A signal orthogonal decomposition method and device

Abstract

The present invention relates to the field of signal processing technology, and provides a method and device for orthogonal signal decomposition. The method first obtains a signal light to be decomposed; then the signal light to be decomposed and two pump lights with orthogonal polarization states and coherent with the signal light to be decomposed are input into a nonlinear optical medium to obtain a mixed signal light containing idle light and a target signal light corresponding to the signal light to be decomposed; thereafter, the idle light and the target signal light in the mixed signal light are separated, and the polarization states of the idle light and the target signal light are adjusted to be consistent; finally, the idle light and the target signal light with consistent polarization states are input into a coupler to obtain two mutually orthogonal components of the signal light to be decomposed output by the coupler. The method can perform orthogonal decomposition of the signal light to be decomposed, and realize the simultaneous output of two mutually orthogonal components. Moreover, the method is based on vector PSA, and the two pump light polarization states are orthogonal, which can effectively reduce the generation of FWM sidebands.

Description

Technical Field

[0001] The present invention relates to the technical field of signal processing, and in particular to a signal orthogonal decomposition method and device. Background Art

[0002] Optical communication networks carry a massive amount of transmission data of up to tens of terabits. The specific manifestation of such a large amount of data at the physical layer is optical signals. Optical signals can generally be used to manipulate the dimensions of transmitted information, including amplitude, phase, polarization, wavelength, time, etc. The most widely used transmission method currently is to modulate information in the amplitude and phase dimensions of optical signals, and multiplex other dimensions. The signal light modulated in the amplitude and phase dimensions can be decomposed into two mutually orthogonal components: in-phase (I) and quadrature-phase (Q). Decomposing an optical signal into I and Q components, or orthogonally superimposing two signal lights to form a new signal light, is a typical idea in the field of all-optical signal processing, which has a wide range of applications in many scenarios, such as all-optical regeneration, format conversion, information decomposition, etc.

[0003] All-optical orthogonal decomposition technology is one of the key technologies in the field of all-optical signal processing. It can realize the orthogonal decomposition of the input signal light in the full optical domain and output its I component and Q component. It is widely used in format conversion, information decomposition, all-optical regeneration and other fields. With the continuous increase in the capacity of optical communication networks, the modulation order of signal light is also increasing. Multiple Quadrature Amplitude Modulation (mQAM) and multilevel Pulse Amplitude Modulation (mPAM) have gradually become the mainstream transmission formats of optical transmission networks. A typical application scenario of all-optical orthogonal decomposition technology is to perform orthogonal decomposition on mQAM signals. By processing the I component and Q component obtained by orthogonal decomposition separately, key requirements such as all-optical regeneration and all-optical shaping in large-capacity and multi-scenario situations can be met.

[0004] Since all-optical orthogonal decomposition technology has a wide range of application scenarios, its implementation schemes usually include orthogonal extraction schemes based on scalar phase-sensitive amplifiers (PSA), orthogonal decomposition schemes based on scalar PSA, and orthogonal extraction schemes based on vector PSA. However, the above-mentioned orthogonal extraction methods based on scalar PSA and orthogonal extraction schemes based on vector PSA cannot extract two orthogonal components at the same time, and the orthogonal decomposition scheme based on scalar PSA will generate sideband harmonics due to scalar four-wave mixing (FWM), which will lead to low decomposition efficiency and difficulty in meeting system phase locking. Summary of the invention

[0005] The present invention provides a signal orthogonal decomposition method and device to solve the defects in the prior art.

[0006] The present invention provides a signal orthogonal decomposition method, comprising:

[0007] Obtaining signal light to be decomposed;

[0008] Inputting the signal light to be decomposed and two pump lights with orthogonal polarization states and coherent with the signal light to be decomposed into a nonlinear optical medium to obtain a mixed signal light including idler light and target signal light corresponding to the signal light to be decomposed;

[0009] Separating the idler light from the target signal light in the mixed signal light, and adjusting the polarization states of the idler light and the target signal light to be consistent;

[0010] The idler light and the target signal light with the same polarization state are input into a coupler to obtain two mutually orthogonal components of the signal light to be decomposed output by the coupler.

[0011] According to a signal orthogonal decomposition method provided by the present invention, the idler light and the target signal light with the same polarization state are input into a coupler to obtain two mutually orthogonal components of the signal light to be decomposed output by the coupler, and then the method includes:

[0012] The two mutually orthogonal components are input to a coherent optical receiving system, and the two mutually orthogonal components are analyzed based on the coherent optical receiving system to determine the signal quality of the two mutually orthogonal components.

