optical band pass filter 36 is generated and output. The second phase adjustment signal 37 is input to the optical power meter 86 and its intensity is measured.

  On the other hand, the reproduction light pulse signal 57-2 for monitoring is input to the optical spectrum analyzer 82, and its wavelength spectrum is observed.

  In the verification experiment described below, an optical time division multiplexed signal having a bit rate of 160 Gbit / s was used as the reproduced optical pulse signal. The symmetry of the wavelength spectrum of the reproduction optical pulse signal 57 was changed by changing the transmission center wavelength of the optical bandpass filter 56.

  The optical bandpass filter 56, the first optical bandpass filter 34, and the second optical bandpass filter 36 used optical fiber Bragg gratings having transmission wavelength bandwidths of 3 nm, 0.3 nm, and 0.3 nm, respectively. The transmission wavelength bandwidth of the optical bandpass filter refers to the full width at half maximum of the wavelength transmission characteristic curve.

  With reference to FIG. 4, a wavelength spectrum of a typical reproduction optical pulse signal observed by the optical spectrum analyzer 82 will be described. FIG. 4 is a diagram showing a wavelength spectrum of a typical reproduction optical pulse signal, where the horizontal axis indicates the wavelength in nm units, and the vertical axis indicates the intensity in dBm units.

  As shown in FIG. 4, the reproduction light pulse signal 57-2 for monitoring has a center wavelength of 1550.3 nm and has a plurality of large and small peaks in its spectrum band. Peaks existing at positions closest to the center wavelength on the short wavelength side and the long wavelength side are referred to as peak A and peak B, respectively. The peak A is a wavelength component having a peak at a position closest to the center wavelength of the wavelength spectrum band, and the peak wavelength is a peak of a wavelength component on the short wavelength side with respect to the center wavelength. Similarly, the peak B is a wavelength component having a peak at a position closest to the center wavelength of the wavelength spectrum band, and the peak wavelength is a peak of a wavelength component on the long wavelength side with respect to the center wavelength.

  A wavelength spectrum of the first phase adjustment signal 39 (see FIG. 1) will be described with reference to FIG. The first phase adjustment signal 39 is obtained by filtering the first reproduction optical pulse signal 33-1 obtained by branching the reproduction optical pulse signal 57-1 by the reproduction optical pulse signal splitter 32 by the first optical bandpass filter 34. The first phase adjustment signal 35 thus generated is input to the first photoelectric converter 38 and generated and output. FIG. 5 is a diagram showing the wavelength spectrum of the first phase adjustment signal 39, where the horizontal axis indicates the wavelength in nm units, and the vertical axis indicates the intensity in dBm units.

  The transmission band wavelength of the first optical bandpass filter 34 is set to a wavelength band including the peak A shown in FIG. The power signal measured by the optical power meter 84 (see FIG. 3) is obtained by photoelectrically converting the first phase adjustment signal 35, and a curve indicating the wavelength spectrum of the first phase adjustment signal 35 shown in FIG. This is a first phase adjustment signal 39 having a magnitude proportional to the enclosed area.

  Next, the wavelength spectrum of the second phase adjustment signal 41 will be described with reference to FIG. The second phase adjustment signal 41 (see FIG. 1) is obtained by converting the second reproduction optical pulse signal 33-2 obtained by branching the reproduction optical pulse signal 57-1 by the reproduction optical pulse signal splitter 32 into the second optical bandpass filter 36. The second phase adjustment signal 37 obtained by filtering by the above is input to the second photoelectric converter 40 and generated and output. FIG. 6 is a diagram showing the wavelength spectrum of the second phase adjustment signal 41. The horizontal axis indicates the wavelength in nm units, and the vertical axis indicates the intensity in dBm units.

  The transmission band wavelength of the second optical bandpass filter 36 is set to a wavelength band including the peak B shown in FIG. The power signal measured by the optical power meter 86 (see FIG. 3) is obtained by photoelectrically converting the second phase adjustment signal 37, and a curve indicating the wavelength spectrum of the second phase adjustment signal 37 shown in FIG. This is a second phase adjustment signal 41 having a magnitude proportional to the enclosed area.

  As described above with reference to FIGS. 3 to 6, the phase adjustment signal extraction device 30 of the present invention comprising the reproduction optical pulse signal splitter 32 and the first and second phase adjustment signal generators 44 and 46 is provided. Accordingly, the phase adjustment signal 43 given by the intensity ratio between the magnitude of the first phase adjustment signal 39 and the magnitude of the second phase adjustment signal 41 is obtained. The phase adjustment signal 43 is a parameter that gives symmetry to the reproduction optical pulse signal wavelength spectrum, and based on this, the ratio of the values of the first phase adjustment signal 39 and the second phase adjustment signal 41 can be known.

