WO2018187911A1

WO2018187911A1 - Chromatic dispersion elimination method and device

Info

Publication number: WO2018187911A1
Application number: PCT/CN2017/079938
Authority: WO
Inventors: 张宏宇; 周娴; 钟康平; 霍佳皓; 陈微; 曾理
Original assignee: 华为技术有限公司
Priority date: 2017-04-10
Filing date: 2017-04-10
Publication date: 2018-10-18
Also published as: CN109314573B; CN109314573A

Abstract

A chromatic dispersion elimination method and device. The device comprises: a digital signal processor for generating a first electrical modulation signal, the first electrical modulation signal comprising a real part signal and an imaginary part signal; a laser for outputting a first path of optical carrier signals and a second path of optical carrier signals; an intensity modulation module for acquiring a second electrical modulation signal, a real part signal and an imaginary part signal of the second electrical modulation signal both being located in the first quadrant of the complex plane, wherein the second electrical modulation signal is generated by the first electrical modulation signal; and the intensity modulation module is used for modulating the real part signal onto the first path of optical carrier signals so as to obtain a first output optical signal, and modulating the imaginary part signal onto the second path of optical carrier signals so as to obtain a second output optical signal, a phase difference between the first output optical signal and the second output optical signal being within a pre-set range; and a beam combiner for combining the first output optical signal and the second output optical signal and then outputting same.

Description

Dispersion elimination method and device

Technical field

The present application relates to the field of optical fiber communication technologies, and in particular, to a method and device for eliminating dispersion.

Background technique

In optical fiber communication systems, Chromatic Dispersion (CD) is one of the important factors affecting the transmission performance of the system. Dispersion is caused by the different propagation speeds of different frequency components of the optical pulse signal in the optical fiber. In the communication C-band (wavelength range is 1530 ~ 1565nm), the standard single mode fiber (SSMF) has a dispersion coefficient of 17 ~ 20ps / nm · km, the dispersion will lead to spectral distortion and broadening of the signal, resulting in communication Performance is degraded. Therefore, eliminating the effects of dispersion is of great significance to fiber-optic communication systems.

Currently, in a coherent optical communication system, dispersion compensation can be performed on the receiving device side using a coherent receiver, or dispersion precompensation can be performed on the transmitting device side using an in-phase quadrature (IQ) modulator. In the intensity modulation direct detection system, a Dispersion Compensation Fiber (DCF) or a Dispersion Compensation Module (DCM) is usually used on the optical layer to eliminate the influence of dispersion. However, whether a coherent receiver, an IQ modulator, a DCF, or a DCM is used, a high cost is incurred, and the above-mentioned modules occupy a large volume, so that the miniaturization of the device cannot be achieved.

Summary of the invention

The present application provides a dispersion elimination method and apparatus for reducing the occupied volume of a device while eliminating dispersion at the transmitting device side.

The application provides a dispersion eliminating device, comprising:

a digital signal processor for generating a first electrical modulation signal, the first electrical modulation signal comprising a real signal and an imaginary signal;

a laser for outputting a first optical carrier signal and a second optical carrier signal;

An intensity modulation module, configured to acquire a second electrical modulation signal, where a real part signal and an imaginary part signal of the second electrical modulation signal are both located in a first quadrant of a complex plane; wherein the second electrical modulation signal is performed by the An electrical modulation signal is generated;

The intensity modulation module is configured to modulate the real part signal onto the first optical carrier signal, obtain a first output optical signal, and modulate the imaginary part signal onto the second optical carrier signal Obtaining a second output optical signal, wherein a phase difference between the first output optical signal and the second output optical signal is within a preset range;

a beam combiner for combining the first output optical signal and the second output optical signal for output.

According to the apparatus provided by the embodiment of the present application, the intensity modulation module respectively modulates the obtained real part signal and the imaginary part signal of the second electrical modulation signal to the first optical carrier signal and the second optical carrier signal output by the laser, A first output optical signal and a second output optical signal having a phase difference within a preset range are obtained, and the first output optical signal and the second output optical signal are combined by a combiner and output. Since the real part signal and the imaginary part signal of the second electrical modulation signal are both located in the first quadrant of the complex plane, the light outputted after the first output optical signal and the second output optical signal modulated according to the second electrical modulation signal are combined The signal has good dispersion immunity, which can eliminate the effects of fiber dispersion. At the same time, due to the small size and relatively low cost of digital signal processors, lasers, intensity modulation modules, and combiners, It is possible to reduce the occupation volume and cost of the device while eliminating the dispersion on the transmitting device side.

Optionally, the intensity modulation module is specifically configured to:

Receiving a first electrical modulation signal, adding a real part signal of the first electrical modulation signal to a first preset DC signal, and adding an imaginary part signal of the first electrical modulation signal to a second preset DC signal And obtaining the second electrical modulation signal, the value of the real part signal and the value of the imaginary part signal of the second electrical modulation signal are both greater than or equal to zero.

In the above device, by adding the real signal of the first electrical modulation signal and the first preset DC signal, the imaginary part signal of the first electrical modulation signal is added to the second preset DC signal, thereby implementing quadrant shifting, A second electrical modulation signal is obtained.

