CA2396121A1 - Method for synchronizing the phase of optical return-to-zero (rz) data signals - Google Patents
Method for synchronizing the phase of optical return-to-zero (rz) data signals Download PDFInfo
- Publication number
- CA2396121A1 CA2396121A1 CA002396121A CA2396121A CA2396121A1 CA 2396121 A1 CA2396121 A1 CA 2396121A1 CA 002396121 A CA002396121 A CA 002396121A CA 2396121 A CA2396121 A CA 2396121A CA 2396121 A1 CA2396121 A1 CA 2396121A1
- Authority
- CA
- Canada
- Prior art keywords
- data signals
- rzs1
- signal
- rzs2
- signals
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04J—MULTIPLEX COMMUNICATION
- H04J14/00—Optical multiplex systems
- H04J14/08—Time-division multiplex systems
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L7/00—Arrangements for synchronising receiver with transmitter
- H04L7/0075—Arrangements for synchronising receiver with transmitter with photonic or optical means
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L7/00—Arrangements for synchronising receiver with transmitter
- H04L7/0016—Arrangements for synchronising receiver with transmitter correction of synchronization errors
- H04L7/0033—Correction by delay
- H04L7/0041—Delay of data signal
Abstract
The invention relates to a method for synchronising the phase of two RZ data signals (RZS1, RZS2) which have been combined to form one time multiplex signal (MS1). According to said method, the power of half a fundamental wave of the multiplex signal (MS1) is measured and the phase differential is regulated in such a way that the power of the wave reaches a minimum.</SDOAB >
Description
Description Method for synchronizing the phase of optical return-to-zero (RZ) data signals The invention relates to a method for synchronizing the phases of synchronous optical RZ data signals.
By contrast with NRZ (not return to zero) pulses, the use of RZ (return to zero) pulses in optical long-distance systems renders it possible to increase the bit rate or substantially increase (approximately double) the regenerator-free range.
RZ transmitting devices are frequency implemented by switching through or blocking the light of a pulse source by means of an electrooptic modulator. Since the pulse width is slight by comparison with the duration of an unmodulated bit, a plurality of data signals can be combined to form a time multiplex signal. In the case of very high data rates and a plurality of RZ data signals, it is necessary continuously to equalize transit time differences and transit time fluctuations that are caused, for example, by temperature changes.
It is the object of the invention to specify a simple method for synchronizing the phases of different RZ
data signals.
This object is achieved by means of a method in accordance with patent claim 1.
Advantageous developments of the invention are given in the subclaims.
The simple way of obtaining a reliable control criterion, and the simple implementability of the method are particularly advantageous. The use of one criterion is already sufficient for reliable control. The control accuracy can be increased by using a further control criterion.
The method according to the invention can be applied for 2, 4, 8 etc. RZ data signals. Other spectral frequencies than control signals can be obtained for channel numbers that do not constitute a power of two.
The invention is explained in more detail with the aid of two exemplary embodiments.
In the drawing:
figure 1 shows two time multiplex signals without and with a phase displacement, figure 2 shows the application of the method for two time multiplex signals, figure 3 shows the control signals obtained, figure 4 shows an arrangement for synchronizing the phases of four time multiplex signals, and figure 5 shows a variant of this arrangement.
The timing diagram in figure 1 shows a first RZ data signal DS1 and a second RZ data signal DS2 whose, for example, pulses representing logic ones are displaced by exactly 180° with reference to the pulses of the first RZ data signal. For the sake of simplicity, it is assumed here that the information consists only of logic ones; corresponding considerations hold for any desired data frequencies.
The two optimally synchronized RZ data signals DS1 and DS2 are combined to form a multiplex signal MS1 with double the pulse or data rate and whose pulse intervals are the same.
By contrast with NRZ (not return to zero) pulses, the use of RZ (return to zero) pulses in optical long-distance systems renders it possible to increase the bit rate or substantially increase (approximately double) the regenerator-free range.
RZ transmitting devices are frequency implemented by switching through or blocking the light of a pulse source by means of an electrooptic modulator. Since the pulse width is slight by comparison with the duration of an unmodulated bit, a plurality of data signals can be combined to form a time multiplex signal. In the case of very high data rates and a plurality of RZ data signals, it is necessary continuously to equalize transit time differences and transit time fluctuations that are caused, for example, by temperature changes.
