A self-referenced balanced probe optical communication method and system based on chaos micro-comb pumping symmetric comb correlation

Abstract

This invention proposes a self-reference balanced detection optical communication method and system based on the correlation of symmetrical comb teeth pumped by a chaotic microcomb. The method utilizes an on-chip microring resonator to generate a chaotic optical frequency comb. At the transmitting end, one comb tooth is selected as the communication carrier, while the reference comb teeth, which are symmetrical about the pump frequency, are bypassed and retained. The modulated communication carrier and the bypass light containing the reference comb teeth are re-beamed and transmitted. At the receiving end, the modulated carrier and the symmetrical reference comb teeth are filtered out by a wavelength selection device and input into a balanced photodetector for differential detection in the optical domain. The highly correlated intensity fluctuations between the two comb teeth are used to suppress the chaotic background, thereby recovering the signal. This invention eliminates the need for an independent chaotic synchronization source, significantly reducing system complexity, and possesses multi-channel expansion potential, making it suitable for highly integrated secure optical communication scenarios.

Description

Technical Field

[0001] This invention belongs to the field of optical communication technology, specifically relating to a self-reference balanced probe optical communication system and method based on the correlation of chaotic microcomb pumped symmetric comb teeth, which is suitable for high-speed optical fiber communication with physical layer security, data center interconnection and confidential information transmission in wavelength division multiplexing networks. Background Technology

[0002] With the rapid development of cloud computing, artificial intelligence, data center interconnection, and new access networks, the data volume carried by optical communication links continues to grow, placing higher demands on transmission rates, spectral efficiency, and communication security. Existing communication systems mainly rely on upper-layer cryptographic algorithms to ensure information security, and their reliability is usually related to computational complexity. As computing power continues to improve, relying solely on algorithm-based encryption faces certain challenges in terms of long-term security. Therefore, moving security mechanisms forward to the optical signal transmission layer, and achieving information hiding and anti-interception through the inherent complexity of the physical signal itself, has become an important technical approach to improving the security of high-speed optical communication.

[0003] Chaotic optical signals, characterized by broadband, quasi-randomness, and difficulty in precise prediction, can be used to mask communication signals, submerging useful information in a complex background of light intensity fluctuations. Traditional chaotic optical communication systems typically employ discrete chaotic lasers, electro-optic feedback loops, or external perturbation structures to generate chaotic carriers. However, these schemes often suffer from system complexity, a large number of components, difficulty in stability control, and insufficient integration. Furthermore, some chaotic communication schemes require establishing chaotic synchronization between the transmitter and receiver, making them susceptible to synchronization errors, parameter drift, and link disturbances in practical applications.

[0004] Microcavity optical frequency combs possess advantages such as miniaturization, multi-wavelength capability, and on-chip integration, providing a new device foundation for constructing compact, multi-channel optical communication systems. When the microcavity operates under complex dynamic states, different comb teeth can carry significant intensity fluctuations, providing usable physical resources for signal masking and secure optical transmission. However, existing technologies still do not fully utilize the correlation characteristics between the comb teeth within chaotic microcombs. Some schemes use chaotic optical frequency combs only as multi-carrier light sources without addressing signal masking functions; while other schemes use chaotic comb teeth as carriers, they still require chaotic synchronization reconstruction at the receiving end or rely on complex electrical domain post-processing algorithms.

[0005] Therefore, it is necessary to develop a new optical communication method that can fully utilize the advantages of multi-wavelength parallelism of chaotic microcombs, simplify the receiver structure, and eliminate the need for complex chaotic synchronization, so as to improve system integration and engineering practicality. Summary of the Invention

[0006] The purpose of this invention is to overcome the shortcomings of existing chaotic optical communication systems, such as complex structure, reliance on chaotic synchronization at the transmitting and receiving ends, low integration, and difficulty in fully utilizing the advantages of multi-wavelength parallelism of chaotic microcombs. The invention provides a self-reference balanced probe optical communication system and method that is structurally simplified, requires no chaotic synchronization, is easy to integrate on-chip, and supports multi-channel expansion.

