O-band high-speed multi-channel long-distance optical fiber transmission interference suppression method and device

Abstract

This invention discloses a method and device for suppressing interference in O-band high-speed, multi-channel, long-distance optical fiber transmission. This method addresses the harmonic mixing interference problem caused by the nonlinear dispersion effect of optical fiber during the long-distance transmission (≥10 km) of high-speed optical modulated signals in modern data centers. It increases the isolation between multiple channels and effectively improves the optical and electrical signal quality of multi-channel, long-distance optical fiber transmission. Based on high-isolation, low-loss, broadband, smooth-response combiners and demultiplexers, adjacent channel harmonic interference prediction technology, and harmonic interference wavelength optimization technology, this method achieves multi-channel in-band, low-loss transmission within the wavelength range of O-band LWDM channels and suppresses out-of-band harmonic interference. It also shifts harmonic interference outside the communication band, completely resolving the nonlinear harmonic interference problem associated with long-distance optical fiber transmission. This significantly improves the transmission quality of O-band multi-channel optical and electrical signals, facilitating the transmission of higher-speed, longer-distance optical and electrical signals in future data centers.

Description

Technical Field

[0001] The present invention relates to the field of high-speed optoelectronic long-distance communications, and in particular to a method and device for suppressing interference in O-band high-speed multi-channel long-distance optical fiber transmission. Background Art

[0002] With the rapid development of technologies such as artificial intelligence, large-scale model training, and cloud computing, the demand for computing power is exploding. Modern data centers, as core infrastructure for basic computing power, are experiencing a continuous increase in both scale and number. Data transmission rates within modern data centers are rapidly doubling from 25 Gbit / s per channel to 50 Gbit / s per channel and then to 100 Gbit / s per channel. Inter-data center communications are becoming increasingly frequent, with transmission distances extending from tens to hundreds of meters within a data center to 10 km between data centers.

[0003] Fiber optic technology is an important foundation for modern computing and communication technologies. Its almost unlimited data transmission bandwidth and low-loss long-distance transmission characteristics make fiber optic technology one of the important communication technologies for modern data centers, and it is particularly suitable for high-speed transmission in modern data centers.

[0004] As the data transmission rate of data centers continues to increase, it is currently evolving from 100Gbit / s per channel to 200Gbit / s per channel. The number of channels is constantly increasing, and the data transmission range is also expanding from a few hundred meters to over 10km. Combined with optical fiber transmission technology, the latest technological development trends in data centers are also facing new challenges, which are manifested as follows: (1) The nonlinear effect of long-distance optical fiber transmission causes new harmonics to be generated between channels, causing channel signals to interfere with each other, seriously affecting the signal transmission quality; (2) Long-distance optical fiber transmission will bring greater signal loss, resulting in weak signals at the receiving end, reducing signal transmission quality. Existing improved technical means include controlling the polarization state of optical signals, that is, channels 1 and 4 use X polarization, and channels 2 and 3 use Y polarization, reducing the signal interaction between channels to reduce harmonic interference, but in essence the interference signal is still within the operating wavelength range of the channel.

[0005] Therefore, in order to solve the problem of signal quality degradation caused by long-distance optical fiber transmission of high-speed signals, it is necessary to suppress interference in multi-channel long-distance optical fiber transmission. By using specific devices and technologies, the quality of multi-channel signals after long-distance optical fiber transmission can be significantly improved to meet the data transmission and exchange needs of future communications. Summary of the Invention

[0006] The purpose of the present invention is to address the deficiencies of the prior art and to provide a method and device for suppressing interference in O-band high-speed multi-channel long-distance optical fiber transmission.

[0007] The object of the present invention is achieved through the following technical solutions: an O-band high-speed multi-channel long-distance optical fiber transmission interference suppression device, the device comprising: an N-channel high-isolation, low-loss, broadband smooth response combiner device, a single long-distance single-mode optical fiber, and an N-channel high-isolation, low-loss, broadband smooth response splitter device;

[0008] The N-channel high-isolation, low-loss, broadband, smooth-response combiner is used to combine N independent optical signals modulated at a rate of s into a total optical signal; the total optical signal includes N optical signals;

[0009] The long-distance single-mode optical fiber is used to transmit the total optical signal, and the transmission distance is ≥10km;

[0010] The N-channel high-isolation, low-loss, broadband, smooth-response combiner is used to decompose the total optical signal into N independent optical signals, and send them to N independent demodulation devices for signal demodulation, thereby completing long-distance optical fiber transmission of high-speed signals.

[0011] Furthermore, the frequency range of any channel m in the N-channel high isolation, low loss, wide frequency smooth response multiplexing device and the N-channel high isolation, low loss, wide frequency smooth response demultiplexing device is ,in, , is the starting frequency of channel m, is the end frequency of channel m; then the LWDM operating frequency range of O band is for ;

[0012] The N-channel high-isolation, low-loss, broadband, smooth-response combiner and the N-channel high-isolation, low-loss, broadband, smooth-response splitter have an amplitude response flatness in each channel better than 0.16 dB, an insertion loss less than 1.4 dB, a channel operating wavelength range greater than 2.5 nm, and adjacent channel isolation greater than 40 dB.

