CN110557218B

CN110557218B - Calibration method and device for wavelength selective switch

Info

Publication number: CN110557218B
Application number: CN201810555941.XA
Authority: CN
Inventors: 贾伟; 毛磊; 邹冰; 赵晗; 冯志勇
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2018-05-31
Filing date: 2018-05-31
Publication date: 2021-03-30
Anticipated expiration: 2038-05-31
Also published as: CN110557218A

Abstract

The embodiment of the application discloses a calibration method and a calibration device for a wavelength selective switch, and relates to the field of optical communication. The method can accurately and quickly detect all WSS frequency offset conditions in the whole network, and reduce the network cost. The method can comprise the following steps: receiving, by a first optical network node, calibration light, wherein the calibration light comprises first calibration light and second calibration light; the first optical network node uses the first calibration light for frequency offset detection of the first optical network node, and transmits the second calibration light to at least one second optical network node.

Description

Calibration method and device for wavelength selective switch

Technical Field

The present disclosure relates to the field of optical communications, and in particular, to a method and an apparatus for calibrating a wavelength selective switch.

Background

The long-distance high-baud-rate optical communication system has long transmission distance, high signal baud rate and extremely close or equal signal spectrum width to channel bandwidth. Signal transmission needs to go up and down through a plurality of levels of light distribution adjustable add drop modules (ROADMs) composed of Wavelength Selective Switches (WSS), and the number of the ROADMs can reach 10 levels, 16 levels or even more. There are numerous ROADMs and WSSs throughout the optical network. Under the influence of factors such as temperature, air pressure, mechanical vibration and aging, the central wavelength or frequency of the WSS filter shifts, i.e., frequency offset occurs. The frequency offset may cause asymmetric filtering of the transmitted signal, degrading signal quality. The influence of frequency offset is worsened under the condition of multistage WSS cascade connection, and the overall filtering bandwidth of a channel can be seriously reduced. Therefore, it is necessary to perform frequency offset calibration on each stage of WSS to eliminate the influence of frequency offset on signal quality.

In the prior art, a method of calibrating frequency offset by connecting a calibration device to each WSS is generally adopted. For example, a calibration device (spectrometer) is externally connected to an output port of each WSS to detect WSS wavelength frequency offset. The wavelength corresponding to a certain column of pixels on the switching engine is deflected to a certain output port by setting a specific phase diagram, then the wavelength corresponding to the column of pixels is detected by using a spectrometer, and compared with a pixel-wavelength corresponding table when leaving a factory, the wavelength frequency offset is detected. Then, the number of pixels with shifted wavelengths is calculated, and the pixel column counter is translated in the control software, so that the pixel columns correspond to the wavelengths one by one again. For example, a calibration device (calibration laser source) is connected to an input port of each WSS, and calibration light output by the calibration laser source is switched to an output port externally connected to a photodetector for detecting optical power. The central wavelength of the filter is changed by adjusting the pixel phase diagram, the optical power is detected, and the central wavelength of the pixel corresponding to the filter is determined. And determining whether the WSS generates frequency offset or not by detecting whether the central wavelength of the pixel changes or not.

However, the frequency offset is calibrated by connecting a calibration device to each WSS, and a calibration device needs to be separately configured for each WSS. On the one hand, the large number of calibration devices increases the network cost; on the other hand, each calibration device is in a different network environment, for example, each ROADM is connected to one calibration device, one ROADM is arranged in beijing, one ROADM is arranged in nanjing, and one ROADM is arranged in uniujiu, each calibration device is far away, the network environment where each calibration device is located has a huge difference, and frequency offset also exists between the calibration devices. Under the condition of WSS cascade, the calibration errors of the detection devices can be converted into errors of the frequency offset detection of each WSS, and the transmission quality of the whole network is influenced. Therefore, a method capable of calibrating the WSS frequency offset of the whole network is needed to be invented, all the WSS frequency offset conditions in the whole network can be accurately and quickly detected, the central wavelengths of all stages of WSSs are calibrated in a unified manner, and the signal transmission quality is improved; and reduces network costs.

Disclosure of Invention

The embodiment of the application provides a calibration method and a calibration device for a wavelength selective switch, which can use calibration light of the same calibration light source to calibrate the central wavelength of each stage of WSS in an optical communication system in a unified manner, accurately and quickly detect the frequency offset condition of all WSS in the whole optical communication system, improve the signal transmission quality and reduce the network cost.

In order to achieve the above purpose, the embodiment of the present application adopts the following technical solutions:

in a first aspect, the present application provides a method of calibrating a wavelength selective switch WSS. The method may be applied to an optical network node, wherein the optical network node comprises W input WSSs and W output WSSs, W being greater than or equal to 1, the method may comprise: receiving, by a first optical network node, calibration light, wherein the calibration light comprises first calibration light and second calibration light; the first optical network node uses the first calibration light for frequency offset detection of the first optical network node; transmitting the second calibration light to at least one second optical network node. In the method, after each optical network node receives calibration light, a part of the calibration light is used for frequency offset detection of the optical network node, and a part of the calibration light is transmitted to other optical network nodes for frequency offset detection of the other optical network nodes. Thus, in the entire optical communication system, one optical network node receives the calibration light of the calibration light source and transmits the calibration light of the calibration light source to each optical network node in the optical communication system. Each optical network node in the optical communication system performs frequency offset detection by using the calibration light of the calibration light source, and the calibration light of the same calibration light source is used, so that calibration errors caused by frequency offsets between different calibration devices are avoided, and the network cost is reduced.

In a possible design of the first aspect, a first input WSS of the first optical network node receives the calibration light, where the first input WSS is any one of W input WSSs, and the W input WSSs are configured to receive the calibration light at different times, respectively; the calibration light comprises a first part of calibration light and a second part of calibration light, and the second part of calibration light comprises a third part of calibration light and a fourth part of calibration light; a first input WSS of the first optical network node transmits a first part of calibration light to a photoelectric detection device connected with the first input WSS of the first optical network node, and transmits a second part of calibration light to a first output WSS of the first optical network node; a first output WSS of the first optical network node receives the second part of the calibration light, transmits a third part of the calibration light to a photoelectric detection device connected with the first output WSS of the first optical network node, and transmits a fourth part of the calibration light to a first input WSS of at least one second optical network node; wherein the first collimated light includes a first portion of collimated light and a third portion of collimated light, and the second collimated light includes a fourth portion of collimated light. In the implementation mode, after an optical network node receives calibration light at a first time, one part of the calibration light is used for frequency offset detection of an input WSS and an output WSS in the optical network node, and the other part of the calibration light is transmitted to other optical network nodes; after the optical network node receives the calibration light at the second moment, one part of the calibration light is used for frequency offset detection of another input WSS and another output WSS in the optical network node, and the other part of the calibration light is transmitted to other optical network nodes; until each WSS of each optical network node in the optical network system utilizes the calibration light to perform frequency offset detection.

In one possible design, the first portion of the calibration light is a first portion of the first input WSS output calibration optical power of the first optical network node, the second portion of the calibration light is a second portion of the first input WSS output calibration optical power of the first optical network node, the third portion of the calibration light is a first portion of the first output WSS output calibration optical power of the first optical network node, and the fourth portion of the calibration light is a second portion of the first output WSS output calibration optical power of the first optical network node.

In one possible design, the first part of the calibration light is the calibration light received within a first time duration of a first input WSS of the first optical network node, the second part of the calibration light is the calibration light received within a second time duration of the first input WSS of the first optical network node, the third part of the calibration light is the calibration light received within a third time duration of a first output WSS of the first optical network node, and the fourth part of the calibration light is the calibration light received within a fourth time duration of the first output WSS of the first optical network node, where the first time duration and the second time duration do not intersect; the third duration and the fourth duration do not intersect.

In one possible design, the first part of the calibration light is the calibration light received within a first time duration of the first input WSS of the first optical network node, the second part of the calibration light is the calibration light received within a second time duration of the first input WSS of the first optical network node, the third part of the calibration light is a first part of the first output WSS output calibration optical power of the first optical network node, and the fourth part of the calibration light is a second part of the first output WSS output calibration optical power of the first optical network node, where the first time duration and the second time duration do not intersect.

In one possible design, the first part of the calibration light is a first part of the output calibration optical power of the first input WSS of the first optical network node, the second part of the calibration light is a second part of the output calibration optical power of the first input WSS of the first optical network node, the third part of the calibration light is the calibration light received within a third time duration of the first output WSS of the first optical network node, and the fourth part of the calibration light is the calibration light received within a fourth time duration of the first output WSS of the first optical network node, where the third time duration and the fourth time duration do not intersect.

In the four possible designs, a mode of splitting the calibration light into power is adopted, the power of the calibration light is attenuated in the transmission process, but the split calibration light has no time delay relative to the original calibration light, the calibration process of the whole optical communication system is fast, and the realization is simple; the mode that the calibration light received in different time lengths is used for different functions is adopted, the transmission process of the calibration light has time delay, the calibration process of the whole optical communication system is slow, but the power of the calibration light is not attenuated in the transmission process, and the quality of the calibration light can be ensured.

In one possible design of the first aspect, a first input WSS of the first optical network node receives the calibration light, wherein the first input WSS is any one of the W input WSSs; a first input WSS of the first optical network node uses the first calibration light for frequency offset detection of each WSS of the first optical network node, and transmits the second calibration light to a first output WSS of the first optical network node; the first output WSS of the first optical network node transmits the second calibration light to the first input WSS of the at least one second optical network node. In the implementation mode, after one optical network node receives the calibration light, one part of the calibration light is used for frequency offset detection of each WSS in the optical network node, and the other part of the calibration light is transmitted to other optical network nodes; until each WSS of each optical network node in the optical network system utilizes the calibration light to perform frequency offset detection.

In one implementation of the first aspect, the calibration light includes a first part of calibration light, a second part of calibration light, and W-1 parts of a third part of calibration light, the second part of calibration light includes a fourth part of calibration light and a fifth part of calibration light, and the parts of the third part of calibration light includes a sixth part of calibration light and a seventh part of calibration light; a first input WSS of the first optical network node transmits the first portion of the calibration light to a first input WSS-connected photo-detection device of the first optical network node; transmitting the second portion of the calibration light to a first output WSS of the first optical network node; and transmitting each of the W-1 parts of the third part of the collimated light to a second output WSS of the first optical network node, wherein the second output WSS is any one of the output WSS of the first optical network node except the first output WSS; a first output WSS of the first optical network node receives the second part of the calibration light, transmits a fourth part of the calibration light to a photoelectric detection device connected with the first output WSS of the first optical network node, and transmits a fifth part of the calibration light to a first input WSS of at least one second optical network node connected with the first output WSS of the first optical network node; the second output WSS of the first optical network node receives a third part of the calibration light, transmits a sixth part of the calibration light to the photoelectric detection device connected with the second output WSS of the first optical network node, and transmits a seventh part of the calibration light to at least one of the second input WSS of the first optical network node; the second input WSS is an input WSS except the first input WSS in the input WSS of the first optical network node; wherein the first collimated light includes a first portion of collimated light, a fourth portion of collimated light, a sixth portion of collimated light, and a seventh portion of collimated light, and the second collimated light includes a fifth portion of collimated light. In the implementation manner, each WSS in the optical network node uses a part of the received calibration light for frequency offset detection of the WSS, and transmits the other part to at least one next WSS until each WSS in the optical network node performs frequency offset detection by using the calibration light received by the first input WSS; and the first output WSS transmits a portion of the received calibration light to other optical network nodes, the calibration light may be transmitted to each WSS of each optical network node in the optical communication system. In one implementation, the second output WSS of the first optical network node transmits the seventh portion of the calibration light to one second input WSS of the first optical network node. In one implementation, the second output WSS of the first optical network node transmits the seventh portion of the calibration light to all of the second input WSSs of the first optical network node.

In one implementation, the first part of the calibration light is a first part of the first input WSS output calibration optical power of the first optical network node, the second part of the calibration light and the W-1 part of the third part of the calibration light are a second part of the first input WSS output calibration optical power of the first optical network node, the fourth part of the calibration light is a first part of the first output WSS output calibration optical power of the first optical network node, the fifth part of the calibration light is a second part of the first output WSS output calibration optical power of the first optical network node, the sixth part of the calibration light is a first part of the second output WSS output calibration optical power of the first optical network node, and the seventh part of the calibration light is a second part of the second output WSS output calibration optical power of the first optical network node.

In one implementation, the first portion of the calibration light is the calibration light received within a first time period of a first input WSS of the first optical network node, the second portion of the calibration light and W-1 of a third portion of the calibration light are the calibration light received within a second time period of the first input WSS of the first optical network node, the fourth portion of the calibration light is the calibration light received within a third time period of a first output WSS of the first optical network node, the fifth portion of the calibration light is the calibration light received within a fourth time period of a first output WSS of the first optical network node, the sixth portion of the calibration light is the calibration light received within a third time period of a second output WSS of the first optical network node, and the seventh portion of the calibration light is the calibration light received within a fourth time period of a second output WSS of the first optical network node, and the first duration and the second duration have no intersection, and the third duration and the fourth duration have no intersection.

In one implementation, the first part of the calibration light is the calibration light received within a first time period of a first input WSS of a first optical network node, and the second part of the calibration light and the W-1 part of the third part of the calibration light are the calibration light received within a second time period of the first input WSS of the first optical network node; the fourth part of the calibration light is a first part of the first output WSS output calibration optical power of the first optical network node, the fifth part of the calibration light is a second part of the first output WSS output calibration optical power of the first optical network node, the sixth part of the calibration light is a first part of the second output WSS output calibration optical power of the first optical network node, and the seventh part of the calibration light is a second part of the second output WSS output calibration optical power of the first optical network node, wherein the first duration and the second duration do not intersect.