[0013] According to a signal orthogonal decomposition method provided by the present invention, the signal light to be decomposed and the two pump lights are determined based on the following steps:

[0014] Based on the laser, determining a target light beam having the same wavelength as the signal light to be decomposed;

[0015] Inputting the target light beam into a first light modulator to obtain a mixed light beam of three wavelengths output by the first light modulator including the target light beam;

[0016] Inputting the mixed light beam into a first filter to obtain the target light beam, the first light beam and the second light beam output by the first filter;

[0017] The target light beam output by the first filter is input to a second optical modulator to obtain the signal light to be decomposed, and the polarization states of the first light beam and the second light beam are adjusted to be orthogonal to obtain the two pump lights.

[0018] According to a signal orthogonal decomposition method provided by the present invention, the signal light to be decomposed and the two pump lights meet the phase matching condition, the idler light has the same wavelength as the signal light to be decomposed, and their polarization states are orthogonal.

[0019] According to a signal orthogonal decomposition method provided by the present invention, the wavelength of the signal light to be decomposed is located in the middle of the wavelengths of the two pump lights.

[0020] The present invention also provides a signal orthogonal decomposition device, comprising: a signal generation source, a nonlinear optical medium, a signal separation element, a first polarization state adjustment element and a coupler connected in sequence;

[0021] The signal generating source is used to output a signal light to be decomposed and two pump lights with orthogonal polarization states and coherent with the signal light to be decomposed;

[0022] The nonlinear optical medium is used to receive the signal light to be decomposed and the two pump lights, generate a four-wave mixing effect, and obtain a mixed signal light including an idler light and a target signal light corresponding to the signal light to be decomposed;

[0023] The signal separation element is used to receive the mixed signal light and separate the idler light and the target signal light in the mixed signal light;

[0024] The first polarization state adjusting element is used to receive the idler light and the target signal light respectively, and adjust the polarization states of the idler light and the target signal light to be consistent;

[0025] The coupler is used to receive the idler light and the target signal light with consistent polarization states, and output two mutually orthogonal components of the signal light to be decomposed.

[0026] According to a signal orthogonal decomposition device provided by the present invention, the signal generation source comprises a laser, a first optical modulator, a first filter, a second optical modulator and a second polarization state adjustment element connected in sequence;

[0027] The laser is used to output a target light beam having the same wavelength as the signal light to be decomposed;

[0028] The first optical modulator is used to receive the target light beam, modulate the target light beam, and output a mixed light beam of three wavelengths including the target light beam;

[0029] The first filter is used to receive the mixed light beam, filter the mixed light beam, and output the target light beam, the first light beam, and the second light beam;

[0030] The second optical modulator is used to receive the target light beam output by the first filter, and modulate the target light beam output by the first filter to output the signal light to be decomposed;

[0031] The second polarization state adjusting element is used to receive the first light beam and the second light beam, and adjust the polarization states of the first light beam and the second light beam to be orthogonal, and output the two pump lights.

[0032] A signal orthogonal decomposition device according to the present invention further includes: a coherent light receiving system, the coherent light receiving system being connected to the coupler;

[0033] The coherent optical receiving system is used to receive the two mutually orthogonal components, analyze the two mutually orthogonal components, and determine the signal quality of the two mutually orthogonal components.

[0034] According to the signal orthogonal decomposition device provided by the present invention, a second filter is further connected between the nonlinear optical medium and the signal separation element.

[0035] According to a signal orthogonal decomposition device provided by the present invention, a noise source is further connected between the signal light output end of the signal generating source for outputting the signal light to be decomposed and the nonlinear optical medium.

[0036] The present invention provides a method and device for orthogonal signal decomposition. The method first obtains the signal light to be decomposed; then the signal light to be decomposed and two pump lights with orthogonal polarization states and coherent with the signal light to be decomposed are input into a nonlinear optical medium to obtain a mixed signal light containing idle light and a target signal light corresponding to the signal light to be decomposed; thereafter, the idle light and the target signal light in the mixed signal light are separated, and the polarization states of the idle light and the target signal light are adjusted to be consistent; finally, the idle light and the target signal light with consistent polarization states are input into a coupler to obtain two mutually orthogonal components of the signal light to be decomposed output by the coupler. The method can perform orthogonal decomposition on the signal light to be decomposed and realize the simultaneous output of two mutually orthogonal components. Moreover, the method is based on vector PSA, and the two pump light polarization states are orthogonal, which can effectively reduce the generation of FWM sidebands. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, for ordinary technicians in this field, other drawings can be obtained based on the drawings in the following description without creative work.

