Device and method for determining sub-signal optical phase difference of optical transmitter

Abstract

The embodiment of the invention provides a device and method for determining the sub-signal optical phase difference of an optical transmitter, and the method comprises the steps: inputting a first input signal to a first electro-optical conversion unit, enabling the first electro-optical conversion unit to modulate light to be modulated according to the first input signal, and obtaining a first output signal; inputting a second input signal to a second electro-optical conversion unit, so that the second electro-optical conversion unit modulates the light to be modulated according to the second input signal to obtain a second output signal; the correlation quantity of the second input signal and the first input signal is not 0; performing coherent detection operation based on the first output signal and the second output signal to obtain a first output quantity and a second output quantity; and determining the optical phase difference between the output signal of the first electro-optical conversion unit and the output signal of the second electro-optical conversion unit according to the first output quantity and the second output quantity. Therefore, the detection of the phase difference of the sub-signal light can be simply and flexibly realized, and the use of high-speed equipment is avoided.

Description

Technical Field

[0001] Embodiments of the present application relate to the field of optical communication technologies. Background Art

[0002] In the field of optical communication, in order to achieve a larger communication capacity, the signal rate output by a transmitter is very high, for example, 100 Gbaud. These signals often consist of multiple sub-signals. For example, a dual-polarization system has two polarization components, x and y; a coherent system has an in-phase component I and a quadrature component Q; in a DAC architecture, PAM8 is a superposition of three 0 / 1 sequences, and each 0 / 1 sequence constitutes a sub-signal; in a multi-segment modulation, the total signal is a superposition of signals of each modulation unit (segment), and each modulation unit constitutes a sub-signal. In hardware implementation, these sub-signals are often generated by different electrical and optical components. Therefore, different sub-signals may have different analog characteristics. For example, there may be different optical phases between different sub-signals. In certain cases, the optical phases of these sub-signals should satisfy a certain relationship. For example, in a coherent transmitter, the optical phase difference between the in-phase component and the quadrature component should be 90 degrees; the optical phase difference between sub-signals with in-phase superposition should be 0 degrees.

[0003] It should be noted that the above introduction of the technical background is only for the convenience of clearly and completely explaining the technical solutions of the present application and facilitating the understanding of those skilled in the art. It cannot be considered that the above technical solutions are well-known to those skilled in the art just because these solutions are described in the background art part of the present application. Summary of the Invention

[0004] However, the inventors found that in certain cases, if the optical phases of the sub-signals of an optical transmitter do not satisfy the required phase relationship, it may cause the output signal of the optical transmitter to be distorted or interference to occur between different sub-signals, thereby resulting in a decline in the performance of the communication system. Therefore, it is very necessary to monitor the phase difference between the sub-signals in the optical transmitter. However, there is currently no simple and feasible method to estimate the optical phase difference between a sub-signal and a reference signal and between the sub-signals.

[0005] To address at least one of the above technical problems, embodiments of the present application provide a device and method for determining the optical phase difference of sub-signals of an optical transmitter. Using the coherent detection quantity of a high-speed sub-signal and another high-speed signal during the communication process of the optical transmitter to indicate the optical phase difference of the optical transmitter or the electro-optical conversion unit of the optical transmitter, the implementation is simple, the implementation method is flexible, and the application range is wide.

[0006] According to one aspect of the embodiments of the present application, a device for determining the optical phase difference of sub-signals of an optical transmitter is provided. The device includes:

[0007] A first signal input unit, which is configured to input a first input signal to a first electro-optic conversion unit, so that the first electro-optic conversion unit modulates the light to be modulated according to the first input signal to obtain a first output signal;

[0008] A second signal input unit, which is configured to input a second input signal to a second electro-optic conversion unit, so that the second electro-optic conversion unit modulates the light to be modulated according to the second input signal to obtain a second output signal; wherein, the correlation quantity between the second input signal and the first input signal is not 0;

[0009] A low-speed coherent detection unit, which is configured to perform a coherent detection operation based on the first output signal and the second output signal to obtain a first output quantity and a second output quantity;

[0010] An optical phase difference determination unit, which is configured to determine the optical phase difference between the output signal of the first electro-optic conversion unit and the output signal of the second electro-optic conversion unit according to the first output quantity and the second output quantity.

[0011] According to one aspect of the embodiments of the present application, there is provided a method for determining the optical phase difference of sub-signals of an optical transmitter, the method comprising:

[0012] Input a first input signal to a first electro-optic conversion unit, so that the first electro-optic conversion unit modulates the light to be modulated according to the first input signal to obtain a first output signal;

[0013] Input a second input signal to a second electro-optic conversion unit, so that the second electro-optic conversion unit modulates the light to be modulated according to the second input signal to obtain a second output signal; wherein, the correlation quantity between the second input signal and the first input signal is not 0;

[0014] Perform a coherent detection operation based on the first output signal and the second output signal to obtain a first output quantity and a second output quantity;

[0015] Determine the optical phase difference between the output signal of the first electro-optic conversion unit and the output signal of the second electro-optic conversion unit according to the first output quantity and the second output quantity.

[0016] One of the beneficial effects of the embodiments of the present application is that: the present application uses the signals output by the electro-optic conversion units of the optical transmitter to determine the optical phase difference, without the optical transmitter sending special signals, and the implementation is simple; the present application can monitor the optical phase differences of the sub-signals of the optical transmitter by using low-speed electrical devices, avoiding the use of high-speed devices, and the low-speed electrical devices can be arranged in an integrated or non-integrated manner, and the implementation method is flexible; in addition, the present application is applicable to the monitoring of the optical phase differences of sub-signals in a variety of optical transmitters, and the application scenarios are diverse.

[0017] With reference to the following description and drawings, specific embodiments of the present application are disclosed in detail, indicating the ways in which the principles of the embodiments of the present application can be employed. It should be understood that the embodiments of the present application are not limited in scope thereby. Within the spirit and terms of the appended claims, the embodiments of the present application include many variations, modifications, and equivalents. Description of the Drawings

[0018] The included drawings are used to provide a further understanding of the embodiments of the present application, which form a part of the specification, illustrate the embodiments of the present application, and, together with the written description, explain the principles of the present application. Obviously, the drawings in the following description are only some embodiments of the present application, and those of ordinary skill in the art can obtain other embodiments based on these drawings without creative efforts. In the drawings:

[0019] Figure 1 is a schematic diagram of a method for determining the optical phase difference of the sub-signal light of the optical transmitter in the embodiment of the present application;

[0020] Figures 2A to 2D is a schematic diagram of the first electro-optical conversion unit in the embodiment of the present application;

[0021] Figure 2E is a schematic diagram of the second electro-optical conversion unit in the embodiment of the present application;

[0022] Figure 3 is a schematic diagram of the operation of the second input signal at intervals in the embodiment of the present application;

[0023] Figure 4 is a schematic diagram of the low-speed coherent detection unit in the embodiment of the present application;

[0024] Figure 5A is a block diagram of the first electro-optical conversion unit, the second electro-optical conversion unit, and the low-speed coherent detection unit provided in the embodiment of the present application;

[0025] Figure 5B is provided in the embodiment of the present application and Figure 5A The corresponding hardware structure schematic diagram of the block diagram;

[0026] Figure 6A is another block diagram of the first electro-optical conversion unit, the second electro-optical conversion unit, and the low-speed coherent detection unit provided in the embodiment of the present application;

[0027] Figure 6B is provided in the embodiment of the present application and Figure 6A The corresponding hardware structure schematic diagram of the block diagram;

[0028] Figure 7is the curve of the monitored optical phase difference and the calculated optical phase difference provided by this application;

[0029] Figure 8 is a schematic diagram of a method for determining the sub-signal optical phase difference of an optical transmitter in an embodiment of this application;

[0030] Figure 9 is the implementation of an embodiment of this application Figure 8 partial schematic diagram of the hardware structure for implementing the method shown;

[0031] Figure 10A is Figure 9 and Figure 5B combined to obtain a schematic diagram of the hardware structure;

[0032] Figure 10B is Figure 9 and Figure 6B combined to obtain a schematic diagram of the hardware structure;

[0033] Figure 11 is a schematic diagram of a device for determining the sub-signal optical phase difference of an optical transmitter in an embodiment of this application;

[0034] Figure 12 is a schematic diagram of an electronic device in an embodiment of this application. Detailed implementation manners

[0035] Referring to the accompanying drawings, through the following description, the foregoing and other features of the embodiments of this application will become apparent. In the description and drawings, specific embodiments of this application are specifically disclosed, which show some embodiments in which the principles of the embodiments of this application can be adopted. It should be understood that this application is not limited to the described embodiments. On the contrary, the embodiments of this application include all modifications, variations, and equivalents falling within the scope of the appended claims.

