JP2011217282A - Modulator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a modulator that is applicable to technologies for optical signal storage, optical signal recovery, optical channel change, optical signal control, and the like.SOLUTION: The modulator includes a signal evaluation device 11 that detects each phase and amplitude relating to a plurality of components from an original signal so as to extract information contained in the original signal, a reference signal source 14 for generating a reference discrete spectrum signal, and a phase and amplitude modulation portion 16 which adds phase modulation and amplitude modulation to each frequency component of the reference discrete spectrum generated by the reference signal source.

Description

  The present invention relates to a modulation device that performs phase modulation / amplitude modulation on an optical signal including phase spectrum / amplitude spectrum information on a frequency axis, and relates to an optical signal storage technique, an optical signal restoration technique, an optical channel change technique, and an optical signal. The present invention relates to a modulation device that can be applied to control technology and the like.

  For example, conventionally, an optical loop is used to temporarily store an optical signal. Further, an optical signal buffer is used to repair an optical signal deteriorated in the transmission process, and an optical channel changing device is used when there is a request to change the transmission channel of the optical signal.

JP-A-6-59383 JP 2001-227911 A

An optical loop circuit is sometimes used to temporarily store an optical signal (Patent Document 1). However, the optical loop circuit has a problem that a large occupied space is required.
In recent years, the communication speed of optical signals has been increased (see Patent Document 1). However, due to restrictions on the processing speed of the electric circuit, the processing speed of the optical signal buffer and the processing speed of the optical channel changing device are increased. However, there is a problem that it cannot keep up with the optical data rate received.

  An object of the present invention relates to a modulation device that performs phase modulation / amplitude modulation on an optical signal including phase spectrum / amplitude spectrum information on a frequency axis, and relates to an optical signal storage technique, an optical signal restoration technique, an optical channel change technique, It is an object of the present invention to provide a modulation device that can be applied to an optical signal control technique or the like.

The gist of the present invention is (1) to (4).
(1) a phase / amplitude measuring device for detecting phases and amplitudes of a plurality of components from an original signal;
A signal evaluator for extracting information contained in the original signal;
A reference signal source for generating a reference discrete spectrum signal;
A phase / amplitude modulation unit that applies phase modulation and amplitude modulation to each frequency component of a reference discrete spectrum signal generated by the reference signal source based on the phase and amplitude extracted by the signal evaluator;
A modulation apparatus comprising:
The present invention can be applied to an optical signal storage device, an optical signal repair device, an optical channel change device, an optical signal control technique, and the like.

(2) The modulation device according to (1), wherein a signal line through which the original signal is transmitted is used as the reference signal source.

(3) In the modulation device according to (1), the original signal is discrete spectrum light.
The modulation apparatus according to (1), wherein a reference signal source built in the phase / amplitude measuring device is used as the reference signal source.

(4) The phase / amplitude modulation unit is provided in the signal source of the original signal, detects the phase and amplitude of the original signal, and feedback-modulates the phase and amplitude of the signal source based on the detection result. The modulation device according to (1), which is characterized.

  In the present invention, when processing information transmitted on the phases and amplitudes of a plurality of signal components, it is not necessary to sequentially measure complicated fluctuations of the original signal.

  That is, since the phase spectrum and amplitude spectrum on the frequency axis within a certain time period may be processed for the original signal, high-speed optical signal storage processing, optical signal storage processing, optical channel change processing, optical signal repair processing, optical signal Control processing is possible.

It is explanatory drawing of embodiment which applied the modulation apparatus of this invention to the optical signal memory | storage device (optical signal buffer). FIG. 2A is a detailed view of a phase measurement unit of the optical signal storage device of FIG. 1, and FIG. 2B is a detailed view of an amplitude measurement unit of the optical signal storage device of FIG. It is a figure which shows the 1st design change example of the optical signal storage device of FIG. It is a figure which shows the 2nd design change example of the optical signal memory | storage device of FIG. It is explanatory drawing of embodiment which applied the modulation apparatus of this invention to the channel change apparatus. It is explanatory drawing of embodiment which applied the modulation apparatus of this invention to the optical signal generator. It is explanatory drawing which shows the example of a design change of the modulation apparatus of FIG.

FIG. 1 is an explanatory diagram of an embodiment in which the modulation device of the present invention is applied to an optical signal storage device (optical signal buffer).
In FIG. 1, a modulation device (optical signal buffer) 1 includes a phase / amplitude measuring device 11, a signal evaluator 12, a phase / amplitude spectrum matrix generator 13, a reference signal source 14, and a reference signal frequency spectrometer 15. And a phase / amplitude modulator 16.