[0038] Figure 1It is one of the flow charts of the signal orthogonal decomposition method provided by the present invention;

[0039] Figure 2 This is the second flow chart of the signal orthogonal decomposition method provided by the present invention;

[0040] Figure 3 It is a schematic diagram of the vector PSA part of the signal processing process in the signal orthogonal decomposition method provided by the present invention;

[0041] Figure 4 It is a schematic diagram of the coherent coupling part of the signal processing process in the signal orthogonal decomposition method provided by the present invention;

[0042] Figure 5 It is a structural schematic diagram of a coherent optical receiving system used in the signal orthogonal decomposition method provided by the present invention;

[0043] Figure 6 It is a schematic diagram of the structure of the signal source used in the signal orthogonal decomposition method provided by the present invention;

[0044] Figure 7 It is a structural schematic diagram of the signal orthogonal decomposition device provided by the present invention. DETAILED DESCRIPTION

[0045] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0046] In the prior art, implementation schemes of the all-optical orthogonal decomposition technology generally include an orthogonal extraction scheme based on scalar PSA, an orthogonal decomposition scheme based on scalar PSA, and an orthogonal extraction scheme based on vector PSA.

[0047] The orthogonal extraction scheme based on scalar PSA can realize the extraction of I component or Q component of signal light. Degenerate PSA has a second-order phase compression function, which can choose to amplify one of the I component or Q component of the signal light and compress the other component. When the compressed component is compressed to 0, the extraction of the selected amplified component is realized. This scheme can only select one of the I component or Q component for extraction at a time, and cannot output the I component and the Q component at the same time. At the same time, because the scheme is based on scalar PSA, more sideband harmonics will be generated when the signal light undergoes the FWM effect, which reduces the extraction efficiency and increases the risk of crosstalk.

[0048] The orthogonal extraction scheme based on vector PSA can realize the extraction of the I component or Q component of the signal light. This scheme is also based on the second-order phase compression function of the degenerate PSA, which selects to amplify one of the I component or Q component of the signal light and attenuates the other component. When the attenuated component is compressed to 0, the selected amplified component can be extracted. Compared with scalar PSA, vector PSA weakens the generation of FWM sidebands and improves the component extraction efficiency because the two pump lights are in orthogonal polarization states. However, this scheme cannot output the I component and Q component of the signal light at the same time, but can only select one of them to be output at a time, so it can only be called orthogonal component extraction, not orthogonal decomposition.

[0049] The orthogonal decomposition scheme based on scalar PSA can output the I component and Q component of the signal light at the same time. Based on the scalar degenerate second-order PSA, this scheme builds a single-medium bidirectional PSA structure, which can amplify the I component and Q component in two directions in a medium at the same time, and output the I component and Q component of the signal light at the same time. Because it is based on scalar bidirectional PSA, this scheme has problems such as low extraction efficiency caused by too many FWM sidebands, complex and difficult system adjustment, and increased crosstalk risk. Moreover, this scheme adopts a bidirectional PSA structure, which increases the difficulty of maintaining the coherence between the pump light and the signal light.

[0050] In summary, the existing full orthogonal decomposition technology, the orthogonal extraction method based on scalar PSA, and the orthogonal extraction scheme based on vector PSA are all unable to extract two orthogonal components at the same time. The orthogonal decomposition scheme based on scalar PSA will generate sideband harmonics due to FWM, which will lead to low decomposition efficiency and difficulty in meeting phase locking.

[0051] Therefore, while achieving the simultaneous extraction of two orthogonal components of the optical signal, avoiding the problems of low FWM efficiency and difficult phase locking has application value and practical significance for realizing flexible and complete all-optical signal processing technology. The embodiment of the present invention provides a signal orthogonal decomposition method, which is implemented based on vector PSA.

[0052] Figure 1 FIG. 1 is a flow chart of a signal orthogonal decomposition method provided in an embodiment of the present invention, such as Figure 1 As shown, the method includes:

[0053] S1, obtaining the signal light to be decomposed;

[0054] S2, inputting the signal light to be decomposed and two pump lights with orthogonal polarization states and coherent with the signal light to be decomposed into a nonlinear optical medium to obtain a mixed signal light including idler light and target signal light corresponding to the signal light to be decomposed;

[0055] S3, separating the idler light and the target signal light in the mixed signal light, and adjusting the polarization states of the idler light and the target signal light to be consistent;

[0056] S4, inputting the idler light and the target signal light with the same polarization state into a coupler to obtain two mutually orthogonal components of the signal light to be decomposed output by the coupler.

[0057] Specifically, the signal orthogonal decomposition method provided in the embodiment of the present invention first performs step S1 to obtain a signal light s to be decomposed, the signal light s to be decomposed can be output from a signal source, the signal light to be decomposed can be a signal light carrying target information after modulation, and the signal light to be decomposed can be a light vector signal.

