CN101107802A - Method for optically transmitting polarisation multiplex signals - Google Patents
Method for optically transmitting polarisation multiplex signals Download PDFInfo
- Publication number
- CN101107802A CN101107802A CNA2006800032449A CN200680003244A CN101107802A CN 101107802 A CN101107802 A CN 101107802A CN A2006800032449 A CNA2006800032449 A CN A2006800032449A CN 200680003244 A CN200680003244 A CN 200680003244A CN 101107802 A CN101107802 A CN 101107802A
- Authority
- CN
- China
- Prior art keywords
- signal
- polarization
- polarisation
- data
- wdm
- 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.)
- Granted
Links
Images
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04J—MULTIPLEX COMMUNICATION
- H04J14/00—Optical multiplex systems
- H04J14/06—Polarisation multiplex systems
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04J—MULTIPLEX COMMUNICATION
- H04J14/00—Optical multiplex systems
- H04J14/02—Wavelength-division multiplex systems
Abstract
The method involves forming polarization-multiplex signals (PMS1, PMS2) from two modulated optical data signals (PS1x, PS1y, PS2x, PS2y) with a phase shift of 90 degree in its carrier signals (TS1z, TX1y, TX2x, TX2y). The polarization multiplex signals are circularly polarized in opposite directions. The data signals (PS2x, PS2y) are transmitted with polarizations rotated around 45 degrees from the data signals (PS1x, PS1y).
Description
The present invention relates to according to the described method that is used to transmit the polarisation-multiplexed signal that is combined into wavelength-division multiplex signals of the aforementioned part of claim 1 and 6.
Utilize multiplex technique transmission to data in transmission system to allow a plurality of users to use a transmission medium simultaneously, transmission capacity is significantly expanded thus.Under the situation of optical wavelength-division multiplex method (English: " wavelength division multiplexing ", be abbreviated as WDM), the NRZ form have middle wavelength (carrier wavelength) λ
1..., λ
NN modulated light signal (being also referred to as data-signal below) be combined into broadband light WDM signal by wavelength division multiplexer, and in N channel, be transmitted.That described WDM signal therefore is made up of the data-signal of N signal and signal.Be used for employed wave-length coverage of transmission of data signals or frequency range and be called as channel.
In order in the optical transmission channel of predesignating, transmission capacity to be doubled, use described palarization multiplexing method.Under the situation of described palarization multiplexing method (English: " polarizationmultiplexing ", be abbreviated as POLMUX), in optical channel when middle wavelength the data-signal of two mutually orthogonal polarizations of transmission.Consequent signal is known as polarisation-multiplexed signal, perhaps abbreviates the POLMUX signal as.Thus, the transmission capacity of single transmission channel is doubled.At publication number is to have described the favorable method that is used for the POLMUX transmission in early the applying for of 10 2,004 005718 A1.
By making up two kinds of transmission technologys, surpassing the data rate that reached on the distance of 300km greater than 10Tbit/s (people's such as Y.Frignac " Transmission of 256 WDMand polarization-division-multiplexed Channels at 42.7Gb/s (10.2Tb/s capacity) over 300km of TeraLight
TMFiber ", in Proc.OFC 2002, Paper FC5).
Certainly, in having the transmission system of palarization multiplexing, the effective range of transfer of data is restricted greatly owing to non-linear disturbing effect.Basically relate to polarization mode dispersion (PMD) and crosstalk effect nonlinear, that depend on bit mode at this.Depend on crosstalking of bit mode by known in the wdm system that does not have POLMUX based on what excited Raman (Rama) scattering (SRS), cross-phase modulation (XPM) and four ripples mixed (FWM), crosstalking of polarization in having the system of POLMUX, then mainly occur depending on.
By with arbitrarily but the relative phase between the vector component of the vector component of the amplitude of the relevant electric field of fixing rectangular coordinate system and electric field provides the polarization state of transverse electromagnetic wave.Therefore the change of the relative phase between the component causes the change of the polarization state of light wave.Therefore cause nonlinear effect in multichannel system, described nonlinear effect causes the change of relative phase, also causes the mutual change of the polarization state of light signal.Therefore relevant with the intensity of the signal of polarization state and participation cross-phase modulation (XPM) thus cause the change of relative phase usually and the change of polarization state.Its time graph trend depends on the bit sequence that is transmitted of co-propagate channel.
In the channel of the wdm system with POLMUX, the polarization of generation changes according to the time owing to the bit sequence of the alternation always of the data-signal of mutually orthogonal polarization in the POLMUX signal.If result's polarization state for two or more channels sometime at interval in consistent (if for example in the channel that institute investigates to some extent, in two polarizations, transmitting identical bit combination), then the intensity in a channel causes the polarization change in all other channels by XPM.This changes owing to the bit sequence of alternation always causes the noise formula of the polarization state of each independent POLMUX signal, and this equals depolarization.Its reason is that the specific depolarization effects of this POLMUX of XPM is called as cross polarization modulation (XpolM) below.As the result of XpolM, the polarization of the data-signal of initial mutually orthogonal polarization is vertical no longer mutually after transmission, and can't be by separated from each other clearly in receiver.Basically do not rely on data rate by crosstalking of causing of XpolM, and just depend on channel separation minutely.Or rather, the XpolM quantity that depends on the gross power of in all channels, introducing and depend on channel.In the wdm system with POLMUX and a plurality of channels, the influence of XpolM is preponderated than XPM.