[0013] The present invention also provides an O-band high-speed multi-channel long-distance optical fiber transmission interference suppression method, which is applied to the above-mentioned O-band high-speed multi-channel long-distance optical fiber transmission interference suppression device and includes the following steps:

[0014] (1) Any channel in the total optical signal input to the long-distance single-mode optical fiber The initial frequency of the optical signal is the starting frequency of the channel ;

[0015] (2) Order , with the initial frequency combination Based on ,aisle and channel Optimize the wavelength of adjacent channel harmonic interference to obtain the channel ,aisle and channel Frequency combination ,in, and ; Then add new channels , 、 and , with frequency combination and frequency Based on the channel ,aisle ,aisle and channel Optimize the wavelength of adjacent channel harmonic interference to obtain the frequency combination Repeat the above steps and continue to add new channels until all remaining channels are added to obtain the frequency combination As the first optimal frequency combination ;

[0016] (3) Order , with the first optimal frequency combination Based on, repeat step (2) to get the second optimal frequency combination ;

[0017] (4) Repeat step (3) until , and obtain the final optimal frequency combination ;

[0018] (5) The frequencies corresponding to the N independent optical signals modulated at a rate of s are then adjusted to the final optimal frequency combination. , complete the control and optimization of N-channel harmonic interference wavelength.

[0019] Furthermore, the step (2) specifically includes the following sub-steps:

[0020] (2.1) Order , with the initial frequency combination Based on the frequency ,frequency and frequency As channels ,aisle and channel The starting fixed frequency value of and ;

[0021] (2.2) First, frequency interval Traversing the channel Frequency range , iterate over the value as a channel Fixed frequency value; then the channel ,aisle and channel traversal;

[0022] aisle ,aisle and channel The traversal process is: channel From channel The frequency increment is the frequency interval. ,aisle and channel The fixed frequency value of the channel remains unchanged; if Has traversed to the end frequency , then the channel Fixed frequency value increases the frequency interval ,aisle The fixed frequency value of the channel remains unchanged, while the Continue from the starting frequency Frequency interval Start traversal; and so on, if the channel The fixed frequency value increases to the end frequency , then the channel Fixed frequency value increases the frequency interval ,aisle From the starting frequency Frequency interval Start traversing, and the channel Continue from the starting frequency Frequency interval Start traversal; and so on until the channel The fixed frequency value increases to the end frequency ;

[0023] (2.3) During the traversal process, if there is no channel ,aisle and channel Adjacent channel harmonic interference satisfy Frequency combination , then the traversal ends;

[0024] (2.4) During the traversal process, if there is a channel ,aisle and channel Adjacent channel harmonic interference satisfy Frequency combination , then the channel ,aisle and channel The traversal is paused and the frequency combination is obtained ; Then add new channels , 、 and , with frequency combination and frequency Based on and If not satisfied, then frequency combination and Get channel based on ,aisle ,aisle and channel The starting fixed frequency value is then followed by the channel in step (2.2). ,aisle ,aisle and channel Traversal; if there is no satisfying and Frequency combination , then the traversal ends;

[0025] (2.5) If there exists and Frequency combination , then continue to add new channels and repeat step (2.4) until all remaining channels are added and the Frequency combination ,in, , and ; and frequency combination As the first optimal frequency combination .

[0026] Furthermore, the channel ,aisle and channel Adjacent channel harmonic interference Defined as ,in, 、 and Channel ,aisle and channel Fixed frequency value.

[0027] Furthermore, in step (4), the final optimal frequency combination Satisfy any , among which, among which, , 、 and .

[0028] Furthermore, the O-band high-speed multi-channel long-distance optical fiber transmission interference suppression method further includes the following steps:

[0029] Adjust the frequency to the final optimal frequency combination N independent optical signals modulated at a rate of s are input into the O-band high-speed multi-channel long-distance optical fiber transmission interference suppression device. After passing through the N-channel high-isolation, low-loss, broadband smooth response combiner and the long-distance single-mode optical fiber in sequence, all adjacent channel harmonic interferences are locked outside the band of the N-channel high-isolation, low-loss, broadband smooth response splitter. After continuing to pass through the N-channel high-isolation, low-loss, broadband smooth response splitter, the amplitude of all out-of-band harmonic interferences is suppressed, with a suppression amplitude of >10.5dB, while the amplitude of the normal signal in the band is suppressed by <1.5dB.

[0030] The beneficial effects of the present invention are as follows: first, a high-isolation, low-loss, broadband, smooth-response multiplexing / demultiplexing device of an O-band LWDM channel wavelength is adopted; second, the high-isolation, low-loss, broadband, smooth-response multiplexing device is utilized to combine multi-channel high-speed optical signals and transmit them over long-distance optical fibers; in order to control the nonlinear harmonic interference caused by long-distance optical fiber transmission, an adjacent channel harmonic interference prediction technology based on nonlinear dispersion effect is adopted, mainly analyzing the adjacent channel harmonic interference; then, combining the performance advantages of the high-isolation, low-loss, broadband, smooth-response multiplexing device, a non-uniform multi-channel wavelength spacing setting and a harmonic interference wavelength optimization technology are adopted to traverse and screen out the optimal frequency combination, thereby completely excluding the interference harmonics from the LWDM working channel wavelength and minimizing the attenuation of the working wavelength during the combining process; finally, a high-isolation, low-loss, broadband, smooth-response demultiplexing device is adopted, and the high isolation and low loss characteristics of the demultiplexing device are utilized to further suppress the amplitude of the out-of-band adjacent channel harmonic interference, while keeping the amplitude attenuation of the in-band working wavelength signal to a minimum, thereby improving the signal-to-noise ratio of the multi-channel high-speed optical and electrical signals. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 This is a structural diagram of an O-band high-speed multi-channel long-distance optical fiber transmission interference suppression device in Example 1;

