WO2022143173A1

WO2022143173A1 - Dispersion compensation apparatus, transmitter, receiver, and dispersion compensation method

Info

Publication number: WO2022143173A1
Application number: PCT/CN2021/138352
Authority: WO
Inventors: 锁靖; 刘源彬; 周林杰
Original assignee: 华为技术有限公司
Priority date: 2020-12-28
Filing date: 2021-12-15
Publication date: 2022-07-07
Also published as: CN114696908A

Abstract

Disclosed in the embodiments of the present invention are a dispersion compensation apparatus, a transmitter, a receiver, and a dispersion compensation method. A dispersion compensation value is adjustable, such that the dispersion compensation is more flexible. The dispersion compensation apparatus comprises a first light splitting apparatus, a first waveguide, a second waveguide, and a plurality of cascaded micro-ring resonant cavities. Each micro-ring resonant cavity is provided with a resonant wavelength adjustment apparatus. The first waveguide is connected to the first light splitting apparatus. The second waveguide is connected to the first light splitting apparatus. Each micro-ring resonant cavity is coupled to the second waveguide. The first light splitting apparatus receives an inputted first light signal by means of the first waveguide. Then, the first light splitting apparatus generates a second light signal according to the first light signal, and outputs the second light signal by means of the second waveguide. The resonant wavelength adjustment apparatus on each micro-ring resonant cavity is used for adjusting the resonance wavelength of each micro-ring resonant cavity. The plurality of cascaded micro-ring resonant cavities are used for performing dispersion compensation on the second light signal.

Description

Dispersion compensation device, transmitter, receiver and dispersion compensation method

This application claims the priority of the Chinese patent application filed on December 28, 2020 with the State Intellectual Property Office of China, the application number is 202011587894.0, and the application name is "A Dispersion Compensation Device, Transmitter, Receiver and Dispersion Compensation Method", The entire contents of which are incorporated herein by reference.

technical field

The present application relates to the field of optical communication, and in particular, to a dispersion compensation device, a transmitter, a receiver and a dispersion compensation method.

Background technique

In the development process of optical communication field, optical fiber plays a crucial role. Dispersion is a major factor affecting the use of optical fibers. The dispersion of optical fiber mainly includes material dispersion and waveguide dispersion. The existence of chromatic dispersion will make the optical signals of different wavelengths in the fiber transmit at different speeds, so that the signal will be broadened after a certain distance of transmission. The main way to solve the fiber dispersion problem is to compensate for it.

A current method of dispersion compensation is to use cascaded microring resonators. The micro-ring resonator has the delay characteristic, which can make the delay of long-wavelength signals short and the delay of short-wavelength signals long. The resonant wavelength of each micro-ring resonator is adjustable, but the coupling coefficient of each micro-ring resonator is fixed, resulting in the inability to adjust the compensation value of dispersion and poor flexibility.

SUMMARY OF THE INVENTION

Embodiments of the present application provide a dispersion compensation device, a transmitter, a receiver, and a dispersion compensation method, so as to flexibly adjust the dispersion compensation value.

In a first aspect, an embodiment of the present application provides a dispersion compensation device. The dispersion compensation device includes a first optical splitting device, a first waveguide, a second waveguide and a plurality of cascaded microring resonators. A resonance wavelength adjusting device is arranged on each microring resonant cavity. Wherein, the first waveguide is connected to the first light splitting device. The second waveguide is connected to the first light splitting device. Each microring resonator is coupled to the second waveguide.

First, the first optical splitting device is used for receiving the input first optical signal through the first waveguide. After that, the first optical splitting device is used for generating the second optical signal according to the first optical signal, and outputting the second optical signal through the second waveguide. The resonance wavelength adjustment device on each micro-ring resonator is used to adjust the resonant wavelength of each micro-ring resonator. and then. A plurality of cascaded microring resonators are used for dispersion compensation for the second optical signal.

In this embodiment, the optical power of the optical signal transmitted on the second waveguide is also adjustable. That is, the coupling coefficients of multiple microring resonators can be adjusted as a whole. Therefore, the compensation value of the dispersion is adjustable, so that the flexibility of the dispersion compensation is better. In addition, the dispersion compensation device does not need to adjust the coupling coefficient of each micro-ring resonant cavity, and the effect of dispersion compensation is also better, the parameters to be adjusted are reduced, and the adjustment process is simpler.

In some possible implementations, the dispersion compensation device further includes a second light splitting device, a third waveguide and a fourth waveguide. The first light splitting device is connected to the second light splitting device through the second waveguide and the third waveguide. The fourth waveguide is connected to the second light splitting device. The first optical splitting device is further configured to generate a third optical signal according to the first optical signal, and output the third optical signal through the third waveguide. The second optical splitting device is used for receiving the dispersion-compensated second optical signal and the third optical signal. Furthermore, the second optical splitting device is configured to generate a fourth optical signal according to the dispersion-compensated second optical signal and the third optical signal, and output the fourth optical signal through the fourth waveguide.

