A multi-wavelength polarization-independent optical transmitter and a transmission control method thereof

Abstract

The application relates to the technical field of optical communication, and discloses a multi-wavelength polarization-independent optical transmitter and a transmission control method thereof.The transmitter comprises an optical transmission link, a monitoring photoelectric detection module and a control circuit.The optical transmission link is used for receiving a multi-wavelength random polarization state optical signal to perform polarization beam splitting rotation, wavelength gating, power equalization and high-speed electro-optical modulation, and outputs a multi-wavelength polarization-independent modulation optical signal.The monitoring photoelectric detection module is used for acquiring monitoring information of internal nodes of the optical transmission link and the multi-wavelength polarization-independent modulation optical signal to generate a monitoring signal set.The control circuit is used for performing summation, difference and ratio processing on monitoring signals in the monitoring signal set to obtain a control signal set which is sent to the optical transmission link to realize wavelength locking, polarization control locking and micro-ring resonator modulation optimal working point locking, and maintain stable working of the transmitter.The method has high integration, high stability and good scalability while giving consideration to multi-wavelength expansion, polarization-independent transmission and stable collaborative control.

Description

Technical Field

[0001] This invention relates to the field of optical communication technology, and in particular to a multi-wavelength polarization-independent optical transmitter and its transmission control method. Background Technology

[0002] As the demands for bandwidth density, energy efficiency, and transmission stability continue to increase in artificial intelligence computing, data center switching, and high-performance accelerator interconnects, traditional electrical interconnects face significant bottlenecks in terms of loss, crosstalk, power consumption, and bandwidth expansion. Optical interconnect technologies based on silicon photonics platforms, with their advantages of high bandwidth density, low transmission loss, and natural compatibility with wavelength division multiplexing (WDM), are gradually becoming important candidates for next-generation high-performance interconnects. Especially in WDM scenarios requiring simultaneous transmission of multiple wavelength channels, integrated, low-power, and scalable multi-wavelength optical transmitters have significant application value.

[0003] For polarization-independent optical transmitters designed for multi-wavelength transmission, in addition to achieving stable gating of the target wavelength and subsequent modulation, it is also necessary to maintain stable operation of each channel under random polarization input conditions. Microring devices have significant advantages due to their small size, low power consumption, and ease of large-scale integration, but they are also highly sensitive to temperature drift, process variations, input optical power fluctuations, and polarization state disturbances. For a transmit link that includes a polarization beam splitter rotator, microring filter, automatic polarization controller, and microring resonator modulator, changes in the state of the preceding devices will be transmitted to the following devices, making the detection quantity of the microring resonator modulator directly affected by changes in the channel input power, thereby reducing the optimal operating point locking accuracy.

[0004] In existing technologies, microring filters, automatic polarization controllers, and microring resonant modulators are typically configured with independent monitoring ports and independent control loops. While this approach enables individual control of each device, it introduces problems such as an increase in the number of monitoring devices, complex wiring, control link redundancy, and increased system area and power consumption. Furthermore, existing solutions often focus on controlling individual devices, lacking a collaborative design for the overall architecture of multi-wavelength polarization-independent optical transmitters. If the microring resonant modulator uses only a single output monitoring quantity for locking, its locking result is easily affected by changes in upstream optical power, laser power fluctuations, and polarization state changes, making it difficult to balance transmitter control accuracy, system stability, and multi-wavelength expansion capabilities. Existing technologies suffer from a lack of integrated architecture and control design, susceptibility of the microring resonant modulator's optimal operating point locking to upstream optical power fluctuations, mutual coupling of multiple control loops, and redundant monitoring resources. Summary of the Invention

[0005] In view of this, this invention proposes a multi-wavelength polarization-independent optical transmitter and its transmission control method. By adding a pre-stage monitoring photodetector between the automatic polarization controller and the micro-ring resonator modulator, and constructing a normalized criterion based on the ratio of the pre- and post-stage monitoring signals using the micro-ring resonator output-side monitoring photodetector, wavelength locking of the micro-ring filter, polarization control locking of the automatic polarization controller, and optimal operating point locking of the micro-ring resonator modulator can be achieved. This effectively reduces the impact of laser power fluctuations and channel input optical power fluctuations on control accuracy. This invention combines multi-wavelength extension, polarization-independent emission, and stable collaborative control, exhibiting high integration, high stability, and good scalability.

[0006] In a first aspect, the present invention provides a multi-wavelength polarization-independent optical transmitter, including an optical transmission link, a monitoring photoelectric detection module, and a control circuit; The optical transmission link is used to receive multi-wavelength random polarization optical signals, perform polarization beam splitting rotation, wavelength gating, power equalization and high-speed electro-optic modulation on the multi-wavelength random polarization optical signals, and output multi-wavelength polarization-independent modulated optical signals. The monitoring photoelectric detection module is used to acquire monitoring information of internal nodes of the optical transmission link and multi-wavelength polarization-independent modulated optical signals, and generate a monitoring signal set; The control circuit is used to perform summation, difference and ratio processing on the monitoring signals in the monitoring signal set, construct normalization criteria, obtain control signal set, and send the control signal set to the optical transmission link to realize wavelength locking, polarization control locking and micro-ring resonant modulator optimal operating point locking, and maintain stable operation of the transmitter. The control signal set includes a first control signal, a second control signal, a third control signal, and a fourth control signal, and the monitoring signal set includes a first monitoring signal, a second monitoring signal, a third monitoring signal, and a fourth monitoring signal.