[0032] Figure 2 This is the frequency response diagram of the 4-channel high-isolation, low-loss, wide-band, smooth-response multiplexing / demultiplexing device;

[0033] Figure 3 This is a diagram showing harmonic interference generated at the center of channel 1 using the traditional channel center frequency.

[0034] Figure 4 Schematic diagram of the signal amplitude before and after passing through the 4-channel high-isolation, low-loss, broadband and smooth-response splitter device;

[0035] Figure 5 200Gbit / s eye diagram of one channel in a multi-channel optoelectronic transmission system using traditional equidistant channel center spacing;

[0036] Figure 6 This is a 200 Gbit / s eye diagram of the optoelectronic transmission system of one of the multiple channels based on the final optimal frequency combination in Example 2;

[0037] In the figure, 1- N-channel high isolation, low loss, broadband smooth response multiplexing device; 2- long distance single mode optical fiber; 3- N-channel high isolation, low loss, broadband smooth response splitting device. DETAILED DESCRIPTION

[0038] Example 1: Figure 1 As shown, the present invention provides an O-band high-speed multi-channel long-distance optical fiber transmission interference suppression device, which includes: an N-channel high-isolation, low-loss, broadband smooth response combiner 1, a single long-distance single-mode optical fiber 2, and an N-channel high-isolation, low-loss, broadband smooth response splitter 3.

[0039] The O-band high-speed multi-channel long-distance optical fiber transmission interference suppression device is aimed at a multi-channel optoelectronic transceiver system with N channels ( ), operating within the LWDM channel wavelength range of the O band.

[0040] The N-channel high-isolation, low-loss, broadband and smooth-response combiner is used to combine N independent optical signals modulated at a rate of s into a total optical signal; the total optical signal includes N optical signals.

[0041] The long-distance single-mode optical fiber is used to transmit the total optical signal. The length of the long-distance single-mode optical fiber is not less than 10 km.

[0042] The N-channel high isolation, low loss, wideband smooth response combiner is used to decompose the total optical signal into N independent optical signals and send them to N independent demodulation devices for signal demodulation, thus completing the long-distance optical fiber transmission of high-speed signals. The rate s needs to meet Gbit / s.

[0043] The N-channel high-isolation, low-loss, broadband, smooth-response combiner and splitter are optical devices operating within the LWDM operating wavelength range of the O-band. They each feature an 800 GHz channel spacing, polarization mode dispersion of less than 0.2 ps, an optical insertion loss of less than 1.4 dB per channel, an operating wavelength range greater than 2.5 nm, and a smooth amplitude response within the LWDM operating wavelength range, with a response flatness better than 0.16 dB. The isolation between the N channels is greater than 40 dB. Designed and manufactured using a filter-based process, the devices measure 100 mm × 80 mm × 10 mm. Operating within the LWDM operating wavelength range of the O-band, the N-channel high-isolation, low-loss, broadband, smooth-response combiner and splitter exhibit high isolation, low insertion loss, a smooth amplitude response, a wide operating bandwidth, and a compact structure. The N-channel high-isolation, low-loss, wide-band, smooth-response combiner device and the N-channel high-isolation, low-loss, wide-band, smooth-response splitter device are essentially the same device; based on the reversible characteristics of the optical path, the N-channel high-isolation, low-loss, wide-band, smooth-response combiner device and the N-channel high-isolation, low-loss, wide-band, smooth-response splitter device can replace each other.

[0044] In order to suppress the nonlinear harmonic interference caused by single long-distance optical fiber transmission with a rate of s within the LWDM operating wavelength range of the O band, the high isolation, low insertion loss, smooth amplitude effect, and large operating bandwidth of the N-channel high-isolation, low-loss, broadband smooth response combiner and the N-channel high-isolation, low-loss, broadband smooth response splitter are combined. Therefore, a non-channel center wavelength can be selected as the operating wavelength in each channel. The selectable wavelength range of each channel is greater than 2nm, and both have the characteristics of low insertion loss, smooth amplitude response, and high isolation, with the advantage of flexible wavelength setting.

[0045] In order to suppress the nonlinear harmonic interference caused by single long-distance optical fiber transmission, it is necessary to predict the adjacent channel harmonic interference, mainly to analyze the mechanism of adjacent channel harmonic interference, and to carry out the prediction and judgment of adjacent channel harmonic interference.