In this embodiment, the first optical splitting device divides the input first optical signal into two paths, which are the second optical signal and the third optical signal respectively. Wherein, it is only necessary to perform dispersion compensation on the second optical signal. The second optical splitting device then combines the third optical signal and the dispersion-compensated second optical signal into a fourth optical signal and outputs it. The second optical splitting device will try to ensure that the optical power of the fourth optical signal is the maximum, thereby reducing the optical power loss of the first optical signal passing through the dispersion compensation device.

In some possible implementations, the dispersion compensation apparatus further includes a first controller. The first controller is used to adjust the optical power of the second optical signal. Thus, the coupling coefficient of each microring resonator can be adjusted flexibly.

In some possible implementations, the dispersion compensation device further includes a second controller. The second controller is further configured to adjust the resonant wavelength of the at least one micro-ring resonant cavity by controlling the temperature or voltage of the resonant wavelength adjusting device on the at least one micro-ring resonating cavity. In this embodiment, various implementations for adjusting the resonance wavelength of the microring resonator are provided, which improves the scalability of the solution.

In some possible implementations, the first spectroscopic device includes a first multimode interferometer (Multimode Interferometer, MMI), a second MMI and a phase adjustment device. The first MMI is used for splitting the first optical signal to obtain the first sub-signal and the second sub-signal. The phase adjustment device is used for phase adjustment of the first sub-signal. The phase-adjusted first and second sub-signals are output to the second MMI. Since the phase of the first sub-signal is adjusted, the two-way sub-signal received by the second MMI will transition between constructive interference and destructive interference. Therefore, based on the change of the phase adjustment amount of the first sub-signal, the optical power of the second optical signal and the optical power of the third optical signal output by the second MMI will also change accordingly. It should be understood that the optical power of the second optical signal and the optical power of the third optical signal are in a state of trade-offs. The specific implementation of the first spectroscopic device in this embodiment improves the practicability of this solution.

In some possible implementations, the first light splitting device includes a first directional coupler (DC), a second DC and a phase adjustment device. The DC can distribute the optical power of the two optical signals it outputs by adjusting the coupling amount between the two parallel waveguides inside it. That is to say, the DC can realize the similar function of the MMI in the above-mentioned embodiment. Specifically, the first DC is used to split the first optical signal to obtain the first sub-signal and the second sub-signal. The phase adjustment device is used for phase adjustment of the first sub-signal. The second DC is used to generate the second optical signal and the third optical signal according to the phase-adjusted first sub-signal and the second sub-signal. Another specific implementation manner of the first spectroscopic device provided by this embodiment improves the flexibility of this solution.

In some possible embodiments, the dispersion compensation device further includes a polarization converter. The polarization converter is on the second waveguide. The polarization converter is used for converting the first polarization direction of the second optical signal to the second polarization direction. Specifically, the second optical signal can be understood as being formed by combining two optical signals whose polarization directions are orthogonal to each other according to a certain ratio. That is, the first polarization direction of the second optical signal includes two mutually orthogonal deflection direction components. The microring resonator usually supports only one of the polarization direction components, that is, the second polarization direction. In this way, the loss of optical power due to dispersion compensation can be reduced.

In some possible embodiments, the dispersion compensation device further includes a polarization converter. The polarization converter is on the first waveguide. The polarization converter is used to convert the first polarization direction of the first optical signal to the second polarization direction. In this embodiment, another design position of the polarization converter is provided, which improves the scalability of the solution.

In a second aspect, the present application provides a dispersion compensation method. The method includes the following steps. First, the dispersion compensation device receives the first optical signal from the first waveguide. After that, the dispersion compensation device generates a second optical signal according to the first optical signal, and outputs the second optical signal through the second waveguide. Wherein, the dispersion compensation device includes a plurality of cascaded micro-ring resonators, and each micro-ring resonator is coupled with the second waveguide. The dispersion compensation device adjusts the resonance wavelength of the at least one microring resonator. Furthermore, the dispersion compensation device performs dispersion compensation on the second optical signal through a plurality of cascaded microring resonators.

In some possible implementations, the method further includes: the dispersion compensation device generates a third optical signal according to the first optical signal, and outputs the third optical signal through a third waveguide. The dispersion compensation device generates a fourth optical signal according to the dispersion-compensated second optical signal and the third optical signal, and outputs the fourth optical signal through the fourth waveguide.

In some possible implementations, the method further includes: the dispersion compensation device adjusts the optical power of the second optical signal. Wherein, the optical power of the second optical signal is less than or equal to the optical power of the first optical signal.

In some possible implementations, the dispersion compensation device adjusting the resonance wavelength of the at least one micro-ring resonator includes: the dispersion compensating device adjusts the temperature or voltage of the resonance wavelength adjustment device on the at least one micro-ring resonator to adjust the at least one micro-ring resonator. The resonance wavelength of the ring resonator.