[0036] In the embodiments of this application, terms such as "first" and "second" are used to distinguish different elements in terms of name, but do not indicate the spatial arrangement or time sequence of these elements, and these elements should not be limited by these terms. The term "and / or" includes any one and all combinations of one or more of the related listed terms. Terms such as "comprising", "including", and "having" mean the presence of the stated features, elements, components, or assemblies, but do not exclude the presence or addition of one or more other features, elements, components, or assemblies.

[0037] In the embodiments of the present application, singular forms such as "a" and "the" include plural forms and should be broadly understood as "a kind" or "a class" rather than being limited to the meaning of "one"; in addition, the term "the" should be understood to include both singular and plural forms unless the context clearly indicates otherwise. In addition, the term "according to" should be understood as "at least partially according to...", and the term "based on" should be understood as "at least partially based on...", unless the context clearly indicates otherwise.

[0038] Features described and / or illustrated for one embodiment can be used in the same or similar manner in one or more other embodiments, combined with the features in other embodiments, or replace the features in other embodiments. The term "comprising / including" as used herein refers to the presence of features, whole things, steps or components, but does not exclude the presence or addition of one or more other features, whole things, steps or components.

[0039] Embodiments of the first aspect

[0040] The embodiments of the present application provide a method for determining the optical phase difference of sub-signal light of an optical transmitter. Figure 1 is a schematic diagram of the method for determining the optical phase difference of sub-signal light of an optical transmitter in the embodiments of the present application, as Figure 1 shown, the method includes:

[0041] 101. Input a first input signal into a first electro-optic conversion unit, so that the first electro-optic conversion unit modulates the light to be modulated according to the first input signal to obtain a first output signal;

[0042] 102. Input a second input signal into a second electro-optic conversion unit, so that the second electro-optic conversion unit modulates the light to be modulated according to the second input signal to obtain a second output signal; wherein, the correlation quantity between the second input signal and the first input signal is not 0;

[0043] 103. Perform a coherent detection operation based on the first output signal and the second output signal to obtain a first output quantity and a second output quantity;

[0044] 104. Determine the optical phase difference between the output signal of the first electro-optic conversion unit and the output signal of the second electro-optic conversion unit according to the first output quantity and the second output quantity.

[0045] It should be noted that the above appendix Figure 1The embodiments of the present application are only illustrated schematically, but the present application is not limited thereto. For example, some of the above steps may be executed simultaneously or in a sequential order, the execution order between various operations may be appropriately adjusted, and in addition, some other operations may be added or some of the operations may be reduced. Those skilled in the art may make appropriate modifications according to the above content, not limited to the records in the following appended Figure 1 description.

[0046] In step 101, a first input signal is input into a first electro-optic conversion unit, so that the first electro-optic conversion unit modulates the light to be modulated according to the first input signal to obtain a first output signal.

[0047] In some embodiments, the first input signal may be any signal. In the present application, it is represented as the first input signal A[n]. The first input signal A[n] may be a discrete symbol sequence or a continuous signal, where n represents the time sequence number. The first electro-optic conversion unit modulates the light to be modulated input thereto according to the first input signal A[n] to obtain a first output signal, and the first output signal is a high-speed signal and an optical signal. The light to be modulated is, for example, direct current light or an optical signal output from the previous-stage unit connected to the first electro-optic conversion unit, etc.

[0048] In some embodiments, the first electro-optic conversion unit is a unit that has a modulation function and can generate a high-speed signal. For example, the first electro-optic conversion unit is the optical transmitter itself. At this time, the first output signal is the total output optical signal of the optical transmitter. The first electro-optic conversion unit may also be a partial modulation unit of the optical transmitter. At this time, the first output signal is a part of the total output optical signal of the optical transmitter, that is, the first output signal is included in the total output optical signal of the optical transmitter. Among them, the optical transmitter includes, but is not limited to, a coherent transmitter, an intensity modulation transmitter, a phase modulator, a combined signal transmitter based on an optical frequency comb, etc.

[0049] Figures 2A to 2D is a schematic diagram of the first electro-optic conversion unit of the embodiment of the present application. Figure 2A shows an IQ modulator with multiple sub-signal branches in a coherent transmitter. Both the I path and the Q path of the IQ modulator have multiple modulation units. Figure 2A In, the first electro-optic conversion unit may be any one of the modulation units in the IQ modulator. For example, it is the modulation unit corresponding to the first symbol sequence A[n] on the I path, that is, the modulation unit into which the first symbol sequence A[n] is input. Figure 2B In, the first electro-optic conversion unit is the modulation unit corresponding to the first symbol sequence A[n] in the segmented intensity modulator. Figure 2C In, the first electro-optic conversion unit is the modulation unit corresponding to the first symbol sequence A[n] in the segmented phase modulator. Figure 2DAmong them, the first electro-optical conversion unit is the EO MOD unit corresponding to the first symbol sequence A[n] in the combined signal transmitter based on an optical frequency comb. Except Figures 2A to 2D for the structure shown, the first electro-optical conversion unit may also adopt other structures, which are not limited in this application.

[0050] In step 102, the second input signal is input to the second electro-optical conversion unit, so that the second electro-optical conversion unit modulates the optical signal to be modulated according to the second input signal to obtain a second output signal; wherein, the correlation quantity between the second input signal and the first input signal is not 0.

[0051] In some embodiments, the second input signal is a signal whose correlation quantity with the first input signal is not 0. In this application, it is denoted as the second input signal B[n]. Wherein, n represents the time sequence number. The second electro-optical conversion unit modulates the optical signal to be modulated input thereto according to the second input signal B[n] to obtain a second output signal, and the second output signal is also a high-speed signal and an optical signal. The optical signal to be modulated of the second electro-optical conversion unit may be the same as or different from the optical signal to be modulated corresponding to the first electro-optical conversion unit.

[0052] In some embodiments, the second input signal is the same as the first input signal, that is, B[n]=A[n]. At this time, the correlation quantity between the second input signal and the first input signal is the largest.

[0053] In some embodiments, the second input signal is a weighted sum of the first input signals at multiple different times, that is, B[n]=∑ k c i A[n - n i , where 1≤i≤k, both i and k are positive integers, n i is an integer, c i is the weighting coefficient corresponding to A[n - n i ; and when i≠j, n i ≠n j , where 1≤j≤k and j is a positive integer.

[0054] For example, assuming k = 2, the first input signals A[n] at two different times are respectively denoted as A[n - n1] and A[n - n2], and the corresponding weighting coefficients are respectively denoted as c1 and c2, where n1 and n2 are integers and n1≠n2. Then the second input signal B[n] is the weighted sum of A[n - n1] and A[n - n2], that is, B[n]=c1A[n - n1]+c2A[n - n2]. The calculation method of B[n] when k takes other values is similar and will not be elaborated here.