Optionally, the amplitude of the first preset DC signal is equal to the amplitude of the second preset DC signal, and the amplitude of the first preset DC signal is greater than or equal to a real signal in the first electrical modulation signal. The absolute value of the minimum value of the value and the value of the imaginary part signal.

Optionally, the digital signal processor is specifically configured to:

Adding a real signal of the first electrical modulation signal to a third preset DC signal, adding an imaginary part signal of the first electrical modulation signal and a fourth preset DC signal to generate the second The modulated signal, the value of the real signal of the second electrical modulated signal and the value of the imaginary signal are both greater than or equal to zero.

In the above device, by adding the real signal of the first electrical modulation signal and the third preset DC signal, the imaginary part signal of the first electrical modulation signal is added to the fourth preset DC signal, thereby implementing quadrant shifting, A second electrical modulation signal is obtained.

Optionally, the amplitude of the third preset DC signal is equal to the amplitude of the fourth preset DC signal, and the amplitude of the third preset DC signal is greater than or equal to a real signal in the first electrical modulation signal. The absolute value of the minimum value of the value and the value of the imaginary part signal.

Optionally, the digital signal processor is specifically configured to:

Generating a third electrical modulation signal, and performing pre-compensation processing on the third electrical modulation signal according to the obtained fiber link dispersion value to obtain the first electrical modulation signal.

In the above device, the pre-compensation process is performed on the third electrical modulation signal according to the obtained fiber link dispersion value, so that the dispersion is pre-compensated at the transmitting end, so that the dispersion of the optical fiber can cancel the optical fiber through the transmission of the optical fiber. The inverse function of the link dispersion value, that is, the pre-compensation of the dispersion is cancelled, so that the effect of the fiber dispersion at the receiving end is eliminated.

Optionally, the digital signal processor is specifically configured to:

Generating a third electrical modulation signal and performing single sideband filtering on the third electrical modulation signal to obtain the first electrical modulation signal.

In the above device, the third electrical modulation signal is subjected to single sideband filtering. Since the single sideband signal has the ability to overcome the influence of the fiber dispersion, the first electrical modulation signal obtained by the single sideband filtering can effectively cancel the fiber dispersion. influences.

Optionally, the device further includes a signal separation module, a first electrical amplifier, and a second electrical amplifier:

The signal separation module is configured to divide the first electrical modulation signal into a real part signal and an imaginary part signal, input the real part signal to the first electric amplifier, and input the imaginary part signal to the Second electric amplifier;

The first electric amplifier is configured to receive the real part signal and amplify an amplitude of the real part signal;

The second electrical amplifier is configured to receive the imaginary part signal and amplify an amplitude of the imaginary part signal.

Optionally, the apparatus further includes a signal separation module, the intensity modulation module comprising a first intensity modulator and a second intensity modulator:

The first intensity modulator is configured to receive the real part signal after the amplitude amplification, and enlarge the real part of the amplitude Transmitting a signal onto the first optical carrier signal;

The second intensity modulator is configured to receive the amplitude-amplified imaginary part signal, and modulate the amplitude-amplified imaginary part signal onto the second path optical carrier signal.

Optionally, the first intensity modulator is an electroabsorption modulator;

The second intensity modulator is an electroabsorption modulator.

Optionally, the laser is a distributed feedback laser.

The embodiment of the present application provides a method for eliminating a dispersion, including:

Generating a first electrical modulation signal, the first electrical modulation signal comprising a real signal and an imaginary signal;

Outputting a first optical carrier signal and a second optical carrier signal;

Obtaining a second electrical modulation signal, the real signal and the imaginary part of the second electrical modulation signal are both located in a first quadrant of the complex plane; wherein the second electrical modulation signal is generated by the first electrical modulation signal;

Modulating the real part signal onto the first optical carrier signal to obtain a first output optical signal, and modulating the imaginary part signal onto the second optical carrier signal to obtain a second output optical signal, The phase difference between the first output optical signal and the second output optical signal is within a preset range;

The first output optical signal and the second output optical signal are combined and output.

Optionally, the acquiring the second electrical modulation signal includes:

Adding a real signal of the first electrical modulation signal to a first preset DC signal, adding an imaginary part signal of the first electrical modulation signal to a second preset DC signal, to obtain the second The modulated signal, the value of the real signal of the second electrical modulated signal and the value of the imaginary signal are both greater than or equal to zero.

Optionally, the acquiring the second electrical modulation signal includes:

Optionally, the generating the first electrical modulation signal includes:

Optionally, the method further includes:

Separating the first electrical modulation signal into a real signal and an imaginary signal;

Amplifying the amplitude of the real signal and amplifying the amplitude of the imaginary signal.

Optionally, the method further includes:

Receiving the amplified real signal, and modulating the amplitude-amplified real signal to the first optical load Wave signal

The amplitude-amplified imaginary part signal is received, and the amplitude-amplified imaginary part signal is modulated onto the second optical carrier signal.

The embodiments of the present application provide a computer readable storage medium having instructions stored therein that, when run on a computer, cause the computer to perform the methods described in the above aspects.