[0007] Based on the above technical solutions, preferably, the optical transmission link includes a polarization beam splitter rotator, a micro-ring filter, an automatic polarization controller, a first micro-ring resonant modulator, and a second micro-ring resonant modulator; The polarization beam splitter is used to perform polarization rotation and beam splitting on multi-wavelength random polarization optical signals to obtain a first orthogonal component and a second orthogonal component. The polarization rotation mechanism is used to convert the first orthogonal component and the second orthogonal component into a first optical signal suitable for on-chip transmission and a second optical signal suitable for subsequent processing. The micro-ring filter is used to select the target wavelength of the first optical signal and the second optical signal to obtain the first filtered signal and the second filtered signal. The automatic polarization controller is used to dynamically balance the power of the first filtered signal and the second filtered signal to obtain the first channel signal and the second channel signal. The first micro-ring resonant modulator is used to electro-optically modulate the first channel signal to obtain a first modulated signal, and the second micro-ring resonant modulator is used to electro-optically modulate the second channel signal to obtain a second modulated signal; The first modulation signal and the second modulation signal are used as multi-wavelength polarization-independent modulation optical signals.

[0008] Based on the above technical solutions, preferably, the monitoring photoelectric detection module includes a first monitoring photoelectric detector, a second monitoring photoelectric detector, a third monitoring photoelectric detector, and a fourth monitoring photoelectric detector; The first monitoring photodetector and the second monitoring photodetector are used to collect monitoring information of the first channel signal and the second channel signal, and generate the first monitoring signal and the second monitoring signal. The third and fourth monitoring photodetectors are used to collect monitoring information of the first and second modulation signals, and generate the third and fourth monitoring signals.

[0009] Based on the above technical solutions, preferably, the control circuit includes a first monitoring circuit, a first control circuit, a second monitoring circuit, and a second control circuit; The first monitoring circuit is used to perform summation and difference processing on the first monitoring signal and the second monitoring signal to obtain the first control signal and the second control signal, and send the first control signal and the second control signal to the first control circuit; The second monitoring circuit is used to perform ratio processing on the third monitoring signal and the first monitoring signal to obtain the third control signal, and to perform ratio processing on the fourth monitoring signal and the second monitoring signal to obtain the fourth control signal, and to send the third control signal and the fourth control signal to the second control circuit.

[0010] Based on the above technical solutions, preferably, the first control circuit maximizes the first control signal to approach a preset extreme value in order to adjust the wavelength of the micro-ring filter and achieve wavelength locking.

[0011] Based on the above technical solutions, preferably, the first control circuit adjusts the second control signal to approach zero to adjust the automatic polarization controller, so as to balance the two output powers of the automatic polarization controller to achieve polarization control locking.

[0012] Based on the above technical solutions, preferably, the second control circuit adjusts the third control signal to approach the first preset reference value in order to adjust the operating point of the first micro-ring resonant modulator and achieve the optimal operating point locking of the first micro-ring resonant modulator.

[0013] Based on the above technical solutions, preferably, the second control circuit adjusts the fourth control signal to approach the second preset reference value in order to adjust the operating point of the second micro-ring resonant modulator and achieve the optimal operating point locking of the second micro-ring resonant modulator.

[0014] Based on the above technical solutions, preferably, the first port of the first control circuit is connected to the first port of the micro-ring filter, the second port of the first control circuit is connected to the first port of the automatic polarization controller, the third port of the first control circuit is connected to the first port of the first monitoring circuit, the second port of the first monitoring circuit is connected to the second port of the automatic polarization controller, the third port of the first monitoring circuit is connected to the first port of the second control circuit and the first port of the second monitoring circuit, the second port of the second monitoring circuit is connected to the first port of the first micro-ring resonant modulator and the first port of the second micro-ring resonant modulator, the second port of the second control circuit is connected to the second port of the first micro-ring resonant modulator and the second port of the second micro-ring resonant modulator, the first port of the first monitoring photodetector is connected to the third port of the automatic polarization controller, the first port of the second monitoring photodetector is connected to the fourth port of the automatic polarization controller, the first port of the third monitoring photodetector is connected to the third port of the first micro-ring resonant modulator, and the first port of the fourth monitoring photodetector is connected to the third port of the second micro-ring resonant modulator.

[0015] Secondly, the present invention also provides a method for controlling the emission of multi-wavelength polarization-independent light, the method comprising: Acquire multi-wavelength randomly polarized optical signals; The multi-wavelength random polarization optical signal is input into the optical transmission link, and polarization beam splitting, wavelength gating, power equalization and high-speed electro-optic modulation are performed to output a multi-wavelength polarization-independent modulated optical signal. The multi-wavelength polarization-independent modulated optical signals and monitoring information of internal nodes of the optical transmission link are collected and sent to the monitoring photoelectric detection module to generate a monitoring signal set; The generated monitoring signal set is sent to the control circuit for summation, difference and ratio processing, and a normalization criterion is constructed to obtain the control signal set. The control signal set is then sent to the optical transmission link to achieve wavelength locking, polarization control locking and micro-ring resonant modulator optimal operating point locking, and maintain stable operation of the transmitter. The control signal set includes a first control signal, a second control signal, a third control signal, and a fourth control signal, and the monitoring signal set includes a first monitoring signal, a second monitoring signal, a third monitoring signal, and a fourth monitoring signal.