It is the object of the invention to specify a simple method for synchronizing the phases of different RZ
data signals.
This object is achieved by means of a method in accordance with patent claim 1.
Advantageous developments of the invention are given in the subclaims.
The simple way of obtaining a reliable control criterion, and the simple implementability of the method are particularly advantageous. The use of one criterion is already sufficient for reliable control. The control accuracy can be increased by using a further control criterion.
The method according to the invention can be applied for 2, 4, 8 etc. RZ data signals. Other spectral frequencies than control signals can be obtained for channel numbers that do not constitute a power of two.
The invention is explained in more detail with the aid of two exemplary embodiments.
In the drawing:
figure 1 shows two time multiplex signals without and with a phase displacement, figure 2 shows the application of the method for two time multiplex signals, figure 3 shows the control signals obtained, figure 4 shows an arrangement for synchronizing the phases of four time multiplex signals, and figure 5 shows a variant of this arrangement.
The timing diagram in figure 1 shows a first RZ data signal DS1 and a second RZ data signal DS2 whose, for example, pulses representing logic ones are displaced by exactly 180° with reference to the pulses of the first RZ data signal. For the sake of simplicity, it is assumed here that the information consists only of logic ones; corresponding considerations hold for any desired data frequencies.
The two optimally synchronized RZ data signals DS1 and DS2 are combined to form a multiplex signal MS1 with double the pulse or data rate and whose pulse intervals are the same.
If, however, the phase shift of the second data signal DS2x deviates from the ideal position, the result, for example, is the pulse train MSx of the multiplex signal. The spectral components of the two pulse trains MSO and MSx differ from one another considerably and are therefore used as control signals.
Figure 2 shows the principle of an arrangement for phase control. A pulse generator PG generates an optical pulse train IM that is fed to a first modulator MOD1 and a second modulator MOD2. There, the pulses of data signals DS1 and DS2 are modulated - here switched through or suppressed, in order to generate the optical RZ data signals RZS1 and RZS2. The first RZ data signal RZS1 is fed via a first attenuator to an optical multiplexer MX1, while the second RZ data signal RZS2 is fed to the multiplexer MX1 via an attenuator VOA2, a fixed time-delay element DEL and a variable time-delay element VDEL. It is possible, if appropriate, to dispense with the time-delay element DEL depending on the adjusting range of the adjustable time-delay element.
Adjustable time-delay elements can be implemented as integrated optical components or as free beam optical systems.
The multiplex signal MS formed from the two RZ data signals is combined where appropriate with further multiplex signals and transmitted. Moreover, the multiplex signal is fed to a control device RE (for example via a coupler) . There, it is converted into an electric signal by an optoelectric transducer OEW and fed to a first filter FI1 that is tuned to the data rate of an RZ data signal RZS1, RZS2. It can additionally be fed to a second filter FI2 that is tuned to the data rate of the multiplex signal MS.
Figure 2 shows the principle of an arrangement for phase control. A pulse generator PG generates an optical pulse train IM that is fed to a first modulator MOD1 and a second modulator MOD2. There, the pulses of data signals DS1 and DS2 are modulated - here switched through or suppressed, in order to generate the optical RZ data signals RZS1 and RZS2. The first RZ data signal RZS1 is fed via a first attenuator to an optical multiplexer MX1, while the second RZ data signal RZS2 is fed to the multiplexer MX1 via an attenuator VOA2, a fixed time-delay element DEL and a variable time-delay element VDEL. It is possible, if appropriate, to dispense with the time-delay element DEL depending on the adjusting range of the adjustable time-delay element.
Adjustable time-delay elements can be implemented as integrated optical components or as free beam optical systems.
The multiplex signal MS formed from the two RZ data signals is combined where appropriate with further multiplex signals and transmitted. Moreover, the multiplex signal is fed to a control device RE (for example via a coupler) . There, it is converted into an electric signal by an optoelectric transducer OEW and fed to a first filter FI1 that is tuned to the data rate of an RZ data signal RZS1, RZS2. It can additionally be fed to a second filter FI2 that is tuned to the data rate of the multiplex signal MS.