The original signal S _A is transmitted to the signal line PP, and the modulation device 1 takes in this signal and performs modulation processing.
The phase / amplitude measuring device 11 includes a reference signal generation unit 111, a phase measurement unit 112, an amplitude measurement unit 113, and an information reading unit 114.
Reference signal generator 111, the original signal S signal components _A (frequency components) S _A1, S _A2, · · ·, frequency phi _A1 of S _AN, phi _A2, · · ·, frequency for phi _AN shift The reference signals S _B1 , S _B2 ,..., S _BN are generated.

  As shown in FIG. 2A, the phase measurement unit 112 includes an arrayed waveguide diffraction grating (AWG) 1121, a beat signal generation / extraction unit 1122, a beat signal selection unit 1123, a beat signal multiplication unit 1124, A phase detector 1125.

The beat signal generation / extraction unit 1122 converts the combined light of the original signal S _A and the reference signal S _Bk input from the k-th terminal (k = 1, 2,..., N) of the AWG 1121 to the photodiode PD _k. To perform photoelectric conversion. The output of PD _k includes various beat signals of the reference signal S _Bk and the original signal S _A. The band pass filter BPF _k extracts the beat signal B _k (B ₁ , B ₂ , B ₃ ,...) From the reference signal S _Bk and the signal component S _Ak from the beat signal.

The beat signal selection unit 1123 selects two (beat signal pair B _m , B _n ) simultaneously from B ₁ , B ₂ , B ₃ ,..., And each mixer MX of the beat signal multiplication unit 1124 selects these. Multiply

Relative phase detection unit 1125, each detector _{D 1, D 2, D 3} , ···, D N inputs a multiplication signal from each mixer of the beat signal multiplication section 1124, the creation of the multiplication beat signal pairs The relative phases of the signal components of the original original signal S _A are obtained.

For example, when the beat signal pair multiplied is B _m and B _n , the relative phase detector 1125 can obtain the relative phase φ _n −φ _m between the signal components S _Am and S _An . The relative phase detector 1125 obtains the amplitudes A _Am and A _An of the signal components S _Am and S _An measured by the amplitude measuring unit 113 and calculates the relative phase φ _n −φ _m . Note that the beat signal selection unit 1123 performs a selection process so that at least one beat signal pair constituting a certain beat signal pair constitutes any other beat signal pair. The beat signal selector 1123 can select beat signal pairs such as B ₁ and B ₂ , B ₁ and B ₃ , B ₁ and B ₃ ,..., Or B ₁ and B _2. , B ₂ and B ₃ , B ₃ and B ₄ ,... Can be selected. The beat signal selection unit 1123 performs selection processing so that B _x does not form a beat signal pair when a certain beat signal B _x is indefinite (for example, when the amplitude of S _Ax is zero or very small). I do.

As shown in FIG. 2B, the amplitude measurement unit 113 includes an arrayed waveguide diffraction grating (AWG) 1131, a beat signal generation / extraction unit 1132, and an amplitude detection unit 1133.
The beat signal generating / extracting unit 1132 outputs the combined light of the original signal S _A and the reference signal S _Bk input from the k-th terminal (k = 1, 2,..., N) of the AWG 1131 to the photodiode PD _k. To perform photoelectric conversion. The output of PD _k includes various beat signals of the reference signal S _Bk and the original signal S _A. The band pass filter BPF _k extracts the beat signal B _k (B ₁ , B ₂ , B ₃ ,...) From the reference signal S _Bk and the signal component S _Ak from the beat signal.

Each detector G _1, G ₂ of the amplitude detector 1133, · · ·, G _N is the original signal and multiplied beat signal pair creation of the amplitude of the signal component of the original signal S _A which was based respectively Ask.

It can be handled signal component S _A1, S _A2, ···, and phi _n -.phi _m if based on any one phase of the S _AN as absolute phase. Therefore, the information reading unit 114 can specify the phase spectrum φ _SA (ω) of the original signal S _A from the relative phase φ _n −φ _m obtained by the relative phase detection unit 1125, and the amplitude obtained by the amplitude detection unit 1133. From A _An , the amplitude spectrum A _SA (ω) of the original signal S _A can be specified.

In the present embodiment, the signal evaluator 12 includes the pattern information of the phase spectrum φ _SA (ω) and the amplitude spectrum A _SA (ω) and the information included in the original signal S _A (for example, this information includes binary data). may be, it has a table associating a limited not) and the binary data, it is possible to know the information contained in the original signal S _a.

The phase / amplitude spectrum matrix generator 13 generates the same phase spectrum φ _SA (ω) and amplitude spectrum A _SA (ω) as the information contained in the original signal S _A , and the phase / amplitude modulator 16 The signal flowing through the reference signal frequency spectrometer 15 is modulated.
In this embodiment, the reference signal source 14 includes the wavelength tunable light source 141 and the optical comb generator 142. However, the reference signal source 14 may include only the optical comb generator 142. The variable wavelength light source 141 generates a carrier wave, and the comb light generated by the optical comb generator 142 is input to the reference signal frequency spectrometer 15.