[0016] The multi-wavelength polarization-independent light transmitter provided by this invention has the following advantages over the prior art: (1) By adding a pre-stage monitoring photodetector between the automatic polarization controller and the micro-ring resonant modulator, and constructing a normalized criterion based on the ratio of the pre- and post-stage monitoring signals using the monitoring photodetector on the output side of the micro-ring resonant modulator, wavelength locking of the micro-ring filter, polarization control locking of the automatic polarization controller, and optimal operating point locking of the micro-ring resonant modulator can be achieved. This effectively reduces the impact of laser power fluctuations and channel input optical power fluctuations on control accuracy. It takes into account multi-wavelength extension, polarization-independent emission, and stable coordinated control, and has high integration, high stability, and good scalability.

[0017] (2) By splitting and rotating the random polarization state multi-wavelength input light through a polarization beam splitter, and combining the wavelength gating function of the micro-ring filter and the power balance adjustment function of the automatic polarization controller, the target wavelength under different input polarization states can be stably coupled into the subsequent dual-path modulation channel. Under the random polarization state input condition, the target wavelength can be stably gated, the power is balanced and the dual-path modulation output is realized, thereby reducing the system's dependence on fixed input polarization state and external polarization management link; thus realizing multi-wavelength polarization-independent emission.

[0018] (3) By using a ratio-based collaborative control method with wavelength control and polarization control as the main lines, and combined with optimal operating point control, the influence of laser power fluctuation, channel input power fluctuation and polarization disturbance on the locking criterion can be effectively suppressed, thereby improving the overall control accuracy and operational stability of the transmitter. By supporting multi-device collaborative control with shared monitoring information, the independent monitoring and control resource configuration can be reduced while ensuring functional integrity. This is beneficial for reducing system area, power consumption and wiring complexity, and improving the expansion capability and architecture versatility of multi-wavelength channels. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a schematic diagram of the structure of the multi-wavelength polarization-independent light transmitter provided by the present invention; Figure 2 This is one of the schematic diagrams of the optical path implementation of the multi-wavelength polarization-independent light transmitter provided by the present invention; Figure 3 A second schematic diagram of the optical path implementation of the multi-wavelength polarization-independent light transmitter provided by the present invention; Figure 4The third schematic diagram of the optical path implementation of the multi-wavelength polarization-independent light transmitter provided by the present invention; Figure 5 The fourth schematic diagram of the optical path implementation of the multi-wavelength polarization-independent light transmitter provided by the present invention; Figure 6 One of the schematic diagrams for implementing a multi-wavelength polarization-independent optical transmitter in a single wavelength channel according to the present invention; Figure 7 The second schematic diagram of the implementation principle of the multi-wavelength polarization-independent light transmitter provided by the present invention in a single wavelength channel; Figure 8 This is a flowchart illustrating the multi-wavelength polarization-independent light emission control method provided by the present invention; Explanation of reference numerals in the attached figures: 1. Optical transmission link; 2. Monitoring photodetector module; 3. Control circuit; 11. Polarization beam splitter / rotator; 12. Micro-ring filter; 13. Automatic polarization controller; 14. First micro-ring resonant modulator; 15. Second micro-ring resonant modulator; 21. First monitoring photodetector; 22. Second monitoring photodetector; 23. Third monitoring photodetector; 24. Fourth monitoring photodetector; 31. First monitoring circuit; 32. First control circuit; 33. Second monitoring circuit; 34. Second control circuit. Detailed Implementation

[0021] The technical solutions of the embodiments of this application will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application are within the scope of protection of this application.

[0022] Unless otherwise defined, the technical or scientific terms used in this invention shall have the ordinary meaning understood by one of ordinary skill in the art to which this invention pertains. The terms "first," "second," and similar terms used in this invention do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Similarly, the terms "an" or "a" and similar terms do not indicate a quantity limitation, but rather indicate the presence of at least one. The terms "connected" or "linked" and similar terms are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. "Up," "down," "left," "right," etc., are used only to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship also changes accordingly.

[0023] like Figure 1 As shown, the present invention provides a multi-wavelength polarization-independent optical transmitter, including an optical transmission link 1, a monitoring photoelectric detection module 2, and a control circuit 3; The optical transmission link 1 is used to receive multi-wavelength random polarization optical signals, perform polarization beam splitting rotation, wavelength gating, power equalization and high-speed electro-optic modulation on the multi-wavelength random polarization optical signals, and output multi-wavelength polarization-independent modulated optical signals. In some embodiments, the optical transmission link 1 includes a polarization beam splitter rotator 11, a micro-ring filter 12, an automatic polarization controller 13, a first micro-ring resonant modulator 14, and a second micro-ring resonant modulator 15. The polarization beam splitter 11 is used to perform polarization rotation and beam splitting on multi-wavelength random polarization optical signals to obtain a first orthogonal component and a second orthogonal component. The first orthogonal component and the second orthogonal component are converted into a first optical signal suitable for on-chip transmission and a second optical signal suitable for subsequent processing through the polarization rotation mechanism. The micro-ring filter 12 is used to select the target wavelength of the first optical signal and the second optical signal to obtain the first filtered signal and the second filtered signal. The automatic polarization controller 13 is used to dynamically balance the power of the first filtered signal and the second filtered signal to obtain the first channel signal and the second channel signal. The first micro-ring resonant modulator 14 is used to perform electro-optic modulation on the first channel signal to obtain a first modulated signal, and the second micro-ring resonant modulator 15 is used to perform electro-optic modulation on the second channel signal to obtain a second modulated signal; The first modulation signal and the second modulation signal are used as multi-wavelength polarization-independent modulation optical signals.