[0007] The technical solution of this invention is as follows:

[0008] The first aspect of this invention is to provide a self-reference balanced probe optical communication system based on the correlation of chaotic microcomb pumped symmetric comb teeth, comprising: a transmitter and a receiver.

[0009] The transmitting end includes: a chaotic optical frequency comb generation module for generating a chaotic optical frequency comb with multiple comb teeth; a first wavelength selection module for selecting one comb tooth from the chaotic optical frequency comb as a communication comb tooth and using the remaining comb teeth as bypass comb teeth; the bypass comb teeth include a reference comb tooth that is symmetrical to the communication comb tooth about the pump frequency; an intensity modulator for loading the signal to be transmitted onto the communication comb tooth to generate a modulated communication comb tooth; and an optical combiner for combining the modulated communication comb tooth and the bypass comb tooth to form a combined optical signal.

[0010] The receiving end includes: a second wavelength selection module, used to filter out the modulation communication comb and the reference comb from the received combined optical signal; a balanced photodetector having a first optical input port and a second optical input port, wherein the modulation communication comb is coupled to the first optical input port and the reference comb is coupled to the second optical input port; the balanced photodetector is used to perform differential detection using the correlation intensity fluctuations between the modulation communication comb and the reference comb to suppress the chaotic intensity background in the modulation communication comb and recover the signal to be transmitted.

[0011] Furthermore, the chaotic optical frequency comb generation module includes: a continuous wave source module; an optical amplifier connected to the output end of the continuous wave source module for amplifying the pump light output by the continuous wave source module; and an on-chip micro-ring resonator optically coupled to the output end of the optical amplifier. The pump light amplified by the optical amplifier is injected into the on-chip micro-ring resonator, and by adjusting the pump wavelength, input power, and polarization state, the micro-ring resonator operates in a complex dynamic state to generate the chaotic optical frequency comb.

[0012] Furthermore, the transmitting end also includes a power adjustment module and / or an optical amplification module, disposed between the first wavelength selection module and the intensity modulator, for adjusting the power of the communication comb.

[0013] Furthermore, the receiver also includes: an adjustable optical delay line, disposed on the optical path of the modulation communication comb or the reference comb, for compensating for the relative time delay between the two optical signals; and / or, an adjustable optical attenuator, disposed on the optical path of the modulation communication comb or the reference comb, for adjusting the power matching of the two optical signals.

[0014] Furthermore, the cross-correlation coefficient between the communication comb teeth and the reference comb teeth is greater than a preset threshold, and the preset threshold is not less than 0.8, so as to ensure the suppression effect of the balanced photodetector on the chaotic intensity background.

[0015] A second aspect of the present invention is to provide a self-reference balanced probe optical communication method based on the correlation of chaotic microcomb pump symmetric comb teeth, comprising the following steps:

[0016] Transmitter steps: Generate a chaotic optical frequency comb with multiple comb teeth; select one comb tooth from the chaotic optical frequency comb as the communication comb tooth, and use the remaining comb teeth as bypass comb teeth; the bypass comb teeth include a reference comb tooth that is symmetrical to the communication comb tooth about the pump frequency; load the signal to be transmitted onto the communication comb tooth to generate a modulated communication comb tooth; combine the modulated communication comb tooth and the bypass comb tooth to form a combined optical signal and transmit it;

[0017] Receiver steps: Filter out the modulation communication comb and the reference comb from the received combined optical signal; couple the modulation communication comb to the first optical input port of the balanced photodetector, and couple the reference comb to the second optical input port of the balanced photodetector; perform differential detection through the balanced photodetector, and use the correlation intensity fluctuations between the modulation communication comb and the reference comb to suppress the chaotic intensity background in the modulation communication comb, thereby recovering the signal to be transmitted.

[0018] Furthermore, the method further includes: adjusting the optical power of the modulation communication comb and / or the reference comb at the receiving end to match the photocurrent amplitudes of the two optical signals in the balanced photodetector; and / or adjusting the relative time delay of the modulation communication comb or the reference comb at the receiving end to align the chaotic intensity fluctuations of the two optical signals in time.