The disturbing effect that is caused by XpolM can reduce by less gross power in each transmission highway section.This can realize at interval or by reducing channel quantity by shortening the highway section.Another possibility that is used for reducing a little XpolM is, uses raman amplifier, then reason be on the highway section comprehensive power ratio less.Yet what be suitable for is, in wdm system gross power reduce be associated with other power loss, and XpolM just reduces conditionally to the influence of transfer of data.
Therefore seek new possibility, when transmitting the WDM-POLMUX signal, to reduce mutual interference.
This task is by solving in the method described in claim 1 and the claim 6.
In order to reduce the mutual interference of POLMUX signal in the channel of wdm system, advantageously, polarisation-multiplexed signal is made of two data-signals with mutual 90 ° of phase shifts respectively.
The present invention based on knowledge be, if in channel the POLMUX signal or the light data-signal of the identical polarization of transmission, the then maximum of mutual interferences between the POLMUX signal.The signal that transmitted in channel constitutes the signal (the E field vector of generation) that produces, and the signal of generation for example is arranged in a plane under the situation of linear polarization, and if disturbed signal have identical plane of polarization, then disturbed especially.Be transmitted if having the circularly polarized POLMUX signal that produces of generation, so described POLMUX signal (E field vector), makes and realizes from maximum reducing to the moderate interference influence with different speed rotations owing to different wavelength in adjacent channel.
If adjacent channel has mutually orthogonal (being round) polarization here, then mutual influence is continued to reduce.
Have only when two light data-signals in the POLMUX channel have activation signal (being generally the logical one of binary data signal) simultaneously, just have the POLMUX signal that is produced that has with respect to the altered polarization of each modulated data-signal.(another modulated data-signal is corresponding to logical zero when the modulated data-signal that only transmits an activation in a channel respectively, carrier signal is suppressed under the situation of described logical zero) time, if the modulated data-signal of remaining channel has identical polarization, then other measure does not cause strong mutual interference.This is advantageously avoided in the following manner, i.e. 45 ° of the plane of polarization of the modulated data-signal in making each second channel rotations." worst case " disturbed to be reduced.Though cause the mutual influence strengthened a little with respect to optimal cases, wherein the initial modulated data-signal of adjacent channel is mutually orthogonal polarization under described optimal cases; Yet the more important thing is the minimizing of interference effect under worst case.
Also advantageously, in first channel, the first smooth data-signal and the second smooth data-signal do not have to be combined into polarisation-multiplexed signal under other situation of phase difference in its carrier signal, and in second channel, the carrier signal of the second smooth data-signal with respect to the carrier signal of its first smooth data-signal by 180 ° of phase shifts, and be combined into second polarisation-multiplexed signal with the first smooth data-signal, make that when sending two light data-signals respectively simultaneously the deflection of the generation of the polarization of the generation of second polarisation-multiplexed signal of second channel and first polarisation-multiplexed signal of first channel differs 90 °.
If all light signals all have identical polarization in a large amount of channels, and logical one is transmitted, then because the interference role especially severe of XpolM.If but the polarization of the generation of the polarisation-multiplexed signal of channel differs 90 ° with respect to the polarization of the generation of adjacent respectively polarisation-multiplexed signal, situation then above-mentioned is avoided, and disturbs and be reduced.Described thus method advantageously causes the increase of transmission effective range.Under the situation of other bit combination of light signal, wherein for described light signal, the polarization of the data-signal of adjacent respectively channel is mutually orthogonal, and nonlinear crosstalk after all is reduced.
If the setting of the phase place of modulated light signal is conditioned mutually, then draw additional advantage.Represent this possibility thus: polarization poor of so regulating the generation of POLMUX signal at transmitter side, until at receiver side for example in view of " eye aperture cost " (Eye openingpenalty, set up till the minimum value when EOP) studying eye pattern, and measurable improvement of transmission quality therefore occurs.
By making conditioning signal branch advantageously control the polarization of POLMUX signal.Producing best interference thus reduces.
In a kind of enforcement modification of this method, advantageously when transfer of data transmission in the highway section at least one position check and the polarization state of regulating the POLMUX signal.
Other favourable improvement provides in the dependent claims.
Illustrate in greater detail the present invention according to embodiment now:
Fig. 1 illustrates the polarization and the phase place of POLMUX signal,
Fig. 2 be illustrated in the polarization on the Poincar é ball expression and
Fig. 3 illustrates to be used to produce has principle device different circles and POLMUX signal linear polarization,
Fig. 4 illustrates the sketch that is used to illustrate the polarization when POLMUX transmits,
Fig. 5 illustrates the sketch that is used for the wdm system of the staggered polarization of explanation on principle,
Fig. 6 moves towards according to the curve that the polarization differential between the result of 5 POLMUX signals goes out an aperture cost EOP,
Fig. 7 illustrates the basic circuit diagram of the POLMUX dispensing device with the conditioning equipment that is used for checking (Kontrolle) polarization state,
Fig. 8 illustrates the basic circuit diagram of first modification of POLMUX dispensing device,
Fig. 9 illustrates the basic circuit diagram of second modification of POLMUX dispensing device.