[0024] In some embodiments, the polarization beam splitter rotator 11 decomposes and converts the input multi-wavelength randomly polarized light into two optical signals suitable for on-chip transmission and subsequent processing; the micro-ring filter 12 is used to select the target wavelength from the multi-wavelength input and guide it into the corresponding channel; the automatic polarization controller 13 is used to dynamically adjust the two optical signals to keep the optical power entering the first micro-ring resonant modulator 14 and the second micro-ring resonant modulator 15 balanced; the first micro-ring resonant modulator 14 and the second micro-ring resonant modulator 15 respectively complete electro-optic modulation and output the modulated optical signal from the corresponding output terminal. The above devices work together to form the main transmission link of the multi-wavelength polarization-independent optical transmitter, enabling the system to maintain stable injection of the target wavelength and dual-channel modulation output even when the input polarization state changes.

[0025] In this embodiment, through the coordinated configuration of a polarization beam splitter, a micro-ring filter, an automatic polarization controller, and two micro-ring resonant modulators, the input multi-wavelength light can still achieve target wavelength gating, two-way optical power balancing, and stable modulation output even when the polarization state changes randomly, thereby realizing multi-wavelength polarization-independent emission.

[0026] The monitoring photoelectric detection module 2 is used to acquire monitoring information of internal nodes and multi-wavelength polarization-independent modulated optical signals of the optical transmission link 1, and generate a monitoring signal set; In some embodiments, the monitoring photoelectric detection module 2 includes a first monitoring photoelectric detector 21, a second monitoring photoelectric detector 22, a third monitoring photoelectric detector 23, and a fourth monitoring photoelectric detector 24; The first monitoring photodetector 21 and the second monitoring photodetector 22 are used to collect monitoring information of the first channel signal and the second channel signal, and generate the first monitoring signal and the second monitoring signal. The third monitoring photodetector 23 and the fourth monitoring photodetector 24 are used to collect monitoring information of the first modulation signal and the second modulation signal, and generate the third monitoring signal and the fourth monitoring signal.

[0027] It is easy to understand that in each wavelength channel, a first monitoring photodetector 21 and a second monitoring photodetector 22 are respectively set between the APC (Automatic Polarization Controller) and the two micro-ring resonant modulators to acquire two pre-stage monitoring information after the APC and before the micro-ring resonant modulators; a third monitoring photodetector 23 and a fourth monitoring photodetector 24 are respectively set on the output side of the corresponding two micro-ring resonant modulators to acquire two post-stage monitoring information. The first monitoring circuit 31 performs summation and difference processing on the outputs of the first monitoring photodetector 21 and the second monitoring photodetector 22. The first control circuit 32 generates the wavelength locking control quantity of the micro-ring filter 12 based on the summation result and generates the polarization control locking control quantity of the automatic polarization controller 13 based on the difference result. The second monitoring circuit 33 and the second control circuit 34 construct the ratio of the front and rear monitoring signals based on the third monitoring photodetector 23, the fourth monitoring photodetector 24, and the aforementioned first monitoring photodetector 21 and second monitoring photodetector 22, forming a ratio-based normalized criterion for locking the optimal operating point of the two micro-ring resonant modulators, thereby constituting a cooperative control method for the transmitter.

[0028] Optionally, the APC is preferably of type MZI, and the monitoring photodetector can be a resonant photodetector, waveguide photodetector, all-silicon photodetector, or germanium-silicon photodetector. This application does not limit the type of photodetector.

[0029] The control circuit 3 is used to perform summation, difference and ratio processing on the monitoring signals in the monitoring signal set, construct normalization criteria, obtain control signal set, and send the control signal set to optical transmission link 1 to realize wavelength locking, polarization control locking and micro-ring resonant modulator optimal operating point locking, and maintain stable operation of the transmitter. The control signal set includes a first control signal, a second control signal, a third control signal, and a fourth control signal, and the monitoring signal set includes a first monitoring signal, a second monitoring signal, a third monitoring signal, and a fourth monitoring signal.

[0030] In some embodiments, the control circuit 3 includes a first monitoring circuit 31, a first control circuit 32, a second monitoring circuit 33, and a second control circuit 34. The first monitoring circuit 31 is used to perform summation and difference processing on the first monitoring signal and the second monitoring signal to obtain the first control signal and the second control signal, and send the first control signal and the second control signal to the first control circuit 32. It is easy to understand that the outputs of the first monitoring photodetector 21 and the second monitoring photodetector 22, and the total optical power of the target wavelength coupled into the channel after passing through the automatic polarization controller 13, can achieve wavelength locking of the micro-ring filter 12 by maximizing the outputs or making them approach a preset extreme value; the output difference between the two represents the degree of power imbalance between the two outputs of the automatic polarization controller 13, and the polarization control locking of the automatic polarization controller 13 can be achieved by making the output difference approach zero; the ratio of the front and rear stage monitoring signals represents the relative transmission state of the corresponding first micro-ring resonant modulator 14 and the second micro-ring resonant modulator 15 under the current input power conditions, and the optimal operating point of the micro-ring resonant modulator can be locked by comparing this ratio with the target reference value. The target reference value can be determined by sweeping the bias voltage during the system power-on calibration stage (corresponding to the maximum slope point or 50% transmission point of the micro-ring resonant modulator), or updated in real time using an adaptive tracking algorithm.