In one implementation, the first part of the calibration light is a first part of the output calibration optical power of the first input WSS of the first optical network node, the second part of the calibration light and the W-1 part of the third part of the calibration light are a second part of the output calibration optical power of the first input WSS of the first optical network node, the fourth part of the calibration light is the calibration light received within a third time period of the first output WSS of the first optical network node, the fifth part of the calibration light is the calibration light received within a fourth time period of the first output WSS of the first optical network node, the sixth part of the calibration light is the calibration light received within a third time period of the second output WSS of the first optical network node, and the seventh part of the calibration light is the calibration light received within a fourth time period of the second output WSS of the first optical network node, where the third time period and the fourth time period do not intersect.

In one implementation of the first aspect, the calibration light comprises a first portion of calibration light and a second portion of calibration light; the first calibration light comprises a first portion of calibration light and the second calibration light comprises a second portion of calibration light; the first part of the calibration light is the calibration light received within a first time length of a first input WSS of the first optical network node, the second part of the calibration light is the calibration light received within a second time length of the first input WSS of the first optical network node, and the first time length and the second time length are not intersected; the first part of the calibration light comprises a third part of the calibration light, a fourth part of the calibration light and W-1 parts of a fifth part of the calibration light, and each part of the fifth part of the calibration light comprises a first component calibration light and a second component calibration light; the first input WSS of the first optical network node transmits the third part of the calibration light to the photoelectric detection device connected with the first input WSS of the first optical network node; transmitting the fourth partially collimated light to a first output WSS of the first optical network node; and transmitting each of the W-1 parts of the fifth part of the collimated light to a second output WSS of the first optical network node, wherein the second output WSS is any one of the output WSS of the first optical network node except the first output WSS; the first output WSS of the first optical network node transmits the fourth partially collimated light to the photo-detection device to which the first output WSS of the first optical network node is connected; the second output WSS of the first optical network node transmits the received first component calibration light corresponding to the fifth portion of calibration light to the photodetection device connected to the second output WSS of the first optical network node, and transmits the received second component calibration light corresponding to the fifth portion of calibration light to at least one of the second input WSSs of the first optical network node; the second input WSS is an input WSS except the first input WSS in the input WSS of the first optical network node; the first input WSS of the first optical network node transmits the second portion of the calibration light to the first output WSS of the first optical network node; the first output WSS of the first optical network node transmits the second portion of the calibration light to the first input WSS of the at least one second optical network node. In this implementation manner, each optical network node uses all calibration light received at the first time for frequency offset detection of each WSS in the optical network node, and transmits all calibration light received at the second time to other optical network nodes. In one implementation, the second output WSS of the first optical network node transmits the received second component-calibrated light corresponding to the fifth portion of the calibrated light to a second input WSS of the first optical network node. In one implementation, the second output WSS of the first optical network node transmits the received one of the fifth portions of the calibration light corresponding to the second component calibration light to all of the second input WSSs of the first optical network node.

In one implementation of the first aspect, the first WSS of the first optical network node transmits the calibration light to the regeneration device of the first optical network node; regenerating the calibration light by a regeneration device of the first optical network node, and transmitting the regenerated calibration light to at least one WSS connected with an output port of the first WSS; the first WSS is any one WSS in the first optical network node. In the method, the optical power and the optical signal-to-noise ratio of the calibration light are improved by the regeneration device in the transmission process, so that the power attenuation caused by splitting the calibration light can be eliminated.

In a second aspect, the present application also provides a method of calibrating a wavelength selective switch WSS. The method can comprise the following steps: the first WSS receives the calibration light; the first WSS transmits a first portion of the collimated light to the photo-detection device and a second portion of the collimated light to N second WSSs connected to the first WSS, where N is greater than or equal to 1. In the method, after each WSS in the optical communication system receives the calibration light, one part of the calibration light is used for frequency offset detection of the WSS, and the other part of the calibration light is transmitted to other WSSs for frequency offset detection of the other WSSs. Therefore, all WSSs in the optical communication system can use the calibration light of the same calibration light source to perform frequency offset detection, thereby avoiding calibration errors caused by frequency offsets among different calibration devices and reducing network cost.

In one possible design of the second aspect, the first WSS splits the collimated light into N +1 parts, one part being a first portion of the collimated light and N parts being a second portion of the collimated light, after which the first WSS transmits the first portion of the collimated light to the photodetection device and the second portion of the collimated light to N second WSSs connected to the first WSS. In this implementation, each WSS splits the received calibration light, using a portion of the calibration light power for frequency offset detection for that WSS and another portion of the calibration light power for frequency offset detection for other WSSs. The power of the calibration light is attenuated in the transmission process, but the split calibration light has no time delay relative to the original calibration light, the calibration process of the whole optical communication system is fast, and the realization is simple.

In one possible design of the second aspect, the first portion of the calibration light is calibration light received by the first WSS for a first time period; the second portion of the calibration light is the calibration light received by the first WSS for a second time period, wherein the first time period and the second time period do not intersect. In the implementation mode, a mode that calibration light received in different time lengths is used for different functions is adopted, the transmission process of the calibration light has time delay, the calibration process of the whole optical communication system is slow, but the power of the calibration light is not attenuated in the transmission process, and the quality of the calibration light can be ensured.

In a third aspect, the present application further provides an optical network node. The optical network node comprises W input WSSs and W output WSSs, wherein each of the W input WSSs is respectively connected with the W output WSSs, and W is greater than or equal to 1. The W input WSSs and the W output WSSs include: a first input WSS, a first output WSS and a calibration WSS. A first input WSS for receiving calibration light, wherein the first input WSS is any one of W input WSSs, and the calibration light includes first calibration light and second calibration light; the first input WSS is further configured to use the first calibration light for frequency offset detection of the first input WSS; a first output WSS for receiving the first calibration light and using the first calibration light for frequency offset detection of the first output WSS; a first output WSS further for receiving the second collimated light and transmitting the second collimated light to at least one second optical network node; the calibration WSS is used for receiving the first calibration light and using the first calibration light for calibrating frequency offset detection of the WSS; wherein the calibration WSS is any one of the W input WSS and the W output WSS except the first input WSS and the first output WSS.

In one possible design of the third aspect, W inputs WSSs for receiving the calibration light at different times, respectively; the calibration light comprises a first part of calibration light and a second part of calibration light, the first input WSS is used for transmitting the first part of calibration light to the photoelectric detection device connected with the first input WSS, and the second part of calibration light is transmitted to the first output WSS; a first output WSS for receiving a second portion of the collimated light, the second portion of the collimated light including a third portion of the collimated light and a fourth portion of the collimated light; a first output WSS further adapted to transmit a third portion of the collimated light to a photo detection means connected to the first output WSS and a fourth portion of the collimated light to a first input WSS of at least one second optical network node; wherein the first collimated light includes a first portion of collimated light and a third portion of collimated light, and the second collimated light includes a fourth portion of collimated light.

In one possible design, the first portion of the calibration light is a first portion of the output calibration optical power of the first input WSS, the second portion of the calibration light is a second portion of the output calibration optical power of the first input WSS, the third portion of the calibration light is a first portion of the output calibration optical power of the first output WSS, and the fourth portion of the calibration light is a second portion of the output calibration optical power of the first output WSS.

In one possible design, the first portion of the calibration light is calibration light received within a first time period of the first input WSS, the second portion of the calibration light is calibration light received within a second time period of the first input WSS, the third portion of the calibration light is calibration light received within a third time period of the first output WSS, and the fourth portion of the calibration light is calibration light received within a fourth time period of the first output WSS, where the first time period and the second time period do not intersect; the third duration and the fourth duration do not intersect.

In one possible design, the first portion of the calibration light is the calibration light received during a first time period of the first input WSS, the second portion of the calibration light is the calibration light received during a second time period of the first input WSS, the third portion of the calibration light is the first portion of the output calibration optical power of the first output WSS, and the fourth portion of the calibration light is the second portion of the output calibration optical power of the first output WSS, where the first time period and the second time period do not intersect.

In one possible design, the first portion of the calibration light is a first portion of the output calibration optical power of the first input WSS, the second portion of the calibration light is a second portion of the output calibration optical power of the first input WSS, the third portion of the calibration light is calibration light received within a third time period of the first output WSS, and the fourth portion of the calibration light is calibration light received within a fourth time period of the first output WSS, where the third time period and the fourth time period do not intersect.

In one possible design of the third aspect, the first calibration light is used for frequency offset detection of each WSS of the optical network node; a first input WSS for transmitting the second calibration light to the first output WSS; a first output WSS for transmitting the second calibration light to the first input WSS of the at least one second optical network node.

In one possible design, the collimated light includes a first portion of collimated light, a second portion of collimated light, and W-1 parts of a third portion of collimated light; a first input WSS for transmitting a first portion of the calibration light to a photo-detection device to which the first input WSS is connected; transmitting the second portion of the calibration light to the first output WSS; and transmitting each of the W-1 parts of the third portion of the collimated light to a second output WSS; a first output WSS for receiving a second portion of the collimated light, wherein the second portion of the collimated light comprises a fourth portion of the collimated light and a fifth portion of the collimated light; a first output WSS further for transmitting a fourth portion of the calibration light to the photo-detection means of the first output WSS connection and a fifth portion of the calibration light to the first input WSS of the at least one second optical network node to which the first output WSS is connected; a second output WSS for receiving a third portion of the collimated light, wherein the third portion of the collimated light includes a sixth portion of the collimated light and a seventh portion of the collimated light; a second output WSS further for transmitting a sixth portion of the collimated light to a photo-detection device connected to the second output WSS and a seventh portion of the collimated light to at least one of the second inputs WSS; the second output WSS is any one of the output WSSs of the optical network node except the first output WSS; the second input WSS is an input WSS of the input WSSs of the optical network node other than the first input WSS. Wherein the first collimated light includes a first portion of collimated light, a fourth portion of collimated light, a sixth portion of collimated light, and a seventh portion of collimated light, and the second collimated light includes a fifth portion of collimated light. In one implementation, the second output WSS is used to transmit the seventh portion of the calibration light to one second input WSS of the optical network node; in one implementation, the second output WSS is used to transmit the seventh portion of the calibration light to all second input WSSs of the optical network node.

In one implementation, the first portion of the calibration light is a first portion of the first input WSS output calibration optical power, the second portion of the calibration light and W-1 of the third portion of the calibration light are a second portion of the first input WSS output calibration optical power, the fourth portion of the calibration light is a first portion of the first output WSS output calibration optical power, the fifth portion of the calibration light is a second portion of the first output WSS output calibration optical power, the sixth portion of the calibration light is a first portion of the second output WSS output calibration optical power, and the seventh portion of the calibration light is a second portion of the second output WSS output calibration optical power.

In one implementation, the first portion of the calibration light is calibration light received within a first time period of the first input WSS, the second portion of the calibration light and W-1 of the third portion of the calibration light are calibration light received within a second time period of the first input WSS, the fourth portion of the calibration light is calibration light received within a third time period of the first output WSS, the fifth portion of the calibration light is calibration light received within a fourth time period of the first output WSS, the sixth portion of the calibration light is calibration light received within a third time period of the second output WSS, and the seventh portion of the calibration light is calibration light received within a fourth time period of the second output WSS, where the first time period and the second time period do not intersect; the third duration and the fourth duration do not intersect.

In one implementation, the first portion of calibration light is calibration light received within a first time period of the first input WSS, and the second portion of calibration light and the W-1 portion of the third portion of calibration light are calibration light received within a second time period of the first input WSS; the fourth portion of the calibration light is a first portion of the first output WSS output calibration optical power, the fifth portion of the calibration light is a second portion of the first output WSS output calibration optical power, the sixth portion of the calibration light is a first portion of the second output WSS output calibration optical power, and the seventh portion of the calibration light is a second portion of the second output WSS output calibration optical power, wherein the first duration and the second duration do not intersect.

In one implementation, the first portion of the calibration light is a first portion of the output calibration optical power of the first input WSS, the second portion of the calibration light and W-1 of the third portion of the calibration light are a second portion of the output calibration optical power of the first input WSS, the fourth portion of the calibration light is the calibration light received within a third time period of the first output WSS, the fifth portion of the calibration light is the calibration light received within a fourth time period of the first output WSS, the sixth portion of the calibration light is the calibration light received within a third time period of the second output WSS, and the seventh portion of the calibration light is the calibration light received within a fourth time period of the second output WSS, where the third time period and the fourth time period do not intersect.

In one possible design of the third aspect, the calibration light includes a first portion of calibration light and a second portion of calibration light; the first portion of the calibration light is the calibration light received within a first time duration of the first input WSS, and the second portion of the calibration light is the calibration light received within a second time duration of the first input WSS, wherein the first time duration and the second time duration do not intersect; the first calibration light comprises a first portion of calibration light and the second calibration light comprises a second portion of calibration light; the first portion of the calibration light comprises a third portion of the calibration light, a fourth portion of the calibration light, and W-1 parts of a fifth portion of the calibration light, wherein each part of the fifth portion of the calibration light comprises a first component calibration light and a second component calibration light; a first input WSS for transmitting a third portion of the collimated light to a photo-detection device to which the first input WSS is connected; transmitting the fourth portion of the collimated light to the first output WSS; and transmitting each of the W-1 parts of the fifth part of the collimated light to a second output WSS; a first output WSS for transmitting the fourth portion of the collimated light to a photo-detection device to which the first output WSS is connected; a second output WSS for transmitting a first component calibration light corresponding to the received fifth portion of calibration light to a photodetector device connected to the second output WSS; transmitting a second component-collimated light corresponding to the received fifth portion of collimated light to at least one of the second inputs WSSs; the first input WSS is further for transmitting the second portion of the collimated light to the first output WSS; a first output WSS further for transmitting the second portion of the collimated light to the first input WSS of the at least one second optical network node. The second output WSS is any one of the output WSSs of the optical network node except the first output WSS; the second input WSS is an input WSS of the input WSSs of the optical network node other than the first input WSS. In one implementation, the second output WSS is configured to transmit the second component calibration light corresponding to the received fifth portion of calibration light to a second input WSS of the optical network node; in one implementation, the second output WSS is configured to transmit the second component-calibrated light corresponding to the received one of the fifth portions of calibrated light to all of the second input WSSs of the optical network node.