[0058] Then, step S2 is performed, and the signal light s to be decomposed and two pump lights p1 and p2 whose polarization states are orthogonal and coherent with the signal light s to be decomposed are input into the nonlinear optical medium, and a mixed signal light including idler light i and target signal light o corresponding to the signal light s to be decomposed is obtained from the nonlinear optical medium. Here, the signal light s to be decomposed and the two pump lights p1 and p2 can be output from the signal generating source, that is, the signal generating source can simultaneously generate the signal light s to be decomposed and the two pump lights p1 and p2 whose polarization states are orthogonal and coherent with the signal light s to be decomposed. Coherent with the signal light s to be decomposed means that the two pump lights p1 and p2 have a fixed and controllable relative phase with the signal light s to be decomposed.

[0059] The signal light s to be decomposed may have the same polarization state as one of the two pump lights p1 and p2, which is not specifically limited here. The wavelengths of the signal light s to be decomposed and the two pump lights p1 and p2 are λs, λ1 and λ2 respectively, and λs, λ1 and λ2 are all different.

[0060] In the embodiment of the present invention, the nonlinear optical medium can be a highly nonlinear optical fiber (HNLF), a silicon waveguide, a potassium dihydrogen phosphate (KPD) crystal, a potassium titanyl phosphate (KTP) crystal, a barium borate (BBO) crystal, a lithium niobate (LN) crystal, and a silver gallium sulfide (AGS) crystal, etc., which are not specifically limited here.

[0061] After the signal light s to be decomposed and two pump lights p1 and p2 with orthogonal polarization states are input into the nonlinear optical medium, the FWM effect will be generated in the nonlinear optical medium, and then a mixed signal light including the idler light i and the target signal light o corresponding to the signal light s to be decomposed is obtained. Among them, the idler light i has the same wavelength as the signal light s to be decomposed and has an orthogonal polarization state to the signal light s to be decomposed.

[0062] According to the coupled wave equation, the expression of the mixed signal light is:

[0063]

[0064] in, and are the vector expressions of the signal light s to be decomposed, the target signal light o and the generated idler light i. μ and v are the transfer functions of the FWM effect, which are determined by the length and nonlinear coefficient of the nonlinear optical medium, the power of the pump light and the phase matching of the FWM effect.

[0065] Then, step S3 is performed to separate the idler light and the target signal light in the mixed signal light. The separation action can be achieved by inputting the mixed signal light into a signal separation element, and the idler light and the target signal light are output by the signal separation element. The signal separation element can be a polarization beam splitter.

[0066] Thereafter, the polarization states of the idler light and the target signal light can be adjusted to be consistent. This adjustment can be achieved through two polarization state adjustment elements, that is, the idler light and the target signal light are synchronously input to the corresponding polarization state adjustment elements, so that the polarization states of the idler light and the target signal light can be adjusted to be consistent. The idler light and the target signal light with consistent polarization states are output through the corresponding polarization state adjustment elements. In the embodiment of the present invention, the polarization state adjustment element can be a polarization controller (POL).

[0067] Finally, step S4 is performed to input the idler light and the target signal light with the same polarization state into the coupler to obtain two mutually orthogonal components of the signal light to be decomposed output by the coupler. The coupler can be a 2×2 coupler, that is, the coupler includes two input ends and two output ends, the two input ends respectively input the idler light and the target signal light with the same polarization state, and the two output ends respectively output two mutually orthogonal components of the signal light to be decomposed. The two mutually orthogonal components are the in-phase component (i.e., I component) and the orthogonal component (i.e., Q component) of the signal light to be decomposed, and the two components are mutually orthogonal. The power ratio of the coupler can be 50:50.

[0068] Overall, if Figure 2 As shown, the signal orthogonal decomposition method provided in the embodiment of the present invention realizes all-optical orthogonal decomposition based on the coherent coupling of the vector degenerate PSA, and orthogonally decomposes the signal light to be decomposed into an in-phase component (ie, I component) and an orthogonal component (ie, Q component).

[0069] The signal processing process of all-optical orthogonal decomposition may include a vector PSA part and a coherent coupling part. The vector PSA part is as follows: Figure 3As shown, the signal light s to be decomposed and two pump lights p1 and p2 with orthogonal polarization states are input into the nonlinear optical medium 31, and a mixed signal light 32 including the idler light i and the target signal light o corresponding to the signal light s to be decomposed is obtained. Figure 3 It can be seen that the polarization state of the signal light s to be decomposed is consistent with that of the target signal light o and the polarization state of the polarized light p1, and the polarization state of the idler light i is orthogonal to that of the signal light s to be decomposed and the polarization state of the polarized light p1, and is consistent with that of the polarized light p2. Figure 3 The nonlinear optical medium 31 is HNLF.

[0070] The coherent coupling part is as follows Figure 4 As shown, the idler light i and the target signal light o in the mixed signal light 32 are separated and polarization-adjusted before being input into the coupler 33 , and the orthogonal in-phase component and orthogonal quadrature component of the signal light to be decomposed are obtained through the coupler 33 .