[0019] Furthermore, the signal to be transmitted is a multi-channel parallel signal; the method further includes: selecting multiple sets of pump symmetric comb pairs from the chaotic optical frequency comb, each set including one communication comb tooth and one corresponding reference comb tooth; loading the multiple signals to be transmitted onto the multiple communication comb teeth respectively; at the receiving end, filtering out each set of communication comb teeth and its corresponding reference comb tooth respectively, and inputting them into multiple balanced detection units for parallel recovery.

[0020] Advantages and beneficial effects of the present invention:

[0021] 1. No chaotic synchronization required, simplifying system structure. This invention utilizes an on-chip chaotic microcomb to simultaneously provide communication comb teeth and symmetrical reference comb teeth. The receiver does not need to generate an independent chaotic reference source or establish transceiver chaotic synchronization. It only needs to perform power matching and time delay matching on the two comb teeth with the same source, and the information can be recovered through balanced detection, which significantly reduces the system complexity and the difficulty of synchronization control.

[0022] 2. Optical domain self-reference balanced detection with good real-time performance. This invention directly inputs the unmodulated symmetrical reference comb as an optical signal into the balanced photodetector, and performs optical domain differential detection with the modulated communication comb. It utilizes the correlation intensity fluctuation between the symmetrical combs to suppress chaotic background in real time, avoiding the delay and circuit noise caused by the "photoelectric conversion → electrical domain subtraction" post-processing path in traditional schemes, and has a nanosecond-level response speed.

[0023] 3. Compatible with multiple intensity modulation formats, with strong applicability. This invention has no special restrictions on the modulation format of the signal to be transmitted and is compatible with signal formats based on optical intensity envelope modulation or direct intensity modulation detection, such as NRZ, OOK, PAM, DMT, and OFDM, which can flexibly adapt to the needs of different communication scenarios.

[0024] 4. Naturally supports multi-channel parallel expansion, resulting in large communication capacity. The chaotic microcomb naturally contains multiple discrete comb teeth. This invention can be extended to multiple sets of pump-symmetric comb teeth working in parallel. Each set of comb teeth undertakes the functions of communication carrier and related reference light, and performs wavelength division multiplexing transmission in the same optical fiber link. The receiving end recovers the signal in parallel through wavelength selection devices and multiple balanced detection units, which fully utilizes the multi-wavelength parallel advantage of the chaotic microcomb and significantly improves the system communication capacity.

[0025] 5. Easy on-chip integration and strong engineering practicality. The core components involved in this invention—micro-ring resonators, wavelength selection devices, electro-optic intensity modulators, and balanced photodetectors—can all be integrated on-chip based on material platforms such as silicon nitride, silicon, and lithium niobate. Furthermore, a wide variety of material platforms are currently available for generating optical frequency combs, such as silicon nitride, silicon dioxide, silicon, silicon carbide, lithium niobate, aluminum nitride, and aluminum gallium arsenide, greatly enhancing application potential. Therefore, the solution proposed in this invention has the potential to develop into compact, low-power, and high-reliability optical communication modules, suitable for data center interconnection, metropolitan area networks, and dedicated secure communication scenarios. Attached Figure Description

[0026] Figure 1 A schematic diagram of the chaotic microcomb spectrum and symmetrical comb teeth;

[0027] Figure 2 The electrical spectrum of a single chaotic comb tooth at different EDFA output powers;

[0028] Figure 3This is a structural diagram of a self-referenced balanced probe optical communication system based on a chaotic microcomb.

[0029] Figure 4 This is a differential output diagram for symmetrical comb tooth balanced detection. Detailed Implementation

[0030] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. All other embodiments obtained by those skilled in the art without inventive effort are within the scope of protection of this invention.