[0046] The broadband characteristics (>2.5nm), high isolation (>40dB), and smoothness (flatness better than 0.16dB) of the multi-channel, high-isolation, low-loss, broadband, smooth-response combiner and splitter devices described above provide an excellent foundation for suppressing nonlinear harmonic interference caused by long-haul single-mode fiber transmission. The high-isolation, low-loss, broadband, smooth-response combiner and splitter devices enable flexible selection of operating wavelengths within each channel (broadband and smoothness). By leveraging adjacent channel harmonic interference prediction and harmonic interference wavelength optimization technologies, harmonic interference is controlled outside the channel wavelength and its amplitude is further suppressed (high isolation), completely eliminating the impact of harmonic interference on high-speed communications while minimizing transmission losses (low loss).

[0047] The adjacent channel harmonic interference prediction technology analyzes the mixing interference caused by nonlinear dispersion effects in long-haul single-mode optical fibers, which generates new mixing harmonics. These mixing harmonics can disrupt the signal quality of the original channel, especially when the mixing harmonics and the original operating wavelength are within the same operating wavelength channel. Harmonic interference prediction technology primarily analyzes the wavelength or frequency of harmonic interference generated by adjacent channels.

[0048] Example 2: In this embodiment, the N-channel high-isolation, low-loss, wide-band smooth response combiner device is a 4-channel high-isolation, low-loss, wide-band smooth response combiner device (N=4), and the N-channel high-isolation, low-loss, wide-band smooth response splitter device is a 4-channel high-isolation, low-loss, wide-band smooth response splitter device (N=4).

[0049] Through high-speed electrical signals (single channel rate Gbit / s) modulated 4 optical signals (4 wavelengths, within the LWDM operating wavelength range), respectively working on the four channels in the LWDM operating wavelength range, are synthesized into a total optical signal through a 4-channel high-isolation, low-loss, broadband smooth response combiner, and the total optical signal contains 4 optical signals; then the total optical signal is transmitted through a long-distance single-mode optical fiber, the distance of which exceeds 10km. Nonlinear interference will occur during the transmission process of the long-distance single-mode optical fiber, resulting in serious inter-channel interference and reducing the transmission quality of the total optical signal. The total optical signal is then decomposed into 4 optical signals of different wavelengths through a 4-channel high-isolation, low-loss, broadband smooth response splitter, and sent to 4 independent demodulation devices for signal demodulation, converting the high-speed electrical signal (single-channel rate Gbit / s) to complete the long-distance optical fiber transmission of high-speed signals.

[0050] The frequency responses of the 4-channel high isolation, low loss, wide frequency smooth response combiner and the 4-channel high isolation, low loss, wide frequency smooth response splitter are as follows: Figure 2As shown, the LWDM operating wavelength range in the O band has four channels: channel 1, channel 2, channel 3 and channel 4. The operating wavelength range of channel 1 is : ; The operating wavelength range of the channel 2 is : ; The operating wavelength range of the channel 3 is : ; The operating wavelength range of the channel 4 is : That is, the LWDM operating wavelength range of the O band of the 4-channel high isolation low loss broadband smooth response multiplexing device and the 4-channel high isolation low loss broadband smooth response splitter device : According to the LWDM operating wavelength range of the O band , the frequency range of any channel m is ,in, , is the starting frequency of channel m, is the end frequency of channel m; then the LWDM operating frequency range of O band is for .

[0051] LWDM operating wavelength range in O-band The 4-channel high-isolation, low-loss, broadband smooth-response combiner and splitter devices have an amplitude response flatness better than 0.16dB, with insertion losses of 0.95dB for channel 1, 1.4dB for channel 2, 0.5dB for channel 3, and 0.35dB for channel 4. The operating wavelength range of these devices covers LWDM operating channels, with wavelengths greater than 2.5nm: 2.8nm for channel 1, 2.7nm for channel 2, 3.2nm for channel 3, and 2.9nm for channel 4. Channel isolation exceeds 40dB.

[0052] The present invention also provides an O-band high-speed multi-channel long-distance optical fiber transmission interference suppression method, which is applied to the above-mentioned O-band high-speed multi-channel long-distance optical fiber transmission interference suppression device, comprising the following steps:

[0053] (1) Any channel in the total optical signal input to the long-distance single-mode optical fiber The initial frequency of the optical signal is the starting frequency of the channel In this embodiment, the N-channel high isolation low loss broadband smooth response combiner device and the N-channel high isolation low loss broadband smooth response splitter device are 4 channels, that is .

[0054] For channels ,aisle and channel Adjacent channel harmonic interference Defined as ,in, 、 and Channel ,aisle and channel Fixed frequency value.

[0055] (2) First, , with the initial frequency combination Based on this, channel 1, channel 2 and channel 3 are selected to optimize the adjacent channel harmonic interference wavelength, and the adjacent channel harmonic interference of channel 1, channel 2 and channel 3 is obtained. satisfy Frequency combination .

[0056] (2.1) Order , with the initial frequency combination Based on the frequency and They are used as fixed frequency values ​​for channel 2 and channel 3 respectively.