[0031] In some embodiments, the first monitoring circuit 31 sums and subtracts the two preceding monitoring signals and outputs them to the corresponding control units in the first control circuit 32. The sum of the two preceding monitoring signals characterizes the total optical power coupled to the target wavelength into the channel; the first control circuit 32 adjusts the micro-ring filter 12 accordingly to achieve wavelength locking. The difference between the two preceding monitoring signals characterizes the power imbalance between the two outputs of the automatic polarization controller 13; the first control circuit 32 adjusts the automatic polarization controller 13 accordingly to achieve polarization control locking. Simultaneously, the second monitoring circuit 33 acquires two subsequent monitoring signals and constructs a ratio between the preceding and subsequent monitoring signals together with the corresponding preceding monitoring signals. The second control circuit 34 adjusts the first micro-ring resonant modulator 14 and the second micro-ring resonant modulator 15 according to this ratio to achieve optimal operating point locking. The wavelength control, polarization control, and optimal operating point control described above together constitute a ratio-based collaborative control method for the transmitter.

[0032] The second monitoring circuit 33 is used to perform ratio processing on the third monitoring signal and the first monitoring signal to obtain the third control signal, and to perform ratio processing on the fourth monitoring signal and the second monitoring signal to obtain the fourth control signal, and to send the third control signal and the fourth control signal to the second control circuit 34.

[0033] In a preferred embodiment, a first ratio R1 and a second ratio R2 are constructed for the first micro-ring resonator modulator 14 and the second micro-ring resonator modulator 15, respectively. R1 is composed of a third monitoring signal and a first monitoring signal, and R2 is composed of a fourth monitoring signal and a second monitoring signal. The control circuit adjusts the control terminals of the two micro-ring resonator modulators according to the deviations of R1 and R2 from their respective reference values ​​to achieve independent optimal operating point locking. Since the ratios use the corresponding preceding stage monitoring signal as a normalization reference, the influence of laser power fluctuations, preceding stage coupling fluctuations, and changes in automatic polarization control state on the micro-ring resonator locking results can be effectively reduced. For multi-wavelength systems, different wavelength channels can be cascaded, parallelized, or multiplexed using the same control unit structure to maintain consistency in the transmitter architecture.

[0034] The aforementioned first control signal, second control signal, third control signal, and fourth control signal work together to ensure the stable operation of the multi-wavelength polarization-independent optical transmitter. The first and second control signals correspond to the wavelength and polarization control main lines, respectively, while the third and fourth control signals are used to maintain the transmission output quality and long-term stability.

[0035] In some embodiments, the first control circuit 32 adjusts the wavelength of the micro-ring filter 12 by maximizing the first control signal to approach a preset extreme value, thereby achieving wavelength locking. The first control circuit 32 adjusts the automatic polarization controller 13 by adjusting the second control signal to approach zero, thereby balancing the two output powers of the automatic polarization controller 13 to achieve polarization control locking.

[0036] In some embodiments, the second control circuit 34 adjusts the operating point of the first micro-ring resonator 14 by adjusting the third control signal to approach the first preset reference value, thereby locking the optimal operating point of the first micro-ring resonator 14. The second control circuit 34 adjusts the operating point of the second micro-ring resonator 15 by adjusting the fourth control signal to approach the second preset reference value, thereby locking the optimal operating point of the second micro-ring resonator 15.

[0037] In this embodiment, by focusing on wavelength control and polarization control, and further combining them with the optimal operating point control of the micro-ring resonator, the robustness of the transmitter to input polarization disturbances and power fluctuations is improved while maintaining the high integration of the micro-ring device and WDM (Wavelength Division Multiplexing) compatibility. This provides a system-level implementation path for stable multi-wavelength transmission in high-density optical interconnects.

[0038] In some embodiments, such as Figure 1 As shown, the first port of the first control circuit 32 is connected to the first port of the micro-ring filter 12; the second port of the first control circuit 32 is connected to the first port of the automatic polarization controller 13; the third port of the first control circuit 32 is connected to the first port of the first monitoring circuit 31; the second port of the first monitoring circuit 31 is connected to the second port of the automatic polarization controller 13; the third port of the first monitoring circuit 31 is connected to the first port of the second control circuit 34 and the first port of the second monitoring circuit 33; the second port of the second monitoring circuit 33 is connected to the first port of the first micro-ring resonant modulator 14 and the first port of the second micro-ring resonant modulator 15; the second port of the second control circuit 34 is connected to the second port of the first micro-ring resonant modulator 14 and the second port of the second micro-ring resonant modulator 15; the first port of the first monitoring photodetector 21 is connected to the third port of the automatic polarization controller 13; the first port of the second monitoring photodetector 22 is connected to the fourth port of the automatic polarization controller 13; the first port of the third monitoring photodetector 23 is connected to the third port of the first micro-ring resonant modulator 14; and the first port of the fourth monitoring photodetector 24 is connected to the third port of the second micro-ring resonant modulator 15.

[0039] It should be noted that the above port connection relationships can be adjusted equivalently according to the actual layout wiring, as long as the signal flow and control logic remain unchanged.

[0040] It should be noted that the polarization beam rotator used in this application can also be a non-circular filter.