In some possible implementations, the dispersion compensation device generating the second optical signal and the third optical signal according to the first optical signal includes: the dispersion compensation device splits the first optical signal to obtain the first sub-signal and the second sub-signal. The dispersion compensation device performs phase adjustment on the first sub-signal. The dispersion compensation device generates the second optical signal and the third optical signal according to the phase-adjusted first sub-signal and the second sub-signal.

In some possible implementations, the method further includes: the dispersion compensation device converts the first polarization direction of the second optical signal to the second polarization direction.

In some possible implementations, the method further includes: the dispersion compensation device converts the first polarization direction of the first optical signal to the second polarization direction.

In a third aspect, the present application provides a transmitter. The transmitter includes a light emitting device and a dispersion compensating device as shown in any embodiment of the first aspect. The dispersion compensation device is used for performing dispersion compensation on the optical signal emitted by the light emitting device, and outputting the optical signal after dispersion compensation.

In a fourth aspect, the present application provides a receiver. The receiver includes an optical receiving device and a dispersion compensating device as shown in any one of the embodiments of the first aspect. The dispersion compensation device is used for performing dispersion compensation on the received optical signal, and sending the dispersion-compensated optical signal to the optical receiving device.

In the embodiment of the present application, the optical power of the input optical signal can be adjusted by a light splitting device, and the optical signal output by the light splitting device is transmitted through a waveguide, and a plurality of cascaded microring resonators are coupled to the waveguide. Multiple cascaded microring resonators are used for dispersion compensation of the optical signal transmitted on the waveguide. Among them, the resonance wavelength of each microring resonator is tunable. In addition, the optical power of the optical signal transmitted on the waveguide is also adjustable, that is, the coupling coefficient of the plurality of microring resonators can be adjusted as a whole. Therefore, the compensation value of the dispersion is adjustable, so that the flexibility of the dispersion compensation is better. In addition, the dispersion compensation device does not need to adjust the coupling coefficient of each micro-ring resonant cavity, and the effect of dispersion compensation is also better, the parameters to be adjusted are reduced, and the adjustment process is simpler.

Description of drawings

1 is a schematic structural diagram of a current dispersion compensation device;

FIG. 2 is a schematic structural diagram of a first structure of a dispersion compensation device provided by an embodiment of the present application;

3 is a schematic diagram of a second structure of a dispersion compensation device provided by an embodiment of the present application;

FIG. 4 is a schematic diagram of a third structure of a dispersion compensation device provided by an embodiment of the present application;

FIG. 5 is a schematic diagram of a fourth structure of a dispersion compensation device provided by an embodiment of the present application;

FIG. 6 is a schematic diagram of a fifth structure of a dispersion compensation device provided by an embodiment of the present application;

FIG. 7 is a schematic diagram of a sixth structure of a dispersion compensation device provided by an embodiment of the present application;

FIG. 8(a) is a schematic diagram of a parameter adjustment amount of the dispersion compensation device in the embodiment of the present application;

8(b) is a schematic diagram of a dispersion curve realized by a dispersion compensation device in an embodiment of the application;

FIG. 9 is a schematic flowchart of a dispersion compensation method provided by an embodiment of the present application;

FIG. 10 is a schematic structural diagram of a transmitter according to an embodiment of the present application;

FIG. 11 is a schematic structural diagram of a receiver provided by an embodiment of the present application.

Detailed ways

Embodiments of the present application provide a dispersion compensation device, a transmitter, a receiver, and a dispersion compensation method. The compensation value of dispersion is adjustable, which makes dispersion compensation more flexible.

It should be noted that the terms "first", "second", "third" and "fourth" in the description and claims of the present application and the above drawings are used to distinguish similar objects, rather than limiting specific order or sequence. It is to be understood that the above terms are interchangeable under appropriate circumstances so that the embodiments described herein can be practiced in sequences other than those described herein. Furthermore, the terms "comprising" and "having", and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device comprising a series of steps or units is not necessarily limited to those steps or units expressly listed, but may include steps or units not expressly listed or for such process, method, product or Other steps or units inherent to the device.

FIG. 1 is a schematic structural diagram of a current dispersion compensation device. As shown in Figure 1, dispersion compensation is achieved by using multiple cascaded microring resonators. Among them, each micro-ring resonator is coupled with the waveguide, and the coupling coefficient of each micro-ring resonator is fixed. In actual use, the resonant wavelength of each microring resonator can only be adjusted to an appropriate position. However, the coupling coefficient of each microring resonator cannot be adjusted, so that the compensation value of dispersion cannot be adjusted, and the flexibility of dispersion compensation is poor.

Therefore, the present application provides a dispersion compensation device, which improves the flexibility of dispersion compensation.