[0057] (2.2) First, frequency interval Traverse the frequency range of channel 1 , the traversal value is used as the fixed frequency value of channel 1; then the traversal of channels 1, 2 and 3 is performed;

[0058] The traversal process of channel 1, channel 2 and channel 3 is as follows: channel 1 starts from the fixed frequency value of channel 1 At the beginning, each frequency increase is the frequency interval , the fixed frequency values ​​of channel 2 and channel 3 remain unchanged, and are kept at the corresponding starting frequencies and ; If channel 1 has traversed to the end frequency , then the fixed frequency value of channel 2 increases the frequency interval , that is, at this time, channel 2 starts from the fixed frequency value Increased frequency spacing , the fixed frequency value of channel 3 remains unchanged, while channel 1 continues to Frequency interval Start traversal; and so on, if the fixed frequency value of channel 2 increases to the end frequency , then the fixed frequency value of channel 3 increases the frequency interval , that is, at this time, channel 3 starts from the fixed frequency value Increased frequency spacing , channel 2 starts from the starting frequency Frequency interval Start traversal, and channel 1 continues from the starting frequency Frequency interval Start traversal; and so on, until the fixed frequency value of channel 3 increases to the end frequency .

[0059] (2.3) During the traversal of channels 1, 2, and 3, if there is no adjacent channel harmonic interference between channels 1, 2, and 3 satisfy Frequency combination , then the traversal ends; if there is adjacent channel harmonic interference of channel 1, channel 2 and channel 3 satisfy Frequency Combination , then the traversal of channel 1, channel 2 and channel 3 is suspended, and the frequency combination is obtained ,in, 、 and respectively satisfy Fixed frequency values ​​for channel 1, channel 2, and channel 3.

[0060] (3) Then add a new channel 4, with frequency combination and frequency Based on this, the wavelength of adjacent channel harmonic interference is optimized for channel 1, channel 2, channel 3 and channel 4 to obtain the frequency combination .

[0061] (3.1) Due to the presence of adjacent channel harmonic interference between channels 1, 2 and 3 satisfy Frequency combination , then add a new channel 4, with frequency combination and frequency Based on and If not satisfied, then frequency combination and Based on this, we get the starting fixed frequency values ​​of channel 1, channel 2, channel 3 and channel 4. That is, the starting fixed frequency value of channel 1 is , the starting fixed frequency value of channel 2 is , the starting fixed frequency value of channel 3 is , the starting fixed frequency value of channel 4 is , then traverse channel 1, channel 2, channel 3 and channel 4 according to step (2.2).

[0062] The traversal process of channel 1, channel 2, channel 3 and channel 4 is as follows: channel 1 starts from the fixed frequency value of channel 1 At the beginning, each frequency increase is the frequency interval , the fixed frequency values ​​of channel 2, channel 3 and channel 4 remain unchanged, and are respectively kept at the corresponding starting fixed frequency values 、 and ; If channel 1 has traversed to the end frequency , then the fixed frequency value of channel 2 increases the frequency interval , that is, at this time, channel 2 starts from the fixed frequency value Increased frequency spacing , the fixed frequency values ​​of channels 3 and 4 remain unchanged, while channel 1 continues to Frequency interval Start traversal; and so on, if the fixed frequency value of channel 2 increases to the end frequency , then the fixed frequency value of channel 3 increases the frequency interval , that is, at this time, channel 3 starts from the fixed frequency value Increased frequency spacing , the fixed frequency value of channel 4 remains unchanged, and the fixed frequency value of channel 2 is Frequency interval Start traversal, and channel 1 continues from the starting frequency Frequency interval Start traversal; and so on, if the fixed frequency value of channel 3 increases to the end frequency , then the fixed frequency value of channel 4 increases the frequency interval , that is, at this time, channel 4 starts from the fixed frequency value Increased frequency spacing , channel 3 starts from the starting frequency Frequency interval Start traversal, channel 2 starts from the starting frequency Frequency interval Start traversal, and channel 1 continues from the starting frequency Frequency interval Start traversal; and so on, until the fixed frequency value of channel 4 increases to the end frequency .

[0063] (3.2) During the traversal of channels 1, 2, 3 and 4, if there is no adjacent channel harmonic interference of channels 1, 2 and 3 satisfy And the adjacent channel harmonic interference of channel 1, channel 2 and channel 4 satisfy Frequency combination , then the traversal ends; if there is adjacent channel harmonic interference of channel 1, channel 2 and channel 3 satisfy And the adjacent channel harmonic interference of channel 1, channel 2 and channel 4 satisfy Frequency combination , then the traversal of channel 1, channel 2, channel 3 and channel 4 is suspended, and the frequency combination is obtained ,in, 、 、 、 respectively satisfy and The fixed frequency values ​​of channel 1, channel 2, channel 3 and channel 4 are displayed.

[0064] At this point, new channels have been added until all remaining channels have been added, and the frequency combination is obtained. As the first optimal frequency combination .

[0065] (4) Order , with the first optimal frequency combination Based on, repeat steps (2)-step (3) to obtain the second optimal frequency combination .

[0066] (4.1) Order , with the first optimal frequency combination Based on 、 、 and If not satisfied, the first optimal frequency combination Based on this, the initial fixed frequency values ​​of channel 1, channel 2, channel 3 and channel 4 are obtained. That is, the initial fixed frequency value of channel 1 is , the starting fixed frequency value of channel 2 is , the starting fixed frequency value of channel 3 is , the starting fixed frequency value of channel 4 is , then traverse channel 1, channel 2, channel 3 and channel 4 according to step (2.2).