Reference signal frequency spectrometer 15 consists AWG151 and AWG152 Prefecture, the signal component S _A1 of the original signal S _A comb light incident AWG151, S _A2, ···, the signal component having the same frequency as the S _AN (S _C1 , _SC2 ,..., _SCN ). The phase / amplitude modulator 16 includes a phase modulator 161 and an amplitude modulator 162. The separated signal component is phase-modulated by the phase modulator 161 and amplitude-modulated by the amplitude modulator 162.

Signal components by the phase and amplitude modulation _{(S C1, S C2, ···} , S CN) is the signal component of the original signal _{S A S A1, S A2,} ···, is modulated to the same signal as S _AN.

AWG152 is multiplexes these signals whose phase and amplitude modulation, and sends as a new original signal S _A.
The modulator (optical signal buffer) 1 performs buffering, but as can be seen from the above, the amount of calculation by the processor is extremely small. Therefore, ultrafast buffering can be performed.

FIG. 3 is an explanatory diagram showing a first design modification example of the modulation device 1 of FIG. 1. The reference signal source 14 used in the modulation device 1 of FIG. 1 is not provided, and the signal line PP is used as a reference signal. The propagating original signal S _A is input to the AWG 151 of the reference signal frequency spectrometer 15. Thereby, the structure of the modulation apparatus 1 is simplified.

FIG. 4 is an explanatory diagram showing a second design modification example of the modulation device 1 of FIG. 1. The reference signal source 14 used in the modulation device 1 of FIG. 1 is not provided, and the phase / amplitude is used as the reference signal. meter reference signals from the reference signal generating unit 111 of the _{11 S B1, S B2, ···} , S BN is input to AWG151 of the reference signal frequency spectrometer 15. Thereby, the structure of the modulation apparatus 1 is simplified by this.

3 and 4, if a frequency shifter is provided between the signal line PP and the reference signal frequency spectrometer 15, the reference signal frequency is similar to the application to the channel changing device described below. An original signal S _A propagating through a channel different from the original channel can be generated from the spectroscope 15.

FIG. 5 is an explanatory diagram of an embodiment in which the modulation device of the present invention is applied to a channel changing device.
In FIG. 5, the modulation device (channel changing device) 2 includes a phase / amplitude measuring device 21, a signal evaluator 22, a phase / amplitude spectrum matrix generator 23, a reference signal source 24, and a reference signal frequency spectrometer 25. A phase / amplitude modulator 26, a wavelength selector 27, and a photoelectric converter 28. The operations of the phase / amplitude measuring device 21, the signal evaluator 22, the phase / amplitude spectrum matrix generator 23, the reference signal source 24, the reference signal frequency spectrometer 25, and the phase / amplitude modulator 26 are the same as those of the modulation device 1 shown in FIG. This is the same as the phase / amplitude measuring device 11, signal evaluator 12, phase / amplitude spectrum matrix generator 13, reference signal source 14, reference signal frequency spectrometer 15, and phase / amplitude modulator 16. In addition, the reference signal generation unit 211, the phase measurement unit 212, the amplitude measurement unit 213, and the information reading unit 214 constituting the phase / amplitude measurement device 21 are the reference signal generation unit 111 and the phase measurement unit 112 of the phase / amplitude measurement device 11, respectively. The same as the amplitude measuring unit 113 and the information reading unit 114. The phase modulator 261 and the amplitude modulator 262 constituting the phase / amplitude modulator 26 are the same as the phase modulator 161 and the amplitude modulator 162 constituting the phase / amplitude modulator 16. The AWG 251 and AWG 252 constituting the reference signal frequency spectrometer 25 are the same as the AWG 151 and AWG 152 constituting the reference signal frequency spectrometer 15.

The variable wavelength light source 241 and the optical comb generator 242 that constitute the reference signal source 24 are also substantially the same as the variable wavelength light source 141 and the optical comb generator 142 that constitute the reference signal source 14, but the variable wavelength light source 241 is a signal line. It is possible to generate a carrier wave having a channel different from that of the original signal S _A propagating through the PP.

  In FIG. 5, the wavelength selector 27 gives the signal frequency from a predetermined channel propagating through the signal line PP to the reference signal generator 211 of the optical comb generator 242 via the photoelectric converter 28. Thereby, the phase / amplitude measuring device 21 does not erroneously measure the phase and amplitude of other channels.

In FIG. 5, the wavelength selector 27 also supplies the signal frequency from a predetermined channel propagating through the signal line PP to the optical comb generator 242 of the reference signal source 24 via the photoelectric converter 28. The wavelength variable light source 241 is generating a carrier wave of channel different from the channel of the original signal S _A propagating signal line PP, original signal propagating channels different from the original channel from the reference signal frequency spectrometer 25 S _A is generated.