FIG. 2 is a schematic structural diagram of a first structure of a dispersion compensation apparatus provided by an embodiment of the present application. The dispersion compensation device includes: a first optical splitting device 10 , a first waveguide 20 , a second waveguide 30 and a plurality of cascaded microring resonators 40 . Wherein, two ends of the first optical splitting device 10 are respectively connected to the first waveguide 20 and the second waveguide 30 . Each microring resonator is coupled to the second waveguide 30 . A resonance wavelength adjustment device 401 is also arranged on each microring resonator. Specifically, the first optical splitting device 10 is configured to receive the input first optical signal through the first waveguide 20 . After that, the first optical splitting device 10 generates a second optical signal according to the first optical signal, and outputs the second optical signal through the second waveguide 30 . A plurality of cascaded microring resonators 40 are used for dispersion compensation for the second optical signal. In addition, the resonance wavelength adjustment device 401 on each micro-ring resonator is used to adjust the resonant wavelength of each micro-ring resonator, so that dispersion compensation can be realized at different resonant wavelengths.

It should be understood that the first optical splitting device 10 can adjust the optical power of the second optical signal output by the first optical splitting device 10 . Thus, the optical energy coupled to each microring resonator by the second waveguide 30 is tunable. That is to say, the first optical splitting device 10 can adjust the coupling coefficient of each microring resonator as a whole, so that the compensation value of dispersion can be adjusted. For example, if the optical power of the second optical signal is equal to the optical power of the first optical signal, the coupling coefficient of each microring resonator is equal to the coupling coefficient of the respective factory design. For another example, if the optical power of the second optical signal is equal to 0, the coupling coefficient of each microring resonator is equal to 0. For another example, if the optical power of the second optical signal is greater than 0 and less than the optical power of the first optical signal, the coupling coefficient of each microring resonator is between 0 and the coupling coefficient at the factory design. In a possible implementation manner, the first light splitting device 10 may be an optical attenuator. The first optical splitting device 10 performs power attenuation processing on the first optical signal, so that the optical power of the second optical signal is smaller than the optical power of the first optical signal. Among them, the attenuation of the power is adjustable, so that the coupling coefficient of each microring resonator can be flexibly adjusted.

It should be noted that the coupling coefficient of each microring resonator can be the same. Alternatively, the coupling coefficients of at least two microring resonators are different, so that the adjustable range of the dispersion compensation value is larger. Specifically, the initial coupling coefficient of the microring resonant cavity can be adjusted by changing the distance between the microring resonating cavity and the second waveguide 30 .

The microring resonator in this application may be an all-pass type microring, or a Mach Zehnder Interferometer (Mach Zehnder Interferometer, MZI)-assisted microring, which is not specifically limited. In addition, as long as the microring resonator has a closed structure, the present application does not limit its specific shape. For example, it may be a micro-ring structure as shown in FIG. 1, or a micro-disk structure or the like.

FIG. 3 is a schematic diagram of a second structure of a dispersion compensation apparatus provided in an embodiment of the present application. On the basis of the structure shown in FIG. 2 , the dispersion compensation device further includes: a second light splitting device 60 , a third waveguide 50 and a fourth waveguide 70 . One end of the first optical splitting device 10 is connected to the first waveguide 20 . The other end of the first spectroscopic device 10 is connected to one end of the second spectroscopic device 60 through the second waveguide 30 and the third waveguide 50 . The other end of the second light splitting device 60 is connected to the fourth waveguide 70 . Specifically, the first optical splitting device 10 splits the inputted first optical signal to obtain the second optical signal and the third optical signal, which are respectively output through the second waveguide 30 and the third waveguide 50 . The second optical splitting device 60 receives the dispersion-compensated second optical signal and the third optical signal. Furthermore, the second optical splitting device 60 generates a fourth optical signal according to the dispersion-compensated second optical signal and the third optical signal, and outputs the fourth optical signal through the fourth waveguide 70 .

It should be understood that the first optical splitting device 10 can adjust the optical power ratio of the second optical signal and the third optical signal, so as to adjust the coupling coefficient of each microring resonator as a whole. The optical power of the first optical signal should be greater than or equal to the sum of the optical power of the second optical signal and the optical power of the third optical signal. After the second optical signal is subjected to dispersion compensation, there will be a certain degree of power loss. However, the second optical splitting device 60 will try to ensure that the optical power of the fourth optical signal after the multiplexing of the two optical signals is the maximum. That is, compared with the structure shown in FIG. 2 , the structure shown in FIG. 3 reduces the optical power loss of the first optical signal passing through the dispersion compensation device.

It should be noted that the above description is made by taking the light input from the first spectroscopic device 10 and output from the second spectroscopic device 60 as an example. In practical applications, light can also be input from the second light splitting device 60 and output from the first light splitting device 10 . In this case, the functions implemented by the first spectroscopic device 10 and the second spectroscopic device 20 will be interchanged, and details will not be repeated here.

FIG. 4 is a schematic diagram of a third structure of the dispersion compensation apparatus provided by the embodiment of the present application. In a possible implementation manner, the dispersion compensation device further includes a controller 80 for controlling the first spectroscopic device 10 and the second spectroscopic device 60. For example, the controller 80 controls the first optical splitting device 10 according to the required dispersion compensation value to adjust the optical power of the second optical signal. The controller 80 can also control the resonance wavelength adjusting device 401 on each micro-ring resonant cavity to adjust the resonant wavelength of each micro-ring resonating cavity. Optionally, the controller 80 may control the resonance wavelength adjustment device 401 on one or more microring resonators according to actual needs. On the basis of not changing the structure of the dispersion compensation device, the number of microring resonators used can be flexibly selected. In another possible implementation manner, the first optical splitting device 10, the second optical splitting device 60 and the multiple cascaded microring resonators 40 may be controlled by different controllers. For example, as shown in FIG. 4 , the first controller 801 is used to control the first spectroscopic device 10 and the second spectroscopic device 60 . The second controller 802 is used to control a plurality of cascaded microring resonators 40 .