The embodiments of the present application provide a computer program product comprising instructions that, when run on a computer, cause the computer to perform the methods described in the above aspects.

DRAWINGS

FIG. 1 is a schematic structural diagram of a dispersing device according to an embodiment of the present disclosure;

2 is a schematic structural diagram of a dispersing device according to an embodiment of the present disclosure;

FIG. 3 is a schematic diagram of a signal constellation provided by an embodiment of the present application;

4 is a schematic diagram of a signal constellation provided by an embodiment of the present application;

FIG. 5 is a schematic diagram of a signal spectrum block according to an embodiment of the present application;

FIG. 6 is a schematic diagram of a signal spectrum block according to an embodiment of the present application;

FIG. 7 is a schematic diagram of a signal constellation provided by an embodiment of the present application;

FIG. 8 is a schematic structural diagram of a dispersing device according to an embodiment of the present disclosure;

FIG. 9 is a schematic structural diagram of a dispersing device according to an embodiment of the present disclosure;

FIG. 10 is a schematic flowchart of a method for eliminating a dispersion according to an embodiment of the present application.

detailed description

The embodiments of the present application will be further described in detail below with reference to the accompanying drawings.

The terms used in the embodiments of the present application are for the purpose of describing particular embodiments only, and are not intended to limit the application. It should also be understood that the term "and/or" as used herein refers to and encompasses any and all possible combinations of one or more of the associated listed items. The character "/" in this article generally indicates that the contextual object is an "or" relationship.

FIG. 1 is a schematic structural diagram of a dispersing device according to an embodiment of the present application.

Referring to FIG. 1, the dispersion eliminating apparatus 100 includes a digital signal processor 101, a laser 102, an intensity modulation module 103, and a combiner 104.

It should be noted that, in the embodiment of the present application, the digital signal processor 101 may be an optical digital signal processor (oDSP). The laser 102 can be any type of laser, optionally a Distributed Feedback Laser (DFB). The laser 102 can be a separate module or integrated in the same module as the intensity modulation module 103. When the laser 102 and the intensity modulation module 103 are integrated in the same module, it can be called a double-ended electroabsorption modulation laser (Electro). -absorption Modulated Laser, EML).

With reference to FIG. 1, in the embodiment of the present application, the digital signal processor 101 is configured to generate a first electrical modulation signal, where the first electrical modulation signal includes a real signal and an imaginary signal.

The laser 102 is configured to output a first optical carrier signal and a second optical carrier signal.

An intensity modulation module 103, configured to acquire a second electrical modulation signal, a real signal of the second electrical modulation signal, and a virtual The partial signals are all located in a first quadrant of the complex plane; wherein the second electrical modulated signal is generated by the first electrical modulated signal.

The intensity modulation module 103 is configured to modulate the real part signal onto the first optical carrier signal, obtain a first output optical signal, and modulate the imaginary part signal to the second optical carrier signal And obtaining a second output optical signal, wherein a phase difference between the first output optical signal and the second output optical signal is within a preset range.

The combiner 104 is configured to combine the first output optical signal and the second output optical signal and output the same.

In the embodiment of the present application, the received first electrical modulation signal may be generated by the intensity modulation module 103 as a second electrical modulation signal in which the real part signal and the imaginary part signal are both moved to the first quadrant of the complex plane, or may be digital. The signal processor 101 generates the first electrical modulation signal as a second electrical modulation signal such that the real and imaginary signals of the second electrical modulation signal can both be located in the first quadrant of the complex plane, as described below.

The first possible scenario: the intensity modulation module 103 generates a second electrical modulation signal according to the received first electrical modulation signal, and the real part signal and the imaginary part signal of the second electrical modulation signal are both located in the first quadrant of the complex plane.

In this scenario, as shown in FIG. 2, the dispersion eliminating apparatus 100 may include a digital signal processor 101 and intensity modulation in addition to the digital signal processor 101, the laser 102, the intensity modulation module 103, and the combiner 104. A first electrical amplifier 1051 and a second electrical amplifier 1052 between the modules 103. Meanwhile, the digital signal processor 101 may include a signal generating module 1011 and a signal separating module 1012. The intensity modulating module 103 may include a first intensity modulator 1031 and a second intensity modulator 1032. The signal separation module 1012 is configured to divide the signal output by the signal generation module 1011 in the digital signal processor 101 into a real part signal and an imaginary part signal, and input the real part signal to the first electric amplifier 1051, and input the imaginary part signal to the Two electric amplifiers 1052. Wherein, the first intensity modulator can be any type of intensity modulator, optionally an Electro-absorption Modulator (EAM); the second intensity modulator can be any type of intensity modulator Optional is an electroabsorption modulator.

The first electrical amplifier 1051 is configured to amplify the received real signal and output it to the first intensity modulator 1031 in the intensity modulation module 103. The second electrical amplifier 1052 is configured to amplify the received imaginary signal and output the signal. Up to the second intensity modulator 1032 in the intensity modulation module 103. Correspondingly, the first intensity modulator 1031 is configured to receive the amplitude-amplified real part signal, and modulate the amplitude-amplified real part signal onto the first path optical carrier signal; The intensity modulator 1032 is configured to receive the amplitude-amplified imaginary part signal, and modulate the amplitude-amplified imaginary part signal onto the second path optical carrier signal.