In one possible design of the third aspect, the optical network node further includes: a first WSS and a regeneration device. A first WSS for transmitting the calibration light to a regeneration device; regenerating means for regenerating the calibration light and for transmitting the regenerated calibration light to at least one WSS connected to an output port of the first WSS; the first WSS is any one WSS in the optical network node.

In a fourth aspect, the present application also provides a wavelength selective switch WSS. The WSS includes: the device comprises a receiving module and a transmitting module. A receiving module for receiving the calibration light; and the transmission module is used for transmitting the first part of the calibration light to the photoelectric detection device and transmitting the second part of the calibration light to N second WSSs connected with the WSSs, wherein N is greater than or equal to 1.

In one possible design of the fourth aspect, the WSS further includes: and a light splitting module. The light splitting module is used for splitting the calibration light into N +1 parts before the transmission module transmits the first part of the calibration light to the photoelectric detection device, wherein one part is the first part of the calibration light, and N parts is the second part of the calibration light.

In one possible design of the fourth aspect, the first part of the calibration light is the calibration light received by the receiving module for a first time period; the second part of the calibration light is the calibration light received by the receiving module within a second time period, wherein the first time period and the second time period do not intersect.

The present application also provides a computer-readable storage medium having stored therein instructions, which when run on a computer, cause the computer to perform the method of any of the above aspects.

The present application also provides a computer program product comprising instructions which, when run on a computer, cause the computer to perform the method of any of the above aspects.

The present application further provides a chip system, which includes a processor, a memory, and a transceiver circuit, and is configured to implement the method according to any one of the above aspects.

The present application provides an optical communication system, comprising the optical network node according to the third aspect, and/or the WSS according to the fourth aspect.

Any of the above-mentioned optical network nodes, WSSs, computer-readable storage media, computer program products, chip systems, or optical communication systems is configured to execute the above-mentioned corresponding methods, so that the beneficial effects that can be achieved by the above-mentioned optical network nodes, WSSs, computer-readable storage media, computer program products, chip systems, or optical communication systems can refer to the beneficial effects of the corresponding schemes in the above-mentioned corresponding methods, and are not described herein again.

Drawings

Fig. 1 is a schematic structural diagram of an optical communication system to which the technical solution provided in the present application is applied;

fig. 2 is a first hardware structure diagram of an optical network node according to an embodiment of the present disclosure;

fig. 3 is a schematic hardware structure diagram of a WSS according to an embodiment of the present application;

fig. 4 is a first schematic diagram illustrating a calibration method of a wavelength selective switch according to an embodiment of the present disclosure;

fig. 5a is a first schematic diagram illustrating a calibration optical transmission path in a calibration method of a wavelength selective switch according to an embodiment of the present disclosure;

fig. 5b is a schematic diagram of a calibration optical transmission path in a calibration method of a wavelength selective switch according to an embodiment of the present application;

fig. 6 is a second schematic diagram illustrating a calibration method of a wavelength selective switch according to an embodiment of the present disclosure;

fig. 7a is a schematic diagram of a third calibration optical transmission path in a calibration method of a wavelength selective switch according to an embodiment of the present application;

fig. 7b is a schematic diagram of a calibration optical transmission path in a calibration method of a wavelength selective switch according to an embodiment of the present application;

fig. 8 is a third schematic diagram illustrating a calibration method of a wavelength selective switch according to an embodiment of the present disclosure;

fig. 9 is a fourth schematic diagram illustrating a calibration method of a wavelength selective switch according to an embodiment of the present disclosure;

fig. 10 is a fifth schematic diagram illustrating a calibration method of a wavelength selective switch according to an embodiment of the present disclosure;

fig. 11 is a schematic diagram of a hardware structure of an optical network node according to an embodiment of the present application;

fig. 12 is a sixth schematic diagram illustrating a calibration method of a wavelength selective switch according to an embodiment of the present disclosure;

fig. 13 is a seventh schematic diagram illustrating a calibration method of a wavelength selective switch according to an embodiment of the present disclosure;

fig. 14 is a fifth schematic diagram illustrating a calibration optical transmission path in a calibration method of a wavelength selective switch according to an embodiment of the present disclosure;

fig. 15 is a schematic diagram illustrating a method for detecting frequency offset in a calibration method of a wavelength selective switch according to an embodiment of the present application;

fig. 16 is a first schematic structural diagram of an optical network node according to an embodiment of the present application;

fig. 17 is a schematic structural diagram of a second optical network node according to an embodiment of the present application;

FIG. 18 is a first schematic structural diagram of a WSS according to an embodiment of the present disclosure;

fig. 19 is a schematic structural diagram of a WSS according to an embodiment of the present application.

Detailed Description

The following describes in detail a calibration method and apparatus for a wavelength selective switch according to an embodiment of the present application with reference to the accompanying drawings.

The technical scheme provided by the application can be applied to an optical communication system, and the optical communication system can be applied to various communication scenes. Such as local trunks, long-distance trunked communications, global communications networks, public telecommunication networks of various countries. The optical communication system can also be used for high-quality color television transmission, industrial production site monitoring and scheduling, traffic monitoring control command, urban cable television network, community antenna system (CATV), and fiber local area network. For example, optical communication systems may be used in aircraft, spacecraft, naval vessels, mines, power departments, military and corrosive and radiative scenarios.

The optical communication system may be a ring network, a mesh network or other network architecture, including optical network nodes and optical channels. The optical channel is used to transmit optical signals, and for example, the optical channel may be an optical fiber. The optical network node is used for realizing the up-down wave, blocking and direct configuration of optical signals with any wavelength and wavelength group. The optical network node sends the information which needs to be downloaded at the optical network node to the processing equipment, and the information which does not need to be processed by the optical network node directly passes through the optical channel from the optical network node. The optical network node may be an optical add-drop multiplexer (OADM) or an optical cross-connect (OXC) device. OADM allows different wavelength signals of different optical communication systems to be subjected to add-drop multiplexing at different places, and the OXC equipment allows different optical communication systems to be dynamically combined, so that wavelength resources are allocated according to requirements, and a wider range of network interconnection is realized. Among them, OADMs include two types, a fixed type and a reconfigurable type. The fixed type can only be used for one or more fixed wavelengths, and the routing of the node is determined; the reconfigurable optical add/drop multiplexer can dynamically adjust the wavelength of the upper channel and the lower channel of the OADM node, and can realize the dynamic reconfiguration of an optical communication system. A light distribution enabled optical add drop module (ROADM) is a reconfigurable OADM, and an optical network node is taken as an example in the present application for explanation.

The technical solution provided by the embodiment of the present application may be applied to an optical communication system architecture as shown in fig. 1, where the system architecture may include at least one ROADM, and the ROADMs are connected to each other through an optical channel. One of the ROADMs may be connected to any number of other ROADMs, i.e. the ROADMs have different dimensions. The optical communication system includes a calibration device including a calibration light source that provides calibration light for the optical communication system. For example, the calibration light source may be a distributed feedback laser or a distributed bragg grating laser. The calibration device may be connected to any ROADM in the optical communication system, i.e. the calibration light of the calibration light source may be uploaded by one dimension of any ROADM in the optical communication system. It should be noted that the system architecture shown in fig. 1 is only for example and is not used to limit the technical solution of the present application. It should be understood by those skilled in the art that in the implementation process, other devices may be included in the system architecture, and the number of optical network nodes may also be configured according to the actual situation.

In one example, a ROADM may include a line side and a client side. The line side can be formed by cascading a plurality of Wavelength Selective Switches (WSS), so that the wavelength scheduling function among different dimensions is realized; the client side can be composed of optical cross-connect devices to implement the up and down wave functions. As shown in fig. 2, taking a 3-dimensional ROADM as an example, the line side of the ROADM includes 3 input WSS and 3 output WSS, each dimension including one input WSS and one output WSS. Each input WSS optical signal in the ROADM can be transmitted to any output WSS and the client side, and each output WSS in the ROADM can receive any input WSS and the client side optical signal.

In one example, the hardware architecture of the WSS may be as shown in FIG. 3. The WSS includes an input port, an output port, a collimating mirror, a grating, a main lens, and a switching engine. The input port is used for transmitting the optical signal to the WSS, and the output port is used for outputting the optical signal to the WSS. It should be noted that the number of input ports and output ports in the WSS can be determined according to actual needs, for example, taking fig. 3 as an example, the WSS includes 5 input/output ports, one of which is connected to the photo-detection device for outputting an optical signal to the photo-detection device; if the WSS is an output WSS, the output WSS may further include 3 input ports and 1 output port, where 3 input ports are used to transmit optical signals of other WSSs in the line side of the ROADM and the client side to the output WSS, and 1 output port is used to transmit optical signals of the output WSS to other ROADMs; the WSS may also be an input WSS, and then the input WSS may further include 1 input port and 3 output ports, where 1 input port is used to input the optical signals of other ROADMs to the input WSS, and 3 output ports are used to output the optical signals to other WSS inside the ROADM on the line side and the client side. The photo detection means is used to detect the optical power of the calibration light output by the WSS, and the photo detection means may be a Photo Detector (PD), for example, a PN photodiode, a PIN photodiode, an avalanche photodiode, a photoconductive detector, or a phototransistor. The collimating lens is used for collimating the light input by the input port into a group of approximately parallel light beams; the grating is used for diffracting light with different wavelengths to different directions to generate angular dispersion; the main lens is used for converting angular dispersion into displacement dispersion and transmitting light to the optical switching engine; the switching engine is used for selecting optical signals of different channels and deflecting the optical signals to corresponding output ports, for example, the switching engine may be a Liquid Crystal On Silicon (LCOS) or a Micro Electro Mechanical Systems (MEMS). It should be noted that the WSS may also employ other general hardware architectures in the specific implementation process, and is not limited to only the general hardware architecture shown in fig. 3.

Some of the terms referred to in this application are explained below for the convenience of the reader:

1. fractional power

The optical splitting power is divided into N, that is, the energy of the light is divided into N, each split light is only different from the light before splitting in light power, and the characteristics of the light, such as the wavelength of the light and the information carried by the optical signal, are not changed.

2. Alignment light

The calibration light is light used to detect and calibrate the WSS frequency offset. The calibration light can be combined with the optical signal of the input port through the coupler through one input port of the WSS, the combined light is transmitted to the collimating lens through the input port, and is transmitted to the switching engine after passing through the collimating lens, the grating and the main lens. The collimated light may be demultiplexed from the optical signal and transmitted to a corresponding output port by the splitting and deflecting functions of the switching engine. And a part of the calibration light is deflected to an output port connected with the photoelectric detection device and output to the photoelectric detection device for detecting and calibrating the frequency offset of the WSS. And a part of the calibration light is transmitted to an output port connected with other WSSs and is output to other WSSs, so that the calibration light can be used for other WSSs to detect and calibrate frequency offset.

3. The term "plurality" herein means two or more. The terms "first" and "second" herein are used to distinguish between different objects, and are not used to describe a particular order of objects. For example, "first calibration light" and "second calibration light" are used to distinguish between different calibration lights, rather than to describe a particular order of the calibration lights. The term "and/or" herein is merely an association describing an associated object, meaning that three relationships may exist, e.g., a and/or B, may mean: a exists alone, A and B exist simultaneously, and B exists alone.

In the embodiments of the present application, words such as "exemplary" or "for example" are used to mean serving as an example, instance, or illustration. Any embodiment or design described herein as "exemplary" or "e.g.," is not necessarily to be construed as preferred or advantageous over other embodiments or designs. Rather, use of the word "exemplary" or "such as" is intended to present concepts related in a concrete fashion.

The embodiment of the application provides a calibration method of a WSS, which can be applied to an optical communication system shown in fig. 1. As shown in fig. 4, the method may include S101-S102:

s101, the first optical network node receives the calibration light.

In particular, the first optical network node may be any one of ROADMs in fig. 1. The optical communication system shown in fig. 1 includes a calibration light source, and if the first optical network node is an optical network node connected to the calibration light source, the calibration light received by the first optical network node is the calibration light output by the calibration light source; and if the first optical network node is an optical network node except the optical network node connected with the calibration light source, the calibration light received by the first optical network node is the calibration light output by other optical network nodes.

Specifically, the first optical network node comprises W input WSSs and W output WSSs, wherein W is greater than or equal to 1. In one implementation, the first optical network node receives the calibration light, that is, the first input WSS of the first optical network node receives the calibration light, and the first input WSS may be any one of W input WSSs of the first optical network node.

S102, the first optical network node uses the first calibration light for frequency offset detection of the first optical network node, and transmits the second calibration light to at least one second optical network node.

Specifically, the calibration light received by the first optical network node includes first calibration light and second calibration light, and the first optical network node uses the first calibration light for frequency offset detection of the first optical network node and transmits the second calibration light to at least one second optical network node. The second optical network node is any one optical network node connected with the first optical network node. The calibration light received by the second optical network node also comprises a first calibration light and a second calibration light, the second optical network node uses the first calibration light for frequency offset detection of the second optical network node, and transmits the second calibration light to at least one third optical network node, wherein the third optical network node is any one optical network node connected with the second optical network node. In this way, each optical network node uses the first calibration light for frequency offset detection of the optical network node, and transmits the second calibration light to at least one other optical network node until each WSS of each optical network node in the optical communication system completes frequency offset detection by using the received calibration light.