[0055] In some embodiments, the second input signal is a sign sequence of the weighted sum of the first input signals at multiple different times, that is, B[n] = sign(∑ k c i A[n - n i ), where 1 ≤ i ≤ k, both i and k are positive integers, n i is an integer, c i is the weighting coefficient corresponding to A[n - n i ; and when i ≠ j, n i ≠ n j , where 1 ≤ j ≤ k, j is a positive integer; sign() is the sign function.

[0056] For example, assume k = 2. The first input signals A[n] at two different times are respectively represented as A[n - n1] and A[n - n2], and the corresponding weighting coefficients are respectively represented as c1 and c2, where n1 and n2 are integers and n1 ≠ n2, and the sign function is sign(). Then the second input signal B[n] is the sign sequence of the weighted sum of A[n - n1] and A[n - n2], that is, B[n] = sign(A[n - n1] + A[n - n2]). The calculation method of B[n] when k takes other values is similar and will not be elaborated here.

[0057] In some embodiments, the second input signal is the product of a sign sequence of the weighted sum of the first input signals at multiple different times and a random amplitude sequence, that is, B[n] = Amp[n] * sign(∑ k c i A[n - n i ), where 1 ≤ i ≤ k, both i and k are positive integers, n i is an integer, c i is the weighting coefficient corresponding to A[n - n i ; and when i ≠ j, n i ≠ n j , where 1 ≤ j ≤ k, j is a positive integer; sign() is the sign function, and Amp[n] is the random amplitude sequence.

[0058] For example, assume k = 2. The first input signal A[n] at two different times is represented as A[n - n1] and A[n - n2] respectively, and the corresponding weighting coefficients are represented as c1 and c2 respectively, where n1 and n2 are integers and n1 ≠ n2, the sign function is sign(), and the random amplitude sequence is Amp[n]. Then the second input signal B[n] is the product of the sign sequence of the weighted sum of A[n - n1] and A[n - n2] and Amp[n], that is, B[n] = Amp[n] * sign(A[n - n1] + A[n - n2]). Among them, Amp[n] can be an amplitude sequence with finite values or an amplitude sequence with infinite values; Amp[n] is, for example, a series of random amplitude sequences of positive values.

[0059] In some embodiments, the second input signal is a finite value. For example, the value set of the second output signal can be {1, -1}, {1, 0} or {1, 0, -1}, etc. The second input signal with a finite value can be implemented in the following ways:

[0060] For example, when the value of the first input signal is {1, -1}, the second input signal can be the same as the first input signal. At this time, the value of the second input signal is also {1, -1}; or the second input signal can be the weighted sum of the first input signals at multiple different times. At this time, the value of the second input signal is also a finite level {1, 0, -1}.

[0061] For another example, when the value of the first input signal is not {1, -1}, the second input signal can be the sign function of the first input signal, so as to obtain a finite value of {1, -1} or {1, 0, -1}.

[0062] If the value of the second input signal is {1, 0, -1}, but the input of the second electro-optical conversion unit can only take two levels, such as {1, -1}, then the signals at all time positions where B[n] = 0 can be replaced with a random sequence with a value of {1, -1}; similarly, if the input of the second electro-optical conversion unit can only take {1, 0}, then the signals at all time positions where B[n] = -1 can be replaced with a random sequence with a value of {1, 0}.

[0063] In some embodiments, the second input signal is made to run at intervals. The meaning of running at intervals is that the signal input to the second electro-optical conversion unit is not assigned the second input signal B[n] at all times, but is assigned the second input signal B[n] at preset partial times. In this way, at the preset time, the second input signal B[n] is input to the second electro-optical conversion unit; at times other than the preset time, a 0 signal or a signal whose correlation with the first input signal A[n] is 0 is input to the second electro-optical conversion unit.

[0064] In some embodiments, the preset moment may be a periodically occurring moment, that is, the second input signal runs at fixed periodic intervals. For example, Figure 3 is a schematic diagram of the second input signal running at intervals in the embodiments of the present application. Figure 3 Five rows of square grids are shown. Each square grid in each row of square grids represents a moment. The square grid with a white background indicates that the moment corresponding to it is assigned the signal marked on the left side of the row of square grids. As Figure 3 shown, the first row of square grids indicates that at all moments, the first input signal A[n] is input into the first electro-optical conversion unit; the second row of square grids indicates that at all moments, the second input signal B[n] is input into the second electro-optical conversion unit; the third row of square grids indicates that the second input signal runs at an interval of 1 / 2 rate (Half-assigned B[n]), that is, taking two moments as a period, at one moment in each period, the second input signal B[n] is input into the second electro-optical conversion unit; the fourth row of square grids indicates that the second input signal runs at an interval of 1 / 4 rate (1 / 4-assigned B[n]), that is, taking four moments as a period, at one moment in each period, the second input signal B[n] is input into the second electro-optical conversion unit; the fifth row of square grids indicates that the second input signal runs at an interval of 1 / 8 rate (1 / 8-assigned B[n]), that is, taking eight moments as a period, at one moment in each period, the second input signal B[n] is input into the second electro-optical conversion unit.

[0065] In practical applications, the length of the interval running period of the second input signal B[n] is not limited to the above examples.

[0066] In some embodiments, the preset moment may be a randomly selected moment, that is, the second input signal runs at random intervals.

[0067] In some embodiments, the second input signal running at intervals may be any of the second input signals provided in the present application above.

[0068] In the above embodiments, by making the second input signal run at intervals, the number of moments when the second input signal is input is reduced, and the output obtained through the coherent detection operation will also be reduced accordingly, which is beneficial to reducing the power consumption of the operation for determining the phase difference of the sub-signal light of the optical transmitter.

[0069] In some embodiments, the second electro-optical conversion unit is a unit with a modulation function that can generate high-speed signals. In the present application, the second electro-optical conversion unit may be an existing electro-optical conversion unit. Figure 2E is a schematic diagram of the second electro-optical conversion unit in the embodiments of the present application, Figure 2EAmong them, the second electro-optic conversion unit is an MZ modulator (MZM) with one modulation unit. In addition, the second electro-optic conversion unit can also be an MZ modulator (MZM) with two modulation units of equal length, or an electro-absorption modulator (EAM), or a phase modulator (PM), or a structure in which an amplitude modulator (such as an MZ modulator (MZM) or an electro-absorption modulator (EAM)) and a phase modulator (PM) are connected in series. In addition to the structures of the above examples, the second electro-optic conversion unit can also adopt other structures, and this application does not limit this.

[0070] In some embodiments, the second output signal output by the second electro-optic conversion unit is a continuous signal.

[0071] In some embodiments, the second electro-optic conversion unit outputs a finite number of states, that is, the second output signal output by the second electro-optic conversion unit is a discrete signal with a finite number of values. For example, the value set of the second output signal output by the second electro-optic conversion unit can be {1, -1}, {1, 0} or {1, 0, -1}, etc.

[0072] When the second electro-optic conversion unit only outputs a finite number of states, the second electro-optic conversion unit only needs logical operations, and its complexity, cost and power consumption are all reduced.

[0073] In step 103, a coherent detection operation is performed based on the first output signal and the second output signal to obtain a first output quantity and a second output quantity.