Fig. 1 is illustrated in the polarization and the phase angle value of adjacent POLMUX channel K1 and two POLMUX signals among the K2.The present invention should describe by means of two adjacent channels, correspondingly is applicable to other channel.Utilize two the light data-signal PS1x and the PS1y of logical one modulation in a POLMUX channel K1, to be transmitted.Show the amplitude of E field vector in the mode of snapshots in time (Momentaufnahme).The direction of propagation in the optical fiber is perpendicular to the drawing plane.Through the data-signal PS1x of amplitude modulation is horizontal polarization here, and is vertical polarization through the data-signal PS1y of amplitude modulation.In addition, two signals have between its optical carrier mutually ± 90 ° phase shift (PS1x for example-90 °, Fig. 1 b) here, make the POLMUX signal PMS1 that produces have right circular polarization (shown in the dotted line).POLMUX signal in other channel of wdm system is circularly polarized equally; Yet because they have different wavelength, the field of generation also with different rotary speed rotations, therefore obtains medium interference effect.
In Fig. 1 C, adjacent or when the wavelength-division multiplex signals that has more than two POLMUX signals each the 2nd POLMUX signal be circularly polarized on the contrary.This by set up between two modulated data-signal PS2x and PS2y, realize with respect to the modulated data-signal PS1x of first channel phase shift opposite (PS2x+90 ° here, Fig. 1 d) with PS1y.Therefore in second channel K2, produce the POLMUX signal PMS2 of generation with opposite left.The E field that produces is rotation on the contrary and influence minimum therefore.In wdm system, reasonably to odd number POLMUX signal n=1,3,5 ... (as PMS1) carries out polarization, and to all even number POLMUX signal n=2,4,6 ... (as PMS2) carries out polarization.
But do not having under the situation of other measure, the maximum that obtains once more between these signals when every channel only transmits a modulated data-signal (for example PS1x and PS2x) respectively influences each other.By rotation in the second channel modulated data-signal PS2x and the plane of polarization of PS2y, obtain in this plane of polarization being respectively 45 ° difference with the modulated data-signal of first channel, mutual thus interference is reduced.
The polarization that Fig. 2 produces when sending two logical ones at the polarization that modulated data-signal (perhaps its carrier signal) is shown on the Poincar é ball with in channel K1.If have only signal PS1x ( bit 1,0 in the POLMUX channel) to be transmitted, this signal has horizontal polarization (in prospect) so; If have only modulated data-signal PS1y (0,1) to be transmitted, this has vertical polarization (in the background of Poincar é ball) so.These two signals are mutually orthogonal and are to influence each other minimumly therefore.If two modulated data-signals (1,1) are transmitted, the POLMUX signal (1,1) of Chan Shenging has right circular polarization (South Pole) so.When only transmitting a modulated data-signal PS2x or PS2y ( bit 1,0 or 0,1), in POLMUX channel K2, obtain angle of polarization θ=± 45 °; On Poincar é ball, this corresponds respectively to the different polarization in π/4 (being 90 ° under traditional calibration situation) with PS1y with respect to each modulated data-signal PS1x of channel K1.If two modulated data-signals (1,1 in two channel K1 and K2; 1,1) be transmitted respectively, these signals are mutually orthogonal circularly polarized so.When in channel K1, transmitting two modulated smooth data-signals and in channel K1, only transmitting a data-signal, also obtain different polarizations; Therefore between the modulated arbitrarily data-signal of channel K1 and K2, on Poincar é ball, show at least 90 ° difference.By on the Poincar é ball in any direction on rotation keep identical relation, be possible on principle, but technical solution is very debatable.
Fig. 3 illustrates two principle devices that are used to produce desirable signal.The linear polarization signal is generated by laser LA1, and described linear polarization signal (in case of necessity by polarization adjuster POLS) has 45 ° plane of polarization.This signal is divided into the carrier signal TS1x of horizontal polarization and the carrier signal TS1y of vertical polarization by polarization splitter POLSP.Two signals utilize data-signal DS1x and DS1y to be modulated respectively, and are combined into POLMUX signal PMS1 in palarization multiplexing device PM.Realize phase shift by the first phase shifter PH1, described phase shifter symbolically causes-90 ° the phase shift (PH also is inserted in the signal path of signal TS1y in case of necessity) of carrier signal TS1x here.
The generation of the 2nd POLMUX signal PMS2 realizes in the corresponding way.The second laser diode LA2 produces the signal with another wavelength, the polarization of described signal in case of necessity in polarization adjuster POLS by perpendicular alignmnet.Ensuing polarization splitter POLSP is split into two mutually orthogonal carrier signal TS2x and TS2y to laser signal, and described carrier signal has been rotated 45 ° respectively with respect to the carrier signal of first channel.Though so disturb owing to crosstalk when only sending one of data-signal can't be minimum forever, always is reduced for this reason.Under more channel quantity situation, the polarization of data-signal also can be rotated corresponding less value, so reason is to make disturbing effect average.Repeatedly 90 ° additional rotation causes identical result.Carrier signal TS2x specifically by the second phase shifter PH2 with respect to another carrier signal TS2y by phase shift+90 °.Two carrier signals utilize data-signal DS2x or DS2y to be modulated, and in palarization multiplexing device PM, be combined into the 2nd POLMUX signal PMS2, if two carrier signals (1 wherein, 1) be transmitted, then described the 2nd POLMUX signal PMS2 has rightabout circular polarization with respect to a POLMUX signal PMS1.Polarization and phase shift in case of necessity are held constant by adjusting.
Described method can be replenished by addition thereto, and described addition thereto reduces the mutual influence of POLMUX signal.Therefore make for example modulated data-signal integral multiple of mutual retardation ratio bit length during the transmission, between the POLMUX signal, to cause decorrelation.