[0031] This invention proposes a self-reference balanced probe optical communication method based on the correlation of pumped symmetric comb teeth in a chaotic microcomb. This method utilizes an integrated microring resonator to generate a chaotic optical frequency comb. At the transmitter, one chaotic comb tooth is selected as the communication carrier, and it is fed into an electro-optic intensity modulator to load an intensity envelope modulation or intensity modulation direct probe compatible signal. The remaining chaotic comb teeth, including the pumped symmetric reference comb tooth of the communication comb tooth, are bypassed and retained without passing through the electro-optic modulator. The modulated communication comb tooth and the unmodulated comb tooth in the bypass are re-bundled and transmitted together to the receiver. At the receiver, the modulated communication comb tooth and the unmodulated symmetric reference comb tooth are filtered out separately, and the chaotic intensity background in the communication comb tooth is suppressed through balanced photoelectric detection, thereby recovering the loaded signal.

[0032] The specific implementation of this embodiment will be described in detail below with reference to the accompanying drawings.

[0033] 1. Chaotic microcombing generation

[0034] The system employs an on-chip microring resonator as its core light source device. The continuous wave light source module, amplified by an optical amplifier, is injected into the microring resonator. By adjusting the pump wavelength, input power, and polarization state, the microring resonator operates in a complex dynamic state, generating a chaotic optical frequency comb with multiple comb teeth, such as... Figure 1 As shown by the blue line, the electrical spectrum of the comb teeth is as follows: Figure 2 As shown.

[0035] The resulting chaotic microcomb consists of multiple comb teeth distributed around the pump frequency. A pair of comb teeth located on opposite sides of the pump with equal frequency spacing can be defined as a pump-symmetric comb, such as... Figure 1 As shown by the black and red lines, the intensity fluctuations of these comb teeth are correlated because they participate in the four-wave mixing and intracavity nonlinear evolution process. This invention utilizes these correlated intensity fluctuations, using one comb tooth as the communication carrier and the other symmetrical comb tooth as the receiving reference light.

[0036] It should be noted that the generation of chaotic microcombs is entirely feasible. When the pump optical power reaches the microcavity nonlinear threshold, the intracavity Kerr nonlinear effect and four-wave mixing process induce complex dynamic evolution, forming a chaotic optical frequency comb containing multiple comb teeth. This type of optical comb exhibits broadband, aperiodic, noise-like intensity fluctuations in the time domain, and can serve as a natural complex carrier in the optical domain. As the pump power increases, the electrical spectrum of the comb teeth broadens significantly, indicating an increase in the bandwidth of the chaotic signal. By increasing the bandwidth of the chaotic signal, the signal to be transmitted can be more deeply masked in a complex chaotic background, thereby improving the anti-interception capability of physical layer transmission. At the same time, a wider bandwidth is also beneficial for achieving higher signal-to-noise ratio noise cancellation during balanced detection at the receiver.

[0037] Due to the advantages of microring resonators, such as small size, high nonlinearity, and easy integration, the generation of chaotic microcombs using on-chip devices has a solid engineering foundation. Experimentally, by simultaneously detecting the light intensity waveforms of two symmetrical comb teeth and calculating their cross-correlation coefficients, it can be verified that their correlation is higher than that of asymmetric comb combinations. This provides a physical basis for constructing self-reference light at the receiver.

[0038] 2. Transmitter Design

[0039] like Figure 3 As shown, the left side of the transmission link is the transmitter. First, wavelength selection devices such as wavelength-selective switches, optical filters, or arrayed waveguide gratings are used to split the chaotic optical frequency comb into two paths. The first path is the selected communication comb tooth, which, after power adjustment and necessary optical amplification, is input to the electro-optic intensity modulator. The second path consists of the remaining unmodulated chaotic comb teeth, including a reference comb tooth symmetrical to the communication comb tooth about the pump frequency. This path does not pass through the electro-optic intensity modulator but is reserved as a bypass light.

[0040] The signal to be transmitted can use optical intensity envelope modulation formats such as NRZ, OOK, and PAM, or multi-carrier signal formats compatible with direct intensity modulation detection such as DMT and OFDM. After the data signal is generated by a pattern generator, arbitrary waveform generator, or high-speed electric drive module, it is input to the RF terminal of the electro-optic intensity modulator to modulate the selected communication comb. After modulation, the communication information is loaded onto the optical intensity envelope of the chaotic comb and is masked by the broadband noise intensity fluctuations of the comb itself.