[0071] The signal orthogonal decomposition method provided in the embodiment of the present invention first obtains the signal light to be decomposed; then the signal light to be decomposed and two pump lights with orthogonal polarization states and coherent with the signal light to be decomposed are input into a nonlinear optical medium to obtain a mixed signal light containing idle light and target signal light corresponding to the signal light to be decomposed; thereafter, the idle light and the target signal light in the mixed signal light are separated, and the polarization states of the idle light and the target signal light are adjusted to be consistent; finally, the idle light and the target signal light with consistent polarization states are input into a coupler to obtain two mutually orthogonal components of the signal light to be decomposed output by the coupler. This method can perform orthogonal decomposition on the signal light to be decomposed and realize the simultaneous output of two mutually orthogonal components. Moreover, this method is based on vector PSA, and its two pump light polarization states are orthogonal, which can effectively reduce the generation of FWM sidebands.

[0072] On the basis of the above embodiments, the signal orthogonal decomposition method provided in the embodiments of the present invention, wherein the idler light and the target signal light with the same polarization state are input into a coupler to obtain two mutually orthogonal components of the signal light to be decomposed output by the coupler, and then comprises:

[0073] The two mutually orthogonal components are input to a coherent optical receiving system, and the two mutually orthogonal components are analyzed based on the coherent optical receiving system to determine the signal quality of the two mutually orthogonal components.

[0074] Specifically, in an embodiment of the present invention, after obtaining two mutually orthogonal components of the signal light to be decomposed, the two mutually orthogonal components can be input into a coherent optical receiving system, and the two mutually orthogonal components are analyzed by the coherent optical receiving system to calculate index parameters for characterizing the signal quality of the two mutually orthogonal components, such as bit rate, bit rate, signal-to-noise ratio, bit signal-to-noise ratio, bit error rate, modulation order, number of bits per symbol, quality factor, error amplitude vector, optical signal-to-noise ratio, noise power spectral density, signal power, noise power, average symbol energy, and average bit energy, etc., and then the signal quality of the two mutually orthogonal components is evaluated according to the values ​​of the index parameters to evaluate the effect of the signal orthogonal decomposition method, so as to facilitate the improvement and optimization of the process of the signal orthogonal decomposition method.

[0075] like Figure 5 As shown, the coherent optical receiving system may include two coherent receivers, each of which has an input end, and the input ends of the two coherent receivers are B and C, respectively, which are used to receive two mutually orthogonal components, that is, each input end is used to receive two mutually orthogonal components. Each coherent receiver includes a 90° mixer and two balanced detectors. The 90° mixer is used to implement a mixing function based on a local oscillator (LO) signal from a voltage-controlled oscillator, and then perform data analysis after passing through two balanced detectors to obtain the value of the index parameter. The input end of each coherent receiver is also connected to a noise source (ASE) to provide noise for the two mutually orthogonal input components to simulate the real signal light component.

[0076] On the basis of the above-mentioned embodiment, in the signal orthogonal decomposition method provided in the embodiment of the present invention, the signal light to be decomposed and the two pump lights are determined based on the following steps:

[0077] Based on the laser, determining a target light beam having the same wavelength as the signal light to be decomposed;

[0078] Inputting the target light beam into a first light modulator to obtain a mixed light beam of three wavelengths output by the first light modulator including the target light beam;

[0079] Inputting the mixed light beam into a first filter to obtain the target light beam, the first light beam and the second light beam output by the first filter;

[0080] The target light beam output by the first filter is input to a second optical modulator to obtain the signal light to be decomposed, and the polarization states of the first light beam and the second light beam are adjusted to be orthogonal to obtain the two pump lights.

[0081] Specifically, in the embodiment of the present invention, the signal light s to be decomposed and the two pump lights p1 and p2 with orthogonal polarization states can be output from the signal generation source. Figure 6 As shown, the signal generating source may include a laser 61, a first optical modulator 62, a first filter 63 and a second optical modulator 64 connected in sequence.

[0082] When determining the signal light to be decomposed and the two pump lights, a target beam having the same wavelength as the signal light to be decomposed can be determined based on the laser 61, that is, the laser outputs a target beam having the same wavelength as the signal light to be decomposed, that is, λs.

[0083] Then, the target light beam is input to the first optical modulator 62, and the target light beam is photoelectrically modulated by the first optical modulator 62. Coherent harmonics are obtained by photoelectric modulation to generate a light comb, and then a mixed light beam of three wavelengths including the target light beam is obtained. The three wavelengths may be λs, λ1 and λ2, respectively, and the target light beam has a fixed and controllable relative phase with the light beams of the other two wavelengths. The first optical modulator may be a Mach-Zehnder modulator (MZM). The other two light beams in the mixed light beam except the target light beam are respectively located on both sides of the target light beam, that is, the wavelength of the target light beam among the three wavelengths is located between the wavelengths of the other two light beams, for example, λ1<λs<λ2. When applying MZM, a 100 GHz radio frequency signal (RF) may be introduced.