[0074] In some embodiments, the coherent detection operation is implemented by a low-speed coherent detection unit. Figure 4 is a schematic diagram of the low-speed coherent detection unit of the embodiment of the present application. As Figure 4 shown, the low-speed coherent detection unit includes a phase shifter a 90-degree mixer (90° hybrid) and two balanced detectors (BPDs), where the phase shifter is optional, that is Figure 4 may include a phase shifter or may not include a phase shifter. Figure 4 Among them, the low-speed coherent detection unit has two input signals, namely signal 1 and signal 2; and the low-speed coherent detection unit includes two output signals, that is, a first output quantity and a second output quantity are obtained according to the first output signal and the second output signal. In addition to Figure 4 the structure shown, the low-speed coherent detection unit can also adopt other structures, and this application does not limit this.

[0075] In some embodiments, the principle of the low-speed coherent detection unit performing a coherent detection operation on the input signals 1 and 2 to obtain a first output quantity and a second output quantity is as follows:

[0076] Assume that signal 1 is represented as E1(t), signal 2 is represented as E2(t), and the optical phase difference between signal 1 and signal 2 is After passing through an ideal 90-degree mixer, the output optical signal can be expressed as:

[0077]

[0078] Subsequently, the output currents of the two balanced detectors can be respectively expressed as:

[0079]

[0080]

[0081] In the above formulas 2 and 3, R BPD is the response of the balanced detector. Since electrical devices such as balanced detectors are of low bandwidth and low rate, it can be considered that the two output quantities of the low-speed coherent detection unit are the averages of the signals. Therefore, the first output quantity and the second output quantity can be respectively expressed as:

[0082]

[0083]

[0084]

[0085] In some embodiments, performing a coherent detection operation based on the first output signal and the second output signal includes: performing a coherent detection operation on the first output signal and the second output signal to obtain the first output quantity and the second output quantity.

[0086] Figure 5A is a block diagram of the first electro-optical conversion unit, the second electro-optical conversion unit, and the low-speed coherent detection unit provided by the embodiments of the present application. As Figure 5A shown, the first electro-optical conversion unit and the second electro-optical conversion unit are in parallel. At this time, the first input signal, that is, the first symbol sequence A[n], is input to the first electro-optical conversion unit, so that the first electro-optical conversion unit modulates the optical signal to be modulated 1 and outputs the first output signal; the second input signal, that is, the second symbol sequence B[n], is input to the second electro-optical conversion unit, so that the second electro-optical conversion unit modulates the optical signal to be modulated 2 and outputs the second output signal; then the first output signal and the second output signal are respectively input to the low-speed coherent detection unit for a coherent detection operation. That is, in this embodiment, one of the signal 1 and the signal 2 input to the low-speed coherent detection unit is the optical signal of the first output signal output by the first electro-optical conversion unit, and the other of the signal 1 and the signal 2 is the optical signal of the second output signal output by the second electro-optical conversion unit. Subsequently, the low-speed coherent detection unit outputs the first output quantity and the second output quantity.

[0087] Figure 5B is a schematic diagram of the hardware structure corresponding to the block diagram provided by an embodiment of the present application. This structure includes a first electro-optical conversion unit, a second electro-optical conversion unit, and a low-speed coherent detection unit. Among them, the first electro-optical conversion unit and the second electro-optical conversion unit are connected in parallel, that is, the first electro-optical conversion unit is connected to the first input end of the low-speed coherent detection unit and inputs the first output signal to this first input end. The second electro-optical conversion unit is connected to the second input end of the low-speed coherent detection unit and inputs the second output signal to this second input end. And, the first electro-optical conversion unit can be Figure 5A any of the first electro-optical conversion units shown in Figures 2A to 2D or other structures, and the second electro-optical conversion unit can be Figure 2E the second electro-optical conversion unit shown in Figure 4 or other structures, and the low-speed coherent detection unit can be

[0088] For example, in the structure shown in Figure 5B , the first electro-optical conversion unit adopts the structure shown in Figure 2A , which is a part of the transmitter. The second electro-optical conversion unit adopts the structure shown in Figure 2E , and the low-speed coherent detection unit adopts the structure shown in Figure 4 .

[0089] Figure 5B In Figure 5B , the light to be modulated of the first electro-optical conversion unit and the second electro-optical conversion unit is both direct current light. Before the modulator, a part (for example, 95%) of the direct current light is delivered to the first electro-optical conversion unit, and another part (for example, 5%) is delivered to the second electro-optical conversion unit. Among them, the coherent transmitter forms multiple output ports through a beam splitter MMI. Therefore, the first output signal output by it can be included in the output signal I + jQ of the I + jQ detection end, or included in the output signal I - jQ of the I - jQ detection end, or included in the output signals of other detection branches. The acquisition of the output signal can be achieved through a beam splitter. A part (for example, 5%) of the output signal is split out through the beam splitter and applied to this application. For details, reference can be made to the prior art. Figure 5B Taking the example that the signal to be measured is included in the output signal I - jQ of the I - jQ detection end, but this application is not limited thereto.

[0090] After receiving the first output signal and the second output signal, the low-speed coherent detection unit obtains the first output quantity I1 and the second output quantity I2 according to the above formulas 1 to 5. Among them, E1(t) and E2(t) in formulas 1 to 5 are the first output signal and the second output signal respectively.

[0091] In some embodiments, performing a coherent detection operation based on the first output signal and the second output signal includes: performing a coherent detection operation on the product of the first output signal and the second output signal and a preset reference signal to obtain the first output quantity and the second output quantity.

[0092] Figure 6A FIG. 4 is another block diagram of the first electro-optical conversion unit, the second electro-optical conversion unit, and the low-speed coherent detection unit provided by the embodiments of the present application. As Figure 6A shown, the first electro-optical conversion unit and the second electro-optical conversion unit are connected in series. At this time, the first input signal, that is, the first symbol sequence A[n], is input to the first electro-optical conversion unit, so that the first electro-optical conversion unit modulates the light to be modulated 3 and obtains a first output signal; the second input signal, that is, the second symbol sequence B[n], is input to the second electro-optical conversion unit, so that the second electro-optical conversion unit modulates the light to be modulated 4 and obtains a second output signal; as Figure 6A shown, when the output end of the first electro-optical conversion unit is connected in series with the input end of the second electro-optical conversion unit, the light to be modulated 3 can be direct current light, and the light to be modulated 4 includes the signal to be measured output by the first electro-optical conversion unit; conversely, when the output end of the second electro-optical conversion unit is connected in series with the input end of the first electro-optical conversion unit (not shown), the light to be modulated 4 can be direct current light, and the light to be modulated 3 includes the correlation signal output by the second electro-optical conversion unit. The series structure formed by the first electro-optical conversion unit and the second electro-optical conversion unit outputs the product of the first output signal and the second output signal in the optical domain, that is, the optical signal of the product of the first output signal and the second output signal; then, the product of the first output signal and the second output signal and a preset reference signal are input to the low-speed coherent detection unit for a coherent detection operation, that is, in this embodiment, one of the signal 1 and the signal 2 input to the low-speed coherent detection unit is the optical signal of the product of the first output signal and the second output signal, and the other of the signal 1 and the signal 2 is the preset reference signal. Subsequently, the low-speed coherent detection unit outputs the first output quantity and the second output quantity. Among them, the preset reference signal is, for example, direct current light.

[0093] Figure 6B FIG. 5 is a schematic hardware structure diagram corresponding to the block diagram of Figure 6A of the embodiments of the present application. The structure includes a first electro-optical conversion unit, a second electro-optical conversion unit, and a low-speed coherent detection unit. Among them, the first electro-optical conversion unit and the second electro-optical conversion unit are connected in series, and the series structure of the first electro-optical conversion unit and the second electro-optical conversion unit is connected to the first input end of the low-speed coherent detection unit, and the product of the first output signal and the second output signal is input to the first input end, and the preset reference signal is input to the second input end of the low-speed coherent detection unit. In addition, the first electro-optical conversion unit may be Figures 2A to 2DAny of the first electro-optical conversion units or other structures shown, the second electro-optical conversion unit can be Figure 2E The second electro-optical conversion unit or other structures shown, the low-speed coherent detection unit can be Figure 4 The low-speed coherent detection unit or other structures shown.