It should be noted that the resonance wavelength adjustment device 401 may be a micro electrode. The controller 80 can adjust the resonance wavelength of each microring resonator by controlling the temperature of the micro electrodes on each microring resonator. Specifically, the microring resonator can use materials with thermo-optic effects, such as dielectric materials (silicon dioxide and silicon nitride) or semiconductor materials (III-V and silicon). The temperature change of the micro-electrode will change the local temperature of the micro-ring resonator. Based on the thermo-optic effect, the refractive index of the material will be changed to adjust the resonant wavelength of the micro-ring resonator. Alternatively, the microring resonator can also be based on electrical tuning. For example, silicon-based optoelectronic modulation utilizing the plasmonic dispersion effect. As another example, electro-optical materials such as lithium niobate are utilized. The controller 80 changes the refractive index of the material by controlling the voltage on the micro-electrodes, thereby adjusting the resonant wavelength of the micro-ring resonant cavity.

FIG. 5 is a schematic diagram of a fourth structure of the dispersion compensation device provided by the embodiment of the present application. The dispersion compensation device may further include a first polarization converter 901 and a second polarization converter 902 . Wherein, the first polarization converter 901 and the second polarization converter 902 are arranged on the second waveguide 30 . A plurality of cascaded microring resonators 40 are located between the first polarization converter 901 and the second polarization converter 902 . Specifically, the second optical signal can be understood as being formed by combining two optical signals whose polarization directions are orthogonal to each other according to a certain ratio. That is, the polarization direction of the second optical signal includes two mutually orthogonal deflection direction components. For example, the two mutually orthogonal deflection direction components are a transverse electric (Transverse Electric, TE) polarization direction and a transverse magnetic (Transverse Magnetic, TM) polarization direction, respectively. In order to reduce the loss of optical power due to dispersion compensation, microring resonators usually only support the TE polarization direction. Therefore, the first polarization converter 901 is used to convert the original polarization direction of the second optical signal into the TE polarization direction. The second optical signal whose polarization direction is converted no longer has the TM polarization direction component. The second polarization converter 902 is used for reconverting the TE polarization direction of the dispersion-compensated second optical signal to the original polarization direction. Ensure that the polarization directions of the input optical signal and the output optical signal are synchronized.

It should be noted that the positions of the first polarization converter 901 and the second polarization converter 902 in the dispersion compensation device may have various changes. It only needs to ensure that the first polarization converter 901 performs polarization conversion before dispersion compensation, and the second polarization converter 902 performs polarization conversion after dispersion compensation, which is not specifically limited here. For example, the first polarization converter 901 is arranged on the first waveguide 20 , and the second polarization converter 902 is arranged on the fourth waveguide 70 . For another example, the first polarization converter 901 is arranged on the first waveguide 20 , and the second polarization converter 902 is arranged on the second waveguide 30 . For another example, the first polarization converter 901 is arranged on the second waveguide 30 , and the second polarization converter 902 is arranged on the fourth waveguide 70 . Through the above design method, polarization conversion can be performed before dispersion compensation, thereby reducing the loss of optical power caused by dispersion compensation. In addition, the function of polarization conversion is integrated in the dispersion compensation device, which also expands the function of the dispersion compensation device.

It should be noted that, the above-mentioned first spectroscopic device 10 may have various internal implementation manners, which will be introduced separately below.

FIG. 6 is a schematic diagram of a fifth structure of the dispersion compensation device provided by the embodiment of the present application. The first spectroscopic device 10 includes a multimode interferometer (MMI) 101 , a phase adjustment device 102 and a multimode interferometer 103 . Specifically, the multimode interferometer 101 is used for splitting the first optical signal to obtain the first sub-signal and the second sub-signal. Wherein, the multimode interferometer 101 may perform equal splitting or unequal splitting on the first optical signal, which is not specifically limited here. The phase adjustment device 102 is used for phase adjustment of the first sub-signal. The phase-adjusted first sub-signal and the second sub-signal are output to the multimode interferometer 103 . Since the phase of the first sub-signal is adjusted, the two sub-signals received by the multimode interferometer 103 will transition between constructive interference and destructive interference. Therefore, based on the change of the phase adjustment amount of the first sub-signal, the optical power of the second optical signal and the optical power of the third optical signal output by the multimode interferometer 103 will also change accordingly. It should be understood that the optical power of the second optical signal and the optical power of the third optical signal are in a state of trade-offs. Optionally, the phase adjustment device 102 only needs to perform phase adjustment on any one of the sub-signals output by the multimode interferometer 101 , which is not specifically limited here.