[0041] Figure 2 This is one of the schematic diagrams illustrating the optical path implementation of the multi-wavelength polarization-independent light transmitter provided by the present invention, such as... Figure 2 As shown, the polarization beam splitter rotator is a ring filter structure at this time. Figure 3 This is the second schematic diagram of the optical path implementation of the multi-wavelength polarization-independent light transmitter provided by the present invention, as shown below. Figure 3As shown, the polarization beam rotator is a non-ring filter structure. This is a specific optical path implementation of a multi-wavelength polarization-independent optical transmitter under WDM conditions. The multi-wavelength randomly polarized input light is divided into two transmission optical paths after passing through the polarization beam rotator (PSR). Micro-ring filters MRR1, MRR2…MRRn are set for each wavelength to sequentially select the target wavelengths λ1, λ2…λn from the main waveguide. Each wavelength channel is followed by an automatic polarization controller (APC), preferably of the MZI type. By adjusting the distribution relationship of the two light paths in the subsequent modulation branches, the corresponding wavelengths maintain power balance before the two micro-ring resonant modulators. A first monitoring photodetector (MPD) and a second monitoring photodetector are then set to collect the monitoring information from the two preceding paths. A third and fourth monitoring photodetector are respectively set on the output side of the two micro-ring resonant modulators to collect the monitoring information from the subsequent stages. With the above structure, on the one hand, wavelength locking of the micro-ring filter, polarization control locking of the automatic polarization controller, and optimal operating point locking of the micro-ring resonant modulator (MRM) can be realized in each wavelength channel; on the other hand, each target wavelength can be stably modulated under random polarization input conditions and output from channel a and channel b respectively, thereby forming a scalable multi-wavelength polarization-independent optical transmitter architecture.

[0042] exist Figure 2 In this circuit, the optical power detected by the pre-stage tap can be denoted as P1, and the optical power detected by the post-stage tap can be denoted as P2. When the ratios of the two taps are not consistent, the OMA is maximized and locked based on OMA detection by comparing the post-stage OMA signal with P1, thus eliminating the influence of laser power fluctuations. The ratio of the pre-stage tap detection is arbitrary. The ratio is used to offset the influence of laser power fluctuations and achieve extinction ratio locking based on average value detection. The post-stage tap is used to absorb all signal light. The control circuit can also compare the OMA signal obtained by the post-stage tap in conjunction with the OMA monitoring circuit with P1. By maximizing this normalized OMA determination value, OMA maximization locking based on OMA detection is achieved.

[0043] Figure 4 The third schematic diagram of the optical path implementation of the multi-wavelength polarization-independent light transmitter provided by the present invention is shown below. Figure 4 As shown, the polarization beam splitter rotator is a ring filter structure at this time. Figure 5 The fourth schematic diagram of the optical path implementation of the multi-wavelength polarization-independent light transmitter provided by the present invention is shown below. Figure 5As shown, the polarization beam splitter rotator is a non-ring filter structure at this time. When the two tap ratios are consistent or have been calibrated to be consistent, insertion loss locking based on average value detection is achieved by subtracting P1 from P2. The detection ratio of the two taps is arbitrary, but it is necessary to ensure that the detection ratios of the two taps are equal. Since the subsequent taps only detect part of the signal light, a terminator is required at the waveguide terminal to terminate the light in the waveguide. The structure of this terminator is not restricted.

[0044] Figure 6 This is one of the schematic diagrams illustrating the implementation principle of the multi-wavelength polarization-independent light transmitter provided by the present invention in a single wavelength channel, as shown below. Figure 6 As shown, Vdetect1 and Vdetect2 correspond to the front-end monitoring signals output by the first monitoring photodetector 21 and the second monitoring photodetector 22, respectively, while Vdetect3 and Vdetect4 correspond to the back-end monitoring signals output by the third monitoring photodetector 23 and the fourth monitoring photodetector 24, respectively. In the first control path, Controller1 receives the sum of Vdetect1 and Vdetect2 and outputs Vctrl1 to adjust the micro-ring filter MRR, achieving wavelength locking; Controller2 receives the difference between Vdetect1 and Vdetect2 and outputs Vctrl2 to adjust the automatic polarization controller, achieving polarization control locking.

[0045] In the second control path, Controller3 constructs a first ratio criterion based on Vdetect3 and Vdetect1, and outputs Vctrl3 to adjust the first micro-ring resonator modulator MRM1; Controller4 constructs a second ratio criterion based on Vdetect4 and Vdetect2, and outputs Vctrl4 to adjust the second micro-ring resonator modulator MRM2. The two ratio criteria respectively characterize the relative transmission states of the two micro-ring resonator modulators under corresponding input optical power conditions. The controller locks the optimal operating point of the corresponding micro-ring resonator modulator by making the ratios tend towards their respective target reference values. Since the ratio criteria simultaneously contain monitoring information from both the preceding and following stages, they can mitigate the impact of laser power fluctuations, preceding stage power changes, and polarization disturbances on the micro-ring resonator locking results, and maintain the output stability of the transmitter under multi-wavelength operating conditions.

[0046] Since the ratio criterion includes information from both the preamplifier and the power amplifier, the absolute power changes caused by temperature drift and process deviations are normalized and canceled out, and the system can maintain long-term lock-up without the need for an additional temperature sensor.

[0047] In practical implementation, each controller can employ analog extreme value search, digital step search, proportional-integral control, lookup table control, or a combination of these methods. Proportional-integral control combined with periodic extreme value search is preferred to balance locking speed and steady-state accuracy. Wavelength locking of the micro-ring filter, polarization control locking of the automatic polarization controller, and optimal operating point locking of the micro-ring resonant modulator can be executed sequentially according to a preset order, or a combination of parallel operation and periodic updates can be used. For multi-wavelength systems, each wavelength channel can reuse the same control logic structure, or group control, time-division multiplexing control, or distributed control can be used as needed to achieve scalable collaborative control for multi-wavelength polarization-independent optical transmitters.