  Next, referring to FIG. 7, when adjusting the phase difference between the optical clock signal and the first stage reproduction optical pulse signal so that the values of the first phase adjustment signal 39 and the second phase adjustment signal 41 are equal, The wavelength spectrum of the reproduction light pulse signal 57-2 for monitoring (see FIG. 3) will be described. FIG. 7 shows a reproduction optical pulse signal for monitoring when the phase difference between the optical clock signal and the first-stage reproduction optical pulse signal is adjusted so that the values of the first phase adjustment signal 39 and the second phase adjustment signal 41 are equal. It is a figure which shows the wavelength spectrum of 57-2, The wavelength is scaled in nm unit on the horizontal axis, and the intensity is scaled in dBm unit on the vertical axis.

  By adjusting the phase difference between the optical clock signal and the first stage reproduction optical pulse signal so that the values of the first phase adjustment signal 39 and the second phase adjustment signal 41 are equal, the peak A and the length of the wavelength component on the short wavelength side are increased. It can be seen that the peak B of the wavelength component on the wavelength side can be made equal. At this time, the phase of the optical clock signal matches the phase of the first-stage reproduced optical pulse signal, and the time waveform of the reproduced optical pulse signal 71 has high symmetry of the optical pulse, and is an ideal all-optical 3R signal. I confirmed that the replay was made.

  Next, referring to FIG. 8, the phase difference between the optical clock signal and the first-stage reproduced optical pulse signal so that the magnitude of the second phase adjustment signal 41 is larger than the magnitude of the first phase adjustment signal 39. The wavelength spectrum of the reproduction light pulse signal 57-2 for monitoring in the case where is adjusted will be described.

  FIG. 8 shows the reproduction light for monitoring when the phase difference between the optical clock signal and the first-stage reproduction optical pulse signal is adjusted so that the second phase adjustment signal 41 is larger than the first phase adjustment signal 39. It is a figure which shows the wavelength spectrum of the pulse signal 57-2, the wavelength is scaled in nm unit on the horizontal axis, and the intensity is scaled in dBm unit on the vertical axis. When the magnitude of the second phase adjustment signal 41 is larger than that of the first phase adjustment signal 39, the phase of the optical clock signal and the phase of the first stage reproduction optical pulse signal are shifted, and the time waveform of the reproduction optical pulse signal 71 is It was confirmed that the symmetry of the optical pulse was broken and the ideal all-optical 3R signal regeneration was not performed.

  Similarly, although not shown, the phase difference between the optical clock signal and the first stage reproduction optical pulse signal is adjusted so that the magnitude of the second phase adjustment signal 41 is smaller than the magnitude of the first phase adjustment signal 39. In this case, the phase of the optical clock signal is out of phase with the phase of the first-stage reproduced optical pulse signal, the wavelength spectrum is asymmetrical, and the time waveform of the reproduced optical pulse signal 71 has lost its symmetry. It was confirmed that ideal all-optical 3R signal reproduction was not performed.

  On the other hand, as described above, the phase of the optical clock signal 25 is changed by the optical clock signal phase adjuster 50, or the phase of the first stage reproduced optical pulse signal 15-1 is changed by the first stage reproduced optical pulse signal phase adjuster 52, By changing the phase difference between the optical clock signal 25 (or 51) and the first stage reproduction optical pulse signal 15-1 (or 53), the symmetry of the wavelength spectrum of the reproduction optical pulse signal 57-2 for monitoring can be freely adjusted. I confirmed that it can be changed. Then, it was confirmed that the symmetry of the wavelength spectrum of the reproduced optical pulse signal was realized in a state where the phases of the optical clock signal and the first-stage reproduced optical pulse signal matched.

  From the results of the above verification experiment, it was confirmed that ideal all-optical 3R signal reproduction can be performed by setting the magnitude of the first phase adjustment signal 39 and the magnitude of the second phase adjustment signal 41 equal.

  The intensity ratio between the first phase adjustment signal 39 and the second phase adjustment signal 41 is a value that reflects the symmetry of the reproduction optical pulse signal 57. That is, if the intensity ratio between the first phase adjustment signal 39 and the second phase adjustment signal 41 is 1: 1, the wavelength spectrum curve of the reproduction optical pulse signal 57 has symmetry.

  When the phase of the first stage reproduction optical pulse signal and the phase of the optical clock signal are out of phase, the wavelength spectrum curve of the reproduction optical pulse signal 57 has lost its symmetry. By adjusting the relationship between the phase of the first-stage reproduction optical pulse signal and the phase of the optical clock signal so that the magnitude of the two-phase adjustment signal 41 is equal, the phase of the first-stage reproduction optical pulse signal and the phase of the optical clock signal are It is possible to eliminate the deviation.