[0041] Subsequently, the modulated communication comb teeth are re-bundled with the unmodulated chaotic comb teeth in the bypass to form a full comb optical signal containing the modulated communication comb teeth and the unmodulated symmetric reference comb teeth, and then sent into the transmission link.

[0042] Unlike traditional schemes that use independent chaotic sources for electrical domain superposition, this invention directly utilizes chaotic comb teeth as optical communication carriers. It eliminates the need for generating separate broadband chaotic electrical signals or complexly synthesizing chaotic signals with information signals in the electrical domain. Therefore, this scheme helps simplify the transmitter structure and improves the system's compatibility with on-chip photonic integration platforms.

[0043] From the perspective of signal masking and recovery, due to the strong chaotic intensity fluctuations of the communication carrier itself, the modulated signal is superimposed on a complex light intensity background, resulting in poor signal quality during direct single-end detection. External receivers find it difficult to obtain clear data directly through ordinary intensity detection. This provides a natural physical layer security foundation for this invention.

[0044] 3. Full comb transport method

[0045] After the modulation of a single communication comb tooth is completed, the modulated communication comb tooth is recombined with the remaining unmodulated chaotic comb teeth in the transmitter bypass to form a full comb optical signal containing the modulated communication comb tooth and the unmodulated symmetrical reference comb tooth, and then transmitted to the receiver through a standard single-mode fiber or other optical transmission link.

[0046] The communication comb teeth carry the information to be transmitted, while the pump symmetric comb teeth do not carry data signals but instead serve as the correlation light required for self-reference recovery at the receiver. Since the two comb teeth originate from the same chaotic microcomb and transmit along the same link, their relative correlation and transmission path consistency can be maintained to a certain extent, providing conditions for subsequent balanced detection.

[0047] 4. Receiver Design

[0048] like Figure 3 As shown, the right side of the transmission link is the receiving end. After receiving the full comb optical signal, the receiving end uses wavelength selection devices such as wavelength selective switches, optical filters, or arrayed waveguide gratings to filter out the modulated communication comb teeth and its pump symmetrical reference comb teeth respectively.

[0049] The first path is the communication comb that carries data, denoted as... The second path is the unmodulated symmetrical reference comb, denoted as... Two optical signals are input to the two optical input ports of a balanced photodetector, respectively. To ensure that the correlation intensity fluctuations of the two signals are as synchronized as possible within the detector, an adjustable optical delay line can be added to one of the signals to compensate for the relative time delay caused by the devices, optical fiber, and filtering path. Simultaneously, the power of the two optical signals is adjusted by an adjustable optical attenuator or optical amplifier to match the photocurrent amplitudes in the balanced detector. The experimental differential effect is shown below. Figure 4 As shown.

[0050] The differential current output by the balanced photodetector can be expressed as: .in, and These represent the gain or power weight of the two detectors, respectively. This represents the relative delay between the two signals. Because there are correlated intensity fluctuations between the communication comb teeth and the reference comb teeth, this can be adjusted... , and This allows the shared chaotic intensity background of the two paths to be partially canceled in the differential output, while the data signal modulated on the communication comb is preserved.

[0051] For binary intensity modulated signals such as NRZ and OOK, the balanced detection output can be further input to an electrical amplifier, filter, clock recovery module, and decision circuit to achieve binary data recovery. For PAM signals, a multi-threshold decision method can be used to recover multi-level data; for multi-carrier signals such as DMT and OFDM, electrical domain sampling, equalization, and digital demodulation can be performed after balanced detection to recover the original data. In practical applications, the receiving eye diagram opening can be maximized and the bit error rate reduced by optimizing the reference optical power, relative delay, and decision threshold.