- 3a -After the filtering, the power of the output signals is measured in power meters LMl, LM2, in order to obtain corresponding control signals RS1 and RS2. These are fed to a controller R that generates an adjusting signal ERS that adjusts the time-delay element VDEL2 optimally such that the pulse trains of the two data signals are phase-shifted by 180° relative to one another.
The principal values of the control signals RS1 and RS2 are illustrated in figure 3 as a function of the phase difference cp/~ between two RZ data signals. Similar profiles are repeated periodically. It suffices that the adjustable time-delay element adjusts the phase difference such that the first control signal RS1 reaches its minimum. In addition, the second control signal RS2 can then be adjusted to a maximum. It is also possible to superimpose the two control signals, one control signal having a reversed sign, and the amplitude of the second control signal RS2 being reduced so far that there is no local minimum.
The control method can consist in that an attempt is made to use a digital control to adjust the optical time-delay element VDEL by changing the adjusting signal ERS, and the change in the control signal RS1 is evaluated, whereupon further adjustments are performed until the power minimum of the control signal RSl is reached. Another method can consist in varying the phase continuously by sweeping the adjusting signal, and obtaining the adjusting signal ERS by correlating the control signal RS1 with the sweep signal using the lock-in principle.
If the amplitudes of the two RZ data signals RZS1 and RZS2 are not equal, this likewise results in deviations from the minimum of the control signal RS1 and the maximum of the control signal RS2. The method can therefore also be used in a corresponding way to adjust the amplitudes. This is performed in figure 2 with the i~TO 01/50664 PCT/DE00/04545 - 4a -aid of an amplitude control signal ARS which is based on the same criteria RS1 and RS2. In the case of more _ 5 _ than two data signals, however, a fixed reference value should be used for all the RZ data signals.
An arrangement for generating a multiplex signal MS3, containing four data signals DS1 to DS4, in with the appropriate modulators MODl - MOD4 and adjusting elements VOA1 - VOA4, VDEL1, VDEL4, VDELM is illustrated in figure 4 in a simplified form.
In each case two RZ data signals RZS1 and RZS2 or RZS3 and RZS4 are combined to form a multiplex signal MS1 or MS2. The control devices RE1 and RE2 in each case combine the two RZ data signals to form time multiplex signals MS1 and MS2. The latter are combined via a further multiplexer MX3 to form a multiplex signal MS3 of higher order, a further control device RE3 ensuring via the time-delay element VDELM that there is an ideal phase angle between the two multiplex signals MS1 and MS2.
Figure 5 illustrates a variant in which a controllable time-delay element VDEL2 to VDEL4 is inserted in each data branch except for the first, and via the second control device RE2 the third control device RE3 also influences the time-delay elements VDEL3 and VDEL4 such that all the RZ data signals are merged, in turn, with exact phase angles. A plurality of synchronized pulse generators apply the pulse trains here.
It remains to add that the control criteria can likewise be used to adjust electric time-delay elements or to synchronize pulse generators that permit phase control in a corresponding way.
The principal values of the control signals RS1 and RS2 are illustrated in figure 3 as a function of the phase difference cp/~ between two RZ data signals. Similar profiles are repeated periodically. It suffices that the adjustable time-delay element adjusts the phase difference such that the first control signal RS1 reaches its minimum. In addition, the second control signal RS2 can then be adjusted to a maximum. It is also possible to superimpose the two control signals, one control signal having a reversed sign, and the amplitude of the second control signal RS2 being reduced so far that there is no local minimum.
The control method can consist in that an attempt is made to use a digital control to adjust the optical time-delay element VDEL by changing the adjusting signal ERS, and the change in the control signal RS1 is evaluated, whereupon further adjustments are performed until the power minimum of the control signal RSl is reached. Another method can consist in varying the phase continuously by sweeping the adjusting signal, and obtaining the adjusting signal ERS by correlating the control signal RS1 with the sweep signal using the lock-in principle.