[0067] (4.2) During the traversal of channels 1, 2, 3 and 4, if there is no adjacent channel harmonic interference of channels 1, 2 and 3 satisfy , adjacent channel harmonic interference of channel 1, channel 2 and channel 4 satisfy , Channel 2, Channel 3 and adjacent channel harmonic interference of Channel 1 satisfy And the adjacent channel harmonic interference of channel 2, channel 3 and channel 4 satisfy Frequency combination , then the traversal ends; if there is adjacent channel harmonic interference of channel 1, channel 2 and channel 3 satisfy , adjacent channel harmonic interference of channel 1, channel 2 and channel 4 satisfy , Channel 2, Channel 3 and adjacent channel harmonic interference of Channel 1 satisfy And the adjacent channel harmonic interference of channel 2, channel 3 and channel 4 satisfy Frequency combination , then the traversal of channel 1, channel 2, channel 3 and channel 4 is suspended, and the frequency combination is obtained and as the second optimal frequency combination, where 、 、 and respectively satisfy 、 、 and The fixed frequency values ​​of channel 1, channel 2, channel 3 and channel 4 are displayed.

[0068] (5) Order , with the second best frequency combination Based on, repeat steps (2)-step (3) to obtain the third optimal frequency combination .

[0069] (5.1) Order , with the second best frequency combination Based on 、 、 、 、 and If not satisfied, the second best frequency combination Based on this, the initial fixed frequency values ​​of channel 1, channel 2, channel 3 and channel 4 are obtained. That is, the initial fixed frequency value of channel 1 is , the starting fixed frequency value of channel 2 is , the starting fixed frequency value of channel 3 is , the starting fixed frequency value of channel 4 is , then traverse channel 1, channel 2, channel 3 and channel 4 according to step (2.2).

[0070] (4.2) During the traversal of channels 1, 2, 3 and 4, if there is no adjacent channel harmonic interference of channels 1, 2 and 3 satisfy , adjacent channel harmonic interference of channel 1, channel 2 and channel 4 satisfy , Channel 2, Channel 3 and adjacent channel harmonic interference of Channel 1 satisfy , Channel 2, Channel 3 and Channel 4 adjacent channel harmonic interference satisfy , Channel 3, Channel 4 and adjacent channel harmonic interference of Channel 1 satisfy And the adjacent channel harmonic interference of channel 3, channel 4 and channel 2 satisfy Frequency combination , then the traversal ends; if there is adjacent channel harmonic interference of channel 1, channel 2 and channel 3 satisfy , adjacent channel harmonic interference of channel 1, channel 2 and channel 4 satisfy , Channel 2, Channel 3 and adjacent channel harmonic interference of Channel 1 satisfy , Channel 2, Channel 3 and Channel 4 adjacent channel harmonic interference satisfy , Channel 3, Channel 4 and adjacent channel harmonic interference of Channel 1 satisfy And the adjacent channel harmonic interference of channel 3, channel 4 and channel 2 satisfy Frequency combination , then the traversal of channel 1, channel 2, channel 3 and channel 4 is suspended, and the frequency combination is obtained and as the third optimal frequency combination, where 、 、 and respectively satisfy 、 、 、 、 and The fixed frequency values ​​of channel 1, channel 2, channel 3 and channel 4 are displayed.

[0071] at this time, , the third optimal frequency combination As the final optimal frequency combination.

[0072] (6) The frequencies corresponding to the four independent optical signals modulated at a rate of s are then adjusted to the final optimal frequency combination. , complete the control and optimization of 4-channel harmonic interference wavelength.

[0073] The harmonic interference wavelength control and optimization technology method is applied to the harmonic interference and wavelength control of the 4-channel optoelectronic transceiver system, and the final optimal frequency combination The wavelengths of the corresponding four channels are: 1294.9nm for channel 1, 1300.7nm for channel 2, 1305.35nm for channel 3, and 1308.5nm for channel 4. The primary adjacent channel first harmonics generated within the 1293.5nm to 1311.5nm range are 1297.6nm and 1311.2nm, both outside the wavelength range of the four operating channels of O-band LWDM. This achieves the design goal of eliminating major harmonic interference outside the operating channel wavelength range.

[0074] The harmonic interference wavelength control and optimization technology is another key to removing the harmonic interference generated by long-distance optical fiber transmission to outside the wavelength range of the four working channels of LWDM. If the harmonic interference wavelength control and optimization measures are not adopted, and the traditional channel center is used as the working wavelength, the generated harmonic interference will coincide with the working wavelength, causing greater interference. Figure 3 , channel 2, channel 3, and channel 4 operate at the center wavelength of their respective channels. Long-distance optical fiber transmission will produce a harmonic that falls exactly on the center wavelength of channel 1, which will significantly interfere with the communication quality.