For other modules in FIG. 2, reference may be made to the description in FIG. 1, and details are not described herein again.

In the dispersion eliminating apparatus 100 shown in FIG. 2, after the signal generating module 1011 in the digital signal processor 101 generates the first electrical modulation signal, the first electrical modulation signal is output to the signal separation module 1012, and the signal separation module 1012 will eventually be the first. The electrical modulation signal is divided into a real signal and an imaginary signal. For example, the first electrical modulation signal E _cdc (t)=I _cdc (t)+j×Q _cdc (t), where I _cdc (t) is the real signal and Q _cdc (t) is the imaginary signal. The signal separation module 1012 can separate I _cdc (t) and Q _cdc (t) into two separate signals for subsequent module processing.

It should be noted that the signal separation module 1012 may be a software module or a hardware module, may be integrated in the signal generation module 1011 in the digital signal processor 101, or may be a separate module in the digital signal processor 101. The signal separation module 1012 is described as a separate module. Other types of signal separation modules may be referred to herein, and details are not described herein. As for how the signal separation module 1012 divides the first electrical modulation signal into a real part signal and an imaginary part signal, the embodiment of the present application is not limited thereto, and may be implemented by referring to any method in the prior art, and details are not described herein again.

In the embodiment of the present application, the digital signal processor 101 can generate the first electrical modulation signal in various manners.

In a first possible implementation of generating a first electrical modulated signal, the digital signal processor 101 may first pass the signal. The number generation module 1011 generates a third electrical modulation signal, and performs pre-compensation processing on the third electrical modulation signal according to the acquired fiber link dispersion value to obtain the first electrical modulation signal.

It should be noted that, in the embodiment of the present application, the manner of obtaining the dispersion value of the optical fiber link is not limited, and may be fed back by the receiving end, or may be pre-agreed by the transmitting end and the receiving end.

For example, the third electrical modulation signal generated by the digital signal processor 101 is a Pulse Amplitude Modulation (PAM) 4 modulation format signal E _PAM4 (t), and the constellation diagram of the third electrical modulation signal can be as shown in FIG. 3 . Shown. In Fig. 3, the third electrical modulation signal is distributed on the positive half axis of the real coordinate axis, including four discrete points, and the amplitudes are 0, 1, 2, and 3, respectively.

Let the fiber link dispersion value passing through the fiber link be determined by h _cd (t), and its inverse function is

The digital signal processor 101 can perform pre-compensation processing on the third electrical modulation signal according to formula (1) to obtain a first electrical modulation signal:

Where E _cdc (t) is the first electrical modulation signal,

For convolution operations.

It should be noted that the pre-compensation processed signal, that is, the first electrical modulation signal is a signal distributed over the entire complex plane. For example, if the fiber link dispersion value

Where D is the fiber dispersion coefficient, z is the distance traveled by the optical modulation signal in the fiber, and λ is the wavelength of the optical carrier output by the laser, for example, 1550 nm, and c is the vacuum light speed. Referring to FIG. 3, after the third electrical modulation signal shown in FIG. 3 and the above-mentioned fiber link dispersion value are convoluted according to formula (1), the obtained first electrical modulation signal can be referred to FIG. In Figure 4, the first electrical modulation signal is distributed in four quadrants of the complex plane.

Since the dispersion in the fiber link is a linear function, the third intensity modulated signal is convolved in the time domain by means of digital signal processing through a preset or fiber-optic link dispersion value fed back by the receiving end. The inverse function of the dispersion value of the fiber link, so that the dispersion of the fiber can exactly cancel the inverse function of the dispersion value of the fiber link through the transmission of the fiber, that is, the pre-compensation of the dispersion is cancelled, so that the influence of the dispersion of the fiber at the receiving end is eliminated.

In a second possible implementation manner of generating the first electrical modulation signal, the digital signal processor 101 can be configured as a third electrical modulation signal, and the third electrical modulation signal is subjected to single sideband filtering to obtain the first Electrically modulated signal.

In this implementation, the third electrical modulation signal generated by the digital signal processor 101 is a double sideband signal, and its spectrum can be as shown in FIG. By performing single sideband filtering on the third electrical modulated signal, a single sideband signal, ie a first electrical modulated signal, is obtained. Referring to FIG. 5, the spectrum of the first electrical modulation signal obtained after performing single sideband filtering may be as shown in FIG. 6. The spectrums shown in FIGS. 5 and 6 are only examples, and the spectrum of the first electrical modulation signal is not necessarily the spectrum shown in FIGS. 5 and 6.

Since the single sideband signal has the ability to overcome the effects of fiber dispersion, the first electrically modulated signal obtained by single sideband filtering can effectively cancel the effect of fiber dispersion.

Optionally, after the digital signal processor 101 generates the first electrical modulation signal, the signal separation module 1012 divides the first electrical modulation signal into a real signal and an imaginary signal, and then takes the real part of the first electrical modulation signal. The signal is input to the first electrical amplifier 1051, and the imaginary part signal of the first electrical modulation signal is input to the second electrical amplifier 1052.