In the calibration method for the WSS provided in the embodiment of the present application, calibration light output by a calibration light source is uploaded to an optical network node connected to the calibration light source through one optical network node, each optical network node uses a first calibration light of the received calibration light for frequency offset detection of the optical network node, and transmits a second calibration light of the received calibration light to other optical network nodes until each WSS of each optical network node in an optical communication system performs frequency offset detection by using the received calibration light. Compared with the method for performing frequency offset detection by using a calibration device independently for each WSS in an optical communication system in the prior art, the calibration method for the WSS provided by the embodiment of the application has the advantages that all WSSs of all optical network nodes in the optical communication system use the calibration light output by the same calibration light source to perform frequency offset detection, so that not only is the network cost reduced, but also the frequency offset between different calibration devices is avoided, and the WSS frequency offset conditions of all optical network nodes in the whole optical communication system can be accurately and rapidly detected.

The first optical network node may use the first calibration light for frequency offset detection of the first optical network node in an arbitrary routing manner, and transmit the second calibration light to at least one second optical network node, which is not limited in this embodiment of the present application. For example, after receiving the calibration light, the first optical network node may calibrate the frequency offset of a part of WSSs in the first optical network node, transmit the calibration light to other optical network nodes, and calibrate the frequency offset of a second part of WSSs after the first optical network node receives the calibration light at the next time; for example, after the first optical network node receives the calibration light, the calibration light may also be used to calibrate frequency offsets of all WSSs in the first optical network node, and transmit the calibration light to other optical network nodes. In the following, an explanation is given, exemplarily, for two implementations thereof.

The first method is as follows:

after the first optical network node receives the calibration light, the frequency offset of one input WSS and one output WSS in the first optical network node is calibrated, and the calibration light is transmitted to the next optical network node until the calibration light is transmitted to each WSS of each optical network node in the optical communication system.

Illustratively, as shown in fig. 5a, the optical communication system includes 5 ROADMs, which are ROADM a, ROADM B, ROADM C, ROADM D, and ROADM E, respectively, and the calibration light source is connected to the ROADM a. Calibration light from the calibration light source is uploaded by the ROADM a into the optical communication system for frequency offset detection of all WSSs in the optical communication system. Taking the first optical network node as ROADM B as an example, as shown in fig. 6, the method may include S201-S204:

s201, a first input WSS of the first optical network node receives the calibration light.

The first input WSS is any one of W input WSSs of the first optical network node, and the W input WSSs are configured to receive the calibration light at different times, respectively.

Illustratively, ROADM B includes 3 input WSSs, WSS1, WSS3, and WSS5, respectively, and 3 output WSSs, WSS2, WSS4, and WSS6, respectively, as shown in fig. 5B. Taking the first input WSS of the first optical network node as WSS3 in fig. 5b as an example, WSS3 receives the calibration light at a first time instant. The WSS1 receives the collimated light at the second time and the WSS5 receives the collimated light at the third time.

S202, the first input WSS of the first optical network node transmits the first part of the calibration light to the photodetection device connected to the first input WSS of the first optical network node, and transmits the second part of the calibration light to the first output WSS of the first optical network node.

Illustratively, the WSS3 in fig. 5b receives calibration light that includes a first portion of calibration light and a second portion of calibration light.

In one implementation, the first portion of the calibration light is a first portion of the WSS3 output calibration optical power and the second portion of the calibration light is a second portion of the WSS3 output calibration optical power; that is, after the WSS3 receives the collimated light, it splits the received collimated light into two portions, a first portion of the collimated light and a second portion of the collimated light. It should be noted that, the WSS3 may divide the calibration light into two portions with the same power, or into two portions with different powers, which is not limited in the embodiment of the present application. In this way, the first and second portions of calibration light have no time delay, but have reduced power compared to the received calibration light; the calibration process of the whole optical communication system is fast, but the power of the calibration light is attenuated during transmission.

In one implementation, the first portion of the calibration light is the calibration light received during a first time period of WSS3 and the second portion of the calibration light is the calibration light received during a second time period of WSS3, wherein the first time period and the second time period do not intersect. In this way, the power of the first portion of calibration light and the second portion of calibration light is unchanged from the received calibration light, but the second portion of calibration light has a time delay compared to the first portion of calibration light; the calibration light is not changed in power during transmission, but the calibration process of the entire optical communication system is slow.

The WSS3 transmits the first portion of the collimated light to the photo-detection device to which the WSS3 is connected and the second portion of the collimated light to the first output WSS of the first optical network node. The first output WSS of the first optical network node may be any one of the output WSSs of ROADM B, for example, the first output WSS of the first optical network node is WSS4 in fig. 5B.

Illustratively, the WSS3 receives the collimated light and splits the collimated light into two portions, one for the first portion of the collimated light and one for the second portion of the collimated light. The WSS3 transmits the first portion of the collimated light to the photo-detection device to which the WSS3 is connected and the second portion of the collimated light to the first output WSS of the first optical network node.

For example, the WSS3 may switch the calibration light received during the first time period to the photodetection device connected to the WSS3 and switch the calibration light received during the second time period to the first output WSS of the first optical network node.

S203, the first output WSS of the first optical network node receives the second portion of the collimated light.

Specifically, for example, WSS4 in FIG. 5b receives the second portion of the collimated light.

S204, the first output WSS of the first optical network node transmits the third part of the calibration light to the photodetection device connected to the first output WSS of the first optical network node, and transmits the fourth part of the calibration light to the first input WSS of the at least one second optical network node.

In particular, the second portion of the collimated light received by WSS4 includes a third portion of the collimated light and a fourth portion of the collimated light.

In one implementation, the third portion of the calibration light is a first portion of the WSS4 output calibration optical power, and the fourth portion of the calibration light is a second portion of the WSS4 output calibration optical power; that is, after the WSS4 receives the second portion of the collimated light, it splits the received second portion of the collimated light into two portions, a third portion of the collimated light and a fourth portion of the collimated light. It should be noted that, the WSS4 may split the second part of the calibration light into two parts with the same power, or may split the second part of the calibration light into two parts with different powers, which is not limited in this embodiment of the present application.

In one implementation, the third portion of the calibration light is the calibration light received within a third time period of WSS4, and the fourth portion of the calibration light is the calibration light received within a fourth time period of WSS4, where the third time period and the fourth time period do not intersect.

It should be noted that, implementation manners of the first part of calibration light and the second part of calibration light in S202 may be the same as or different from implementation manners of the third part of calibration light and the fourth part of calibration light in S204, and this is not limited in this embodiment of the application.

For example, in one implementation, the first portion of the calibration light is a first portion of the WSS3 that outputs the calibration optical power, the second portion of the calibration light is a second portion of the WSS3 that outputs the calibration optical power, the third portion of the calibration light is a first portion of the WSS4 that outputs the calibration optical power, and the fourth portion of the calibration light is a second portion of the WSS4 that outputs the calibration optical power; in one implementation, the first portion of the calibration light is a first portion of the WSS3 output calibration optical power, the second portion of the calibration light is a second portion of the WSS3 output calibration optical power, the third portion of the calibration light is the calibration light received within a third time period of WSS4, and the fourth portion of the calibration light is the calibration light received within a fourth time period of WSS 4; in one implementation, the first portion of the calibration light is the calibration light received during a first time period of WSS3, the second portion of the calibration light is the calibration light received during a second time period of WSS3, the third portion of the calibration light is the first portion of WSS4 that outputs the calibration optical power, and the fourth portion of the calibration light is the second portion of WSS4 that outputs the calibration optical power; in one implementation, the first portion of the calibration light is the calibration light received during the first time period of WSS3, the second portion of the calibration light is the calibration light received during the second time period of WSS3, the third portion of the calibration light is the calibration light received during the third time period of WSS4, and the fourth portion of the calibration light is the calibration light received during the fourth time period of WSS 4.

The WSS4 transmits the third portion of the collimated light to the photodetection device to which the WSS4 is connected and the fourth portion of the collimated light to the first input WSS of the at least one second optical network node.

The second optical network node is any optical network node except the first optical network node. For example, one second optical network node is ROADM C of fig. 5 a. WSS4 transmits the fourth partially collimated light to one input WSS of ROADM C. In one implementation, the first output WSS of the first optical network node may also transmit the fourth partially collimated light to a plurality of second optical network nodes. For example, WSS4 transmits the fourth portion of the collimated light to one input WSS of ROADM a, ROADM C, and ROADM E, respectively. This is not limited in the embodiments of the present application.

By the method, after each ROADM in the optical communication system receives the calibration light, the first calibration light is used for frequency offset detection of the optical network node, and the second calibration light is transmitted to at least one other optical network node, so that each WSS of each ROADM in the optical communication system utilizes the calibration light of the calibration light source to perform frequency offset detection. In this manner, the first calibration light includes a first portion of calibration light for frequency offset detection of an input WSS and a third portion of calibration light for frequency offset detection of an output WSS; the second calibration light comprises a fourth portion of calibration light, which is transmitted to the at least one other optical network node.

In one example, shown in conjunction with fig. 5a and 5b, the collimated light is uploaded by one input WSS of ROADM a through a coupler. The ROADM a uses the first calibration light for frequency offset detection of the local optical network node, and transmits the second calibration light to the WSS1 of the ROADM B through the path with the number 1. The ROADM B uses the first calibration light for frequency offset detection of the local optical network node, and transmits the second calibration light to the ROADM a through the path with the number 2 from the WSS 2. And the ROADM A uses the first calibration light for frequency offset detection of the optical network node, and transmits the second calibration light to the ROADM D through the path with the number 3. And the ROADM D uses the first calibration light for frequency offset detection of the local optical network node, and transmits the second calibration light to the ROADM C through a path with the number 4. The ROADM C uses the first calibration light for frequency offset detection of the local optical network node, and transmits the second calibration light to the WSS3 of the ROADM B through the path with the number 5. The ROADM B uses the first calibration light for frequency offset detection of the local optical network node, and transmits the second calibration light from the WSS4 to the ROADM C through the path numbered 6. The calibration light then continues to traverse all WSSs in the optical communication system in the numbered sequence through the numbered 7 to the numbered 16 paths. Of course, the above transmission path is only an example, and in each ROADM, the corresponding relationship between the input WSS and the output WSS is not fixed, and the next ROADM of each ROADM transmission path is also not fixed, as long as the calibration optical transmission of the calibration optical source to each WSS of each ROADM in the optical communication system can be realized, which is not limited in the embodiment of the present application.

The second method comprises the following steps:

after the first optical network node receives the calibration light, the frequency offset of all WSSs in the first optical network node is calibrated, and the calibration light is transmitted to the next optical network node until the calibration light is transmitted to each optical network node in the optical communication system.

Illustratively, as shown in fig. 7a, the optical communication system includes 5 ROADMs, which are ROADM a, ROADM B, ROADM C, ROADM D, and ROADM E, respectively, and the calibration light source is connected to the ROADM B. The calibration light of the calibration light source is uploaded into the optical communication system by the ROADM B, transmitted to the ROADM B, the ROADM C, the ROADM D, the ROADM E and the ROADM A and used for frequency offset detection of all WSSs in the optical communication system. Taking the first optical network node as ROADM B as an example, as shown in fig. 8, the method may include S301-S302:

s301, a first input WSS of the first optical network node receives the calibration light.

Wherein the first input WSS is any one of the W input WSSs of the first optical network node.

Illustratively, ROADM B includes 3 input WSSs, WSS1, WSS3, and WSS5, respectively, and 3 output WSSs, WSS2, WSS4, and WSS6, respectively, as shown in fig. 7B. The first input WSS of the first optical network node is for example WSS3, the calibration light of the calibration light source is uploaded to WSS3 via path number 1, and WSS3 receives the calibration light.

S302, a first input WSS of a first optical network node uses first calibration light for frequency offset detection of each WSS of the first optical network node, and transmits second calibration light to a first output WSS of the first optical network node; the first output WSS of the first optical network node transmits the second calibration light to the first input WSS of the at least one second optical network node.

Exemplarily, the WSS3 in fig. 7B receives calibration light, the calibration light includes a first calibration light and a second calibration light, the WSS3 uses the first calibration light for frequency offset detection of the WSS1, the WSS2, the WSS3, the WSS4, the WSS5, and the WSS6 in ROADM B, and transmits the second calibration light to the first output WSS of the first optical network node, which may be any one of the output WSSs of the ROADM B, for example, the first output WSS is the WSS4 in fig. 7B.

In one example, shown in conjunction with fig. 7a and 7B, the collimated light is uploaded by one input WSS of ROADM B through a coupler. And the ROADM B uses the first calibration light for frequency offset detection of the node of the optical network and transmits the second calibration light to the ROADM C through the path with the number 2. And after receiving the calibration light, the ROADM C uses the first calibration light for frequency offset detection of the optical network node, and transmits the second calibration light to the ROADM D through the path with the number 3. And after receiving the calibration light, the ROADM D uses the first calibration light for frequency offset detection of the optical network node, and transmits the second calibration light to the ROADM E through a path with the number 4. And after receiving the calibration light, the ROADM E uses the first calibration light for frequency offset detection of the optical network node, and transmits the second calibration light to the ROADM A through a path with the number 5. And the ROADM A uses the first calibration light for frequency offset detection of the optical network node. The calibration light traverses all WSSs of all ROADMs a in the optical communication system. Of course, the transmission path is only an example, the next ROADM of each ROADM transmission path is not fixed, and one ROADM may also transmit the calibration light to multiple ROADMs at the same time, as long as the calibration light of the calibration light source can be transmitted to each WSS of each ROADM in the optical communication system, which is not limited in this embodiment of the application.

Specifically, in the embodiment of the present application, for the first input WSS of the first optical network node, the first calibration light is used for frequency offset detection of each WSS of the first optical network node, and a specific manner of transmitting the second calibration light to the first output WSS of the first optical network node is not limited. Exemplary, the following two implementations may be included.

As shown in fig. 9, this implementation may include S30201-S30206:

s30201, the first input WSS of the first optical network node transmits the first part of the calibration light to the photodetection device connected to the first input WSS of the first optical network node; transmitting the second portion of the calibration light to a first output WSS of the first optical network node; and transmitting each of the W-1 copies of the third partially collimated light to a second output WSS of the first optical network node.