  That is, if the operation of delaying the phase of the first-stage reproduction optical pulse signal or the phase of the optical clock signal is performed so that the intensity ratio between the first phase adjustment signal 39 and the second phase adjustment signal 41 is always 1: 1. It is possible to stably realize the all-optical 3R signal reproduction function.

It is a schematic block diagram of the optical pulse signal reproduction | regeneration apparatus of embodiment of this invention. It is a schematic block diagram of a first stage reproduction optical pulse signal generator. FIG. 4 is a schematic block configuration diagram of an experimental apparatus for verifying a relationship between a wavelength spectrum of a reproduction optical pulse signal and a shift amount between the phase of the first-stage reproduction optical pulse signal and the phase of the optical clock signal. It is a figure which shows the wavelength spectrum of a typical reproduction | regeneration optical pulse signal. FIG. 4 is a diagram showing a wavelength spectrum of a first phase adjustment signal. It is a figure which shows the wavelength spectrum of a 2nd phase adjustment signal. The figure which shows the wavelength spectrum of the reproduction | regeneration optical pulse signal for a monitor when the phase difference of an optical clock signal and an initial stage reproduction | regeneration optical pulse signal is adjusted so that the value of a 1st phase adjustment signal and a 2nd phase adjustment signal may become equal It is. The wavelength spectrum of the reproduction optical pulse signal for monitoring when the phase difference between the optical clock signal and the first-stage reproduction optical pulse signal is adjusted so that the second phase adjustment signal is larger than the first phase adjustment signal. FIG.

Explanation of symbols

10: First stage regenerative optical pulse signal generator
14, 80: Optical splitter
20: Optical clock signal extraction device
22: Electric clock signal extractor
24: Mode-locked semiconductor laser
30: Phase adjustment signal extraction device
32: Regenerative light pulse signal splitter
34: First optical bandpass filter
36, second optical bandpass filter
38: 1st photoelectric converter
40: Second photoelectric converter
42: Strength comparator
44: First phase adjustment signal generator
46: Second phase adjustment signal generator
50: Optical clock signal phase adjuster
52: First stage regenerative optical pulse signal phase adjuster
54: Optical circulator
56, 70: Optical bandpass filter
60: Nonlinear optical loop mirror (NOLM)
62: Directional optical coupler
64: Optical fiber
66: Optical coupler
82: Optical spectrum analyzer
84, 86: Optical power meter
100: First optical amplifier
102: 1st HN-DFF
104: (10-1) bandpass filter
106: Second optical amplifier
108: Second HN-DFF
110: (10-2) bandpass filter

Claims (7)