Should illustrate in conventional POLMUX transmission with according to the difference that is used to avoid based between the modification of crosstalking of XpolM of the present invention according to the sketch among Fig. 4.To two channel K1 and K2, the E field vector of generation is shown at the possible bit constellation figure (Konstellation) of two data-signals of POLMUX signal at a time with different wave length.
Fig. 4 a represents the situation of conventional POLMUX transmission, wherein fails the light data-signal PS1x and the PS1y of two modulated mutually orthogonal polarizations here in a channel of difference (being K1 or K2) at affiliated wavelength time-division supplementary biography.The polarization of the generation of POLMUX signal depends on the bit mode of being transmitted (Bitmuster).For the situation of the data-signal (logical one) (bit combination, ' 10 ' and ' 01 ') of a transmission or level or vertical polarization, the E field vector of the polarization of the generation of POLMUX signal is credited in x or the y direction.If two logical ones are transmitted on two planes simultaneously as data-signal, the E field vector of the polarization of the generation of POLMUX signal is positioned under 45 ° (bit combination, " 11 ") of relative x direction so.The result's of the POLMUX signal by changing each second channel according to method of the present invention polarization state is as shown in Fig. 4 B.In each second channel, the phase place of the first modulated data-signal PS2x is passed 180 °, and this can find out according to the E field vector of channel K2.For combination ' 10 ', the E field vector is presented on the negative x direction.If 1 is transmitted in two channels, the E field vector of the polarization of the generation of POLMUX signal is positioned under 135 ° of relative x direction so, and promptly the polarization that produces in channel K2 differs 90 ° with the polarization that produces in channel K1.At this is that the polarization of which kind of type is to inessential according to method of the present invention.This generally is equally applicable to the light signal of linear polarization or circle or elliptical polarization.
In Fig. 5 at 5 channel lambda with the wdm system that increases progressively wavelength X
1-λ
5Spectrum (the sign of lambda wherein of having drawn the POLMUX signal formed by two data-signals respectively
1-λ
5The different wavelength of carrier signal CW is described simultaneously).On each POLMUX signal PMS1-PMS5, according to the E field vector of the polarization of the generation that each POLMUX signal is described at possible bit combination at Fig. 1.In respectively adjacent channel respectively two data-signal PSnx and Psny (n=1,2,3 ...) and the situations of 11 combinations under, the mutually orthogonal polarization of the POLMUX signal that obtains producing.In the non-linear coupling of interchannel, owing to the different polarization state of adjacent channel is reduced with same bit pattern.Because the bit sequence in each channel is alternation always, so can not be eliminated fully based on the interference of crosstalking.However, have POLMUX is arranged and according to the present invention in the wdm system of so-called staggered polarization (English: " interleaved polarization ") systematic function be improved always because be the effect that influences systematic function the most consumingly based on crosstalking of XpolM.
The improvement of transmission feature not only also is confirmed by experiment by emulation in the wdm system with POLMUX and staggered polarization.In theory is investigated, be starting point with Ma Nakefu (Manakov) equation, in having the wdm system of a plurality of channels, the change of the polarization of light signal on the direction of propagation calculated.In Fig. 6, relate to such simulation result.In the wdm system of 2 * 10Gbit/s with 5 channels and POLMUX, on the y direction, draw (EOP) at " eye aperture cost " at receiver place.Described eye aperture cost is defined as the twice at 20% mean intensity of dividing by the maximum eye aperture of eye pattern of bit period, and is that unit provides with dB.EOP is the yardstick of the maximum eye aperture of eye pattern qualitatively.When the value of EOP was 3dB, eyes closed was to half, and disturbing effect partly is very high.Relative polarization at the polarization that the generation of distinguishing the POLMUX signal in the adjacent channel has been described on the x of Fig. 3 axle is poor.The power of every channel 7.8dBm is accepted.For 90 ° of x values and 270 °, can find out the minimum value of EOP clearly.On these aspects, the E field vector of the polarization of the generation of the POLMUX signal of adjacent channel is almost mutually orthogonal respectively.This shows, for the staggered polarization of the POLMUX signal in adjacent channel, only influenced by XpolM rarely in the aperture of receiver side eye pattern, and based on the interference of XpolM by farthest being reduced according to method of the present invention.
In order to realize the method according to this invention technically, should pay attention to following condition in principle: in order to generate POLMUX signal with two data-signals, independent lasing light emitter is indispensable, because could set up the fixing phase difference between two data-signals only so.The setting of accurate polarization state should be carried out very carefully when the transmission highway section begins.Importantly, the reference planes of the polarization of all channels are identical.The efficient of described method depends on: whether 90 ° of differences of the result's of the POLMUX signal in adjacent respectively channel polarization keep.
Therefore the use of polarization-maintaining fiber or multiplexer is favourable, and the existence of the regulating loop of same polarization state and check mechanism also is favourable.Use " array waveguide grating (arrayed waveguide grating) " that polarization keeps (AWG) to be used for being created on the benefit that staggered POLMUX signal brings aspect its polarization and to be: in multiplexer, not need verification unit (Kontrolleinheit) at wdm system.Described device also can be embedded in the POLMUX transmission highway section that has existed simply.The bit sequence that is transmitted in these external all channels must be a time synchronized, so that reach the maximum interaction time.