[0048] exist Figure 6 In the process, when the ratio of the two taps in the front stage and the rear stage is not required to be consistent, the OMA is maximized and locked based on OMA detection by calculating the ratio of the OMA signal of the rear stage to P1, and the influence of laser power fluctuation is eliminated. The ratio of the detection of the front stage tap is arbitrary. The ratio is used to offset the influence of laser power fluctuation and to achieve extinction ratio locking based on average value detection. The rear stage tap is used to absorb all signal light. Figure 7 The second schematic diagram of the implementation principle of the multi-wavelength polarization-independent light transmitter provided by the present invention in a single wavelength channel is shown below. Figure 7 As shown, when the ratios of the two taps in the current stage and the subsequent stage are consistent or have been calibrated to be consistent, insertion loss locking based on average value detection is achieved by calculating the difference between P1 and P2. The ratio of the two taps can be arbitrary, but it is necessary to ensure that the ratios of the two taps are equal. Since the subsequent stage taps only detect part of the signal light, a terminator is required at the waveguide terminal to terminate the light in the waveguide. There are no restrictions on the structure of this terminator.

[0049] In this embodiment, by using a ratio-based collaborative control method with wavelength control and polarization control as the main lines, combined with optimal operating point control, the influence of laser power fluctuations, channel input power fluctuations, and polarization disturbances on the locking criterion can be effectively suppressed, thereby improving the overall control accuracy and operational stability of the transmitter. By supporting multi-device collaborative control with shared monitoring information, the configuration of independent monitoring and control resources is reduced while ensuring functional integrity. This is beneficial for reducing system area, power consumption, and wiring complexity, and improving the scalability and architectural versatility of multi-wavelength channels.

[0050] Figure 8 This is a schematic flowchart of the multi-wavelength polarization-independent light emission control method provided by the present invention, as shown below. Figure 8 As shown, the multi-wavelength polarization-independent light emission control method includes steps 810, 820, 830, and 840.

[0051] Step 810: Acquire multi-wavelength random polarization state light signals; Step 820: Input the multi-wavelength random polarization state optical signal into the optical transmission link 1, perform polarization beam splitting rotation, wavelength gating, power equalization and high-speed electro-optic modulation, and output a multi-wavelength polarization-independent modulated optical signal; Step 830: Collect multi-wavelength polarization-independent modulated optical signals and monitoring information of internal nodes of optical transmission link 1 and send them to monitoring photoelectric detection module 2 to generate a monitoring signal set; Step 840: The generated monitoring signal set is sent to the control circuit 3 for summation, difference and ratio processing, and a normalization criterion is constructed to obtain the control signal set. The control signal set is then sent to the optical transmission link 1 to achieve wavelength locking, polarization control locking and micro-ring resonant modulator optimal operating point locking, and maintain stable operation of the transmitter. The control signal set includes a first control signal, a second control signal, a third control signal, and a fourth control signal, and the monitoring signal set includes a first monitoring signal, a second monitoring signal, a third monitoring signal, and a fourth monitoring signal.

[0052] In this embodiment, a polarization beam splitter is used to split and rotate the random polarization state multi-wavelength input light. Combined with the wavelength gating function of the micro-ring filter and the power balance adjustment function of the automatic polarization controller, the target wavelength under different input polarization states can be stably coupled into the subsequent dual-path modulation channel. Stable gating, power equalization and dual-path modulation output of the target wavelength are achieved under random polarization state input conditions, thereby reducing the system's dependence on fixed input polarization state and external polarization management link; thus realizing multi-wavelength polarization-independent emission.

[0053] 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 within the protection scope of the present invention.

Claims

1. A multi-wavelength polarization-independent light transmitter, characterized in that, It includes an optical transmission link (1), a monitoring photoelectric detection module (2), and a control circuit (3); The optical transmission link (1) is used to receive multi-wavelength random polarization state optical signals, perform polarization beam splitting rotation, wavelength gating, power equalization and high-speed electro-optic modulation on the multi-wavelength random polarization state optical signals, and output multi-wavelength polarization-independent modulated optical signals. The monitoring photoelectric detection module (2) is used to acquire monitoring information of internal nodes and multi-wavelength polarization-independent modulated optical signals of the optical transmission link (1) and generate a monitoring signal set; The control circuit (3) is used to perform summation, difference and ratio processing on the monitoring signals in the monitoring signal set, construct normalization criteria, obtain control signal set, and send the control signal set to the optical transmission link (1) to realize wavelength locking, polarization control locking and micro-ring resonant modulator optimal operating point locking, and maintain stable operation of the transmitter. The control signal set includes a first control signal, a second control signal, a third control signal, and a fourth control signal, and the monitoring signal set includes a first monitoring signal, a second monitoring signal, a third monitoring signal, and a fourth monitoring signal.

2. The multi-wavelength polarization-independent light transmitter as described in claim 1, characterized in that, The optical transmission link (1) includes a polarization beam splitter (11), a micro-ring filter (12), an automatic polarization controller (13), a first micro-ring resonant modulator (14), and a second micro-ring resonant modulator (15). The polarization beam splitter (11) is used to perform polarization rotation and beam splitting on multi-wavelength random polarization optical signals to obtain a first orthogonal component and a second orthogonal component. The first orthogonal component and the second orthogonal component are converted into a first optical signal suitable for on-chip transmission and a second optical signal for subsequent processing through the polarization rotation mechanism. The micro-ring filter (12) is used to select the target wavelength of the first optical signal and the second optical signal to obtain the first filtered signal and the second filtered signal; The automatic polarization controller (13) is used to dynamically balance the power of the first filtered signal and the second filtered signal to obtain the first channel signal and the second channel signal; The first micro-ring resonant modulator (14) is used to perform electro-optic modulation on the first channel signal to obtain a first modulated signal, and the second micro-ring resonant modulator (15) is used to perform electro-optic modulation on the second channel signal to obtain a second modulated signal; The first modulation signal and the second modulation signal are used as multi-wavelength polarization-independent modulation optical signals.