If the amplitudes of the two RZ data signals RZS1 and RZS2 are not equal, this likewise results in deviations from the minimum of the control signal RS1 and the maximum of the control signal RS2. The method can therefore also be used in a corresponding way to adjust the amplitudes. This is performed in figure 2 with the i~TO 01/50664 PCT/DE00/04545 - 4a -aid of an amplitude control signal ARS which is based on the same criteria RS1 and RS2. In the case of more _ 5 _ than two data signals, however, a fixed reference value should be used for all the RZ data signals.
An arrangement for generating a multiplex signal MS3, containing four data signals DS1 to DS4, in with the appropriate modulators MODl - MOD4 and adjusting elements VOA1 - VOA4, VDEL1, VDEL4, VDELM is illustrated in figure 4 in a simplified form.
In each case two RZ data signals RZS1 and RZS2 or RZS3 and RZS4 are combined to form a multiplex signal MS1 or MS2. The control devices RE1 and RE2 in each case combine the two RZ data signals to form time multiplex signals MS1 and MS2. The latter are combined via a further multiplexer MX3 to form a multiplex signal MS3 of higher order, a further control device RE3 ensuring via the time-delay element VDELM that there is an ideal phase angle between the two multiplex signals MS1 and MS2.
Figure 5 illustrates a variant in which a controllable time-delay element VDEL2 to VDEL4 is inserted in each data branch except for the first, and via the second control device RE2 the third control device RE3 also influences the time-delay elements VDEL3 and VDEL4 such that all the RZ data signals are merged, in turn, with exact phase angles. A plurality of synchronized pulse generators apply the pulse trains here.
It remains to add that the control criteria can likewise be used to adjust electric time-delay elements or to synchronize pulse generators that permit phase control in a corresponding way.
Claims (10)
1. Method for synchronizing the phase of synchronous optical RZ data signals (RZS1, RZS2,..), in which in each case two RZ data signals (DS1, DS2) are combined to form a multiplex signal (MS1,...) in conjunction with the same pulse intervals, in the case of which method the spectral power of the multiplex signal (MS1, ...) is measured at a frequency corresponding to the data rate of the RZ data signals (RZS1, RZS2), and the phase shift between the RZ data signals (RZS1, RZS2) is controlled such that the measured power reaches a minimum.
2. The method as claimed in claim 1, characterized in that in addition the spectral power is measured at a frequency that corresponds to the data rate of the multiplex signal (MS1), and in that the phase shift between the RZ data signals (RZS1, RZS2) is controlled such that the power reaches a local maximum at this frequency.
3. The method as claimed in claim 1, characterized in that in each case two optical RZ data signals (RZ1, RZ2) are combined to form a multiplex signal (MS1), at least in each case one of the two being guided via an adjustable time-delay element (VDEL), in that the multiplex signal (MS1) is converted into an electric signal and fed to a first filter (FI1), whose passband corresponds to the data rate of an RZ data signal (RZS1, RZS2), in that a first control signal (RS1) is obtained by measuring the power, and in that the phase shift between the RZ data signals (RZS1, RZS2) is controlled, by adjusting the time-delay element (VDEL), such that the power of the first control signal (RS1) reaches a minimum.
4. The method as claimed in claim 2 and claim 3, characterized in that the multiplex signal (MS1, ..) is fed to a second filter (FI2) whose passband corresponds to the data rate of the multiplex signal (MS1, MS2), in that a second control signal (RS2) is obtained by power measurement, and in that the phase shift between the RZ
data signals (RZS1, RZS2) is controlled such that the power of the second control signal (RS2) reaches a local maximum at an at least approximate minimum of the first control signal (RS1).
data signals (RZS1, RZS2) is controlled such that the power of the second control signal (RS2) reaches a local maximum at an at least approximate minimum of the first control signal (RS1).
5. The method as claimed in one of the preceding claims, characterized in that a single control signal is formed by overlapping the two control signals (RS1, RS2).
6. The method as claimed in one of the preceding claims, characterized in that in each case two RZ data signals (RZS1, RZ2, RZ3, R24) are combined to form a multiplex signal (MS1, MS2), and in each case two multiplex signals (MS1, MS2) are combined to form a multiplex signal (MS3) of higher order, and in that a control device (RE1, RE2, RE3) is provided for in each case two RZ data signals or two multiplex signals (MS1, MS2).