Fig. 7 shows the basic circuit diagram of the transmitter side POLMUX device with polarization state conditioning equipment.The continuous optical carrier TSn (n=1 of the emission wavelength given in advance of laser, 2,3...) be fed to beam splitter ST1, described beam splitter is divided into described optical carrier the CW sub-signal TSnx and the TSny of two same-amplitude, described CW sub-signal is as having n=1,2, the carrier signal of each channel of 3....Next the device that is used to the POLMUX of channel n generation arbitrarily signal PMSn is described.The one CW sub-signal/carrier signal TSnx is fed to the first modulator MOD1, and a described there CW sub-signal/carrier signal utilizes the first data-signal DS1 by amplitude modulation.Adjust element POLC at the light signal PSnx through amplitude modulation of the output place of described modulator MOD1 output via polarization and be fed to polarization combiner PBS, wherein said polarization is adjusted element polarization is adjusted 90 °.The 2nd CW sub-signal/carrier signal TSny is fed to the second modulator MOD2, and described there the 2nd CW sub-signal/carrier signal utilizes the second data-signal DS2 by amplitude modulation.The light data-signal PSny through amplitude modulation in the output of the output place of described modulator is fed to phase-modulator PMOD, and described phase-modulator is controlled by conditioning equipment RE.In phase-modulator PMOD, can set up 180 ° of phase shifts with respect to light data-signal PSnx.180 ° of phase shifts cause 90 ° polarization rotation of the POLMUX signal of generation.Light data-signal PSny then is fed to described polarization combiner PBS, and described polarization combiner PBS is combined into polarisation-multiplexed signal PMSn with it with described smooth data-signal PSnx.POLMUX signal PMSn in the output of the output place of polarization combiner is fed to beam splitter ST2, and first output of described beam splitter ST2 leads to the transmission highway section, and measuring-signal is through being directed into conditioning equipment RE by second output.There, the polarization state of the POLMUX signal of generation is measured, and produces check signal KS, and described check signal is fed to described phase-modulator PMOD.In this way, the phase shift between light signal PSnx and PSny is accurately set up.
In order to realize method of the present invention, for example all even-numbered channels of wdm system are implemented the illustrated modification of POLMUX dispensing device.So under the odd-numbered channels situation, the carrier phase of modulated data-signal PSny is retained as 0 ° at the phase-modulator place.The POLMUX signal of even number and the odd-numbered channels waveguide optical grating that is used to utilize polarization to keep (English: " arrayed waveguide grating (array waveguide grating) ", be abbreviated as AWG) the transmission data that are combined.
The polarization of two light signals of POLMUX signal and the setting of phase place also can realize before data-modulated alternatively.For this reason, carrier signal TS is divided into carrier signal TSnx two same-amplitude, mutually orthogonal polarization and TSny by means of polarization splitter PBS.Described carrier signal is fed to different modulators respectively.Realize the phase place setting after one in described modulator.
Figure 8 illustrates the basic circuit diagram of a kind of modification of the POLMUX multiplexer that is used to realize the inventive method.Odd-numbered channels K1, K3, K5 ..., be fed to the input of the AWG AWGU that polarization keeps by having POLMUX signal PMS1, PMS3, PMS5... that two mutually orthogonal data-signal PSix that i is an odd number and PSiy form respectively, wherein said POLMUX signal is combined into a WDM signal WDM_PMSU.The channel separation of each channel is 100GHz in this example.The optical fiber that the output of AWGU keeps via polarization is adjusted element POLCU with polarization and is linked to each other with the first input end of interleaver PI.Even-numbered channels K2, K4, K6 ... POLMUX signal PMS2, PMS4, PMS6... compare difference with the POLMUX signal of odd-numbered channels as follows: the carrier signal of one of data-signal of two mutually orthogonal polarizations with respect to another by 180 ° of phase shifts.POLMUX signal PMS2, PMS4, PMS6... are fed to the input of the AWG AWGG of polarization maintenance, and wherein said POLMUX signal is combined into the 2nd WDM signal WDM_PMSG.The channel separation of each channel is 100GHz here.The optical fiber that the output of AWGG keeps via polarization is adjusted element POLCG with polarization and is linked to each other with second input of interleaver PI.At the output of described interleaver PI, output WDM-POLMUX signal WDM_PMS, described WDM-POLMUX signal WDM_PMS is made up of the N with interlaced polarization POLMUX signal.Channel separation is 50GHz now.WDM-POLMUX signal WDM_PMS is divided into two sub-signals in beam splitter ST.First sub-signal is fed to the transmission highway section, and second sub-signal is fed to the AWG AWG_N that polarization keeps, and the AWGAWG_N that described polarization keeps works as demodulation multiplexer.At the output of demodulation multiplexer AWG_N, described POLMUX signal can be fed among the polarization inspection machine C (Kn) in the mode that channel is selected, and n=1...N wherein determines the polarization state of POLMUX signal as required in described polarization inspection machine.The polarization inspection machine C (Kn) of even number or odd-numbered channels adjusts element POLCG with corresponding polarization and links to each other with POLCU.The polarization state of WDM signal WDM_PMSG and WDM_PMSU is examined and regulates by means of check signal CSG and CSU.
Figure 9 illustrates the basic circuit diagram of second modification of the POLMUX dispensing device that is used to realize the inventive method.