[0084] Afterwards, the mixed light beam can be input to the first filter 63, and the light beams of different wavelengths in the mixed light beam can be separated by the first filter 63, and the target light beam, the first light beam and the second light beam can be output. The wavelength of the first light beam can be λ1, and the wavelength of the second light beam can be λ2.

[0085] Finally, the target beam output by the first filter 63 is input to the second optical modulator 64, the target information is modulated onto the target beam to obtain the signal light to be decomposed, and the polarization states of the first beam and the second beam are adjusted to be orthogonal to obtain two pump lights p1 and p2.

[0086] In the embodiment of the present invention, the signal light to be decomposed and its coherent pump light can be generated by a signal generating source.

[0087] On the basis of the above embodiments, in the signal orthogonal decomposition method provided in the embodiments of the present invention, the signal light to be decomposed and the two pump lights satisfy the phase matching condition, the idler light has the same wavelength as the signal light to be decomposed, and the polarization states are orthogonal.

[0088] Specifically, in the embodiment of the present invention, when the signal light s to be decomposed and the two pump lights p1 and p2 meet the phase matching condition, formula (1) can be expressed as:

[0089]

[0090] in, and are the phases of pump lights p1 and p2 respectively, where |μ and |v| are two real numbers.

[0091] It can be seen from formula (2) that the idler light i and the signal light s to be decomposed have the same wavelength and their polarization states are orthogonal to each other.

[0092] On this basis, according to the coupler transfer function, the output of the coupler can be obtained from formula (2) as formula (3), that is,

[0093]

[0094] Among them, S1 and S2 are the components output from the two output ports of the coupler. It can be regarded as the carrier phase With information phase The sum of At this time, the relative phase is defined m = |v| / |μ|. The necessary condition for the realization of the PSA process is that the carrier of the signal light s to be decomposed must be coherent with the carrier of the pump light, that is, their relative phase θ is a controllable constant. m can be regarded as the power ratio of the target signal light o to the generated idler light i, which can be controlled by adjusting the power ratio of the signal light s to be decomposed and the pump light. At this time, the relative phase of the signal light s to be decomposed and the pump light is controlled to θ = 2nπ, n is an integer, and the power ratio is adjusted to m = 1, then formula (3) can be transformed into formula (4), that is:

[0095]

[0096] It can be observed that in formula (4) and They are the I component and Q component of the signal light s to be decomposed, respectively. Thus, the coherent coupling part is completed, and the I component and Q component of the signal light s to be decomposed are output simultaneously.

[0097] On the basis of the above-mentioned embodiment, in the signal orthogonal decomposition method provided in the embodiment of the present invention, the wavelength of the signal light to be decomposed is located in the middle position of the wavelengths of the two pump lights, that is, λs=(λ1+λ2) / 2.

[0098] like Figure 7 As shown, based on the above embodiment, an embodiment of the present invention provides a signal orthogonal decomposition device, comprising: a signal source 71, a nonlinear optical medium 31, a signal separation element 72, a first polarization state adjustment element 73 and a coupler 33 connected in sequence;

[0099] The signal generator 71 is used to output the signal light to be decomposed and two pump lights with orthogonal polarization states and coherent with the signal light to be decomposed;

[0100] The nonlinear optical medium 31 is used to receive the signal light to be decomposed and two pump lights, generate a four-wave mixing effect, and obtain a mixed signal light including an idler light and a target signal light corresponding to the signal light to be decomposed;

[0101] The signal separation element 72 is used to receive the mixed signal light and separate the idler light and the target signal light in the mixed signal light;

[0102] The first polarization state adjusting element 73 is used to receive the idler light and the target signal light respectively, and adjust the polarization states of the idler light and the target signal light to be consistent;

[0103] The coupler 33 is used to receive idler light and target signal light with the same polarization state, and output two mutually orthogonal components of the signal light to be decomposed.

[0104] Specifically, in the embodiment of the present invention, the signal generator 71 may include three output ends, namely a signal light output end for outputting the signal light to be decomposed, a first pump light output end for outputting the pump light p1, and a second pump light output end for outputting the pump light p2.

[0105] The three output ends of the signal generator 71 can be connected to one end of the nonlinear optical medium 31, and the other end of the nonlinear optical medium 31 is connected to the input end of the signal separation element 72. The signal separation element 72 can include two output ends, which are respectively used to output the idle frequency light and the target signal light in the mixed signal light.