[0075] (7) The O-band high-speed multi-channel long-distance optical fiber transmission interference suppression method further includes the following steps:

[0076] Adjust the frequency to the final optimal frequency combination Four independent optical signals modulated at a rate of s are input into the O-band high-speed multi-channel long-distance optical fiber transmission interference suppression device. After passing through the 4-channel high-isolation, low-loss, broadband smooth response combiner and the long-distance single-mode optical fiber in sequence, all adjacent channel harmonic interferences are locked outside the band of the 4-channel high-isolation, low-loss, broadband smooth response splitter. After continuing to pass through the 4-channel high-isolation, low-loss, broadband smooth response splitter, the amplitude of all out-of-band harmonic interferences is suppressed, with a suppression amplitude of >10.5dB, while the amplitude of the normal signal in the band is suppressed by <1.5dB, thereby further improving the signal-to-noise ratio by >9dB.

[0077] After the main harmonic interference has been excluded from the wavelength range of the four working channels of O-band LWDM based on the harmonic interference wavelength control and optimization technology, in order to further suppress the amplitude of harmonic interference, the four-channel combined signal transmitted through a long-distance single-mode optical fiber of 10km is passed through a four-channel high-isolation, low-loss, broadband smooth response splitter to separate the combined signal into four independent signals. The high isolation characteristics of the splitter further suppress the amplitude of harmonic interference. Figure 4 Within the four working channels of O-band LWDM, the maximum amplitude attenuation of the frequency response is less than 1.5dB (smooth characteristic). Outside the four working channel wavelengths of O-band LWDM, the harmonic interference amplitude is further suppressed (>10.5dB) (high isolation characteristic), further improving the signal-to-noise ratio of long-distance single-mode optical fiber by more than 9dB.

[0078] from Figure 5 and Figure 6 To demonstrate the effectiveness of high-speed signal transmission using a four-channel, high-isolation, low-loss, broadband, smooth-response multiplexing / demultiplexing device, along with harmonic interference wavelength control and optimization technology, four channels of 200Gbit / s signals were modulated and transmitted through an O-band, high-speed, multi-channel, long-haul optical fiber transmission interference suppression device, for a total transmission rate of 800Gbit / s. This was compared to a conventional setup using the four-channel center wavelength as the operating wavelength, similarly modulating four channels of 200Gbit / s signals and transmitting them through an O-band, high-speed, multi-channel, long-haul optical fiber transmission interference suppression device. Signal quality was compared by observing the eye diagram of one channel after demodulation of the high-speed signal through the four-channel, long-haul optical fiber transmission system. Figure 5 Eye diagram of one channel obtained using traditional wavelength setting, Figure 6 This is the same channel eye diagram obtained after using the O-band high-speed multi-channel long-distance optical fiber transmission interference suppression method provided by the present invention. It can be clearly seen that the signal eye diagram obtained by using the O-band high-speed multi-channel long-distance optical fiber transmission interference suppression method provided by the present invention is clear, the signal eye is large, and the interference is small. The calculated bit error rate is at the 1E-15 level; while the signal eye diagram obtained by the traditional method is fuzzy, the eye is closed, and the calculated bit error rate is at the 1E-3 level, which does not meet the bit error rate standard of less than 2.4E-4.

[0079] The present invention provides an O-band high-speed multi-channel long-distance optical fiber transmission interference suppression method and device. Based on a high-isolation, low-loss, broadband smooth response multiplexer / demultiplexer, and utilizing its advantages of high isolation, low loss, large bandwidth, and smooth response, the invention combines the prediction technology of harmonic interference and the control and optimization technology of harmonic interference wavelength to effectively control the wavelength and suppress the amplitude of harmonic interference caused by long-distance (≥10km) optical fiber transmission of high-speed signals (≥200Gbit / s per channel). The performance is as follows: (1) the harmonic interference wavelength is controlled outside the wavelengths of the four working channels of the O-band LWDM; (2) the harmonic interference amplitude is further suppressed by 9dB on the basis of the above, which improves the quality of high-speed signal transmission and improves the system bit error rate by 12 orders of magnitude. Based on the above implementation approach and effect, the O-band high-speed multi-channel long-distance optical fiber transmission interference suppression method and device have significant performance advantages and anti-interference advantages, laying a good foundation for higher-speed and longer-distance optical fiber transmission in future data centers.

[0080] The implementation process of the functions and effects of each unit in the above-mentioned device is specifically described in the implementation process of the corresponding steps in the above-mentioned method, and will not be repeated here.

[0081] For the device embodiments, since they basically correspond to the method embodiments, the relevant parts can be referred to the partial description of the method embodiments. The device embodiments described above are merely illustrative, wherein the units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the present invention. A person of ordinary skill in the art can understand and implement the present invention without inventive work.