After receiving the real signal of the first electrical modulation signal, the first electrical amplifier 1051 amplifies the amplitude of the real signal of the first electrical modulation signal, and the second electrical amplifier 1052 receives the first electrical modulation After the imaginary part signal of the signal, the amplitude of the imaginary part signal of the first electrical modulation signal is amplified.

Subsequently, the first electrical modulation signal is input to the intensity modulation module 103 for intensity modulation. After receiving the first electrical modulation signal, the intensity modulation module 103 adds the real signal of the first electrical modulation signal to the first preset DC signal, and the imaginary part signal of the first electrical modulation signal and the second pre- The DC signal is added to obtain the second electrical modulation signal, wherein the amplitude of the first preset DC signal is greater than or equal to the absolute value of the minimum value of the real signal in the first electrical modulation signal, The amplitude of the second preset DC signal is greater than or equal to the absolute value of the minimum value of the values of the imaginary part signals in the first electrical modulation signal. In combination with the foregoing description, the second electrical modulation signal obtained at this time is composed of an independent real signal and an independent imaginary signal, and the value of the real signal and the value of the imaginary signal of the second electrical modulation signal Both are greater than or equal to zero.

In the embodiment of the present application, when the intensity modulation module 103 includes the first intensity modulator 1031 and the second intensity modulator 1032, the foregoing process is specifically: the first intensity modulator 1031 in the intensity modulation module 103 can use the first power The real part signal of the modulated signal is added to the first preset DC signal to obtain a real part signal of the second electrical modulated signal. The value of the real signal after adding the first preset DC signal is greater than or equal to zero, thereby moving the real signal of the first electrical modulation signal to the first quadrant of the complex plane. Correspondingly, the second intensity modulator 1032 of the intensity modulation module 103 may add the imaginary part signal of the first electrical modulation signal and the second preset DC signal to obtain an imaginary part signal of the second electrical modulation signal. The value of the imaginary part signal added to the second preset DC signal is greater than or equal to zero, thereby moving the imaginary part signal of the first electrical modulation signal to the first quadrant of the complex plane. Finally, the first intensity modulator 1031 modulates the real signal of the first quadrant moved to the complex plane onto the first optical carrier signal, and the intensity modulation module 103 can modulate the first optical light modulated by the first intensity modulator 1031. The signal is used as the first output optical signal; the second intensity modulator 1032 modulates the imaginary part signal of the first quadrant moved to the complex plane onto the second optical carrier signal, and the intensity modulation module 103 can be based on the second intensity modulator 1032. The modulated second optical signal obtains a second output optical signal.

For example, in conjunction with FIG. 4, as shown in FIG. 7, a schematic diagram of a constellation provided by an embodiment of the present application is provided. After the real signal of the first electrical modulation signal shown in FIG. 4 is added to the first preset DC signal, and the imaginary part signal is added to the second preset DC signal, the real signal of the first electrical modulation signal is The imaginary signals are all located in the first quadrant, thereby implementing quadrant shifting to obtain a second electrical modulated signal. It should be noted that the first quadrant herein also includes a non-negative real half axis and a virtual half axis.

Optionally, the amplitude of the first preset DC signal is equal to the amplitude of the second preset DC signal, and the amplitude of the first preset DC signal is greater than or equal to the first electrical modulation signal. The absolute value of the minimum of the value of the real signal and the value of the imaginary signal.

For example, the first electrical modulation signal E _cdc (t)=I _cdc (t)+j×Q _cdc (t), where I _cdc (t) is the real signal and Q _cdc (t) is the imaginary signal. The signal shifting function is implemented by adding a DC signal B(1+j). The signal after moving to the first quadrant is: E' _cdc (t) = {I _cdc (t) + B} + j × {Q _cdc (t) + B}. Where I _cdc (t) + B ≥ 0, Q _cdc (t) + B ≥ 0. The magnitude of the added DC signal B is greater than or equal to the absolute value of the smallest of I _cdc (t) and Q _cdc (t), so that both the real and imaginary information after the shift are non-negative real values.

Before outputting the second optical signal, the intensity modulation module 103 may phase shift the second optical signal modulated by the second intensity modulator 1032, and the phase shift angle is within a preset range, thereby obtaining the first output optical signal. a second output optical signal having a phase difference within a predetermined range.

In the embodiment of the present application, the phase difference preset range may be in the range of 85 degrees to 95 degrees. Of course, the preset range can also be other ranges. For example, when the preset range is 90 degrees, a 90 degree phase shifter may be integrated in the intensity modulation module 103, or by other means, to obtain a first output optical signal and a second output with a phase difference of 90 degrees. Optical signal. Of course, the above is only an example, and may also be in the first intensity modulator 1031 or the second intensity modulator 1032. Integrate a 90 degree phase shifter.