The one WDM signal WDM_S1 is fed to the first input end of beam combiner BC, a described WDM signal with the channel separation of 50GHz by modulated smooth data-signal PS1y (λ
1), PS2y (λ
2) ... PSNy (λ
N) form.The modulated smooth data-signal PS2x (λ of even-numbered channels (channel separation for example is 100GHz)
2), PS4x (λ
4), PS6x (λ
6) ... be fed to multiplexer AWG2G via phase modulator PS, described multiplexer preferably is made up of the AWG that polarization keeps.In phase modulator, the phase place of light signal is passed 180 ° respectively.The signal WDM_S2G that (in the drawings, the polarization state of corresponding signal is illustrated as the E field vector parenthetic) made up in multiplexer AWG2G then is fed to signal interleaver SI.The modulated smooth data-signal PS1x (λ of odd-numbered channels (channel separation is 100GHz)
1), PS3x (λ
3), PS5x (λ
5) ... do not having directly to be fed to the multiplexer AWG2U that polarization keeps under the phase shift situation, wherein said signal is combined into sub-signal WDM_S2U, and is output at output.The first sub-signal WDM_S2U is fed to described signal interleaver.For example can relate to periodic filter (50GHz interleaver) at this with 50GHz cycle.In 50GHz interleaver SI, two WDM sub-signal WDM_S2U and WDM_S2G are combined into the 2nd WDM signal WDM_S2 with 50GHz channel separation.The 2nd WDM signal WDM_S2 is fed to the first input end of beam combiner BC via polarization adjuster POLS.Described polarization adjuster POLS causes 90 ° of polarization rotations of WDM signal WDM_S2.All individual signals of WDM_S1 all have the polarization with the signal in orthogonal of WDM_S2.In beam combiner BC, the WDM signal WDM_S1 and the WDM_S2 of mutually orthogonal polarization are combined, and are output at output.Yes in the plane of polarization can exchange.If the described second data-signal Psny is transfused in the mode with the described first data-signal PSnx quadrature, then can omit the polarization adjuster equally, just as shown in FIG. 9.
The WDM output signal WDM_PMS of Sheng Chenging so every channel are made up of a POLMUX signal PMS like this, and wherein two modulated light signals are mutually orthogonal polarizations.At this, the polarization of the generation of POLMUX signal differs 90 ° with respect to odd-numbered channels in even-numbered channels.This dispensing device is compared to realizing with expending still less in the modification shown in Fig. 8.
Claims (12)
1. be used for being combined into wavelength-division multiplex signals polarisation-multiplexed signal (PMS1 (WDMS), different wave length, PMS2, ...) carry out the method for optical transmission, described polarisation-multiplexed signal respectively by the combination first smooth data-signal (PS1x, PS2x ...) and have the second smooth data-signal (PS1y of the polarization of quadrature therewith, PS2y, ...) constitute, it is characterized in that the described multiplexed signals (PMS1 that shakes; PMS2 ...) by respectively two have its carrier signal (TS1x, TS1y) light data-signal (PS1x, the PS1y of mutual 90 ° of phase shifts; PS2x, Ps2y; ...) constitute.
2. method according to claim 1 is characterized in that, first polarisation-multiplexed signal (PMS1) has its carrier signal (TS1x by two, TS1y) the light data-signal (PS1x of mutual 90 ° of phase shifts, PS1y) constitute, send two light data-signals (PS1x, PS1y thus at the same time; ...) time, first polarisation-multiplexed signal (PMS1) of generation is generated, and described first polarisation-multiplexed signal is circularly polarized, and
Second polarisation-multiplexed signal (PMS2) has its carrier signal (TS2x, TS2y) modulated data-signal (PS2x, the PS2y of mutual 90 ° of opposite phase shifts by two equally; ...) constitute, send two modulated data-signals (S2x, S2y thus at the same time; ...) time, second polarisation-multiplexed signal (PMS2) of generation is generated, and described second polarisation-multiplexed signal is circularly polarized on the contrary.
3. according to claim 1 or 2 described methods, it is characterized in that (PS2x is PS2y) with respect to the modulated data-signal (PS1x of first polarisation-multiplexed signal (PMS1) for the signal of second polarisation-multiplexed signal (PMS2), PS2y ...) be transmitted with the polarization of 45 ° of mutual rotations.
4. according to claim 2 or 3 described methods, it is characterized in that, odd number polarisation-multiplexed signal (PMS1, ...) all modulated data-signal (PS1x, PS1y ...) and the odd number polarisation-multiplexed signal (PMS2 ...) all modulated data-signals be respectively identical polarization, and with at modulated data-signal (PS1x, PS1y; PS2x, PS2y; ...) between identical phase shift be transmitted.
5. according to claim 3 or 4 described methods, it is characterized in that, be implemented in polarisation-multiplexed signal (PMS1, PMS2 ...) and carrier signal (TS1x, TS1y; TS2x, TS2y; ...) in polarization and phase change, and like this processed carrier signal (TS1x, the TS1y of modulation and then; TS2x, TS2y; ...).
6. be used for being combined into wavelength-division multiplex signals (WDMS), polarisation-multiplexed signal (the PMS1 of different wave length, PMS2, ...) carry out the method for optical transmission, wherein said polarisation-multiplexed signal is respectively by the combination first smooth data-signal (PS1x, ...) and have the second smooth data-signal (PS1y of cross-polarization therewith, ...) constitute, it is characterized in that, in first channel (K1), the first smooth data-signal (PS1x) and the second smooth data-signal (PS1y) are at its carrier signal (TS1x, TS2y) there is not to be combined under other situation of phase difference polarisation-multiplexed signal (PMS1)
In second channel (K2), the carrier signal (TS2x) of its first data-signal (PS2x) with respect to the carrier signal (TS2y) of its second data-signal (PS2y) by 180 ° of phase shifts, and be combined into second polarisation-multiplexed signal (PMS2), make and send two light data-signals (PS1x, PS1y at the same time respectively; PS2x, in the time of PS2y), the polarization of the generation of the polarization of the generation of second polarisation-multiplexed signal (PMS2) and first polarisation-multiplexed signal (PMS1) differs 90 °.