[0052] The synchronization required in this scheme mainly involves the relative time delay matching between two optical signals within the same receiver, rather than the dynamic synchronization between two independent chaotic sources. Since the communication comb and reference comb originate from the same chaotic microcomb and reach the receiver via the same transmission link, their relative drift is small. In practical systems, adjustable optical delay lines can be used to compensate for the time delay differences caused by filters, optical fibers, and device paths; simultaneously, adjustable optical attenuators or optical amplifiers can be used to adjust the power ratio of the two signals, enabling the balanced probe output to achieve a larger eye diagram opening and a lower bit error rate. Therefore, this scheme is less complex than traditional transceiver chaotic synchronization schemes.

[0053] 5. Data Recovery Process

[0054] Data recovery at the receiver may include the following steps: First, wavelength separation is performed on the received full comb signal to obtain the communication comb teeth and their symmetrical reference comb teeth. Second, the power of the two optical paths is adjusted to ensure that the DC photocurrent of the communication path and the reference path in the balanced detector are in a suitable ratio. For intensity-modulated signals, the power of the reference path does not necessarily need to be exactly equal to the power of the communication path, but should be optimized according to the signal modulation depth, chaotic fluctuation amplitude, and eye diagram quality. Third, the adjustable optical delay line is adjusted to align the chaotic intensity fluctuations of the two paths in time. When the delay is matched, the chaotic background in the balanced detector output is minimized, and the data modulation component is most obvious; when the delay is mismatched, the correlation noise cancellation effect is reduced, and the output signal quality deteriorates. Finally, the balanced detector output is subjected to electrical domain filtering, amplification, sampling, and corresponding demodulation processing. For NRZ and OOK signals, binary data can be recovered through clock recovery and threshold decision; for PAM signals, multi-level decision can be used; for DMT and OFDM signals, equalization and digital demodulation can be combined to recover the original data. This process does not rely on complex digital decryption algorithms and has the potential for real-time reception and hardware implementation.

[0055] 6. Multi-channel expansion method

[0056] Since the chaotic microcomb naturally contains multiple comb teeth, this invention can also be extended to a multi-channel parallel communication architecture. Specifically, multiple sets of pump-symmetric comb tooth pairs can be selected, each set containing one communication comb tooth and one corresponding reference comb tooth. Different communication comb teeth can be loaded with independent data signals and transmitted in parallel in the same optical fiber link.

[0057] At the receiving end, wavelength selection devices filter out each set of communication comb teeth and corresponding reference comb teeth, which are then input into multiple balanced detection units to achieve parallel recovery of multiple signals. Since each channel is located at a different optical frequency position, this structure is compatible with wavelength division multiplexing systems and is expected to improve system capacity and spectral resource utilization.

[0058] Furthermore, the selection of communication comb teeth and reference comb teeth can be configured according to system requirements. By changing the selection of comb teeth pairs, channel allocation methods, or reference path combinations, system flexibility can be enhanced, and an expansion foundation can be provided for multi-user or multi-service scenarios.

[0059] From an engineering implementation perspective, the key components required for this solution include a continuous wave light source module, an on-chip micro-ring resonator, a wavelength selection device, an electro-optic intensity modulator, an optical amplifier, a tunable optical delay line, a tunable optical attenuator, and a balanced photodetector. These are all relatively mature device types found in existing optical communication and integrated photonic systems. The micro-ring resonator can be implemented based on material platforms such as silicon nitride, silicon dioxide, silicon, silicon carbide, lithium niobate, aluminum nitride, or aluminum gallium arsenide, and has the potential for on-chip integration and mass production. Therefore, this invention has the feasibility of developing into a compact, low-power, multi-channel optical communication module.

[0060] 7. Key Component Composition

[0061] The system involved in this invention may include a continuous wave light source module, an optical amplifier, a polarization controller, an on-chip micro-ring resonator, a wavelength selection switch, an electro-optic intensity modulator, an optical combiner, a standard single-mode fiber, an adjustable optical delay line, an adjustable optical attenuator, a balanced photodetector, an electrical amplifier, a filter, and a decision recovery module, etc.