It should be noted that, the second spectroscopic device 60 may also adopt the same design manner as the first spectroscopic device 10 . That is, the second spectroscopic device 60 includes a multimode interferometer 601 , a phase adjustment device 602 and a multimode interferometer 603 . Specifically, the multimode interferometer 601 is used to receive the dispersion-compensated second optical signal and the third optical signal, and output two optical signals. The powers of the two optical signals output by the multimode interferometer 601 may be the same or different. The phase adjustment device 602 is used to adjust the phase of one of the optical signals output by the multimode interferometer 601 . The multimode interferometer 603 is configured to receive another optical signal output by the multimode interferometer 601 and the phase-adjusted optical signal output by the phase adjusting device 602 . Furthermore, the multimode interferometer 603 generates a fourth optical signal according to the received two-path optical signals. In a preferred embodiment, the optical signal processed by the phase adjusting device 602 should cause constructive interference with another optical signal. Therefore, the optical power of the fourth optical signal after the multiplexing of the two optical signals is maximized.

FIG. 7 is a schematic diagram of a sixth structure of the dispersion compensation device provided by the embodiment of the present application. The difference from the structure shown in FIG. 6 above is that a directional coupler (DC) is used instead of the MMI. That is, the first light splitting device 10 includes a directional coupler 101 , a phase adjusting device 102 and a directional coupler 103 . The second light splitting device 60 includes a directional coupler 601 , a phase adjusting device 602 and a directional coupler 603 . Specifically, the DC can distribute the optical power of the two optical signals output by the DC by adjusting the coupling amount between the two parallel waveguides in the DC. That is to say, the DC in this embodiment can implement the similar functions of the MMI in the above-mentioned embodiment. For the specific working manners of the first light splitting device 10 and the second light splitting device 60, reference may be made to the relevant description of the embodiment shown in FIG. 6 above, and details are not repeated here.

In practical applications, the structures of the first optical splitting device and the second optical splitting device include but are not limited to the structures shown in FIG. 6 and FIG. 7 , and the optical splitting devices capable of realizing adjustable optical power of the output optical signal are all protected by the present application. within the range.

The dispersion compensation effect achieved by the above dispersion compensation device will be described below through a specific simulation example.

FIG. 8( a ) is a schematic diagram of a parameter adjustment amount of the dispersion compensation device in the embodiment of the present application. FIG. 8( b ) is a schematic diagram of a dispersion curve realized by a dispersion compensation device in an embodiment of the present application. Specifically, reference may be made to the dispersion compensation device shown in FIG. 6 or FIG. 7 , in which the number of microring resonators is seven. As shown in Fig. 8(a), the abscissa represents the adjustable parameters in the dispersion compensation device, and the ordinate represents the phase value. Here, phi1 represents the phase shift amount of the phase adjustment device 102 . phi2 represents the phase shift amount of the phase adjustment device 602 . Phi-r1 to Phi-r7 represent the phase shift amounts of the resonance wavelength adjusting means 401 on the seven microring resonators, respectively. Based on the parameter adjustment amounts shown in FIG. 8( a ), as shown in FIG. 8( b ), the abscissa represents the wavelength, and the ordinate represents the dispersion compensation value. The dispersion curve with -650ps/nm as the dispersion compensation value can be realized by the dispersion compensation device, and the dispersion jitter value is less than ±10ps/nm.

In the embodiment of the present application, the optical power of the input optical signal is adjusted by a light splitting device, and the optical signal output by the light splitting device is transmitted through a waveguide, and a plurality of cascaded microring resonators are coupled to the waveguide. Multiple cascaded microring resonators are used for dispersion compensation of the optical signal transmitted on the waveguide. Among them, the resonance wavelength of each microring resonator is tunable. In addition, the optical power of the optical signal transmitted on the waveguide is also adjustable, that is, the coupling coefficient of the plurality of microring resonators can be adjusted as a whole. Therefore, the flexibility of dispersion compensation is made better. In addition, the dispersion compensation device does not need to adjust the coupling coefficient of each micro-ring resonant cavity, and the effect of dispersion compensation is also better, the parameters to be adjusted are reduced, and the adjustment process is simpler.

Based on the introduction of the above-mentioned dispersion compensation device, a dispersion compensation method corresponding to the upper dispersion compensation device is introduced below. It should be noted that, the structure of the apparatus corresponding to the following dispersion compensation method may be as described in the foregoing apparatus embodiment. However, it is not limited to the dispersion compensation device described above.

FIG. 9 is a schematic flowchart of a dispersion compensation method provided by an embodiment of the present application. It should be noted that, the dispersion compensating device in this embodiment may specifically be the dispersion compensating device in any of the embodiments shown in FIGS. 2-7 above. In this example, the dispersion compensation method includes the following steps.

901. The dispersion compensation apparatus receives the first optical signal from the first waveguide.

902. The dispersion compensation apparatus generates a second optical signal according to the first optical signal, and transmits the second optical signal through the second waveguide.