7. method according to claim 6 is characterized in that, odd-numbered channels (K1 ...) light data-signal (PS1x, PS1y; ...) at its carrier signal (TS1x, TS1y; ...) do not have to be combined under other situation of phase difference polarisation-multiplexed signal (PMS1 ...), and
At even-numbered channels (K2, ...) in, the first smooth data-signal (PS2x, ...) carrier signal (TS2x, ...) with respect to the second smooth data-signal (PS2y ...) carrier signal (TS2y ...) respectively by 180 ° of phase shifts, and be combined into odd-numbered channels the palarization multiplexing channel (PMS2 ...).
8. according to claim 6 or 7 described methods, it is characterized in that (TS1x, TS1y) phase difference between is conditioned the carrier signal of the light data-signal of channel (K1) (PS1x and PS1y).
9. according to claim 6 or 7 described methods, it is characterized in that, in order to obtain phase-adjusted criterion, polarisation-multiplexed signal (PMS1 ...) result's polarization state measured, and draw conditioning signal thus.
10. according to claim 6 or 7 described methods, it is characterized in that, the modulating polarization multiplexed signals (PMS1 ...) light signal before, carrier signal (TS1x, just set up or regulated by polarization state TS1y) and phase place.
11. according to claim 6 or 7 described methods, it is characterized in that, polarisation-multiplexed signal (PMS1, PMS2 ...) and result's polarization during transfer of data, be verified and regulate at least one time.
12. method according to claim 7 is characterized in that, the second smooth data-signal (PSny) with identical polarization of all channels is combined into a WDM signal (WDM_S1), and is fed to the first input end of polarization combiner (BC),
Odd-numbered channels (K1, K3 ...) and the first smooth data-signal (PSnx with identical polarization; N=1,3 ...) and be combined into a WDM sub-signal (WDM_S2U), and even-numbered channels (K2, K4 ...) and be adjusted the first smooth data-signal (PSnx 180 °, that have identical polarization aspect its phase place; N=2,4 ...) being combined into the 2nd WDM sub-signal (WDM_S2G), the polarization of the wherein said second smooth data-signal (PS1y) differs 90 ° with respect to the polarization of described first data-signal (PS1x), perhaps so set up,
And then two WDM sub-signals (WDM_S2U and WDM_S2G) are combined into the 2nd WDM signal (WDM_S2), are fed to second input of polarization combiner (BC),
And the output of described polarization combiner by polarisation-multiplexed signal (PMS1, PMS2 ...) and the WDM output signal WDM_PMS that forms, wherein adjacent polarisation-multiplexed signal (PMS1, PMS2 ...) and between the polarization of generation differ 90 °.
Applications Claiming Priority (5)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE102005003681.3 | 2005-01-26 | ||
| DE200510003681 DE102005003681A1 (en) | 2005-01-26 | 2005-01-26 | Polarization multiplex signals optical transmission method for wave division multiplex system, involves forming polarization-multiplex signals from two optical data signals with phase shift of ninety degree in its carrier signals |
| DE200510003679 DE102005003679A1 (en) | 2005-01-26 | 2005-01-26 | Polarization multiplex signals optical transmission method for wave division multiplex system, involves forming polarization-multiplex signals from two optical data signals with phase shift of ninety degree in its carrier signals |
| DE102005003679.1 | 2005-01-26 | ||
| PCT/EP2006/050429 WO2006079634A1 (en) | 2005-01-26 | 2006-01-25 | Method for optically transmitting polarisation multiplex signals |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN101107802A true CN101107802A (en) | 2008-01-16 |
| CN101107802B CN101107802B (en) | 2012-05-02 |
Family
ID=36709421
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN2006800032449A Expired - Fee Related CN101107802B (en) | 2005-01-26 | 2006-01-25 | Method for optically transmitting polarisation multiplex signals |
Country Status (2)
| Country | Link |
|---|---|
| CN (1) | CN101107802B (en) |
| DE (1) | DE102005003681A1 (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102439887A (en) * | 2011-10-18 | 2012-05-02 | 华为技术有限公司 | Signal modulation device and method |
| CN103222208A (en) * | 2012-11-15 | 2013-07-24 | 华为技术有限公司 | Transmitter, optical signal generation method apparatus and system |
| CN103329461A (en) * | 2010-11-29 | 2013-09-25 | 诺基亚西门子通信公司 | Optical communication system and method |
| CN107241173A (en) * | 2016-03-28 | 2017-10-10 | 马克西姆综合产品公司 | The balanced system and method monitored with eyes opening width of wideband adaptive for being detected for link-quality |
| CN109565335A (en) * | 2016-08-23 | 2019-04-02 | 三菱电机株式会社 | Decode the method and system of the symbol sent on optical communication channel |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| AU5035400A (en) * | 1999-05-20 | 2000-12-12 | University Of Southern California | Polarization-division multiplexing based on power encoding of different polarization channels |
| EP1233563A1 (en) * | 2001-02-16 | 2002-08-21 | Alcatel | Frequency allocation scheme and transmission system for polarisation and wavelength division multiplexed signals with left and right side filtering |
| JP2003209532A (en) * | 2002-01-16 | 2003-07-25 | Nec Corp | Orthogonally polarized wave multiplex transmitter and multiplex method used for the transmitter |