7. The method as claimed in one of the preceding claims, characterized in that the amplitudes of the individual RZ data signals (RZS1, RZS2) are controlled such that the power reaches a minimum at the frequency that corresponds to the data rate of one RZ data signal (RZS1, RZS2) and, where appropriate, is additionally controlled such that the power reaches a local maximum at the frequency that corresponds to the data rate of the multiplex signal (MS1).
8. The method as claimed in one of the preceding claims, characterized in that the control is performed using the lock-in principle with the aid of sweep signals.
9. The method as claimed in claim 7 or 8, characterized in that the phase angle or the amplitudes are alternately adjusted, or an optimization is carried out by means of different lock-in control loops.
10. The method as claimed in one of the preceding claims, characterized in that the carrier frequencies of the RZ data signals (RZS1, ..RZS4) are varied in order to avoid disturbing interference.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE19963802.0 | 1999-12-30 | ||
| DE19963802A DE19963802B4 (en) | 1999-12-30 | 1999-12-30 | Process for phase synchronization of optical data center data signals |
| PCT/DE2000/004545 WO2001050664A2 (en) | 1999-12-30 | 2000-12-19 | Method for synchronising the phase of optical return-to-zero (rz) data signals |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2396121A1 true CA2396121A1 (en) | 2001-07-12 |
Family
ID=7935010
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002396121A Abandoned CA2396121A1 (en) | 1999-12-30 | 2000-12-19 | Method for synchronizing the phase of optical return-to-zero (rz) data signals |
Country Status (6)
| Country | Link |
|---|---|
| US (1) | US7312909B2 (en) |
| EP (1) | EP1243092B1 (en) |
| JP (1) | JP2003530738A (en) |
| CA (1) | CA2396121A1 (en) |
| DE (1) | DE19963802B4 (en) |
| WO (1) | WO2001050664A2 (en) |
Families Citing this family (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2003329989A (en) * | 2002-03-06 | 2003-11-19 | Nippon Telegr & Teleph Corp <Ntt> | Photo transmitting device |
| DE10332837A1 (en) * | 2003-07-18 | 2005-02-10 | Siemens Ag | Method and arrangement for phase synchronization between a plurality of data signals for the generation of an optical OTDM signal |
| WO2005022802A1 (en) * | 2003-08-25 | 2005-03-10 | Siemens Aktiengesellschaft | Method and array for inserting a synchronous data signal in optical networks |
| US8064771B2 (en) * | 2005-06-30 | 2011-11-22 | Infinera Corporation | Active control loop for power control of optical channel groups |
| US7623798B1 (en) * | 2005-10-04 | 2009-11-24 | Sprint Communications Company L.P. | Polarization mode dispersion mitigation of multiple optical communication channels |
| JP4781094B2 (en) * | 2005-11-30 | 2011-09-28 | 富士通株式会社 | Optical transmitter |
| JP6036210B2 (en) * | 2012-11-19 | 2016-11-30 | 富士通株式会社 | Emphasis signal generation circuit |
| US9001925B1 (en) * | 2014-06-27 | 2015-04-07 | L-3 Communications Corp. | Digital architecture for encoding a return-to-zero differential phase shift keying waveform |
Family Cites Families (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5050167A (en) * | 1989-08-10 | 1991-09-17 | Bell Communications Research, Inc. | Timing extraction in multiplexed multichannel high speed fiber optic transmission system |
| DE4130048A1 (en) * | 1991-09-10 | 1993-03-18 | Standard Elektrik Lorenz Ag | Optical multiplexer and demultiplexer for optical fibre communications - has structured waveguide layer formed in surface of doped semiconductor substrate |
| JPH0779198A (en) * | 1993-09-08 | 1995-03-20 | Kokusai Denshin Denwa Co Ltd <Kdd> | Optical communications system and optical transmitter |
| EP0900489B1 (en) * | 1996-05-22 | 2006-01-25 | BRITISH TELECOMMUNICATIONS public limited company | Optical synchronisation arrangement |