Specifically, the calibration light received by the first input WSS of the first optical network node comprises a first part of calibration light, a second part of calibration light and W-1 parts of a third part of calibration light.

In one implementation, the first portion of the calibration light is a first portion of the first input WSS output calibration optical power of the first optical network node, and the second portion of the calibration light and the W-1 portion of the third portion of the calibration light are a second portion of the first input WSS output calibration optical power of the first optical network node. For example, the first input WSS splits the received collimated light into W +1 parts, where one part is the first portion of the collimated light, one part is the second portion of the collimated light, and W-1 parts is the third portion of the collimated light. It should be noted that the first input WSS divides the received calibration light into W +1 parts, may equally divide the optical power of the calibration light into W +1 parts, and may also distribute the optical power of each calibration light as needed, which is not limited in the embodiment of the present application. With this implementation, the first, second, and third portions of calibration light have no time delay, but have reduced power compared to the received calibration light; the calibration process of the whole optical communication system is fast, but the power of the calibration light is attenuated during transmission.

In one implementation, the first part of the calibration light is the calibration light received within a first time duration of the first input WSS of the first optical network node, and the second part of the calibration light and the W-1 part of the third part of the calibration light are the calibration light received within a second time duration of the first input WSS of the first optical network node, where the first time duration and the second time duration do not intersect. In this way, the power of the first part of the calibration light, the second part of the calibration light and the third part of the calibration light is unchanged compared with the received calibration light, but the second part of the calibration light and the third part of the calibration light have time delay compared with the first part of the calibration light; the calibration light is not changed in power during transmission, but the calibration process of the entire optical communication system is slow.

A first input WSS of the first optical network node, such as WSS3 in fig. 7b, transmits a first portion of the collimated light to a photodetection device connected to WSS 3; transmitting the second partially collimated light to a first output WSS of the first optical network node, such as WSS4 in fig. 7 b; and respectively transmitting each of the W-1 parts of the third part of the calibration light to a second output WSS of the first optical network node, wherein the second output WSS is any one of the output WSS of the first optical network node except the first output WSS. For example, the second outputs WSS are WSS2 and WSS6 in FIG. 7 b.

Illustratively, the WSS3 has 4 parts of average received calibration light power, one part is transmitted to a photodetection device connected to the WSS3 for frequency offset detection of the WSS3, one part is transmitted to the WSS4, one part is transmitted to the WSS2, and one part is transmitted to the WSS 6.

S30202, the first output WSS of the first optical network node receives the second partially collimated light.

Illustratively, the WSS4 in FIG. 7b receives the second portion of the collimated light.

S30203, the first output WSS of the first optical network node transmits the fourth portion of the calibration light to the photo-detection means of the first output WSS connection of the first optical network node, and the fifth portion of the calibration light is transmitted to the first input WSS of the at least one second optical network node of the first output WSS connection of the first optical network node.

The first output WSS of the first optical network node receives a second portion of the calibration light, wherein the second portion of the calibration light comprises a fourth portion of the calibration light and a fifth portion of the calibration light.

In one implementation, the fourth part of the calibration light is a first part of the first output WSS output calibration optical power of the first optical network node, and the fifth part of the calibration light is a second part of the first output WSS output calibration optical power of the first optical network node. For example, the first output WSS splits the received second part of the calibration light into 2 parts, wherein one part is the fourth part of the calibration light and one part is the fifth part of the calibration light. It should be noted that the first output WSS divides the received second part of the calibration light into 2 parts, may equally divide the optical power of the second part of the calibration light into 2 parts, and may also distribute the optical power of each part of the second part of the calibration light as needed, which is not limited in the embodiment of the present application. With this implementation, the fourth and fifth portions of calibration light have no time delay, but the power of the fourth and fifth portions of calibration light is reduced compared to the received second portion of calibration light; the calibration process of the whole optical communication system is fast, but the power of the calibration light is attenuated during transmission.

In one implementation, the fourth part of the calibration light is the calibration light received within a third time duration of the first output WSS of the first optical network node, and the fifth part of the calibration light is the calibration light received within a fourth time duration of the first output WSS of the first optical network node, where the third time duration and the fourth time duration do not intersect.

The first output WSS of the first optical network node, such as WSS4 in fig. 7b, transmits the fourth portion of the calibration light to the first output WSS-connected photo-detection means of the first optical network node, and transmits the fifth portion of the calibration light to the first input WSS of the at least one second optical network node to which the first output WSS of the first optical network node is connected. The second optical network node is any optical network node except the first optical network node. In one implementation, the first output WSS of the first optical network node may transmit the fifth portion of the calibration light to one second optical network node; for example, one second optical network node is ROADM C of fig. 7 a. WSS4 of ROADM B transmits the fifth portion of the collimated light to one input WSS of ROADM C. In one implementation, the first output WSS of the first optical network node may also transmit the fifth portion of the calibration light to a plurality of second optical network nodes; for example, WSS4 of ROADM B transmits the fifth portion of the collimated light to one input WSS of ROADM a, ROADM C, and ROADM E, respectively. This is not limited in the embodiments of the present application.

Illustratively, the WSS4 receives the second part of the calibration light transmitted by the WSS3, and the second part of the calibration light is divided into 2 parts on average, wherein one part is transmitted to the photodetection device connected to the WSS4 for frequency offset detection, and the other part is transmitted to an input WSS of the ROADM C.

S30204, the second output WSS of the first optical network node receives one copy of the third partially collimated light.

Illustratively, WSS2 and WSS6 in FIG. 7b each receive a third portion of the collimated light.

S30205, the second output WSS of the first optical network node transmits the sixth portion of the calibration light to the photodetection device connected to the second output WSS of the first optical network node, and the seventh portion of the calibration light is transmitted to at least one of the second inputs WSS of the first optical network node.

Specifically, one of the third portions of the calibration light includes a sixth portion of the calibration light and a seventh portion of the calibration light.

In one implementation, the sixth portion of the calibration light is a first portion of the second output WSS output calibration optical power of the first optical network node, and the seventh portion of the calibration light is a second portion of the second output WSS output calibration optical power of the first optical network node. For example, the second output WSS splits the received third part of the calibration light into 2 parts, wherein one part is the sixth part of the calibration light and one part is the seventh part of the calibration light. It should be noted that the second output WSS divides the received third portion of the calibration light into 2 portions, may equally divide the optical power of the third portion of the calibration light into 2 portions, and may also distribute the optical power of each third portion of the calibration light according to the need, which is not limited in the embodiment of the present application. With this implementation, there is no time delay for the sixth and seventh portions of calibration light, but the power of the sixth and seventh portions of calibration light is reduced compared to the received third portion of calibration light; the calibration process of the whole optical communication system is fast, but the power of the calibration light is attenuated during transmission.

In one implementation, the sixth part of the calibration light is the calibration light received within a third time duration of the second output WSS of the first optical network node, and the seventh part of the calibration light is the calibration light received within a fourth time duration of the second output WSS of the first optical network node, where the third time duration and the fourth time duration do not intersect.

The second output WSS of the first optical network node, such as WSS2 in fig. 7b, transmits the sixth portion of the collimated light to the photo-detection means to which the second output WSS of the first optical network node is connected, and transmits the seventh portion of the collimated light to at least one of the second inputs WSS of the first optical network node. And the second input WSS is an input WSS except the first input WSS in the input WSS of the first optical network node.

In one implementation, a second output WSS of the first optical network node transmits the seventh portion of the calibration light to a second input WSS of the first optical network node; for example, the WSS2 receives a portion of the third part of the calibration light transmitted by the WSS3, and the average power of the third part of the calibration light is 2 portions, wherein one portion is transmitted to the photodetection device connected to the WSS2 for frequency offset detection, and the other portion is transmitted to the WSS 1; the WSS6 receives one part of the third part of the calibration light transmitted by the WSS3, the average power of the third part of the calibration light is 2 parts, one part of the calibration light is transmitted to a photoelectric detection device connected with the WSS6 to carry out frequency offset detection, and the other part of the calibration light is transmitted to the WSS 5.

In one implementation, one second output WSS of the first optical network node transmits the seventh portion of the calibration light to a plurality of second inputs WSS of the first optical network node; for example, the WSS2 receives one part of the third part of the calibration light transmitted by the WSS3, and the average power of the third part of the calibration light is 3 parts, wherein one part of the third part of the calibration light is transmitted to a photoelectric detection device connected with the WSS2 for frequency offset detection, one part of the third part of the calibration light is transmitted to the WSS1, and the other part of the third part of the calibration light is transmitted to the WSS 5; the WSS6 receives a third portion of the collimated light transmitted by the WSS3, and transmits the third portion of the collimated light to a photodetection device connected to the WSS6 for frequency offset detection.

As for the routing manner for transmitting the calibration light from the output WSS to the input WSS, the embodiment of the present application is not limited as long as the calibration light received by the first input WSS can be transmitted to each WSS in the ROADM.

It should be further noted that implementation manners of the first part of calibration light, the second part of calibration light, and the third part of calibration light may be the same as or different from implementation manners of the fourth part of calibration light and the fifth part of calibration light, and implementation manners of the sixth part of calibration light and the seventh part of calibration light, which is not limited in this embodiment of the application.

S30206 the second input WSS of the first optical network node receives the seventh portion of the calibration light and transmits the seventh portion of the calibration light to the photodetection device connected to the second input WSS of the first optical network node.

Specifically, the second input WSS of the first optical network node receives the seventh part of the calibration light, and transmits the seventh part of the calibration light to the photo-detection device connected thereto for frequency offset detection of the second input WSS.

Through the above manner, after each ROADM in the optical communication system receives the calibration light, the first calibration light is used for frequency offset detection of the optical network node, and the second calibration light is transmitted to at least one other optical network node, so that each WSS of each ROADM in the optical communication system performs frequency offset detection by using the calibration light of the calibration light source. In this manner, the first calibration light includes a first portion of calibration light, a fourth portion of calibration light, a sixth portion of calibration light, and a seventh portion of calibration light, the first portion of calibration light is used for frequency offset detection of an input WSS, the fourth portion of calibration light is used for frequency offset detection of a first output WSS, the sixth portion of calibration light is used for frequency offset detection of a second output WSS, and the seventh portion of calibration light is used for frequency offset detection of a second input WSS; the second calibration light comprises a fifth part of the calibration light, which is transmitted to the at least one other optical network node.

(II), as shown in FIG. 10, this implementation may include S30211-S30212:

s30211, the first input WSS of the first optical network node uses the first portion of the calibration light for frequency offset detection of each WSS of the first optical network node.

Specifically, the first part of the calibration light is the calibration light received within the first time period of the first input WSS of the first optical network node. The first portion of the calibration light is used for frequency offset detection of each WSS of the first optical network node without transmission to other optical network nodes.

Specifically, the first part of the calibration light comprises a third part of the calibration light, a fourth part of the calibration light and W-1 parts of a fifth part of the calibration light.

In one implementation, the third portion of the calibration light is a first portion of the first input WSS output calibration optical power of the first optical network node, and the fourth portion of the calibration light and the W-1 portion of the fifth portion of the calibration light are a second portion of the first input WSS output calibration optical power of the first optical network node. For example, the first input WSS splits the received collimated light into W +1 parts, where one part is the third portion of the collimated light, one part is the fourth portion of the collimated light, and W-1 parts is the fifth portion of the collimated light. It should be noted that the first input WSS divides the received calibration light into W +1 parts, may equally divide the optical power of the calibration light into W +1 parts, and may also distribute the optical power of each calibration light as needed, which is not limited in the embodiment of the present application.

The first input WSS of the first optical network node, such as WSS3 in fig. 7b, transmits the third portion of the collimated light to the photo-detection means to which the first input WSS of the first optical network node is connected; transmitting the fourth partially collimated light to a first output WSS of the first optical network node, such as WSS4 in fig. 7 b; and respectively transmitting each of the W-1 parts of the fifth part of the calibration light to a second output WSS of the first optical network node, wherein the second output WSS is any one of the output WSS of the first optical network node except the first output WSS. For example, the second outputs WSS are WSS2 and WSS6 in FIG. 7 b.

The first output WSS of the first optical network node, such as WSS4 in fig. 7b, receives the fourth partially collimated light, which is transmitted to the first output WSS-connected photo-detection means of the first optical network node for frequency offset detection of WSS 4.

Each second output WSS of the first optical network node receives one copy of the fifth partially collimated light. Wherein each fifth portion of the calibration light includes a first component calibration light and a second component calibration light. Illustratively, WSS2 and WSS6 in FIG. 7b each receive a slice of the fifth portion of the collimated light.

In one implementation, the first component-calibrated light is a first portion of the second output WSS output calibrated optical power of the first optical network node and the second component-calibrated light is a second portion of the second output WSS output calibrated optical power of the first optical network node. For example, the second output WSS splits the received one fifth portion of the calibration light into 2 parts, wherein one part is the first component calibration light and one part is the second component calibration light. It should be noted that the second output WSS divides the received fifth part of the calibration light into 2 parts, may equally divide the optical power of the fifth part of the calibration light into 2 parts, and may also distribute the optical power of each part of the calibration light in the fifth part of the calibration light as needed, which is not limited in this embodiment of the present application.

The second output WSS of the first optical network node, such as WSS2 in fig. 7b, transmits the received first component calibration light corresponding to the fifth portion of calibration light to the photodetection device connected to the second output WSS of the first optical network node; transmitting a second component calibration light corresponding to the received fifth part of calibration light to at least one of the second inputs WSSs of the first optical network node; and the second input WSS is an input WSS except the first input WSS in the input WSS of the first optical network node.