[0082] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for suppressing interference in O-band high-speed multi-channel long-distance optical fiber transmission, characterized in that: The method uses an O-band high-speed multi-channel long-distance optical fiber transmission interference suppression device, which includes: an N-channel high-isolation, low-loss, broadband smooth response combiner, a single long-distance single-mode optical fiber, and an N-channel high-isolation, low-loss, broadband smooth response splitter; The N-channel high isolation, low loss, wideband smooth response combiner adopts a filter process to synthesize N independent optical signals modulated at a rate of s into a total optical signal; the total optical signal contains N optical signals; the rate s needs to meet Gbit / s; ; The long-distance single-mode optical fiber is used to transmit the total optical signal, and the transmission distance is ≥10km; The N-channel high-isolation, low-loss, broadband, smooth-response combiner is used to decompose the total optical signal into N independent optical signals, and send them to N independent demodulation devices for signal demodulation, thereby completing long-distance optical fiber transmission of high-speed signals. The frequency range of any channel m in the N-channel high isolation, low loss, wide frequency smooth response combiner and the N-channel high isolation, low loss, wide frequency smooth response splitter is ,in, , is the starting frequency of channel m, is the end frequency of channel m; then the LWDM operating frequency range of O band is for ; The N-channel high-isolation, low-loss, broadband, smooth-response combiner and the N-channel high-isolation, low-loss, broadband, smooth-response splitter have adjacent channel spacing of 800 GHz, polarization mode dispersion of less than 0.2 ps, amplitude response flatness within each channel better than 0.16 dB, insertion loss less than 1.4 dB, channel operating wavelength range greater than 2.5 nm, and adjacent channel isolation greater than 40 dB. The method comprises the following steps: (1) Any channel in the total optical signal input to the long-distance single-mode optical fiber The initial frequency of the optical signal is the starting frequency of the channel ; (2) Order , with the initial frequency combination Based on ,aisle and channel Optimize the wavelength of adjacent channel harmonic interference to obtain the channel ,aisle and channel Frequency combination ,in, and ; Then add new channels , 、 and , with frequency combination and frequency Based on the channel ,aisle ,aisle and channel Optimize the wavelength of adjacent channel harmonic interference to obtain the frequency combination Repeat the above steps and continue to add new channels until all remaining channels are added to obtain the frequency combination As the first optimal frequency combination ; (3) Order , with the first optimal frequency combination Based on, repeat step (2) to get the second optimal frequency combination ; (4) Repeat step (3) until , and obtain the final optimal frequency combination ; (5) The frequencies corresponding to the N independent optical signals modulated at a rate of s are then adjusted to the final optimal frequency combination. , complete the control and optimization of N-channel harmonic interference wavelength.

2. The method for suppressing interference in O-band high-speed multi-channel long-distance optical fiber transmission according to claim 1, characterized in that: The step (2) specifically includes the following sub-steps: (2.1) Order , with the initial frequency combination Based on the frequency ,frequency and frequency As channels ,aisle and channel The starting fixed frequency value of and ; (2.2) First, frequency interval Traversing the channel Frequency range , iterate over the value as a channel Fixed frequency value; then the channel ,aisle and channel traversal; aisle ,aisle and channel The traversal process is: channel From channel The frequency increment is the frequency interval. ,aisle and channel The fixed frequency value of the channel remains unchanged; if Has traversed to the end frequency , then the channel Fixed frequency value increases the frequency interval ,aisle The fixed frequency value of the channel remains unchanged, while the Continue from the starting frequency Frequency interval Start traversal; and so on, if the channel The fixed frequency value increases to the end frequency , then the channel Fixed frequency value increases the frequency interval ,aisle From the starting frequency Frequency interval Start traversing, and the channel Continue from the starting frequency Frequency interval Start traversal; and so on until the channel The fixed frequency value increases to the end frequency ; (2.3) During the traversal process, if there is no channel ,aisle and channel Adjacent channel harmonic interference satisfy Frequency combination , then the traversal ends; (2.4) During the traversal process, if there is a channel ,aisle and channel Adjacent channel harmonic interference satisfy Frequency combination , then the channel ,aisle and channel The traversal is paused and the frequency combination is obtained ; Then add new channels , 、 and , with frequency combination and frequency Based on and If not satisfied, then frequency combination and Get channel based on ,aisle ,aisle and channel The starting fixed frequency value is then followed by the channel in step (2.2). ,aisle ,aisle and channel Traversal; if there is no satisfying and Frequency combination , then the traversal ends; (2.5) If there exists and Frequency combination , then continue to add new channels and repeat step (2.4) until all remaining channels are added and the Frequency combination ,in, , and ; and frequency combination As the first optimal frequency combination .

3. The method for suppressing interference in O-band high-speed multi-channel long-distance optical fiber transmission according to claim 2, characterized in that: The channel ,aisle and channel Adjacent channel harmonic interference Defined as ,in, 、 and Channel ,aisle and channel Fixed frequency value.

4. The method for suppressing interference in O-band high-speed multi-channel long-distance optical fiber transmission according to claim 2, characterized in that: In step (4), the final optimal frequency combination Satisfy any , Among them, among them, , 、 and .

5. The method for suppressing interference in O-band high-speed multi-channel long-distance optical fiber transmission according to claim 1, characterized in that: The O-band high-speed multi-channel long-distance optical fiber transmission interference suppression method further comprises the following steps: Adjust the frequency to the final optimal frequency combination N independent optical signals modulated at a rate of s are input into the O-band high-speed multi-channel long-distance optical fiber transmission interference suppression device. After passing through the N-channel high-isolation, low-loss, broadband smooth response combiner and the long-distance single-mode optical fiber in sequence, all adjacent channel harmonic interferences are locked outside the band of the N-channel high-isolation, low-loss, broadband smooth response splitter. After continuing to pass through the N-channel high-isolation, low-loss, broadband smooth response splitter, the amplitude of all out-of-band harmonic interferences is suppressed, with a suppression amplitude of >10.5dB, while the amplitude of the normal signal in the band is suppressed by <1.5dB.

Images