[0062] Among them, the on-chip micro-ring resonator is used to generate the chaotic micro-comb; the wavelength selection device is used to select the communication comb teeth and the symmetrical reference comb teeth; the electro-optic intensity modulator is used to load the intensity envelope modulation or intensity modulation direct detection compatible signal onto the communication comb teeth; the balanced photodetector is used to realize the differential detection of two related light intensity signals; the tunable optical delay line and the tunable optical attenuator are used to optimize the time matching and power matching between the reference light and the communication light.

[0063] The core of this implementation lies in not simply using the chaotic microcomb as a broadband noise source, but further utilizing the correlation intensity fluctuations between the symmetrical comb teeth pumped internally, enabling the receiver to achieve self-reference signal recovery with the help of the same-source reference comb teeth. Compared to schemes relying on independent chaotic synchronization sources, this method has a more compact structure, a more direct control path, and the potential to be extended to on-chip integration and multi-channel parallel communication.

[0064] Main Inventive Contribution of the Invention

[0065] In summary, the present invention makes the following inventive contributions compared to existing chaotic optical communication solutions:

[0066] First, it significantly reduces system synchronization complexity. Existing chaotic optical communication schemes typically require discrete chaotic lasers, electro-optic feedback loops, or external chaotic sources to generate masking signals, and rely on chaotic synchronization or pre-shared system parameters at the transmitter and receiver to achieve signal recovery. This results in complex structures and sensitivity to environmental disturbances. This invention utilizes a single on-chip chaotic microcomb to simultaneously provide communication comb teeth and symmetrical reference comb teeth. The communication comb teeth are loaded with information via an electro-optic intensity modulator, while the reference comb teeth are bypassed at the transmitter and do not participate in modulation. The receiver does not need to generate a separate chaotic reference source; it only needs to perform power matching and time delay matching on the two co-source comb teeth to recover the signal through balanced detection. This fundamentally avoids the challenges of chaotic synchronization.

[0067] Second, self-reference balanced detection recovery is achieved. This invention selects one tooth from the chaotic microcomb as the communication carrier and loads an intensity modulation signal through an electro-optic intensity modulator. During transmission, this signal is masked by the broadband intensity fluctuations of the chaotic comb tooth itself, making it difficult to obtain clear data through direct single-end detection. The receiving end further selects the pump-symmetric comb tooth of this communication comb as the correlated reference light. Since both originate from the same microcavity nonlinear dynamic process and have correlated intensity fluctuations, balanced photoelectric detection can suppress the chaotic intensity background in the communication comb tooth while retaining the intensity envelope modulation information loaded on it. This method does not require additional reconstruction of the independent chaotic signal and has the potential for real-time recovery.

[0068] Third, it supports multi-channel parallel expansion. Chaotic microcombs naturally contain multiple discrete comb teeth, possessing single-source multi-wavelength characteristics. This invention can not only be used for self-reference recovery between a single communication comb tooth and its symmetrical reference comb tooth, but can also be extended to multiple sets of pumped symmetrical comb tooth pairs working in parallel. Different communication comb teeth can each load independent data streams and transmit them in the same fiber optic link; the receiving end recovers each signal separately through wavelength selection and balanced detection units. Compared to schemes using multiple independent lasers or multiple chaotic sources, this invention features a compact structure, convenient channel expansion, and good compatibility with wavelength division multiplexing systems, showing application potential in integrated optical communication and physical layer secure transmission scenarios.

Claims

1. A self-reference balanced probe optical communication system based on the correlation of chaotic microcomb pumped symmetric comb teeth, characterized in that, include: Transmitter and receiver, The transmitting end includes: A chaotic optical frequency comb generation module is used to generate a chaotic optical frequency comb with multiple comb teeth; The first wavelength selection module is used to select one comb tooth from the chaotic optical frequency comb as the communication comb tooth, and use the remaining comb teeth as bypass comb teeth; the bypass comb teeth include a reference comb tooth that is symmetrical to the communication comb tooth about the pump frequency; An intensity modulator is used to load the signal to be transmitted onto the communication comb teeth to generate modulated communication comb teeth. An optical combiner is used to combine the modulated communication comb and the bypass comb to form a combined optical signal. The receiving end includes: The second wavelength selection module is used to filter out the modulation communication comb and the reference comb from the received combined optical signal, respectively. A balanced photodetector has a first optical input port and a second optical input port, wherein the modulation communication comb is coupled to the first optical input port and the reference comb is coupled to the second optical input port; The balanced photodetector is used to perform differential detection by utilizing the correlation intensity fluctuations between the modulation communication comb and the reference comb, so as to suppress the chaotic intensity background in the modulation communication comb and recover the signal to be transmitted.