FIG. 6 is an explanatory diagram of an embodiment in which the modulation device of the present invention is applied to an optical signal generator.
In FIG. 6, a modulation device (optical signal generator) 3 includes a phase / amplitude measuring device 31, a signal evaluator 32, a phase / amplitude spectrum matrix generator 33, a reference signal source 34, and a reference signal frequency spectrometer. 35 and a phase / amplitude modulator 36. The operations of the phase / amplitude measuring device 31, the reference signal source 34, the reference signal frequency spectrometer 35, and the phase / amplitude modulator 36 are the same as the phase / amplitude measuring device 11, the reference signal source 14, and the reference signal of the modulation device 1 shown in FIG. The frequency spectrometer 15 and the phase / amplitude modulator 16 are substantially the same.

  In this embodiment, the signal evaluator 32 also functions as a feedback control device, and can set a predetermined phase / amplitude spectrum. The phase / amplitude spectrum matrix generator 33 generates a reference phase / amplitude spectrum matrix in response to this. it can.

  Further, the phase measuring unit 312, the amplitude measuring unit 313, and the information reading unit 314 constituting the phase / amplitude measuring device 31 are the same as the phase measuring unit 112, the amplitude measuring unit 113, and the information reading unit 114 of the phase / amplitude measuring device 11. It is. The phase modulator 361 and the amplitude modulator 362 constituting the phase / amplitude modulator 36 are the same as the phase modulator 161 and the amplitude modulator 162 constituting the phase / amplitude modulator 16. The AWG 351 and AWG 352 constituting the reference signal frequency spectrometer 35 are the same as the AWG 151 and AWG 152 constituting the reference signal frequency spectrometer 15.

  Unlike FIG. 1, the reference signal source 34 includes an optical comb generator 342. This optical comb generator 342 is the same as the optical comb generator 142 constituting the reference signal source 14 of FIG.

  In the modulation device (optical signal generation device) 3 of FIG. 6, as described above, the signal evaluator 32 functions as a feedback control device and can set a predetermined phase / amplitude spectrum, and a phase / amplitude spectrum matrix can be set accordingly. The generator 33 can generate a reference phase / amplitude spectrum matrix. Therefore, when the reference signal source 34 and the reference signal frequency spectrometer 35 are unstable, phase / amplitude spectrum control can be performed.

FIG. 7 is an explanatory diagram showing a design change example of the modulation device 3 in FIG. 6, and a frequency shifter 315 is provided instead of the reference signal generation unit 311 in FIG. 7. The frequency shifter 315 shifts the frequency of the signal from the reference signal source 34 and supplies it to the phase measuring unit 312 and the amplitude measuring unit 313.
As a result, the original signal can be shaped into an ideal waveform, and fluctuations and the like caused by disturbance due to the atmosphere can be suppressed.

1, 2, 3 Modulator 11, 21, 31 Phase / amplitude measuring device 12, 22, 32 Signal evaluator 13, 23, 33 Phase / amplitude spectrum matrix generator 14, 24, 34 Reference signal source 15, 25, 35 Reference signal frequency spectrometer 16, 26, 36 Phase / amplitude modulator 27 Wavelength selector 28 Photoelectric converter 111, 211, 311 Reference signal generation unit 112, 212, 312 Phase measurement unit 113, 213, 313 Amplitude measurement unit 114, 214,314 Information reading unit 141,241 Wavelength variable light source 142,242 Optical comb generator 151,152,251,252,351,352,1121,1131 AWG
161,261,361 Phase modulator 162,262,362 Amplitude modulator 315 Frequency shifter 342 Optical comb generator 1122,1132 Beat signal generator / extractor 1123 Beat signal selector 1124 Beat signal multiplier 1125 Relative phase detector 1133 Amplitude Detection unit

Claims (4)

A phase / amplitude measuring device for detecting the phase and amplitude of a plurality of components from the original signal,
A signal evaluator for extracting information contained in the original signal;
A reference signal source for generating a reference discrete spectrum signal;
A phase / amplitude modulation unit that applies phase modulation and amplitude modulation to each frequency component of a reference discrete spectrum signal generated by the reference signal source based on the phase and amplitude extracted by the signal evaluator;
A modulation apparatus comprising:
The present invention can be applied to an optical signal storage device, an optical signal repair device, an optical channel change device, an optical signal control technique, and the like.   2. The modulation apparatus according to claim 1, wherein a signal line through which the original signal is transmitted is used as the reference signal source. The modulation apparatus according to claim 1, wherein the original signal is discrete spectrum light.
A modulation apparatus using a reference signal source built in the phase / amplitude measuring device as the reference signal source.   The phase / amplitude modulation unit is provided in the signal source of the original signal, detects the phase and amplitude of the original signal, and feedback-modulates the phase and amplitude of the signal source based on the detection result. The modulation device according to claim 1.

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