In one implementation, a second output WSS of the first optical network node transmits a second component-calibrated light corresponding to a fifth portion of the calibrated light to a second input WSS of the first optical network node; for example, the WSS2 receives a portion of the fifth part of the calibration light transmitted by the WSS3, and the average power of the fifth part of the calibration light is 2 portions, wherein one portion is transmitted to the photodetection device connected to the WSS2 for frequency offset detection, and the other portion is transmitted to the WSS 1; the WSS6 receives one part of the fifth part of the calibration light transmitted by the WSS3, the average power of the fifth part of the calibration light is 2 parts, one part of the calibration light is transmitted to a photoelectric detection device connected with the WSS6 to carry out frequency offset detection, and the other part of the calibration light is transmitted to the WSS 5.

In one implementation, a second output WSS of the first optical network node transmits a second component-calibrated light corresponding to a fifth portion of the calibrated light to a plurality of second input WSSs of the first optical network node, respectively; for example, the WSS2 receives one part of the fifth part of the calibration light transmitted by the WSS3, and the average power of the fifth part of the calibration light is 3 parts, wherein one part of the calibration light is transmitted to a photoelectric detection device connected with the WSS2 for frequency offset detection, one part of the calibration light is transmitted to the WSS1, and the other part of the calibration light is transmitted to the WSS 5; the WSS6 receives a fifth portion of the collimated light transmitted by the WSS3, and transmits the fifth portion of the collimated light to a photodetection device connected to the WSS6 for frequency offset detection.

And the second input WSS of the first optical network node receives second component calibration light corresponding to the fifth part of calibration light, and transmits the second component calibration light corresponding to the fifth part of calibration light to the photoelectric detection device connected with the second input WSS of the first optical network node for self frequency offset detection.

S30212, the first input WSS of the first optical network node transmits the second portion of the calibration light to the first output WSS of the first optical network node, and the first output WSS of the first optical network node transmits the second portion of the calibration light to the first input WSS of the at least one second optical network node.

Specifically, the second part of the calibration light is the calibration light received within the second duration of the first input WSS of the first optical network node, where the first duration and the second duration do not intersect. The first input WSS of the first optical network node transmits the second portion of the calibration light to the first output WSS of the first optical network node, which transmits the second portion of the calibration light to the first input WSS of the at least one second optical network node, i.e. the first optical network node transmits the second calibration light to the at least one other optical network node.

The second optical network node is any optical network node except the first optical network node. Optionally, the first output WSS of the first optical network node transmits the second part of the calibration light to the first input WSS of one second optical network node; for example, one second optical network node is ROADM C of fig. 7 a. WSS4 of ROADM B transmits the second portion of the collimated light to one input WSS of ROADM C. Optionally, the first output WSS of the first optical network node may also transmit the second portion of the calibration light to a plurality of second optical network nodes. For example, WSS4 of ROADM B transmits the second portion of the collimated light to one input WSS of ROADM a, ROADM C, and ROADM E, respectively. This is not limited in the embodiments of the present application.

In the above implementation, the first calibration light includes a first portion of the calibration light and the second calibration light includes a second portion of the calibration light. A first part of calibration light received by a first input WSS of a first optical network node in a first time period is used for frequency offset detection of each WSS of the first optical network node, and a second part of calibration light received in a second time period is used for transmitting to other optical network nodes. In the implementation mode, the calibration light is transmitted to each WSS in the optical network node in a power-division mode in the optical network node, and after all the WSSs in one optical network node complete frequency offset detection, the second part of the calibration light is transmitted to other optical network nodes, so that the attenuation of the calibration light power can be avoided. After each ROADM in the optical communication system receives the calibration light, the first calibration light is used for frequency offset detection of the optical network node, and the second calibration light is transmitted to at least one other optical network node, so that each WSS of each ROADM in the optical communication system utilizes the calibration light of the calibration light source to perform frequency offset detection.

In an optical communication system, if the ROADM and the WSS are numerous, the distance between the WSS connected with a calibration light source and certain WSS is far, and the optical power can be attenuated in the process of calibrating optical transmission; in the calibration light transmission, if a power division mode is adopted, the light power of the calibration light is attenuated; amplifying the calibration light using an amplifier in an optical communication system also causes deterioration of an optical signal-to-noise ratio of the calibration light. The calibration method for WSSs provided in the embodiment of the present application can be applied to the optical network node shown in fig. 11, as shown in fig. 11, the optical network node includes W input WSSs and W output WSSs, and further includes a regeneration device, where the regeneration device is used to regenerate light, and compared with received light, light output by the regeneration device can improve light energy and optical signal-to-noise ratio. In one example, the regeneration device may include an optical circulator to inject light from an output port of a WSS into a locked laser and to couple a signal reflected from the locked laser into an input port of another WSS, and an injection locked laser. The injection locked laser is used to improve the quality of the calibration light, such as optical power and optical signal to noise ratio. For example, the laser may be a Digital Supermode Distributed Bragg Reflector (DS-DBR) laser. It should be noted that, in fig. 11, the example is that the regeneration device is connected between one input WSS and one output WSS, in practical cases, the regeneration device may be connected between any two WSSs, and after regenerating the calibration light output by one WSS, the regeneration device inputs another WSS, and the two WSSs may belong to the same ROADM or may belong to different ROADMs. For example, ROADM a includes a regeneration device connected between an output WSS of ROADM a and an input WSS of ROADM B. The reproduction apparatus may further be connected to a plurality of WSSs, for example, an input end of the reproduction apparatus is connected to one WSS, and an output end of the reproduction apparatus is connected to a plurality of WSSs, which is not limited in this embodiment of the present application.

An embodiment of the present application provides a calibration method of a WSS, and as shown in fig. 12 in conjunction with fig. 4, the method may further include S103-S104:

s103, the first WSS of the first optical network node transmits the calibration light to the regeneration device of the first optical network node.

The first WSS is any one WSS in the first optical network node. For example, the first WSS is WSS3 in fig. 11. The collimated light output by the WSS3 is transmitted to a regeneration device.

S104, the regenerating means of the first optical network node transmits the regenerated calibration light to at least one WSS connected to the output port of the first WSS.

Specifically, the regenerating device of the first optical network node regenerates the received calibration light, for example, the regenerating device in fig. 11 receives the calibration light output by the WSS3, and the calibration light is regenerated by the regenerating device, so that the optical energy and the optical signal-to-noise ratio are increased. The regenerating means transmits the regenerated collimated light to at least one WSS connected to the output port of the first WSS.

The WSS calibration method provided by the embodiment of the application is characterized in that the regeneration device is connected between the WSS, the calibration light output by the WSS is regenerated by the regeneration device, the light energy and the optical signal to noise ratio of the calibration light can be increased, the attenuation of the calibration light in the transmission process is solved, the quality of the calibration light in an optical communication network is improved, and the accurate rapid detection of all WSS frequency deviation conditions in the whole network is ensured.

The embodiment of the application provides a calibration method of a WSS, which can be applied to an optical communication system shown in fig. 1. As shown in fig. 13, the method may include S401-S403:

s401, the first WSS receives the calibration light.

Specifically, the first WSS may be any one of WSSs in an optical communication system. For example, the first WSS is WSS1, WSS3, WSS5, WSS2, WSS4 or WSS6 in fig. 5b, and the first WSS may also be WSS3, WSS2, WSS4 or WSS6 in fig. 7 b. Optionally, the first WSS receives calibration light from a previous WSS or calibration light source.

S402, the first WSS transmits a first portion of the collimated light to a photo-detection device.

The calibration light includes a first portion of the calibration light and a second portion of the calibration light.

In one implementation, the first WSS splits the collimated light into N +1 parts, where one part is a first portion of the collimated light and N parts is a second portion of the collimated light, where N is greater than or equal to 1.

Illustratively, the first WSS is WSS1, WSS3, WSS5, WSS2, WSS4, or WSS6 in fig. 5b, or the first WSS is WSS2, WSS4, or WSS6 in fig. 7b, and the first WSS splits the collimated light into 2 parts, one of which is the first portion of the collimated light and one of which is the second portion of the collimated light.

Illustratively, the first WSS is WSS3 of fig. 7b, which splits the collimated light into 4 parts, one part being the first portion of the collimated light and 3 parts being the second portion of the collimated light.

In one implementation, the first portion of the calibration light is calibration light received by the first WSS for a first time period; the second portion of the calibration light is the calibration light received by the first WSS for a second time period, wherein the first time period and the second time period do not intersect.

The first WSS transmits a first portion of the calibration light to the photo-detection device for frequency offset detection by the first WSS.

S403, the first WSS transmits the second portion of the collimated light to N second WSSs connected to the first WSS.

The first WSS transmits a second portion of the collimated light to N second WSSs connected to the first WSS, where N is greater than or equal to 1.

Illustratively, the first WSS is WSS1, WSS3, WSS5, WSS2, WSS4, or WSS6 in fig. 5b, or the first WSS is WSS2, WSS4, or WSS6 in fig. 7b, and the first WSS transmits the second portion of the collimated light to 1 second WSS connected to the first WSS.

Illustratively, the first WSS is WSS3 in fig. 7b, which transmits the second portion of the collimated light to 3 second WSSs connected to the first WSS, WSS2, WSS4 and WSS 6.

Alternatively, each WSS in the optical communication system may transmit a first portion of the calibration light to the connected photo-detection device and a second portion of the calibration light to the N second WSSs connected thereto. The path of the WSS transmitting the calibration light may be in any manner as in the above embodiments, as long as it is possible to implement that each WSS in the optical communication system performs frequency offset detection by using the calibration light of the calibration light source.

Illustratively, as shown in FIG. 14, WSS3 receives calibration light from a calibration light source at one input port along path 1, transmits a first portion of the calibration light along path 2 to a photodetector device connected to WSS3, and transmits a second portion of the calibration light along path 3 to WSS 2. The WSS2 receives the collimated light transmitted by the WSS3 at one input port along path 4, transmits a first portion of the collimated light along path 5 to the photo-detection device to which the WSS2 is connected, and transmits a second portion of the collimated light along path 6 to the WSS 1. The WSS1 receives the collimated light transmitted by WSS2 at one input port along path 7, and transmits a first portion of the collimated light along path 8 to the WSS1 connected photodetector device. In this way, each WSS in the optical communication system can perform frequency offset detection using the calibration light of the calibration light source.

In the calibration method for the WSS provided in the embodiment of the application, calibration light output by the calibration light source is uploaded to the WSS connected with the calibration light source through one WSS, and each WSS uses a first part of the calibration light for frequency offset detection of the WSS and transmits a second part of the calibration light to other WSSs until each WSS in the optical communication system performs frequency offset detection by using the received calibration light. Compared with the method for performing frequency offset detection by using a calibration device independently for each WSS in an optical communication system in the prior art, the calibration method for the WSS provided by the embodiment of the application has the advantages that all WSSs in the optical communication system use the calibration light output by the same calibration light source to perform frequency offset detection, not only is the network cost reduced, but also the frequency offset between different calibration devices is avoided, and all WSS frequency offset conditions in the whole optical communication system can be accurately and quickly detected.

In the calibration method for the WSSs provided in the embodiment of the present application, each WSS uses the calibration light to perform frequency offset detection, which is not limited in the embodiment of the present application.

For example, the photo detection device is PD, and the switching engine of the WSS is LCOS.

The WSS receives the calibration light, and transmits the calibration light to the LCOS surface through the collimating lens, the grating and the main lens. As shown in fig. 15, the calibration light wavelength is at the LCOS edge channel, separate from the signal channel. Two phases are superposed on the pixel area of the LCOS where the calibration light is located, wherein the first phase exchanges a part of the calibration light energy to the output port connected with the PD, and the second phase exchanges a part of the calibration light energy from the other output port to the next stage WSS.

In the first step, the LCOS edge channel of WSS adjusts the pixel phase information, and generates a narrow band filter with the channel middle pixel as the center. And step scanning to calibrate the optical center wavelength, and detecting the maximum output power of an output port connected with the PD by using the PD. And comparing the maximum output power detected by the PD with a factory-calibrated channel-center wavelength relation table, and determining the change value delta f of the center wavelength of the edge channel. Thus, frequency offset detection of a WSS is accomplished. Furthermore, the LCOS pixel positions of each channel can be redistributed based on the detected frequency offset value Δ f, and the center wavelength frequency offsets of all channels are calibrated, that is, the frequency offset calibration of a WSS is completed.

An embodiment of the present application provides an optical network node, which may be any optical network node in the foregoing embodiments, and may include W input WSSs and W output WSSs, where each of the W input WSSs is connected to the W output WSSs, and W is greater than or equal to 1. As shown in fig. 16, the W input WSSs and the W output WSSs may include a first input WSS and a first output WSS. The first input WSS may be used to perform S101 and S102 in fig. 4, S201 and S202 in fig. 6, S301 and S302 in fig. 8, S30201 in fig. 9, S30211 and S30212 in fig. 10, S101-S103 in fig. 12, and/or to perform other steps described herein. The first output WSS may be used to perform S102 in fig. 4, S203-S204 in fig. 6, S302 in fig. 8, S30202 and S30203 in fig. 9, S30212 in fig. 10, S103 and S104 in fig. 12, and/or to perform other steps described herein.

Optionally, in conjunction with fig. 16, as shown in fig. 17, the optical network node may further include a second input WSS and a second output WSS. The second input WSS may be used to perform S30206 in fig. 9, and/or to perform other steps described herein. The second output WSS may be used to perform S30204 and S30205 in fig. 9, S103 in fig. 12, and/or perform other steps described in this application.

Optionally, in conjunction with fig. 16, as shown in fig. 17, the optical network node may further include a regeneration device, and the regeneration device may be configured to perform S104 in fig. 12, and/or perform other steps described in this application.

All relevant contents of each step related to the above method embodiment may be referred to the functional description of the optical network node, and are not described herein again.