[0106] Each output end of the signal separation element 72 may be connected to a first polarization state adjustment element 73 , that is, the signal orthogonal decomposition device may include two first polarization state adjustment elements 73 , which are respectively used to adjust the polarization states of the idler light and the target signal light.

[0107] Each first polarization state adjusting element 73 can be connected to an input end of the coupler 33 to input the idler light and the target signal light into the coupler 33 , and then output two mutually orthogonal components of the signal light to be decomposed through the two output ends of the coupler 33 .

[0108] The signal orthogonal decomposition device provided in the embodiment of the present invention comprises: a signal source, a nonlinear optical medium, a signal separation element, a first polarization state adjustment element and a coupler connected in sequence. The device can perform orthogonal decomposition on the signal light to be decomposed, and output two mutually orthogonal components simultaneously. Moreover, the method is based on vector PSA, and its two pump light polarization states are orthogonal, which can effectively reduce the generation of FWM sidebands.

[0109] On the basis of the above-mentioned embodiment, in the signal orthogonal decomposition device provided in the embodiment of the present invention, the signal generation source comprises a laser, a first optical modulator, a first filter, a second optical modulator and a second polarization state adjustment element connected in sequence;

[0110] The laser is used to output a target light beam having the same wavelength as the signal light to be decomposed;

[0111] The first optical modulator is used to receive the target light beam, modulate the target light beam, and output a mixed light beam of three wavelengths including the target light beam;

[0112] The first filter is used to receive the mixed light beam, filter the mixed light beam, and output the target light beam, the first light beam, and the second light beam;

[0113] The second optical modulator is used to receive the target light beam output by the first filter, and modulate the target light beam output by the first filter to output the signal light to be decomposed;

[0114] The second polarization state adjusting element is used to receive the first light beam and the second light beam, and adjust the polarization states of the first light beam and the second light beam to be orthogonal, and output the two pump lights.

[0115] Specifically, Figure 6 As shown, the signal source includes a laser 61, a first optical modulator 62, a first filter 63, a second optical modulator 64 and a second polarization state adjusting element connected in sequence. The laser 61 can generate a target light beam with the same wavelength as the signal light to be decomposed. The first optical modulator 62 can be used to perform photoelectric modulation on the target light beam, and output a mixed light beam of three wavelengths including the target light beam. The mixed light beam is filtered by the first filter 63, and the target light beam, the first light beam and the second light beam are output. The target light beam output by the first filter 63 is modulated by the second optical modulator 64 to obtain target information, and the signal light to be decomposed is output.

[0116] The second polarization state adjusting element can receive the first light beam and the second light beam, and adjust the polarization states of the first light beam and the second light beam so that the polarization states of the two light beams are orthogonal, thereby obtaining two pump lights. Here, there can be two second polarization state adjusting elements, each used to adjust the polarization state of the first light beam and the second light beam, thereby outputting a pump light respectively.

[0117] In the embodiment of the present invention, the signal light to be decomposed and its coherent pump light can be generated by a signal generating source.

[0118] On the basis of the above-mentioned embodiment, the signal orthogonal decomposition device provided in the embodiment of the present invention further includes: a coherent optical receiving system, the coherent optical receiving system is connected to the coupler;

[0119] The coherent optical receiving system is used to receive two mutually orthogonal components, analyze the two mutually orthogonal components, and determine the signal quality of the two mutually orthogonal components.

[0120] Specifically, in the embodiment of the present invention, the structure of the coherent optical receiving system is as follows: Figure 5 As shown, the implementation process can be found in the above embodiment and will not be repeated here.

[0121] like Figure 7 As shown, based on the above embodiment, in the signal orthogonal decomposition device provided in the embodiment of the present invention, a second filter 74 is further connected between the nonlinear optical medium 31 and the signal separation element 72 .

[0122] Specifically, in an embodiment of the present invention, in order to ensure that the signal separation element can successfully separate the idler light and the target signal light in the mixed signal light, a second filter 74 can also be connected between the nonlinear optical medium 31 and the signal separation element 72. The mixed signal light obtained by the nonlinear optical medium 31 is filtered by the second filter 74, so that the filtered mixed signal light only contains the idler light and the target signal light.

[0123] like Figure 7 As shown, based on the above-mentioned embodiment, a signal orthogonal decomposition device is provided in an embodiment of the present invention, wherein a noise source (ASE) is connected between the signal light output terminal A of the signal generating source 71 for outputting the signal light to be decomposed and the nonlinear optical medium 31 to provide noise for the input signal light wave to be decomposed so as to simulate the real signal light.

[0124] The device embodiments described above are merely illustrative, wherein the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the scheme of this embodiment. Ordinary technicians in this field can understand and implement it without paying creative labor.