[0094] For example, in Figure 6B In the structure shown, the first electro-optical conversion unit adopts Figure 2A The structure shown, which is part of the transmitter, the second electro-optical conversion unit adopts Figure 2E The structure shown, and the low-speed coherent detection unit adopts Figure 4 The structure shown.

[0095] Figure 6B In, the light to be modulated of the first electro-optical conversion unit and the second electro-optical conversion unit is DC light. Before the modulator, a part (e.g., 95%) of the DC light is delivered to the first electro-optical conversion unit, and another part (e.g., 5%) is input as a reference signal (signal 2) to the second input terminal of the low-speed coherent detection unit. Among them, the coherent transmitter has multiple output ports, so the signal to be measured output by it can be included in the output signal I + jQ of the I + jQ detection end, or included in the output signal I - jQ of the I - jQ detection end, or included in the output signals of other detection branches. The acquisition of the output signal can be achieved through a beam splitter. A part (e.g., 5%) of the output signal is split out by the beam splitter and applied in this application. For details, reference can be made to the prior art. Figure 6B Taking the case where the signal to be measured is included in the output signal I - jQ of the I - jQ detection end as an example, but this application is not limited thereto.

[0096] After the low-speed coherent detection unit receives the first output signal and the second output signal, the first output quantity I1 and the second output quantity I2 are obtained according to the above formulas 1 to 5. Among them, E1(t) in formulas 1 to 5 is the product of the first output signal and the second output signal, and E2(t) is the preset reference signal.

[0097] In step 104, the optical phase difference between the output signal of the first electro-optical conversion unit and the output signal of the second electro-optical conversion unit is determined according to the first output quantity and the second output quantity.

[0098] In some embodiments, the first output quantity and the second output quantity are substituted into the following formula to obtain the optical phase difference between the first output signal and the second output signal:

[0099]

[0100] Among them, I1 is the first output quantity, I2 is the second output quantity, is the optical phase difference between the output signal of the first electro-optical conversion unit and the output signal of the second electro-optical conversion unit, and arg(z) is the principal value of the argument of the complex number z.

[0101] Moreover, according to the above formulas 4 and 5, it can be known that

[0102]

[0103] It can be understood that the first output signal is the output signal of the first electro-optical conversion unit, and the second output signal is the output signal of the second electro-optical conversion unit. Therefore, the optical phase difference between the first output signal and the second output signal is the optical phase difference between the output signal of the first electro-optical conversion unit and the output signal of the second electro-optical conversion unit.

[0104] From the above embodiments, it can be seen that for any combination of the first input signal and the second input signal with non-zero relevant quantities, the optical phase difference can be calculated by the method for determining the optical phase difference of the sub-signal of the optical transmitter provided in this application. Figure 7 This is the curve of the monitored optical phase difference and the calculated optical phase difference provided in this application. Figure 7 Shown is the curve of the monitored optical phase difference and the optical phase difference calculated according to the method for determining the optical phase difference of the sub-signal of the optical transmitter of this application when B[n]=A[n]. From Figure 7 it can be seen that the method for determining the optical phase difference of the sub-signal of the optical transmitter of this application can accurately monitor the optical phase difference.

[0105] Figure 8 This is a schematic diagram of the method for determining the optical phase difference of the sub-signal of the optical transmitter in the embodiment of this application. As Figure 8 shown, the method includes:

[0106] 801. Input the first input signal into the first electro-optical conversion unit, so that the first electro-optical conversion unit modulates the optical signal to be modulated according to the first input signal to obtain a first output signal;

[0107] 802. Multiply the second input signal by a low-frequency square wave to obtain a first product signal;

[0108] 803. Input the first product signal of the second input signal and the low-frequency square wave into the second electro-optical conversion unit to obtain a second output signal, and the relevant quantity between the second input signal and the first input signal is not 0;

[0109] 804. Perform a coherent detection operation based on the first output signal and the first product signal to obtain a first output quantity and a second output quantity;

[0110] 805. Multiply the first output quantity by the low-frequency square wave to obtain a second product signal; and multiply the second output quantity by the low-frequency square wave to obtain a third product signal;

[0111] 806. Determine the optical phase difference between the output signal of the first electro-optic conversion unit and the output signal of the second electro-optic conversion unit according to the second product signal and the third product signal.

[0112] It should be noted that the above appendix Figure 8 only schematically illustrates the embodiments of the present application, but the present application is not limited thereto. For example, some of the above steps can be executed simultaneously, or can be executed in sequence, the execution order between each operation can be appropriately adjusted, and in addition, some other operations can be added or some of the operations can be reduced. Those skilled in the art can make appropriate modifications according to the above content, not limited to the records in the above appendix Figure 8 .

[0113] In some embodiments, in step 801, the first input signal is the input symbol sequence of the first electro-optic conversion unit, that is, the first input symbol sequence A[n]. The first electro-optic conversion unit is the transmitter itself, or a partial modulation unit of the transmitter. The first electro-optic conversion unit is, for example, Figures 2A to 2D the structure shown or other structures. The first output signal is a high-speed signal and an optical signal. For the content related to the first input signal, the first electro-optic conversion unit, and the first output signal, please refer to the implementation of step 101.

[0114] In some embodiments, in step 802, multiply the second input signal by the low-frequency square wave, which can be implemented by a multiplier, for example. Figure 9 is a partial schematic diagram of the hardware structure for implementing the method of the embodiments of the present application Figure 8 shown. As Figure 9 shown, multiply the second input signal B[n] by the low-frequency square wave, and then use the product of B[n] and the low-frequency square wave as the symbol sequence of the second electro-optic conversion unit and input it into the second electro-optic conversion unit. Although Figure 9 does not show the hardware structures of the first electro-optic conversion unit, the second electro-optic conversion unit, the low-speed coherent detection unit, etc., those skilled in the art should understand that Figure 9 can be combined with Figure 5B , Figure 6B shown in the hardware structure. For example, Figure 10A is Figure 9 combined with Figure 5B to obtain a schematic diagram of the combined hardware structure, Figure 10B is Figure 9 combined with Figure 6B to obtain a schematic diagram of the combined hardware structure. Figure 10AFor the descriptions of the hardware structures in Figure 5B , Figure 10B For the descriptions of the hardware structures in Figure 6B , which will not be repeated here.

[0115] In some embodiments, in step 803, the second electro-optical conversion unit is, for example, Figure 2E the structure shown or other structures. The second input signal is also a high-speed signal and an optical signal. For the content related to the second input signal, the second electro-optical conversion unit, and the second output signal, please refer to the implementation of step 102.

[0116] In some embodiments, in step 804, a coherent detection operation is performed based on the first output signal and the first product signal to obtain a first output quantity and a second output quantity. For the content related to the coherent detection operation, please refer to the implementation of step 103.

[0117] In some embodiments, in step 805, the first output quantity is multiplied by the low-frequency square wave to obtain a second product signal, and the second output quantity is multiplied by the low-frequency square wave to obtain a third product signal, which can be implemented by a multiplier, for example. The low-frequency square wave in this step is the same low-frequency square wave as that in step 802. For example, as Figure 10A and Figure 10B shown, a multiplier is connected to each of the two output terminals of the low-speed coherent detection unit to implement the multiplication of the first output quantity by the low-frequency square wave and the multiplication of the second output quantity by the low-frequency square wave.