In this embodiment, the dispersion compensation device can adjust the optical power of the second optical signal output by the dispersion compensation device. In a possible implementation manner, the dispersion compensation device may perform power attenuation processing on the first optical signal, so that the optical power of the second optical signal is smaller than the optical power of the first optical signal. In another possible implementation manner, the dispersion compensation device may further generate the second optical signal and the third optical signal according to the first optical signal. Wherein, the optical power ratio of the second optical signal and the third optical signal is adjustable. It should be noted that the dispersion compensation device includes a plurality of cascaded microring resonators. Each microring resonator is coupled to the second waveguide. Since the optical power of the second optical signal is adjustable, the coupling coefficient of each microring resonator can be flexibly adjusted. It should be understood that for the specific structure of the dispersion compensation device, reference may be made to the relevant descriptions of the foregoing device embodiments, and details are not repeated here.

903. The dispersion compensation device adjusts the resonance wavelength of the at least one microring resonant cavity.

A resonance wavelength adjusting device is arranged on each microring resonant cavity. The dispersion compensation device can control the resonance wavelength adjustment device on one or more microring resonators according to actual needs. On the basis of not changing the structure of the dispersion compensation device, the number of microring resonators used can be flexibly selected. Specifically, the dispersion compensation device can adjust the resonant wavelength of the microring resonant cavity by controlling the temperature or voltage on the resonant wavelength adjustment device.

904. The dispersion compensation device performs dispersion compensation on the second optical signal through a plurality of cascaded microring resonators.

In a possible implementation manner, the dispersion compensation device further generates a fourth optical signal according to the dispersion-compensated second optical signal and the third optical signal, and outputs the fourth optical signal. Wherein, the optical power of the first optical signal is not much different from the optical power of the fourth optical signal, which reduces the loss of optical power.

In another possible implementation manner, before performing dispersion compensation, the dispersion compensation device may convert the polarization direction of the optical signal. For example, the dispersion compensation device converts the polarization direction of the first optical signal or the polarization direction of the second optical signal. After the dispersion compensation is completed, the dispersion compensation device restores the polarization direction of the optical signal before the dispersion compensation. For example, the dispersion compensation device converts the polarization direction of the dispersion-compensated second optical signal or the polarization direction of the fourth optical signal.

It should be noted that the dispersion compensation device described above can be implemented as an independent package structure. Alternatively, the dispersion compensation device can also be integrated in the transmitter or the receiver. Further introduction is given below.

FIG. 10 is a schematic structural diagram of a transmitter according to an embodiment of the present application. The transmitter includes a light emitting device 1001 and a dispersion compensation device 1002 . Specifically, the dispersion compensation device 1002 is configured to perform dispersion pre-compensation on the optical signal emitted by the light emitting device 1001, and output the optical signal after dispersion pre-compensation. That is, the dispersion compensation device 1002 is used to perform dispersion compensation on the optical signal in advance before it is coupled into the optical fiber. It should be understood that the dispersion compensating apparatus 1002 in the transmitter is similar to the dispersion compensating apparatus described in the above embodiments, and details are not described herein again. The light emitting device 1001 may be an optical module or a light emitting assembly (Transmitting Optical sub-assembly, TOSA), which is not specifically limited here.

FIG. 11 is a schematic structural diagram of a receiver provided by an embodiment of the present application. The receiver includes an optical receiving device 1101 and a dispersion compensation device 1102 . Specifically, the dispersion compensation device 1102 is configured to perform dispersion compensation on the received optical signal, and output the dispersion-compensated optical signal to the optical receiving device 1101 . It should be understood that the dispersion compensating apparatus 1102 in the receiver is similar to the dispersion compensating apparatus described in the foregoing embodiments, and details are not described herein again. The optical receiving device 1101 may be an optical module or an optical receiving assembly (Receiving Optical sub-assembly, ROSA), which is not specifically limited here.

Claims

A dispersion compensation device, comprising: a first optical splitting device, a first waveguide, a second waveguide and a plurality of cascaded microring resonators, wherein:

the first waveguide is connected to the first optical splitting device, the second waveguide is connected to the first optical splitting device, and each of the microring resonators is coupled to the second waveguide;

The first optical splitting device is configured to: receive an input first optical signal through the first waveguide, generate a second optical signal according to the first optical signal, and output the second optical signal through the second waveguide;

Each of the micro-ring resonators is provided with a resonance wavelength adjustment device, wherein the resonance wavelength adjustment device on each of the micro-ring resonators is used to adjust the resonance wavelength of each of the micro-ring resonators;

The plurality of cascaded microring resonators are used to perform dispersion compensation on the second optical signal.
The dispersion compensation device according to claim 1, wherein the dispersion compensation device further comprises a second optical splitting device, a third waveguide and a fourth waveguide, and the first optical splitting device passes through the second waveguide and the The third waveguide is connected to the second light splitting device, and the fourth waveguide is connected to the second light splitting device;