The solution provided by the embodiment of the present application is also introduced from the perspective of WSS. It is understood that the WSS includes corresponding hardware structures and/or software modules for performing the respective functions in order to implement the above-described functions. Those of skill in the art would readily appreciate that the various illustrative elements and algorithm steps described in connection with the embodiments disclosed herein may be implemented as hardware or combinations of hardware and computer software. Whether a function is performed as hardware or computer software drives hardware depends upon the particular application and design constraints imposed on the solution. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present application.

In the embodiment of the present application, the WSS may be divided into the functional modules according to the above method example, for example, each functional module may be divided corresponding to each function, or two or more functions may be integrated into one processing module. The integrated module can be realized in a hardware mode, and can also be realized in a software functional module mode. It should be noted that, in the embodiment of the present application, the division of the module is schematic, and is only one logic function division, and there may be another division manner in actual implementation. The following description will be given taking the example of dividing each functional module corresponding to each function.

Fig. 18 is a schematic logical structure diagram of the WSS1800 provided in the embodiment of the present application, and the WSS1800 may be a hardware structure, a software module, or a hardware structure plus a software module. As shown in fig. 18, the WSS1800 includes a receiving module 1801 and a transmitting module 1802. The receiving module 1801 may be configured to perform S401 in fig. 13 and/or perform other steps described in this application. The transmission module 1802 may be used to perform S402 and S403 in fig. 13, and/or perform other steps described herein.

Optionally, in conjunction with fig. 18, as shown in fig. 19, the WSS1800 may further include a light splitting module 1803, and the light splitting module 1803 may be configured to execute S402 in fig. 13 and/or perform other steps described in this application.

All relevant contents of each step related to the above method embodiment may be referred to the functional description of the corresponding functional module, and are not described herein again.

In the present embodiment, the optical network node and the WSS1800 are presented in the form of dividing each functional module in an integrated manner. A "module" herein may refer to a particular ASIC, a circuit, a processor and a memory device executing one or more software or firmware programs, an integrated logic circuit, and/or other components that can provide the described functionality.

In a simple embodiment, those skilled in the art may think that the optical network node takes the form shown in fig. 2, and the WSS1800 may take the form shown in fig. 3.

Alternatively, the functions/implementation processes of the first input WSS and the first output WSS in fig. 16 and 17 may be implemented by the WSS in fig. 2. The functions/implementation processes of the second input WSS and the second output WSS in fig. 17 may be implemented by the WSS in fig. 2.

Alternatively, the function/implementation process of the receiving module 1801 in fig. 18 and fig. 19 may be implemented by the input port in fig. 3, the function/implementation process of the transmitting module 1802 may be implemented by the input port, the output port, the collimating mirror, the grating, the main lens, and the switching engine in fig. 3, and the function/implementation process of the splitting module 1803 in fig. 19 may be implemented by the switching engine in fig. 3.

Since the optical network node and the WSS provided in the embodiment of the present application may be used to execute the calibration method of the WSS, reference may be made to the method embodiment for obtaining technical effects, and details are not described herein again.

It will be apparent to those skilled in the art that all or part of the steps of the above method may be performed by hardware associated with program instructions, and the program may be stored in a computer readable storage medium such as ROM, RAM, optical disk, etc.

The embodiment of the application also provides a storage medium.

Optionally, an embodiment of the present application further provides a chip system, where the chip system includes a processor, and is used to support a server to implement the calibration method for the WSS. In one possible design, the system-on-chip further includes a memory. The memory is used for storing program instructions and data necessary for the server. Of course, the memory may not be in the system-on-chip. The chip system may be formed by a chip, and may also include a chip and other discrete devices, which is not specifically limited in this embodiment of the present application.

For the explanation and beneficial effects of the related content in any one of the above-mentioned apparatuses, reference may be made to the corresponding method embodiments provided above, and details are not repeated here.

In the above embodiments, the implementation may be wholly or partially realized by software, hardware, firmware, or any combination thereof. When implemented using a software program, may be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. The procedures or functions described in accordance with the embodiments of the present application are all or partially generated upon loading and execution of computer program instructions on a computer. The computer may be a general purpose computer, a special purpose computer, a network of computers, or other programmable device. The computer instructions may be stored on a computer readable storage medium or transmitted from one computer readable storage medium to another, for example, from one website, computer, server, or data center to another website, computer, server, or data center via wire (e.g., coaxial cable, fiber optic, Digital Subscriber Line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.). The computer-readable storage medium can be any available medium that can be accessed by a computer or can comprise one or more data storage devices, such as a server, a data center, etc., that can be integrated with the medium. The usable medium may be a magnetic medium (e.g., floppy disk, hard disk, magnetic tape), an optical medium (e.g., DVD), or a semiconductor medium (e.g., Solid State Disk (SSD)), among others.

While the present application has been described in connection with various embodiments, other variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed application, from a review of the drawings, the disclosure, and the appended claims. In the claims, the word "comprising" does not exclude other elements or steps, and the word "a" or "an" does not exclude a plurality. A single processor or other unit may fulfill the functions of several items recited in the claims. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage.

Although the present application has been described in conjunction with specific features and embodiments thereof, it will be evident that various modifications and combinations can be made thereto without departing from the spirit and scope of the application. Accordingly, the specification and figures are merely exemplary of the present application as defined in the appended claims and are intended to cover any and all modifications, variations, combinations, or equivalents within the scope of the present application. It will be apparent to those skilled in the art that various changes and modifications may be made in the present application without departing from the spirit and scope of the application. Thus, if such modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents, the present application is intended to include such modifications and variations as well.

Claims

1. A calibration method of a Wavelength Selective Switch (WSS) is applied to an optical network node, wherein the optical network node comprises W input WSSs and W output WSSs, and W is greater than or equal to 1, and the method comprises the following steps:

receiving, by a first optical network node, calibration light, wherein the calibration light comprises first calibration light and second calibration light;

the first optical network node divides the calibration light into first calibration light and second calibration light;

the first optical network node uses the first calibration light for frequency offset detection of the first optical network node;

the first optical network node transmits the second calibration light to at least one second optical network node.

2. A method of calibrating a wavelength selective switch WSS according to claim 1,

the first optical network node receiving the calibration light comprises:

a first input WSS of the first optical network node receives calibration light comprising a first portion of calibration light and a second portion of calibration light; wherein the first input WSS is any one of the W input WSSs for receiving the calibration light at different times, respectively;

the first optical network node uses the first calibration light for frequency offset detection of the first optical network node; the first optical network node transmitting the second calibration light to at least one second optical network node, comprising:

a first input WSS of the first optical network node transmits the first portion of the calibration light to a first input WSS-connected photo-detection device of the first optical network node, and transmits the second portion of the calibration light to a first output WSS of the first optical network node;

a first output WSS of the first optical network node receives the second portion of the calibration light, the second portion of the calibration light comprising a third portion of the calibration light and a fourth portion of the calibration light;

the first output WSS of the first optical network node transmits the third portion of the calibration light to the photo-detection device to which the first output WSS of the first optical network node is connected, and the fourth portion of the calibration light to the first input WSS of at least one second optical network node;

wherein the first calibration light comprises the first portion of calibration light and the third portion of calibration light, and the second calibration light comprises the fourth portion of calibration light.

3. A method of calibrating a wavelength selective switch WSS according to claim 2,

the first portion of the calibration light is a first portion of the first input WSS output calibration optical power of the first optical network node, the second portion of the calibration light is a second portion of the first input WSS output calibration optical power of the first optical network node, the third portion of the calibration light is a first portion of the first output WSS output calibration optical power of the first optical network node, and the fourth portion of the calibration light is a second portion of the first output WSS output calibration optical power of the first optical network node; or the like, or, alternatively,

the first part of calibration light is calibration light received within a first time duration of a first input WSS of the first optical network node, the second part of calibration light is calibration light received within a second time duration of the first input WSS of the first optical network node, the third part of calibration light is calibration light received within a third time duration of a first output WSS of the first optical network node, and the fourth part of calibration light is calibration light received within a fourth time duration of the first output WSS of the first optical network node, wherein the first time duration and the second time duration do not intersect; the third duration and the fourth duration do not intersect.

4. A method of calibrating a wavelength selective switch WSS according to claim 2,

the first part of the calibration light is calibration light received within a first time duration of a first input WSS of the first optical network node, the second part of the calibration light is calibration light received within a second time duration of the first input WSS of the first optical network node, the third part of the calibration light is a first part of a first output WSS of the first optical network node that outputs calibration optical power, and the fourth part of the calibration light is a second part of the first output WSS of the first optical network node that outputs calibration optical power, where the first time duration and the second time duration do not intersect; or the like, or, alternatively,

the first part of the calibration light is a first part of the output calibration optical power of the first input WSS of the first optical network node, the second part of the calibration light is a second part of the output calibration optical power of the first input WSS of the first optical network node, the third part of the calibration light is the calibration light received within a third time period of the first output WSS of the first optical network node, and the fourth part of the calibration light is the calibration light received within a fourth time period of the first output WSS of the first optical network node, wherein the third time period and the fourth time period do not intersect.

5. A method of calibrating a wavelength selective switch WSS according to claim 1,

the first optical network node receiving the calibration light comprises:

a first input WSS of the first optical network node receives calibration light; wherein the first input WSS is any one of the W input WSSs;

a first input WSS of the first optical network node uses the first calibration light for frequency offset detection of each WSS of the first optical network node;

a first input WSS of the first optical network node transmitting a second calibration light to a first output WSS of the first optical network node;

a first output WSS of the first optical network node transmits the second calibration light to a first input WSS of at least one second optical network node.

6. The method of calibrating a wavelength selective switch WSS according to claim 5, wherein said calibration light comprises a first portion of calibration light, a second portion of calibration light and W-1 portions of a third portion of calibration light;

a first input WSS of the first optical network node uses the first calibration light for frequency offset detection of each WSS of the first optical network node; a first input WSS of the first optical network node transmitting a second calibration light to a first output WSS of the first optical network node; a first output WSS of the first optical network node transmitting the second calibration light to a first input WSS of at least one second optical network node, comprising:

a first input WSS of the first optical network node transmits the first portion of the calibration light to a first input WSS-connected photo-detection device of the first optical network node; transmitting the second portion of the calibration light to a first output WSS of the first optical network node; and transmitting each of the W-1 parts of the third part of the collimated light to a second output WSS of the first optical network node, wherein the second output WSS is any one of the output WSSs of the first optical network node except the first output WSS;

a first output WSS of the first optical network node receives the second portion of the calibration light, which includes a fourth portion of the calibration light and a fifth portion of the calibration light;

the first output WSS of the first optical network node transmits the fourth portion of the calibration light to the photo-detection device of the first output WSS connection of the first optical network node, and the fifth portion of the calibration light to the first input WSS of at least one second optical network node of the first output WSS connection of the first optical network node;

a second output WSS of the first optical network node receives a copy of the third portion of the calibration light, the copy of the third portion of the calibration light including a sixth portion of the calibration light and a seventh portion of the calibration light;

a second output WSS of the first optical network node transmits the sixth portion of the calibration light to the photo-detection device to which the second output WSS of the first optical network node is connected, the second output WSS of the first optical network node transmits the seventh portion of the calibration light to at least one of the second input WSSs of the first optical network node; the second input WSS is an input WSS except the first input WSS in the input WSS of the first optical network node;

wherein the first calibration light comprises the first, fourth, sixth, and seventh portions of calibration light, and the second calibration light comprises the fifth portion of calibration light.

7. A method of calibrating a wavelength selective switch WSS according to claim 6,

the second output WSS of the first optical network node transmitting the seventh portion of the calibration light to at least one of the second inputs WSS of the first optical network node, comprising:

the second output WSS of the first optical network node transmits the seventh portion of the calibration light to a second input WSS of the first optical network node; or the like, or, alternatively,

the second output WSS of the first optical network node transmits the seventh portion of the calibration light to all second input WSSs of the first optical network node.

8. A method of calibrating a wavelength selective switch WSS according to claim 7,

the first portion of the calibration light is a first portion of a first input WSS output calibration optical power of the first optical network node, the second portion of the calibration light and the W-1 portion of the third portion of the calibration light are a second portion of the first input WSS output calibration optical power of the first optical network node, the fourth portion of the calibration light is a first portion of a first output WSS output calibration optical power of the first optical network node, the fifth portion of the calibration light is a second portion of the first output WSS output calibration optical power of the first optical network node, the sixth portion of the calibration light is a first portion of a second output WSS output calibration optical power of the first optical network node, and the seventh portion of the calibration light is a second portion of the second output WSS output calibration optical power of the first optical network node; or the like, or, alternatively,

the first part of the calibration light is calibration light received within a first time period of a first input WSS of the first optical network node, the second portion of calibration light and the W-1 portion of third portion of calibration light are calibration light received within a second time period of the first input WSS of the first optical network node, the fourth portion of the calibration light is the calibration light received within a third time period of the first output WSS of the first optical network node, the fifth part of the calibration light is the calibration light received within a fourth time duration of the first output WSS of the first optical network node, the sixth portion of the calibration light is the calibration light received within a third time period of the second output WSS of the first optical network node, the seventh part of the calibration light is the calibration light received within a fourth time duration of the second output WSS of the first optical network node, wherein the first time duration and the second time duration do not intersect; the third duration and the fourth duration do not intersect.

9. A method of calibrating a wavelength selective switch WSS according to claim 7,

the first part of calibration light is calibration light received within a first time period of a first input WSS of the first optical network node, and the second part of calibration light and the W-1 part of third part of calibration light are calibration light received within a second time period of the first input WSS of the first optical network node; the fourth portion of the calibration light is a first portion of the first output WSS output calibration optical power of the first optical network node, the fifth portion of the calibration light is a second portion of the first output WSS output calibration optical power of the first optical network node, the sixth portion of the calibration light is a first portion of the second output WSS output calibration optical power of the first optical network node, and the seventh portion of the calibration light is a second portion of the second output WSS output calibration optical power of the first optical network node, wherein the first duration and the second duration do not intersect; or the like, or, alternatively,

the first portion of the calibration light is a first portion of the first input WSS output calibration optical power of the first optical network node, the second portion of the calibration light and the W-1 third portion of the calibration light are a second portion of the first input WSS output calibration optical power of the first optical network node, the fourth portion of the calibration light is the calibration light received within a third time period of the first output WSS of the first optical network node, the fifth part of the calibration light is the calibration light received within a fourth time duration of the first output WSS of the first optical network node, the sixth portion of the calibration light is the calibration light received within a third time period of the second output WSS of the first optical network node, the seventh part of the calibration light is the calibration light received within a fourth time length of the second output WSS of the first optical network node, where the third time length and the fourth time length do not intersect.