[0118] In some embodiments, in step 806, the optical phase difference between the output signal of the first electro-optical conversion unit and the output signal of the second electro-optical conversion unit is determined according to the second product signal and the third product signal. For the content related to calculating the optical phase difference, please refer to the implementation of step 104.

[0119] Through the above embodiments, in the method for determining the optical phase difference of the sub-signal light of the optical transmitter of the present application, a step of frequency shift by multiplying with a square wave is added, that is, the first product signal obtained by multiplying the low-frequency square wave with a symbol sequence is used as the symbol sequence of the second electro-optical conversion unit, and the first output quantity and the second output quantity obtained through the coherent detection operation are respectively multiplied by the low-frequency square wave to obtain a second product signal and a third product signal, and the optical phase difference between the output signal of the first electro-optical conversion unit and the output signal of the second electro-optical conversion unit is determined based on the second product signal and the third product signal. After adding the step of frequency shift by multiplying with a square wave, the calculated first output quantity and second output quantity can be transferred from direct current to the frequency of the low-frequency square wave, thereby avoiding the 1 / f noise near direct current.

[0120] The above has schematically described the method for determining the optical phase difference of the sub-signal light of the optical transmitter and a part of the hardware structure for implementing this method, but the present application is not limited thereto. The method for determining the optical phase difference of the sub-signal light of the optical transmitter may further include other steps or processes. For the specific content of these steps or processes, reference may be made to the prior art. In addition, the above has made an exemplary description of the hardware structure for implementing the method for determining the optical phase difference of the sub-signal light of the optical transmitter, but the present application is not limited to these hardware structures, and these structures may also be appropriately modified, and the implementation manners of these modifications should all be included within the scope of the embodiments of the present application.

[0121] The above embodiments only make an exemplary description of the embodiments of the present application, but the present application is not limited thereto, and appropriate modifications may also be made on the basis of the above embodiments. For example, the above embodiments may be used alone, or one or more of the above embodiments may be combined.

[0122] As can be seen from the above embodiments, the present application uses the signal output by the electro-optical conversion unit of the optical transmitter to determine the optical phase difference, without the need for the optical transmitter to send special signals, and the implementation is simple; the present application can use low-speed electrical devices to monitor the optical phase difference of each sub-signal light of the optical transmitter, avoiding the use of high-speed devices, and the low-speed electrical devices can be arranged in an integrated or non-integrated manner, and the implementation method is flexible; in addition, the present application is applicable to the monitoring of the optical phase difference of sub-signal light in a variety of optical transmitters, and the application scenarios are diverse.

[0123] Embodiments of the second aspect

[0124] The embodiments of the present application provide a device for determining the optical phase difference of the sub-signal light of an optical transmitter, and the same content as that in the embodiments of the first aspect will not be repeated.

[0125] Figure 11 is a schematic diagram of the device for determining the optical phase difference of the sub-signal light of the embodiments of the present application. As Figure 11 shown, the device for determining the optical phase difference of the sub-signal light of the optical transmitter includes:

[0126] A first signal input unit 1101, which is used to input a first input signal to a first electro-optical conversion unit, so that the first electro-optical conversion unit modulates the light to be modulated according to the first input signal to obtain a first output signal;

[0127] A second signal input unit 1102, which is used to input a second input signal to a second electro-optical conversion unit, so that the second electro-optical conversion unit modulates the light to be modulated according to the second input signal to obtain a second output signal; wherein, the correlation quantity between the second input signal and the first input signal is not 0;

[0128] A low-speed coherent detection unit 1103, which is configured to perform a coherent detection operation based on the first output signal and the second output signal to obtain a first output quantity and a second output quantity;

[0129] An optical phase difference determination unit 1104, which is configured to determine an optical phase difference between the output signal of the first electro-optic conversion unit and the output signal of the second electro-optic conversion unit according to the first output quantity and the second output quantity.

[0130] In some embodiments, the first electro-optic conversion unit is a transmitter or a partial modulation unit of a transmitter.

[0131] In some embodiments, the second electro-optic conversion unit outputs a finite number of states.

[0132] In some embodiments, the second input signal is the same as the first input signal; or

[0133] the second input signal is a weighted sum of the first input signals at multiple different times; or

[0134] the second input signal is a symbol sequence of the weighted sum of the first input signals at multiple different times; or

[0135] the second input signal is a product of a symbol sequence of the weighted sum of the first input signals at multiple different times and a random amplitude sequence.

[0136] In some embodiments, the first electro-optic conversion unit is connected in parallel with the second electro-optic conversion unit, and the first electro-optic conversion unit is connected to a first input end of the low-speed coherent detection unit 1103 and inputs the first output signal to the first input end, and the second electro-optic conversion unit is connected to a second input end of the coherent detection unit and inputs the second output signal to the second input end;

[0137] Moreover, the low-speed coherent detection unit 1103 is specifically configured to:

[0138] Perform a coherent detection operation on the first output signal and the second output signal to obtain the first output quantity and the second output quantity.

[0139] In some embodiments, the first electro-optic conversion unit is connected in series with the second electro-optic conversion unit, and a series structure of the first electro-optic conversion unit and the second electro-optic conversion unit is connected to a first input end of the low-speed coherent detection unit 1103 and inputs a product of the first output signal and the second output signal to the first input end, and a preset reference signal is input to a second input end of the low-speed coherent detection unit 1103;

[0140] Moreover, the low-speed coherent detection unit 1103 is specifically configured to:

[0141] Perform a coherent detection operation on the product of the first output signal and the second output signal and the reference signal to obtain the first output quantity and the second output quantity.

[0142] In some embodiments, the optical phase difference determination unit is specifically configured to:

[0143] Substitute the first output quantity and the second output quantity into the following formula to obtain the optical phase difference:

[0144]

[0145] where I1 is the first output quantity, I2 is the second output quantity, is the optical phase difference between the output signal of the first electro-optic conversion unit and the output signal of the second electro-optic conversion unit, and arg(z) is the principal value of the argument of the complex number z.

[0146] In some embodiments, the device further includes (not shown):

[0147] A first multiplication unit, which is configured to multiply the second input signal by a low-frequency square wave before inputting the second input signal to the second electro-optic conversion unit; two input terminals of the first multiplication unit are respectively input with the second input signal and the low-frequency square wave, and an output terminal of the first multiplication unit is connected to the second signal input unit 1102 and outputs the product of the second input signal and the low-frequency square wave; and

[0148] A second multiplication unit, which is configured to multiply the first output quantity and the second output quantity by the low-frequency square wave respectively before determining the optical phase difference according to the first output quantity and the second output quantity; the number of the second multiplication units is two, and two input terminals of one of the second multiplication units are respectively input with the low-frequency square wave and the first output quantity output by the optical phase difference determination unit, and an output terminal outputs the product of the first output quantity and the low-frequency square wave; two input terminals of the other second multiplication unit are respectively input with the low-frequency square wave and the second output quantity output by the optical phase difference determination unit, and an output terminal outputs the product of the second output quantity and the low-frequency square wave.

[0149] And the second signal input unit 1102 is further configured to: input the product signal of the second input signal and the low-frequency square wave to the second electro-optic conversion unit;

[0150] The optical phase difference determination unit 1104 is further configured to: determine the optical phase according to the product of the first output quantity and the low-frequency square wave and the product of the second output quantity and the low-frequency square wave.

[0151] In some embodiments, the second signal input unit 1102 is further configured to: at a preset moment, input the second input signal into the second electro-optical conversion unit; at moments other than the preset moment, input a signal with a correlation quantity of 0 with the first input signal or a 0 signal into the second electro-optical conversion unit.