First stage reproduction optical pulse signal generation step for generating and outputting the first stage reproduction optical pulse signal by performing time waveform shaping of the optical pulse of the inputted reproduced optical pulse signal and amplification of the optical pulse,
An optical clock signal extraction step for extracting an optical clock signal from the first stage reproduction optical pulse signal;
A reproduction optical pulse signal generation step of generating and outputting a reproduction optical pulse signal, which is a logical product of the first stage reproduction optical pulse signal and the optical clock signal, and a center wavelength of a wavelength spectrum band of the reproduction optical pulse signal Among the plurality of peaks generated in the wavelength spectrum band, each having a short wavelength side peak and a long wavelength side peak closest to the center wavelength of the wavelength spectrum band, and the intensity of both wavelength components A phase adjustment signal extraction step of generating and outputting a phase adjustment signal that is a power signal having a magnitude proportional to the ratio;
A method of reproducing an optical pulse signal, comprising: a phase adjustment step of matching the phase of the optical clock signal with the phase of the first stage reproduction optical pulse signal based on the phase adjustment signal. The optical clock signal extraction step includes extracting an electrical clock signal from the first stage reproduction optical pulse signal;
2. The optical pulse signal regeneration method according to claim 1, further comprising the step of controlling a mode-locked semiconductor laser with the electric clock signal and generating an optical clock signal with the mode-locked semiconductor laser. The phase adjustment signal extraction step includes:
A reproduction optical pulse signal branching step for branching the reproduction optical pulse signal into a first reproduction optical pulse signal and a second reproduction optical pulse signal;
Among the plurality of peaks generated in the wavelength spectrum band with respect to the center wavelength of the wavelength spectrum band of the first reproduction optical pulse signal, the peak on the short wavelength side closest to the center wavelength of the wavelength spectrum band A first phase adjustment signal generation step of generating and outputting a first phase adjustment signal that is a power signal proportional to the intensity of the wavelength component;
Among the plurality of peaks generated in the wavelength spectrum band with respect to the center wavelength of the wavelength spectrum band of the second reproduction optical pulse signal, the peak on the long wavelength side closest to the center wavelength of the wavelength spectrum band A second phase adjustment signal generation step of generating and outputting a second phase adjustment signal that is a power signal proportional to the intensity of the wavelength component;
And a phase adjustment signal generating step of generating and outputting a phase adjustment signal which is a power signal having a magnitude proportional to an intensity ratio between the first phase adjustment signal and the second phase adjustment signal. Item 4. The optical pulse signal regeneration method according to Item 1. A first-stage regenerated optical pulse signal generator that receives a regenerated optical pulse signal, performs time waveform shaping of the light pulse and amplifies the light pulse, generates and outputs a first-stage regenerated light pulse signal;
An optical clock signal extraction device that receives the first stage reproduction optical pulse signal, extracts an optical clock signal from the first stage reproduction optical pulse signal, and outputs the optical clock signal;
The first stage reproduction optical pulse signal and the optical clock signal are input, and a nonlinear optical loop mirror that generates and outputs a reproduction optical pulse signal;
The reproduction optical pulse signal is input, and from the reproduction optical pulse signal, a plurality of peaks generated in the wavelength spectrum band with respect to a center wavelength of the wavelength spectrum band of the reproduction optical pulse signal, A phase adjustment signal that is a wavelength component having a short wavelength side peak and a long wavelength side peak closest to the center wavelength and having a magnitude proportional to the intensity ratio of the two wavelength components is generated. A phase adjustment signal extraction device for output;
Optical clock signal phase adjustment that receives the optical clock signal and generates and outputs a phase adjusted optical clock signal based on the phase adjustment signal to match the phase of the optical clock signal with the phase of the first stage reproduction optical pulse signal An optical pulse signal regenerating apparatus comprising: A first-stage regenerated optical pulse signal generator that receives a regenerated optical pulse signal, performs time waveform shaping of the light pulse and amplifies the light pulse, generates and outputs a first-stage regenerated light pulse signal;
An optical clock signal extraction device that receives the first stage reproduction optical pulse signal, extracts an optical clock signal from the first stage reproduction optical pulse signal, and outputs the optical clock signal;
The first stage reproduction optical pulse signal and the optical clock signal are input, and a nonlinear optical loop mirror that generates and outputs a reproduction optical pulse signal;
The reproduction optical pulse signal is input, and from the reproduction optical pulse signal, a plurality of peaks generated in the wavelength spectrum band with respect to the center wavelength of the wavelength spectrum band of the reproduction optical pulse signal A phase adjustment signal that is a wavelength component having a short wavelength side peak and a long wavelength side peak closest to the center wavelength, and is a power signal having a magnitude proportional to the intensity ratio of the two wavelength components; A phase adjustment signal extraction device for output;
A first stage that receives the first stage reproduction optical pulse signal and generates and outputs a phase adjustment first stage reproduction optical pulse signal by matching the phase of the first stage reproduction optical pulse signal with the phase of the optical clock signal based on the phase adjustment signal. A reproduction optical pulse signal phase adjuster;
An optical pulse signal reproducing device comprising: The optical clock signal extraction device comprises:
An electrical clock signal extractor that receives the first stage reproduction optical pulse signal and extracts and outputs the electrical clock signal;
6. The optical pulse signal regeneration device according to claim 4, further comprising a mode-synchronized semiconductor laser that performs a mode-synchronized operation with the electrical clock signal and generates and outputs an optical clock signal. The phase adjustment signal extraction device comprises:
The reproduction optical pulse signal is inputted, and the reproduction optical pulse signal branching device for branching and outputting the first reproduction optical pulse signal and the second reproduction optical pulse signal;
Short wavelength side closest to the center wavelength of the wavelength spectrum band among the plurality of peaks generated in the wavelength spectrum band with respect to the center wavelength of the wavelength spectrum band when the first reproduction optical pulse signal is input A first phase adjustment signal generator that generates and outputs a first phase adjustment signal that is a power signal proportional to the intensity of the wavelength component having a peak of
The long wavelength side closest to the center wavelength of the wavelength spectrum band among the plurality of peaks generated in the wavelength spectrum band with respect to the center wavelength of the wavelength spectrum band when the second reproduction optical pulse signal is input A second phase adjustment signal generator that generates and outputs a second phase adjustment signal that is a power signal proportional to the intensity of the wavelength component having a peak of
The first phase adjustment signal and the second phase adjustment signal are input, and a phase adjustment signal that is a power signal having a magnitude proportional to an intensity ratio between the first phase adjustment signal and the second phase adjustment signal 6. The optical pulse signal reproducing device according to claim 4, further comprising an intensity comparator that generates and outputs the intensity comparator.

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