| JPH1079705A (en) * | 1996-09-03 | 1998-03-24 | Fujitsu Ltd | Optical modulation device and method |
| US5917528A (en) * | 1996-09-05 | 1999-06-29 | Tektronix, Inc. | Solid ink stick supply apparatus and method |
| JP3681865B2 (en) * | 1997-03-31 | 2005-08-10 | 三菱電機株式会社 | Optical pulse position detection circuit and optical pulse position detection method |
| FR2774832B1 (en) | 1998-02-12 | 2000-08-04 | Alsthom Cge Alcatel | METHOD AND DEVICE FOR RESYNCHRONIZING OPTICAL SIGNALS |
| JP3567763B2 (en) * | 1998-06-12 | 2004-09-22 | Ｋｄｄｉ株式会社 | Optical transmitter |
| US6763197B1 (en) | 1999-06-08 | 2004-07-13 | Nippon Telegraph And Telephone Corporation | Optical transmitter and optical transmitter control method using variable duty ratio setting and alternate phase inversion for optical clock pulses |
-
1999
- 1999-12-30 DE DE19963802A patent/DE19963802B4/en not_active Expired - Fee Related
-
2000
- 2000-12-19 JP JP2001550922A patent/JP2003530738A/en not_active Withdrawn
- 2000-12-19 EP EP00991102A patent/EP1243092B1/en not_active Expired - Lifetime
- 2000-12-19 WO PCT/DE2000/004545 patent/WO2001050664A2/en active IP Right Grant
- 2000-12-19 US US10/168,924 patent/US7312909B2/en not_active Expired - Fee Related
- 2000-12-19 CA CA002396121A patent/CA2396121A1/en not_active Abandoned
Also Published As
| Publication number | Publication date |
|---|---|
| US20020191255A1 (en) | 2002-12-19 |
| DE19963802B4 (en) | 2004-02-05 |
| EP1243092B1 (en) | 2005-11-23 |
| WO2001050664A3 (en) | 2002-01-31 |
| US7312909B2 (en) | 2007-12-25 |
| DE19963802A1 (en) | 2001-07-19 |
| JP2003530738A (en) | 2003-10-14 |
| WO2001050664A2 (en) | 2001-07-12 |
| EP1243092A2 (en) | 2002-09-25 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US5786918A (en) | Optical communication system and optical transmitting device | |
| JP4086912B2 (en) | Control device for optical modulator | |
| US8670674B2 (en) | Optical transmitter and method for controlling the same | |
| US20120106962A1 (en) | Polarization multiplexing and transmitting apparatus | |
| EP0924552A2 (en) | Opto-electronic frequency divider circuit and method of operating same | |
| US20030020985A1 (en) | Receiver for high-speed optical signals | |
| CN103731228A (en) | Optical transmission system and method of adjusting optical transmission device | |
| CA2396121A1 (en) | Method for synchronizing the phase of optical return-to-zero (rz) data signals | |
| CA1215120A (en) | Optical heterodyne detection pulse receiving system and method | |
| US6381056B1 (en) | Dark pulse generation and transmission | |
| AU2003240411B2 (en) | Method and arrangement for reducing the signal degradation in an optical polarisation-multiplex signal | |
| US6940638B2 (en) | Optical frequency conversion systems and methods | |
| US20030142384A1 (en) | Optical transmission apparatus | |
| JP6900764B2 (en) | Optical transmitter | |
| JPH07123073A (en) | Optical time division multiplex | |
| US6839366B1 (en) | Laser frequency control using dithered control signal | |
| US7027466B1 (en) | Multiplexer, demultiplexer and multiplex communication system | |
| JP2001339346A (en) | Optical transmitter and optical transmitter control method | |
| JP3313536B2 (en) | Optical pulse time multiplexing control method and optical pulse time multiplexing control device | |
| CN114070412B (en) | Photon reconfigurable waveform generation method and device | |
| WO2002054204A2 (en) | Apparatus for generating electrical signals with ultra-wide band arbitrary waveforms | |
| US20060269289A1 (en) | Communications system | |
| US20230221613A1 (en) | Optical arbitrary pulse pattern generator | |
| JP3449019B2 (en) | Optical multiplexing equipment | |
| JP2003177362A (en) | Device and method for optical modulation |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| EEER | Examination request | ||
| FZDE | Discontinued |