[0152] It should be noted that only the components or modules related to the present application are described above, but the present application is not limited thereto. The device 1100 for determining the optical phase difference of the sub-signal light of the optical transmitter may further include other components or modules. For the specific content of these components or modules, reference may be made to the related art.

[0153] For simplicity, Figure 11 only the connection relationships or signal directions between the various components or modules are exemplarily shown in the figure, but those skilled in the art should clearly understand that various related technologies such as bus connection can be adopted. The above-mentioned various components or modules can be implemented by hardware facilities such as a processor, a memory, etc.; the embodiments of the present application do not limit this.

[0154] The above embodiments only exemplarily illustrate the embodiments of the present application, but the present application is not limited thereto, and appropriate modifications can also be made on the basis of the above embodiments. For example, the above embodiments can be used alone, or one or more of the above embodiments can be combined.

[0155] As can be seen from the above embodiments, the present application uses the signal output by the electro-optical conversion unit of the optical transmitter to determine the optical phase difference, without the optical transmitter sending special signals, and the implementation is simple; the present application can monitor the optical phase differences of the sub-signal lights of the optical transmitter by using low-speed electrical devices, avoiding the use of high-speed devices, and the low-speed electrical devices can be arranged in an integrated or non-integrated manner, and the implementation method is flexible; in addition, the present application is applicable to the monitoring of the optical phase differences of sub-signal lights in a variety of optical transmitters, and the application scenarios are diverse.

[0156] Embodiments of the third aspect

[0157] The embodiments of the present application provide an electronic device, including the device 1100 for determining the optical phase difference of the sub-signal light of the optical transmitter as described in the embodiments of the second aspect, the content of which is incorporated herein. The electronic device may be, for example, a computer, a server, a workstation, a laptop computer, a smart phone, etc.; but the embodiments of the present application are not limited thereto.

[0158] Figure 12 is a schematic diagram of the electronic device of the embodiments of the present application. As Figure 12As shown, the electronic device 1200 may include: a processor (e.g., a central processing unit CPU) 1210 and a memory 1220; the memory 1220 is coupled to the central processor 1210. The memory 1220 can store various data; in addition, it also stores a program 1221 for information processing and executes the program 1221 under the control of the processor 1210.

[0159] In some embodiments, the function of the determining device 1100 for the optical phase difference of the optical transmitter sub-signal is implemented by being integrated into the processor 1210. Among them, the processor 1210 is configured to implement the method for determining the optical phase difference of the optical transmitter sub-signal as described in the embodiments of the first aspect.

[0160] In some embodiments, the determining device 1100 for the optical phase difference of the optical transmitter sub-signal is separately configured from the processor 1210. For example, the determining device 1100 for the optical phase difference of the optical transmitter sub-signal can be configured as a chip connected to the processor 1210, and the function of the determining device 1100 for the optical phase difference of the optical transmitter sub-signal is implemented through the control of the processor 1210.

[0161] For example, the processor 1210 is configured to perform the following control:

[0162] Input the first input signal into the first electro-optic conversion unit, so that the first electro-optic conversion unit modulates the optical signal to be modulated according to the first input signal to obtain a first output signal; input the second input signal into the second electro-optic conversion unit, so that the second electro-optic conversion unit modulates the optical signal to be modulated according to the second input signal to obtain a second output signal; wherein, the second input signal is a differential signal of the first input signal; perform a correlation operation on the first output signal and the second output signal to obtain a correlation quantity of the first input signal and the second input signal; determine the time delay difference between the output signal of the first electro-optic conversion unit and the output signal of the second electro-optic conversion unit according to the correlation quantity and the preset corresponding relationship between the correlation quantity and the time delay difference.

[0163] In addition, as Figure 12 shown, the electronic device 1200 may further include: an input / output (I / O) device 1230, a display 1240, etc.; among them, the functions of the above components are similar to those in the prior art and will not be elaborated here. It should be noted that the electronic device 1200 does not necessarily have to include Figure 12 all the components shown in Figure 12 ; in addition, the electronic device 1200 may further include components not shown in

[0164] An embodiment of the present application also provides a computer-readable program, which, when executed in an electronic device, causes the computer to execute the method for determining the optical phase difference of the optical transmitter sub-signal as described in the embodiment of the first aspect in the electronic device.

[0165] An embodiment of the present application also provides a storage medium storing a computer-readable program, wherein the computer-readable program causes the computer to execute the method for determining the optical phase difference of the optical transmitter sub-signal as described in the embodiment of the first aspect in the electronic device.

[0166] The above devices and methods of the present application can be implemented by hardware or by a combination of hardware and software. The present application relates to such a computer-readable program that, when executed by a logic component, can cause the logic component to implement the above-described device or component, or cause the logic component to implement the above-described various methods or steps. The present application also relates to a storage medium for storing the above program, such as a hard disk, a magnetic disk, an optical disk, a DVD, a flash memory, etc.

[0167] The method / device described in combination with the embodiments of the present application can be directly embodied as hardware, a software module executed by a processor, or a combination of the two. For example, one or more of the functional block diagrams shown in the figure and / or a combination of one or more of the functional block diagrams can correspond to each software module of the computer program flow, and can also correspond to each hardware module. These software modules can respectively correspond to the respective steps shown in the figure. These hardware modules can be implemented by, for example, using a field-programmable gate array (FPGA) to solidify these software modules.

[0168] The software module can be located in a RAM memory, a flash memory, a ROM memory, an EPROM memory, an EEPROM memory, a register, a hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art. A storage medium can be coupled to the processor so that the processor can read information from the storage medium and write information to the storage medium; or the storage medium can be a component of the processor. The processor and the storage medium can be located in an ASIC. The software module can be stored in the memory of the mobile terminal or in a memory card that can be inserted into the mobile terminal. For example, if the device (such as a mobile terminal) uses a larger-capacity MEGA-SIM card or a large-capacity flash memory device, the software module can be stored in the MEGA-SIM card or the large-capacity flash memory device.

[0169] One or more of the functional blocks described in the accompanying drawings and / or one or more combinations of functional blocks can be implemented as a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or other programmable logic device, discrete gate or transistor logic device, discrete hardware component, or any suitable combination thereof for performing the functions described in this application. One or more of the functional blocks described in the accompanying drawings and / or one or more combinations of functional blocks can also be implemented as a combination of computing devices, for example, a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors in communication combination with a DSP, or any other such configuration.

[0170] The present application has been described in conjunction with specific embodiments, but those skilled in the art should understand that these descriptions are exemplary and do not limit the protection scope of the present application. Those skilled in the art can make various variations and modifications to the present application according to the principles of the present application, and these variations and modifications are also within the scope of the present application.

[0171] Regarding the embodiments including the above embodiments, the following additional notes are also disclosed:

[0172] Additional note 1. A method for determining the optical phase difference of a sub-signal of an optical transmitter, the method comprising:

[0173] Input a first input signal into a first electro-optical conversion unit, and cause the first electro-optical conversion unit to modulate the optical signal to be modulated according to the first input signal to obtain a first output signal;

[0174] Input a second input signal into a second electro-optical conversion unit, and cause the second electro-optical conversion unit to modulate the optical signal to be modulated according to the second input signal to obtain a second output signal; wherein, the correlation quantity between the second input signal and the first input signal is not 0;

[0175] Perform a coherent detection operation based on the first output signal and the second output signal to obtain a first output quantity and a second output quantity;

[0176] Determine the optical phase difference between the output signal of the first electro-optical conversion unit and the output signal of the second electro-optical conversion unit according to the first output quantity and the second output quantity.

[0177] Additional note 2. The method according to additional note 1, wherein the first electro-optical conversion unit is a transmitter or a partial modulation unit of a transmitter.