For example, the intensity modulation module may further include a phase shifter for phase shifting the modulated second optical carrier signal. Specifically, as shown in FIG. 8 , a schematic diagram of a dispersion eliminating apparatus provided in an embodiment of the present application. In FIG. 8, the dispersion eliminating device 100 includes a digital signal processor 101, a laser 102, an intensity modulation module 103, a combiner 104, a first electrical amplifier 1051, and a second electrical amplifier 1052. At the same time, the digital signal processor 101 can include a signal generating module 1011 and a signal separating module 1012. The intensity modulation module 103 can include a first intensity modulator 1031, a second intensity modulator 1032, and a phase shifter 1033. The phase shifter 1033 The input signal can be phase-shifted by 90 degrees and outputted. Of course, it can be other numbers greater than 90 degrees or less than 90 degrees, which can be determined according to actual conditions. After the second intensity modulator 1032 modulates the imaginary part signal of the second electrical modulation signal onto the second optical carrier signal, the phase shifter 1033 phase shifts the modulated second optical signal by 90 degrees to obtain a second The optical signal is output such that the phase difference between the first output optical signal and the second output optical signal is 90 degrees.

Of course, the phase shifter can also be a separate module, directly connected to the second intensity modulator, receiving the modulated second optical signal output by the second intensity modulator, and modulating the second optical signal. After shifting, the second output optical signal is obtained.

A second possible scenario: the digital signal processor 101 generates a second electrical modulated signal in which the first electrical modulated signal is in the first quadrant of the complex plane, both the real signal and the imaginary signal.

In this scenario, in conjunction with FIG. 2, in the dispersion eliminating apparatus 100 shown in FIG. 2, after the digital signal processor 101 generates the first electrical modulated signal by the intensity signal generating module 1011, the real part of the first electrical modulated signal is used. Adding a signal to the third preset DC signal, adding the imaginary part signal of the first electrical modulation signal and the fourth preset DC signal to generate the second electrical modulation signal, where the second electrical modulation signal The value of the real signal and the value of the imaginary signal are both greater than or equal to zero, and finally the second electrical modulation signal is output to the signal separation module 1012.

In the embodiment of the present application, the specific content of the first electrical modulation signal generated by the digital signal processor 101 by the strength signal generating module 1011 can be referred to the foregoing description, and details are not described herein again.

Optionally, the amplitude of the third preset DC signal is equal to the amplitude of the fourth preset DC signal, and the amplitude of the third preset DC signal is greater than or equal to the first electrical modulation signal. The absolute value of the minimum of the value of the real signal and the value of the imaginary signal.

Optionally, the signal separation module 1012 may divide the second electrical modulation signal into a real signal and an imaginary signal, and input a real signal of the second electrical modulation signal to the first electrical amplifier 1051. The imaginary part signal of the second electrical modulation signal is input to the second electrical amplifier 1052.

The first electrical amplifier 1051 receives a real signal of the second electrical modulation signal, and amplifies an amplitude of a real signal of the second electrical modulation signal, and correspondingly, the second electrical amplifier 1052, Receiving an imaginary part signal of the second electrical modulation signal and amplifying an amplitude of the imaginary part signal of the second electrical modulation signal.

The second electrical modulation signal can then be input to the intensity modulation module 103. Specifically, the amplitude-amplified real part signal may be input to the first intensity modulator 1031, and the amplitude-amplified imaginary part signal may be input to the second intensity modulator 1032.

Optionally, the intensity modulation module 103 may further move the quadrant of the obtained real electrical signal and the imaginary signal of the second electrical modulation signal, so that the real signal and the imaginary signal of the second electrical modulation signal are both located in the complex plane. First quadrant. For details of the quadrant shifting of the second electrical modulation signal by the intensity modulation module 103, reference may be made to the foregoing description, and details are not described herein again.

The first intensity modulator 1031 in the intensity modulation module 103 can amplify the received real amplitude signal Modulating onto the first optical carrier signal and outputting the first output optical signal; the second intensity modulator 1032 in the intensity modulation module 103 can modulate the received amplitude-amplified imaginary signal to the second optical carrier signal Up and output a second output optical signal.

After the second intensity modulator 1032 modulates the amplitude-amplified imaginary part signal onto the second optical carrier signal, before the second optical signal is output, the intensity modulation module 103 may modulate the second intensity modulator 1032. The road light signal is phase-shifted, and the phase shift angle is within a preset range, thereby obtaining a second output light signal having a phase difference from the first output light signal within a preset range. For example, a phase shifter is integrated in the intensity modulation module to effect phase shifting of the modulated second optical signal. Of course, the phase shifter can also be a separate module, directly connected to the second intensity modulator, receiving the modulated second optical signal output by the second intensity modulator, and modulating the second optical signal. After shifting, the second output optical signal is obtained. For other contents of the processing of the second electrical modulation signal by the intensity modulation module 103, reference may be made to the foregoing description, and details are not described herein again.

Combined with the foregoing description, in the embodiment of the present application, the dispersion eliminating device may be as shown in FIG. 9. The dispersion eliminating device 900 shown in FIG. 9 includes an oDSP 901, a first electric amplifier 9021, a second electric amplifier 9022, a double-ended EML 903, a phase shifter 904, and a combiner 905. The double-ended EML 903 includes a first EAM9031, a second EAM9032, and a DFB9033.