10. A method of calibrating a Wavelength Selective Switch (WSS) according to claim 5, wherein said calibration light comprises a first portion of calibration light and a second portion of calibration light;

the first part of calibration light is calibration light received within a first time length of a first input WSS of the first optical network node, the second part of calibration light is calibration light received within a second time length of the first input WSS of the first optical network node, and the first time length and the second time length are not intersected; the first collimated light comprises the first portion of collimated light, and the second collimated light comprises the second portion of collimated light;

the first part of the calibration light comprises a third part of calibration light, a fourth part of calibration light and W-1 parts of fifth part of calibration light, and each part of the fifth part of calibration light comprises a first component calibration light and a second component calibration light;

the first input WSS of the first optical network node using the first calibration light for frequency offset detection of each WSS of the first optical network node, comprising:

the first input WSS of the first optical network node transmits the third portion of the calibration light to the first input WSS-connected photo-detection device of the first optical network node; transmitting the fourth partially collimated light to a first output, WSS, of the first optical network node; and transmitting each of the W-1 parts of the fifth part of the collimated light to a second output WSS of the first optical network node, wherein the second output WSS is any one of the output WSSs of the first optical network node except the first output WSS;

a first output WSS of the first optical network node transmits the fourth partially collimated light to a first output WSS-connected photo-detection device of the first optical network node;

the second output WSS of the first optical network node transmits the first component calibration light corresponding to the received fifth portion of calibration light to the photodetection device connected to the second output WSS of the first optical network node; a second output WSS of the first optical network node transmits a received second component-calibrated light corresponding to a fifth portion of the calibrated light to at least one of second input WSSs of the first optical network node; the second input WSS is an input WSS except the first input WSS in the input WSS of the first optical network node;

a first input WSS of the first optical network node transmitting a second calibration light to a first output WSS of the first optical network node; a first output WSS of the first optical network node transmitting the second calibration light to a first input WSS of at least one second optical network node, comprising:

a first input WSS of the first optical network node transmits the second portion of the calibration light to a first output WSS of the first optical network node;

the first output WSS of the first optical network node transmits the second portion of the calibration light to the first input WSS of at least one second optical network node.

11. A method of calibrating a wavelength selective switch WSS according to claim 10,

the second output WSS of the first optical network node transmits the received second component-calibrated light corresponding to the fifth portion of the calibrated light to at least one of the second input WSSs of the first optical network node, including:

a second output WSS of the first optical network node transmits a second component-calibrated light corresponding to the received fifth portion of calibrated light to a second input WSS of the first optical network node; or the like, or, alternatively,

and the second output WSS of the first optical network node transmits the received second component calibration light corresponding to the fifth part of calibration light to all the second input WSSs of the first optical network node.

12. A method of calibrating a wavelength selective switch, WSS, according to any of claims 1-11, wherein said first optical network node comprises regenerating means for regenerating calibration light, said method further comprising:

a first WSS of the first optical network node transmitting calibration light to a regeneration device of the first optical network node; the first WSS is any one WSS in the first optical network node;

regenerating means of the first optical network node regenerates the calibration light, transmitting the regenerated calibration light to at least one WSS connected to an output port of the first WSS.

13. A method of calibrating a wavelength selective switch, WSS, the method comprising:

the first WSS receives the calibration light;

the first WSS splits the collimated light into a first portion of collimated light and a second portion of collimated light;

the first WSS transmits a first portion of the collimated light to a photo-detection device;

14. A method of calibrating a wavelength selective switch, WSS, according to claim 13, wherein before the first WSS transmits the first portion of the calibration light to a photo-detection device, the method further comprises:

the first WSS splits the collimated light into N +1 parts, where one part is a first portion of the collimated light and N parts is a second portion of the collimated light.

15. A method of calibrating a wavelength selective switch WSS according to claim 13, wherein the first portion of the calibration light is the calibration light received by the first WSS for a first time period; the second portion of the calibration light is calibration light received by the first WSS for a second time period, wherein the first time period and the second time period do not intersect.

16. An optical network node, comprising: the system comprises W input WSSs and W output WSSs, wherein each of the W input WSSs is respectively connected with the W output WSSs, and W is greater than or equal to 1; the W input WSSs and the W output WSSs comprise:

a first input WSS for receiving calibration light, wherein the calibration light comprises first calibration light and second calibration light; wherein the first input WSS is any one of the W input WSSs;

the optical network node divides the calibration light into power to obtain first calibration light and second calibration light;

the first input WSS is further used for using the first calibration light for frequency offset detection of the first input WSS;

a first output WSS for receiving first calibration light and using said first calibration light for frequency offset detection of said first output WSS;

the first output WSS is further configured to receive a second calibration light and transmit the second calibration light to at least one second optical network node;

a calibration WSS for receiving first calibration light and using the first calibration light for frequency offset detection of the calibration WSS; wherein the calibration WSS is any one WSS other than the first input WSS and the first output WSS.

17. The optical network node of claim 16, wherein the W input WSSs are configured to receive calibration light at different respective times; the calibration light comprising a first portion of calibration light and a second portion of calibration light,

the first input WSS for transmitting the first portion of the calibration light to the first input WSS connected photo-detection device and the second portion of the calibration light to the first output WSS;

the first output WSS for receiving the second portion of the collimated light, the second portion of the collimated light including a third portion of the collimated light and a fourth portion of the collimated light;

the first output WSS is further configured to transmit the third portion of the calibration light to a photo-detection device to which the first output WSS is connected, and to transmit the fourth portion of the calibration light to a first input WSS of at least one second optical network node;

18. The optical network node of claim 17,

the first portion of the calibration light is a first portion of the first input WSS output calibration optical power, the second portion of the calibration light is a second portion of the first input WSS output calibration optical power, the third portion of the calibration light is a first portion of the first output WSS output calibration optical power, and the fourth portion of the calibration light is a second portion of the first output WSS output calibration optical power; or the like, or, alternatively,

the first portion of the calibration light is the calibration light received within a first time period of the first input WSS, the second portion of the calibration light is the calibration light received within a second time period of the first input WSS, the third portion of the calibration light is the calibration light received within a third time period of the first output WSS, and the fourth portion of the calibration light is the calibration light received within a fourth time period of the first output WSS, wherein the first time period and the second time period do not intersect; the third duration and the fourth duration do not intersect.

19. The optical network node of claim 17,

the first portion of the calibration light is the calibration light received within a first time period of the first input WSS, the second portion of the calibration light is the calibration light received within a second time period of the first input WSS, the third portion of the calibration light is a first portion of the output calibration optical power of the first output WSS, and the fourth portion of the calibration light is a second portion of the output calibration optical power of the first output WSS, wherein the first time period and the second time period do not intersect; or the like, or, alternatively,

the first portion of the calibration light is a first portion of the first input WSS output calibration optical power, the second portion of the calibration light is a second portion of the first input WSS output calibration optical power, the third portion of the calibration light is calibration light received within a third time period of the first output WSS, the fourth portion of the calibration light is calibration light received within a fourth time period of the first output WSS, wherein the third time period and the fourth time period do not intersect.

20. The optical network node of claim 16, wherein the calibration light comprises a first portion of calibration light, a second portion of calibration light, and W-1 portions of a third portion of calibration light;

the first input WSS for transmitting the first portion of the calibration light to a photo-detection device to which the first input WSS is connected; transmitting the second portion of the calibration light to the first output WSS; and transmitting each of the W-1 parts of the third portion of the collimated light to a second output WSS; the second output WSS is any one of the output WSSs of the optical network node except the first output WSS;

the first output WSS is used for receiving the second part of the calibration light, and the second part of the calibration light comprises a fourth part of the calibration light and a fifth part of the calibration light;

the first output WSS is further configured to transmit the fourth portion of the calibration light to the photo-detection means of the first output WSS connection, and to transmit the fifth portion of the calibration light to the first input WSS of at least one second optical network node of the first output WSS connection;

the second output WSS is configured to receive a portion of the third portion of the calibration light, the portion of the third portion of the calibration light including a sixth portion of the calibration light and a seventh portion of the calibration light;

the second output WSS is further configured to transmit the sixth portion of the calibration light to a photo-detection device to which the second output WSS is connected, and to transmit the seventh portion of the calibration light to at least one of the second inputs WSS; the second input WSS is an input WSS except the first input WSS in the input WSS of the optical network node;

21. The optical network node of claim 20, wherein the second output WSS transmits the seventh partially collimated light to at least one of the second input WSSs, comprising:

said second output WSS for transmitting said seventh portion of collimated light to a second input WSS of said optical network node; or the like, or, alternatively,

the second output WSS is configured to transmit the seventh partially collimated light to all second input WSSs of the optical network node.

22. The optical network node of claim 21,

the first portion of the calibration light is a first portion of the first input WSS output calibration optical power, the second portion of the calibration light and the W-1 portion of the third portion of the calibration light is a second portion of the first input WSS output calibration optical power, the fourth portion of the calibration light is a first portion of the first output WSS output calibration optical power, the fifth portion of the calibration light is a second portion of the first output WSS output calibration optical power, the sixth portion of the calibration light is a first portion of the second output WSS output calibration optical power, and the seventh portion of the calibration light is a second portion of the second output WSS output calibration optical power; or the like, or, alternatively,

the first portion of calibration light is calibration light received within a first time period of the first input WSS, the second portion of calibration light and the W-1 portion of third portion of calibration light are calibration light received within a second time period of the first input WSS, the fourth portion of calibration light is calibration light received within a third time period of the first output WSS, the fifth portion of calibration light is calibration light received within a fourth time period of the first output WSS, the sixth portion of calibration light is calibration light received within a third time period of the second output WSS, the seventh portion of calibration light is calibration light received within a fourth time period of the second output WSS, wherein the first time period and the second time period do not intersect; the third duration and the fourth duration do not intersect.

23. The optical network node of claim 21,

the first portion of the calibration light is the calibration light received within a first time period of the first input WSS, and the second portion of the calibration light and the W-1 portion of the third portion of the calibration light are the calibration light received within a second time period of the first input WSS; the fourth portion of the calibration light is a first portion of the first output WSS output calibration optical power, the fifth portion of the calibration light is a second portion of the first output WSS output calibration optical power, the sixth portion of the calibration light is a first portion of the second output WSS output calibration optical power, and the seventh portion of the calibration light is a second portion of the second output WSS output calibration optical power, wherein the first and second durations do not intersect; or the like, or, alternatively,

the first portion of calibration light is a first portion of output calibration optical power of the first input WSS, the second portion of calibration light and the W-1 portion of third portion of calibration light are a second portion of output calibration optical power of the first input WSS, the fourth portion of calibration light is calibration light received within a third time period of the first output WSS, the fifth portion of calibration light is calibration light received within a fourth time period of the first output WSS, the sixth portion of calibration light is calibration light received within a third time period of the second output WSS, the seventh portion of calibration light is calibration light received within a fourth time period of the second output WSS, wherein the third time period and the fourth time period do not intersect.

24. The optical network node of claim 16, wherein the calibration light comprises a first portion of calibration light and a second portion of calibration light;

the first portion of the calibration light is the calibration light received within a first time period of the first input WSS, the second portion of the calibration light is the calibration light received within a second time period of the first input WSS, and the first time period and the second time period do not intersect; the first collimated light comprises the first portion of collimated light, and the second collimated light comprises the second portion of collimated light;

the first input WSS for transmitting the third portion of the collimated light to a photo-detection device to which the first input WSS is connected; transmitting the fourth partially collimated light to the first output WSS; and transmitting each of the W-1 parts of the fifth part of the collimated light to a second output WSS; the second output WSS is any one of the output WSSs of the optical network node except the first output WSS;

the first output WSS for transmitting the fourth portion of the collimated light to a photo-detection device to which the first output WSS is connected;

the second output WSS is used for transmitting the first component calibration light corresponding to the received fifth part of calibration light to a photoelectric detection device connected with the second output WSS; transmitting a second component-collimated light corresponding to the received fifth portion of collimated light to at least one of the second inputs WSSs; the second input WSS is an input WSS except the first input WSS in the input WSS of the optical network node;

the first input WSS transmits second calibration light to the first output WSS; the first output WSS transmitting the second collimated light to a first input WSS of at least one second optical network node, comprising:

the first input WSS for transmitting the second portion of the collimated light to the first output WSS;

the first output WSS for transmitting the second partially collimated light to a first input WSS of at least one second optical network node.

25. The optical network node of claim 24, wherein the second output WSS transmits a corresponding second component-calibrated light of the received fifth portion of calibrated light to at least one of the second input WSSs, comprising:

the second output WSS is configured to transmit the second component-collimated light corresponding to the received fifth portion of collimated light to a second input WSS of the optical network node; or the like, or, alternatively,

and the second output WSS is configured to transmit the second component-collimated light corresponding to the received fifth portion of collimated light to all second input WSSs of the optical network node.

26. The optical network node according to any of claims 16-25, wherein the optical network node further comprises:

a first WSS for transmitting the calibration light to a regeneration device; the first WSS is any one WSS in the optical network node;

the regenerating means is configured to regenerate the calibration light and further configured to transmit the regenerated calibration light to at least one WSS connected to the output port of the first WSS.

27. An optical communication system comprising a plurality of optical network nodes according to any of claims 16 to 26.