2. The system according to claim 1, characterized in that, The chaotic optical frequency comb generation module includes: Continuous wave light source module; An optical amplifier, connected to the output terminal of the continuous wave light source module, is used to amplify the pump light output by the continuous wave light source module; An on-chip microring resonator is connected to the output of the optical amplifier; The pump light, amplified by the optical amplifier, is injected into the on-chip microring resonator. By adjusting the pump wavelength, input power, and polarization state, the microring resonator operates in a complex dynamic state to generate the chaotic optical frequency comb.

3. The system according to claim 1, characterized in that, The cross-correlation coefficient between the communication comb teeth and the reference comb teeth is greater than a preset threshold, and the preset threshold is not less than 0.8, so as to ensure the suppression effect of the balanced photodetector on the chaotic intensity background.

4. The system according to claim 1, characterized in that, The transmitter also includes a power adjustment module and / or an optical amplification module, which are disposed between the first wavelength selection module and the intensity modulator, for adjusting the power of the communication comb.

5. The system according to claim 1, characterized in that, The receiving end also includes: An adjustable optical delay line is disposed on the optical path of the modulation communication comb or the reference comb to compensate for the relative time delay between the two optical signals; And / or, an adjustable optical attenuator is disposed in the optical path of the modulation communication comb or the reference comb to adjust the power matching of the two optical signals.

6. A self-reference balanced probe optical communication method based on the correlation of chaotic microcomb pumped symmetric comb teeth, characterized in that, Includes the following steps: Transmitter steps: A chaotic optical frequency comb with multiple comb teeth is generated; One tooth is selected from the chaotic optical frequency comb as the communication comb tooth, and the remaining comb teeth are used as bypass comb teeth; the bypass comb teeth include a reference comb tooth that is symmetrical to the communication comb tooth about the pump frequency; The signal to be transmitted is loaded onto the communication comb teeth to generate modulated communication comb teeth; The modulation communication comb and the bypass comb are combined to form a combined optical signal and then transmitted. Receiving end steps: The modulated communication comb and the reference comb are filtered out from the received combined optical signal, respectively. The modulation communication comb is coupled to the first optical input port of the balanced photodetector, and the reference comb is coupled to the second optical input port of the balanced photodetector. Differential detection is performed using the balanced photodetector, and the chaotic intensity background in the modulation communication comb is suppressed by the correlation intensity fluctuations between the modulation communication comb and the reference comb, thereby recovering the signal to be transmitted.

7. The method according to claim 6, characterized in that, The cross-correlation coefficient between the communication comb teeth and the reference comb teeth is greater than a preset threshold, and the preset threshold is not less than 0.8, so as to ensure the suppression effect of the balanced photodetector on the chaotic intensity background.

8. The method according to claim 6, characterized in that, Also includes: At the receiving end, the optical power of the modulation communication comb and / or the reference comb is adjusted to match the photocurrent amplitude of the two optical signals in the balanced photodetector. And / or, at the receiving end, relative time delay adjustment is performed on the modulation communication comb or the reference comb to align the chaotic intensity fluctuations of the two optical signals in time.

9. The method according to claim 6, characterized in that, The signal to be transmitted is a multi-channel parallel signal; the method further includes: Multiple sets of pump-symmetric comb tooth pairs are selected from the chaotic optical frequency comb, each set including a communication comb tooth and a corresponding reference comb tooth; Multiple signals to be transmitted are loaded onto multiple communication comb teeth respectively; At the receiving end, each group of communication comb teeth and its corresponding reference comb teeth are filtered out and input into multiple balanced detection units for parallel recovery.

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