The first electric amplifier 9021 receives the real part signal output by the oDSP 901, and amplifies the received real part signal and outputs it to the first EAM9031 in the double-ended EML 903; the second electric amplifier 9022 receives the imaginary part of the digital signal processor 901 output. The signal is amplified and output to the second EAM9032 in the double-ended EML 903.

The DFB9033 outputs a first optical carrier signal and a second optical carrier signal. The first EAM9031 modulates the received real signal into the first optical carrier signal, and outputs the first output optical signal, and may simultaneously move the real signal to the first quadrant of the complex plane while modulating; The EAM9032 modulates the received imaginary part signal into the second optical carrier signal, and may modulate the imaginary part signal to the first quadrant of the complex plane.

The phase shifter 904 phase-shifts the second optical signal modulated by the second EAM9032 to obtain a second output optical signal, such that the phase difference between the output second output optical signal and the first output optical signal is within a preset range. Finally, the combiner 905 combines the first output optical signal and the second output optical signal for output. For details of the above various modules, reference may be made to the foregoing description, and details are not described herein again.

As shown in FIG. 10, a schematic flowchart of a method for eliminating a dispersion provided by an embodiment of the present application is shown in FIG.

Referring to Figure 10, the method includes:

Step 1001: Generate a first electrical modulation signal, where the first electrical modulation signal includes a real signal and an imaginary signal;

Step 1002: Output a first optical carrier signal and a second optical carrier signal.

Step 1003: Acquire a second electrical modulation signal, where a real part signal and an imaginary part signal of the second electrical modulation signal are both located in a first quadrant of a complex plane; wherein the second electrical modulation signal is used by the first electrical modulation Signal generation

Step 1004: Modulate the real part signal onto the first optical carrier signal, obtain a first output optical signal, and modulate the imaginary part signal onto the second optical carrier signal to obtain a second output. An optical signal, wherein a phase difference between the first output optical signal and the second output optical signal is within a preset range;

Step 1005: Combine the first output optical signal and the second output optical signal and output.

The order of the execution steps of the above method is not limited, wherein step 1001 may be performed by a digital signal processor, step 1002 may be performed by a laser, step 1003 and step 1004 may be performed by an intensity modulation module, and step 1005 may be performed by a beam combiner. For details of the above various modules, reference may be made to the foregoing description, and details are not described herein again.

For other contents of the above method, reference may be made to the content of the foregoing dispersion eliminating device, and details are not described herein again.

The relevant parts of the method embodiments of the present application may be referred to each other; the apparatus provided in each device embodiment is used to execute the method provided by the corresponding method embodiment, so each device embodiment may refer to related methods in the related method embodiments. Partial understanding.

A person skilled in the art can understand that all or part of the steps of implementing the above embodiments can be completed by a program to instruct related hardware, and the program can be stored in a readable storage medium of a device, when the program is executed. Including all or part of the above steps, the storage medium, such as: disk storage, optical storage, and the like.

The specific embodiments described above further explain the objects, technical solutions and beneficial effects of the present application. It should be understood that different embodiments may be combined, and the above is only the specific implementation of the present application. It is not intended to limit the scope of the present application, and any combinations, modifications, equivalents, improvements, etc., made within the spirit and scope of the present application are intended to be included within the scope of the present application.

Claims

A dispersion eliminating device, comprising:

a digital signal processor for generating a first electrical modulation signal, the first electrical modulation signal comprising a real signal and an imaginary signal;

a laser for outputting a first optical carrier signal and a second optical carrier signal;

An intensity modulation module, configured to acquire a second electrical modulation signal, where a real part signal and an imaginary part signal of the second electrical modulation signal are both located in a first quadrant of a complex plane; wherein the second electrical modulation signal is performed by the An electrical modulation signal is generated;

The intensity modulation module is configured to modulate the real part signal onto the first optical carrier signal, obtain a first output optical signal, and modulate the imaginary part signal onto the second optical carrier signal Obtaining a second output optical signal, wherein a phase difference between the first output optical signal and the second output optical signal is within a preset range;

a beam combiner for combining the first output optical signal and the second output optical signal for output.
The device according to claim 1, wherein the intensity modulation module is specifically configured to:

Receiving a first electrical modulation signal, adding a real part signal of the first electrical modulation signal to a first preset DC signal, and adding an imaginary part signal of the first electrical modulation signal to a second preset DC signal And obtaining the second electrical modulation signal, the value of the real part signal and the value of the imaginary part signal of the second electrical modulation signal are both greater than or equal to zero.
The device according to claim 2, wherein the amplitude of the first preset DC signal is equal to the amplitude of the second preset DC signal, and the amplitude of the first preset DC signal is greater than or equal to the The absolute value of the minimum value of the value of the real signal and the value of the imaginary part signal in the first electrical modulation signal.
The apparatus according to any one of claims 1 to 3, wherein the digital signal processor is specifically configured to:

Adding a real signal of the first electrical modulation signal to a third preset DC signal, adding an imaginary part signal of the first electrical modulation signal and a fourth preset DC signal to generate the second The modulated signal, the value of the real signal of the second electrical modulated signal and the value of the imaginary signal are both greater than or equal to zero.
The device according to claim 4, wherein the amplitude of the third preset DC signal is equal to the amplitude of the fourth preset DC signal, and the amplitude of the third preset DC signal is greater than or equal to the The absolute value of the minimum value of the value of the real signal and the value of the imaginary part signal in the first electrical modulation signal.
The device according to any one of claims 1 to 5, wherein the digital signal processor is specifically configured to:

Generating a third electrical modulation signal, and performing pre-compensation processing on the third electrical modulation signal according to the obtained fiber link dispersion value to obtain the first electrical modulation signal.
The device according to any one of claims 1 to 5, wherein the digital signal processor is specifically configured to:

Generating a third electrical modulation signal and performing single sideband filtering on the third electrical modulation signal to obtain the first electrical modulation signal.
The apparatus according to any one of claims 1 to 7, wherein said apparatus further comprises a signal separation module, a first electrical amplifier and a second electrical amplifier:

The signal separation module is configured to divide the first electrical modulation signal into a real part signal and an imaginary part signal, input the real part signal to the first electric amplifier, and input the imaginary part signal to the Second electric amplifier;

The first electric amplifier is configured to receive the real part signal and amplify an amplitude of the real part signal;

The second electrical amplifier is configured to receive the imaginary part signal and amplify an amplitude of the imaginary part signal.
The apparatus of claim 8 wherein said apparatus further comprises a signal separation module, said intensity modulation module comprising a first intensity modulator and a second intensity modulator:

The first intensity modulator is configured to receive the amplitude-amplified real part signal, and modulate the amplitude-amplified real part signal onto the first path optical carrier signal;

The second intensity modulator is configured to receive the amplitude-amplified imaginary part signal, and modulate the amplitude-amplified imaginary part signal onto the second path optical carrier signal.
The apparatus of claim 9 wherein said first intensity modulator is an electroabsorption modulator;

The second intensity modulator is an electroabsorption modulator.
Apparatus according to any one of claims 1 to 10 wherein said laser is a distributed feedback laser.
A method for eliminating chromatic dispersion, comprising:

Generating a first electrical modulation signal, the first electrical modulation signal comprising a real signal and an imaginary signal;

Outputting a first optical carrier signal and a second optical carrier signal;

Obtaining a second electrical modulation signal, the real signal and the imaginary part of the second electrical modulation signal are both located in a first quadrant of the complex plane; wherein the second electrical modulation signal is generated by the first electrical modulation signal;

Modulating the real part signal onto the first optical carrier signal to obtain a first output optical signal, and modulating the imaginary part signal onto the second optical carrier signal to obtain a second output optical signal, The phase difference between the first output optical signal and the second output optical signal is within a preset range;

The first output optical signal and the second output optical signal are combined and output.
The method of claim 12, wherein the obtaining the second electrical modulation signal comprises:

Adding a real signal of the first electrical modulation signal to a first preset DC signal, adding an imaginary part signal of the first electrical modulation signal to a second preset DC signal, to obtain the second The modulated signal, the value of the real signal of the second electrical modulated signal and the value of the imaginary signal are both greater than or equal to zero.
The method according to claim 13, wherein the amplitude of the first preset DC signal is equal to the amplitude of the second preset DC signal, and the amplitude of the first preset DC signal is greater than or equal to the The absolute value of the minimum value of the value of the real signal and the value of the imaginary part signal in the first electrical modulation signal.
The method according to any one of claims 12 to 14, wherein the acquiring the second electrical modulation signal comprises:

Adding a real signal of the first electrical modulation signal to a third preset DC signal, adding an imaginary part signal of the first electrical modulation signal and a fourth preset DC signal to generate the second The modulated signal, the value of the real signal of the second electrical modulated signal and the value of the imaginary signal are both greater than or equal to zero.
The method according to claim 15, wherein the amplitude of the third preset DC signal is equal to the amplitude of the fourth preset DC signal, and the amplitude of the third preset DC signal is greater than or equal to the The absolute value of the minimum value of the value of the real signal and the value of the imaginary part signal in the first electrical modulation signal.
The method according to any one of claims 12 to 16, wherein the generating the first electrical modulation signal comprises:

Generating a third electrical modulation signal, and performing pre-compensation processing on the third electrical modulation signal according to the obtained fiber link dispersion value to obtain the first electrical modulation signal.
The method according to any one of claims 12 to 15, wherein the generating the first electrical modulation signal comprises:

Generating a third electrical modulation signal and performing single sideband filtering on the third electrical modulation signal to obtain the first electrical modulation signal.
The method according to any one of claims 12 to 18, wherein the method further comprises:

Separating the first electrical modulation signal into a real signal and an imaginary signal;

Amplifying the amplitude of the real signal and amplifying the amplitude of the imaginary signal.
The method of claim 19, wherein the method further comprises:

Receiving the amplitude-amplified real part signal, and modulating the amplitude-amplified real part signal onto the first optical carrier signal;

The amplitude-amplified imaginary part signal is received, and the amplitude-amplified imaginary part signal is modulated onto the second optical carrier signal.