[0178] Additional note 3. The method according to additional note 1, wherein the second electro-optical conversion unit outputs a finite number of states.

[0179] Remark 4. The method according to Remark 1, wherein,

[0180] the second input signal is the same as the first input signal; or

[0181] the second input signal is a weighted sum of the first input signals at multiple different times; or

[0182] the second input signal is a symbol sequence of a weighted sum of the first input signals at multiple different times; or

[0183] the second input signal is a product of a symbol sequence of a weighted sum of the first input signals at multiple different times and a random amplitude sequence.

[0184] Remark 5. The method according to Remark 1, wherein a coherent detection operation is performed based on the first output signal and the second output signal to obtain a first output quantity and a second output quantity, including:

[0185] Performing a coherent detection operation on the first output signal and the second output signal to obtain the first output quantity and the second output quantity.

[0186] Remark 6. The method according to Remark 1, wherein a coherent detection operation is performed based on the first output signal and the second output signal to obtain a first output quantity and a second output quantity, including:

[0187] Performing a coherent detection operation on the product of the first output signal and the second output signal and a preset reference signal to obtain the first output quantity and the second output quantity.

[0188] Remark 7. The method according to Remark 1, wherein determining an optical phase difference between the output signal of the first electro-optic conversion unit and the output signal of the second electro-optic conversion unit according to the first output quantity and the second output quantity includes:

[0189] Substituting the first output quantity and the second output quantity into the following formula to obtain the optical phase difference:

[0190]

[0191] wherein, I1 is the first output quantity, I2 is the second output quantity, is the optical phase difference between the output signal of the first electro-optic conversion unit and the output signal of the second electro-optic conversion unit, and arg(z) is the principal value of the argument of the complex number z.

[0192] Remark 8. The method according to Remark 1, wherein the method further includes:

[0193] Before inputting the second input signal into the second electro-optical conversion unit, multiply the second input signal by a low-frequency square wave, and input the product signal of the second input signal and the low-frequency square wave into the second electro-optical conversion unit; and

[0194] Before determining the optical phase difference according to the first output quantity and the second output quantity, multiply the first output quantity and the second output quantity by the low-frequency square wave respectively, and determine the optical phase according to the product of the first output quantity and the low-frequency square wave and the product of the second output quantity and the low-frequency square wave.

[0195] Supplementary Note 9. The method according to Supplementary Note 1, wherein at a preset moment, the second input signal is input into the second electro-optical conversion unit; at a moment other than the preset moment, a signal with a correlation quantity of 0 with the first input signal or a 0 signal is input into the second electro-optical conversion unit.

[0196] Supplementary Note 10. An electronic device, comprising a memory and a processor, the memory storing a computer program, and the processor being configured to execute the computer program to implement the method for determining the optical phase difference of the sub-signal of the optical transmitter according to any one of Supplementary Notes 1 to 9.

[0197] Supplementary Note 11. A storage medium storing a computer-readable program, wherein the computer-readable program causes a computer to execute the method for determining the optical phase difference of the sub-signal of the optical transmitter according to any one of Supplementary Notes 1 to 9 in an electronic device.

Claims

1. An apparatus for determining the optical phase difference of sub-signals of an optical transmitter, characterized in that The device includes: A first signal input unit, which is configured to input a first input signal to a first electro-optic conversion unit, so that the first electro-optic conversion unit modulates the light to be modulated according to the first input signal to obtain a first output signal; A second signal input unit, which is configured to input a second input signal to a second electro-optic conversion unit, so that the second electro-optic conversion unit modulates the light to be modulated according to the second input signal to obtain a second output signal; wherein, the correlation quantity between the second input signal and the first input signal is not 0; A coherent detection unit, which is configured to perform a coherent detection operation based on the first output signal and the second output signal to obtain a first output quantity and a second output quantity; An optical phase difference determination unit, which is configured to determine the optical phase difference between the output signal of the first electro-optic conversion unit and the output signal of the second electro-optic conversion unit according to the first output quantity and the second output quantity.

2. The device according to claim 1, wherein The first electro-optic conversion unit is a transmitter or a partial modulation unit of a transmitter.

3. The device according to claim 1, wherein, The second electro-optic conversion unit outputs a finite number of states.

4. The device according to claim 1, wherein, The second input signal is the same as the first input signal; or The second input signal is a weighted sum of the first input signals at multiple different times; or The second input signal is a symbol sequence of the weighted sum of the first input signals at multiple different times; or The second input signal is a product of a symbol sequence of the weighted sum of the first input signals at multiple different times and a random amplitude sequence.

5. The device according to claim 1, wherein The first electro-optic conversion unit and the second electro-optic conversion unit are connected in parallel, and the first electro-optic conversion unit is connected to the first input end of the low-speed coherent detection unit and inputs the first output signal to the first input end, the second electro-optic conversion unit is connected to the second input end of the low-speed coherent detection unit and inputs the second output signal to the second input end; And, the low-speed coherent detection unit is specifically configured to: Perform a coherent detection operation on the first output signal and the second output signal to obtain the first output quantity and the second output quantity.

6. The device according to claim 1, wherein, The first electro-optic conversion unit and the second electro-optic conversion unit are connected in series, and the series structure of the first electro-optic conversion unit and the second electro-optic conversion unit is connected to the first input end of the low-speed coherent detection unit and inputs the product of the first output signal and the second output signal to the first input end, and a preset reference signal is input to the second input end of the low-speed coherent detection unit; And, the low-speed coherent detection unit is specifically configured to: Perform a coherent detection operation on the product of the first output signal and the second output signal and the reference signal to obtain the first output quantity and the second output quantity.

7. The device according to claim 1, wherein The optical phase difference determination unit is specifically configured to: Substitute the first output quantity and the second output quantity into the following formula to obtain the optical phase difference: φ=arg(I1-jI2) Wherein, I1 is the first output quantity, I2 is the second output quantity, φ is the optical phase difference between the output signal of the first electro-optic conversion unit and the output signal of the second electro-optic conversion unit, and arg(z) is the principal value of the argument of the complex number z.

8. The apparatus according to claim 1, wherein The device further includes: A first multiplication unit configured to multiply the second input signal by a low-frequency square wave before inputting the second input signal into the second electro-optic conversion unit; and A second multiplication unit configured to multiply the first output quantity and the second output quantity by the low-frequency square wave respectively before determining the optical phase difference based on the first output quantity and the second output quantity; And the second signal input unit is further configured to: input the product signal of the second input signal and the low-frequency square wave into the second electro-optic conversion unit; The optical phase difference determination unit is further configured to: determine the optical phase based on the product of the first output quantity and the low-frequency square wave and the product of the second output quantity and the low-frequency square wave.

9. The apparatus according to claim 1, wherein The second signal input unit is further configured to: At a preset moment, input the second input signal into the second electro-optic conversion unit; at a moment other than the preset moment, input a signal with a correlation quantity of 0 with the first input signal or a 0 signal into the second electro-optic conversion unit.

10. A method for determining the optical phase difference of sub-signals of an optical transmitter, characterized in that, The method includes: Input a first input signal into a first electro-optic conversion unit, and cause the first electro-optic conversion unit to modulate the light to be modulated according to the first input signal to obtain a first output signal; Input a second input signal into a second electro-optic conversion unit, and cause the second electro-optic conversion unit to modulate the light to be modulated according to the second input signal to obtain a second output signal; wherein, the correlation quantity between the second input signal and the first input signal is not 0; Perform a coherent detection operation based on the first output signal and the second output signal to obtain a first output quantity and a second output quantity; Determine the optical phase difference between the output signal of the first electro-optic conversion unit and the output signal of the second electro-optic conversion unit based on the first output quantity and the second output quantity.

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