3. The multi-wavelength polarization-independent light transmitter as described in claim 2, characterized in that, The monitoring photoelectric detection module (2) includes a first monitoring photoelectric detector (21), a second monitoring photoelectric detector (22), a third monitoring photoelectric detector (23) and a fourth monitoring photoelectric detector (24). The first monitoring photodetector (21) and the second monitoring photodetector (22) are used to collect monitoring information of the first channel signal and the second channel signal, and generate the first monitoring signal and the second monitoring signal; The third monitoring photodetector (23) and the fourth monitoring photodetector (24) are used to collect monitoring information of the first modulation signal and the second modulation signal, and generate the third monitoring signal and the fourth monitoring signal.

4. The multi-wavelength polarization-independent light transmitter as described in claim 3, characterized in that, The control circuit (3) includes a first monitoring circuit (31), a first control circuit (32), a second monitoring circuit (33), and a second control circuit (34); The first monitoring circuit (31) is used to perform summation and difference processing on the first monitoring signal and the second monitoring signal to obtain the first control signal and the second control signal, and send the first control signal and the second control signal to the first control circuit (32). The second monitoring circuit (33) is used to perform ratio processing on the third monitoring signal and the first monitoring signal to obtain the third control signal, and to perform ratio processing on the fourth monitoring signal and the second monitoring signal to obtain the fourth control signal, and to send the third control signal and the fourth control signal to the second control circuit (34).

5. The multi-wavelength polarization-independent light transmitter as described in claim 4, characterized in that, The first control circuit (32) adjusts the wavelength of the micro-ring filter (12) by maximizing the first control signal to make it approach the preset extreme value, thereby achieving wavelength locking.

6. The multi-wavelength polarization-independent light transmitter as described in claim 5, characterized in that, The first control circuit (32) adjusts the second control signal to approach zero to adjust the automatic polarization controller (13), so that the two output power of the automatic polarization controller (13) is balanced to achieve polarization control locking.

7. The multi-wavelength polarization-independent light transmitter as described in claim 6, characterized in that, The second control circuit (34) adjusts the third control signal to approach the first preset reference value to adjust the operating point of the first micro-ring resonator modulator (14) and achieves the optimal operating point locking of the first micro-ring resonator modulator (14).

8. The multi-wavelength polarization-independent light transmitter as described in claim 7, characterized in that, The second control circuit (34) adjusts the fourth control signal to approach the second preset reference value to adjust the operating point of the second micro-ring resonator modulator (15) and achieves the optimal operating point locking of the second micro-ring resonator modulator (15).

9. The multi-wavelength polarization-independent light transmitter as described in claim 8, characterized in that, The first port of the first control circuit (32) is connected to the first port of the micro-ring filter (12), the second port of the first control circuit (32) is connected to the first port of the automatic polarization controller (13), the third port of the first control circuit (32) is connected to the first port of the first monitoring circuit (31), the second port of the first monitoring circuit (31) is connected to the second port of the automatic polarization controller (13), the third port of the first monitoring circuit (31) is connected to the first port of the second control circuit (34) and the first port of the second monitoring circuit (33), and the second port of the second monitoring circuit (33) is connected to the first port of the first micro-ring resonant modulator (14) and the second micro-ring resonator (12). The first port of the resonant modulator (15) is connected, the second port of the second control circuit (34) is connected to the second port of the first micro-ring resonant modulator (14) and the second port of the second micro-ring resonant modulator (15), the first port of the first monitoring photodetector (21) is connected to the third port of the automatic polarization controller (13), the first port of the second monitoring photodetector (22) is connected to the fourth port of the automatic polarization controller (13), the first port of the third monitoring photodetector (23) is connected to the third port of the first micro-ring resonant modulator (14), and the first port of the fourth monitoring photodetector (24) is connected to the third port of the second micro-ring resonant modulator (15).

10. A method for controlling the emission of multi-wavelength polarization-independent light, implemented using a multi-wavelength polarization-independent light transmitter as described in any one of claims 1-9, characterized in that, The method includes: Acquire multi-wavelength randomly polarized optical signals; The multi-wavelength random polarization state optical signal is input into the optical transmission link (1) to perform polarization beam rotation, wavelength gating, power equalization and high-speed electro-optic modulation, and output a multi-wavelength polarization-independent modulated optical signal; The multi-wavelength polarization-independent modulated optical signal and the monitoring information of the internal nodes of the optical transmission link (1) are collected and sent to the monitoring photoelectric detection module (2) to generate a monitoring signal set; The generated monitoring signal set is sent to the control circuit (3) for summation, difference and ratio processing, and normalization criteria are constructed to obtain the control signal set. The control signal set is sent to the optical transmission link (1) to realize wavelength locking, polarization control locking and micro-ring resonant modulator optimal operating point locking, and maintain stable operation of the transmitter. The control signal set includes a first control signal, a second control signal, a third control signal, and a fourth control signal, and the monitoring signal set includes a first monitoring signal, a second monitoring signal, a third monitoring signal, and a fourth monitoring signal.

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