The first optical splitting device is further configured to: generate a third optical signal according to the first optical signal, and output the third optical signal through the third waveguide;

The second optical splitting device is configured to: receive the dispersion-compensated second optical signal and the third optical signal, and generate a fourth optical signal according to the dispersion-compensated second optical signal and the third optical signal signal, and output the fourth optical signal through the fourth waveguide.
The dispersion compensation device according to claim 1 or 2, wherein the dispersion compensation device further comprises a first controller, and the first controller is used to adjust the optical power of the second optical signal, and the first controller is used to adjust the optical power of the second optical signal. The optical power of the second optical signal is less than or equal to the optical power of the first optical signal.
The dispersion compensation device according to any one of claims 1 to 3, wherein the dispersion compensation device further comprises a second controller, and the second controller is further configured to control at least one microring resonant cavity The temperature or voltage on the resonant wavelength adjusting device is adjusted to adjust the resonant wavelength of the at least one micro-ring resonant cavity.
The dispersion compensation device according to any one of claims 2 to 4, wherein the first light splitting device comprises a first multimode interferometer MMI, a second MMI and a phase adjustment device;

The first MMI is used for splitting the first optical signal to obtain a first sub-signal and a second sub-signal;

The phase adjustment device is used to perform phase adjustment on the first sub-signal;

The second MMI is configured to generate the second optical signal and the third optical signal according to the phase-adjusted first sub-signal and the second sub-signal.
The dispersion compensation device according to any one of claims 2 to 4, wherein the first optical splitting device comprises a first directional coupler DC, a second DC and a phase adjustment device;

The first DC is used for splitting the first optical signal to obtain a first sub-signal and a second sub-signal;

The phase adjustment device is used to perform phase adjustment on the first sub-signal;

The second DC is used for generating the second optical signal and the third optical signal according to the phase-adjusted first sub-signal and the second sub-signal.
The dispersion compensation device according to any one of claims 1 to 6, wherein the dispersion compensation device further comprises a polarization converter, and the polarization converter is on the second waveguide;

The polarization converter is used for converting the first polarization direction of the second optical signal into a second polarization direction.
The dispersion compensation device according to any one of claims 1 to 6, wherein the dispersion compensation device further comprises a polarization converter, and the polarization converter is on the first waveguide;

The polarization converter is used to convert the first polarization direction of the first optical signal into a second polarization direction.
A dispersion compensation method, characterized in that the method comprises:

The dispersion compensation device receives the first optical signal from the first waveguide;

The dispersion compensation device generates a second optical signal according to the first optical signal, and outputs the second optical signal through a second waveguide, and the dispersion compensation device includes a plurality of cascaded micro-ring resonators, each of which is the microring resonator is coupled with the second waveguide;

The dispersion compensation device adjusts the resonance wavelength of at least one of the microring resonators;

The dispersion compensation device performs dispersion compensation on the second optical signal through the plurality of cascaded microring resonators.
The method according to claim 9, wherein the method further comprises:

The dispersion compensation device generates a third optical signal according to the first optical signal, and outputs the third optical signal through a third waveguide;

The dispersion compensation device generates a fourth optical signal according to the dispersion-compensated second optical signal and the third optical signal, and outputs the fourth optical signal through a fourth waveguide.
The method according to claim 9 or 10, wherein the method further comprises:

The dispersion compensation device adjusts the optical power of the second optical signal, and the optical power of the second optical signal is less than or equal to the optical power of the first optical signal.
The method according to any one of claims 9 to 11, wherein adjusting the resonance wavelength of at least one of the microring resonators by the dispersion compensation device comprises:

The dispersion compensation device adjusts the resonant wavelength of the at least one micro-ring resonant cavity by controlling the temperature or voltage of the resonant wavelength adjusting device on the at least one micro-ring resonating cavity.
The method according to any one of claims 10 to 12, wherein the step of generating the second optical signal and the third optical signal according to the first optical signal by the dispersion compensation device comprises:

The dispersion compensation device splits the first optical signal to obtain a first sub-signal and a second sub-signal;

The dispersion compensation device performs phase adjustment on the first sub-signal;

The dispersion compensation device generates the second optical signal and the third optical signal according to the phase-adjusted first sub-signal and the second sub-signal.
The method according to any one of claims 9 to 13, wherein the method further comprises:

The dispersion compensation device converts the first polarization direction of the second optical signal into a second polarization direction.
The method according to any one of claims 9 to 13, wherein the method further comprises:

The dispersion compensation device converts the first polarization direction of the first optical signal into a second polarization direction.
A transmitter, characterized in that it comprises a light emitting device and the dispersion compensation device according to any one of claims 1 to 8, wherein the dispersion compensation device is used to perform dispersion compensation on an optical signal emitted by the light emitting device, And output the optical signal after dispersion compensation.
A receiver, characterized by comprising an optical receiving device and the dispersion compensating device according to any one of claims 1 to 8, wherein the dispersion compensating device is used to perform dispersion compensation on the received optical signal, and The dispersion-compensated optical signal is sent to the optical receiving device.