| DE50306800D1 (en) * | 2002-05-10 | 2007-04-26 | Siemens Ag | METHOD AND ARRANGEMENT FOR REDUCING SIGNAL DEGRADATION OF AN OPTICAL POLARIZATION MULTIPLEX SIGNAL |
| DE10243141B4 (en) * | 2002-09-17 | 2006-05-11 | Siemens Ag | Method for transmitting optical polarization multiplexed signals |
-
2005
- 2005-01-26 DE DE200510003681 patent/DE102005003681A1/en not_active Ceased
-
2006
- 2006-01-25 CN CN2006800032449A patent/CN101107802B/en not_active Expired - Fee Related
Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103329461A (en) * | 2010-11-29 | 2013-09-25 | 诺基亚西门子通信公司 | Optical communication system and method |
| CN103329461B (en) * | 2010-11-29 | 2016-03-30 | 诺基亚西门子通信公司 | Optical communication system and method |
| CN102439887A (en) * | 2011-10-18 | 2012-05-02 | 华为技术有限公司 | Signal modulation device and method |
| CN103222208A (en) * | 2012-11-15 | 2013-07-24 | 华为技术有限公司 | Transmitter, optical signal generation method apparatus and system |
| CN103222208B (en) * | 2012-11-15 | 2016-01-13 | 华为技术有限公司 | A kind of transmitter, optical signal generation method, Apparatus and system |
| CN107241173A (en) * | 2016-03-28 | 2017-10-10 | 马克西姆综合产品公司 | The balanced system and method monitored with eyes opening width of wideband adaptive for being detected for link-quality |
| CN107241173B (en) * | 2016-03-28 | 2021-08-24 | 马克西姆综合产品公司 | System and method for broadband adaptive equalization and eye opening monitoring for link quality detection |
| CN109565335A (en) * | 2016-08-23 | 2019-04-02 | 三菱电机株式会社 | Decode the method and system of the symbol sent on optical communication channel |
| CN109565335B (en) * | 2016-08-23 | 2021-09-10 | 三菱电机株式会社 | Method and system for decoding symbols transmitted over an optical communication channel |
Also Published As
| Publication number | Publication date |
|---|---|
| CN101107802B (en) | 2012-05-02 |
| DE102005003681A1 (en) | 2006-08-10 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| AU2006208719B2 (en) | Method for optically transmitting polarisation multiplex signals | |
| US8417126B2 (en) | Polarization multiplexing transmitter and transmission system | |
| JP6852115B2 (en) | Quantum communication network | |
| US7142788B2 (en) | Optical communications systems, devices, and methods | |
| US6522439B2 (en) | Optical distortion compensation apparatuses, methods, and systems | |
| US20160204896A1 (en) | Time division multiplexed orbital angular momentum based communication | |
| US6891981B2 (en) | Optical transmission apparatuses, methods, and systems | |
| Rohde et al. | Next generation optical access: 1 Gbit/s for everyone | |
| US6459515B1 (en) | Method and apparatus for transmitting a WDM optical signal having states of polarization that are pairwise orthogonal | |
| CN101107802B (en) | Method for optically transmitting polarisation multiplex signals | |
| US20070274728A1 (en) | Optical communication system and method using optical channels with pair-wise orthogonal relationship | |
| US20180069625A1 (en) | Optical transmission system, optical receiver, and method for detecting optical signal information | |
| CN112769554A (en) | Noise processing system and noise processing method for quantum classical fusion transmission | |
| EP0717524B1 (en) | Polarization modulation in wavelength division multiplexed transmission systems | |
| JP2013005065A (en) | Optical transmission system and optical transmission method | |
| JP5700965B2 (en) | Optical transmitter, optical transceiver, and optical transmission system | |
| US6411413B1 (en) | Method and apparatus for performing dispersion compensation without a change in polarization and a transmitter incorporating same | |
| Ibrahim et al. | Demonstration of CoWDM using DPSK modulator array with injection-locked lasers | |
| JP2003158488A (en) | Method and device for transmitting optical signal by polarization scramble | |
| JP4627033B2 (en) | Polarization-independent bidirectional optical communication system and polarization-independent bidirectional optical communication method using coherent optical communication system | |
| CN1565095A (en) | Optical signal transmission | |
| Kuri et al. | Novel demultiplexer for dense wavelength-division-mutliplexed millimeter-wave-band radio-over-fiber systems with optical frequency interleaving technique | |
| Ellis et al. | Coherent WDM: The achievement of high information spectral density through phase control within the transmitter | |
| US6571032B1 (en) | Apparatus and method for multiplexing and/or demultiplexing optical signals having substantially equal dispersion | |
| Li et al. | Upstream multi-wavelength shared TDM-PON using RSOA based directly modulated tunable fiber ring laser |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| ASS | Succession or assignment of patent right |
Owner name: XIAOYANG NETWORK CO., LTD. Free format text: FORMER OWNER: NOKIA SIEMENS NETWORKS GMBH Effective date: 20140106 |
|
| C41 | Transfer of patent application or patent right or utility model | ||
| TR01 | Transfer of patent right |
Effective date of registration: 20140106 Address after: Luxemburg Luxemburg Patentee after: Xiaoyang Network Co., Ltd. Address before: Munich, Germany Patentee before: Nokia Siemens Networks GmbH |
|
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20120502 Termination date: 20150125 |
|
| EXPY | Termination of patent right or utility model |