[0125] Through the description of the above implementation methods, those skilled in the art can clearly understand that each implementation method can be implemented by means of software plus a necessary general hardware platform, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solution is essentially or the part that contributes to the prior art can be embodied in the form of a software product, and the computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, a disk, an optical disk, etc., including a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in each embodiment or some parts of the embodiments.

[0126] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A signal orthogonal decomposition method, characterized in that: include: Obtaining signal light to be decomposed; Inputting the signal light to be decomposed and two pump lights with orthogonal polarization states and coherent with the signal light to be decomposed into a nonlinear optical medium to obtain a mixed signal light including idler light and target signal light corresponding to the signal light to be decomposed; Separating the idler light from the target signal light in the mixed signal light, and adjusting the polarization states of the idler light and the target signal light to be consistent; The idler light and the target signal light with the same polarization state are input into a coupler to obtain two mutually orthogonal components of the signal light to be decomposed output by the coupler.

2. The signal orthogonal decomposition method according to claim 1, characterized in that: The step of inputting the idler light and the target signal light with the same polarization state into a coupler to obtain two mutually orthogonal components of the signal light to be decomposed output by the coupler, and then comprising: The two mutually orthogonal components are input to a coherent optical receiving system, and the two mutually orthogonal components are analyzed based on the coherent optical receiving system to determine the signal quality of the two mutually orthogonal components.

3. The signal orthogonal decomposition method according to claim 1, characterized in that: The signal light to be decomposed and the two pump lights are determined based on the following steps: Based on the laser, determining a target light beam having the same wavelength as the signal light to be decomposed; Inputting the target light beam into a first light modulator to obtain a mixed light beam of three wavelengths output by the first light modulator including the target light beam; Inputting the mixed light beam into a first filter to obtain the target light beam, the first light beam and the second light beam output by the first filter; The target light beam output by the first filter is input to a second optical modulator to obtain the signal light to be decomposed, and the polarization states of the first light beam and the second light beam are adjusted to be orthogonal to obtain the two pump lights.

4. The signal orthogonal decomposition method according to any one of claims 1 to 3, characterized in that: The signal light to be decomposed and the two pump lights meet a phase matching condition, the idler light and the signal light to be decomposed have the same wavelength, and their polarization states are orthogonal.

5. The signal orthogonal decomposition method according to any one of claims 1 to 3, characterized in that: The wavelength of the signal light to be decomposed is located in the middle of the wavelengths of the two pump lights.

6. A signal orthogonal decomposition device, characterized in that: include: A signal generating source, a nonlinear optical medium, a signal separation element, a first polarization state adjusting element and a coupler connected in sequence; The signal generating source is used to output a signal light to be decomposed and two pump lights with orthogonal polarization states and coherent with the signal light to be decomposed; The nonlinear optical medium is used to receive the signal light to be decomposed and the two pump lights, generate a four-wave mixing effect, and obtain a mixed signal light including an idler light and a target signal light corresponding to the signal light to be decomposed; The signal separation element is used to receive the mixed signal light and separate the idler light and the target signal light in the mixed signal light; The first polarization state adjusting element is used to receive the idler light and the target signal light respectively, and adjust the polarization states of the idler light and the target signal light to be consistent; The coupler is used to receive the idler light and the target signal light with consistent polarization states, and output two mutually orthogonal components of the signal light to be decomposed.

7. The signal orthogonal decomposition device according to claim 6, characterized in that: The signal generating source comprises a laser, a first optical modulator, a first filter, a second optical modulator and a second polarization state adjusting element connected in sequence; The laser is used to output a target light beam having the same wavelength as the signal light to be decomposed; The first optical modulator is used to receive the target light beam, modulate the target light beam, and output a mixed light beam of three wavelengths including the target light beam; The first filter is used to receive the mixed light beam, filter the mixed light beam, and output the target light beam, the first light beam, and the second light beam; The second optical modulator is used to receive the target light beam output by the first filter, and modulate the target light beam output by the first filter to output the signal light to be decomposed; The second polarization state adjusting element is used to receive the first light beam and the second light beam, and adjust the polarization states of the first light beam and the second light beam to be orthogonal, and output the two pump lights.

8. The signal orthogonal decomposition device according to claim 6, characterized in that: Also includes: A coherent light receiving system connected to the coupler; The coherent optical receiving system is used to receive the two mutually orthogonal components, analyze the two mutually orthogonal components, and determine the signal quality of the two mutually orthogonal components.

9. The signal orthogonal decomposition device according to any one of claims 6 to 8, characterized in that: A second filter is also connected between the nonlinear optical medium and the signal separation element.

10. The signal orthogonal decomposition device according to any one of claims 6 to 8, characterized in that: A noise source is also connected between the signal light output end of the signal generating source for outputting the signal light to be decomposed and the nonlinear optical medium.

Images