An OEO amplifier and optical transmission system with high-speed hard switching function

Abstract

This application discloses an OEO amplifier and optical transmission system with high-speed hard switching capability, relating to the field of optical amplifier technology. The OEO amplifier includes three magneto-optical switches, a beam splitter group, a photodetector group, a real-time comparison circuit, a logic gate control circuit, and a driving circuit. The photodetector group collects optical signal power to generate an electrical signal. The real-time comparison circuit performs voltage threshold judgment on the electrical signal. The logic gate control circuit is connected to the output of the real-time comparison circuit to synchronously control the switching state of the three magneto-optical switches based on the voltage threshold judgment result. The driving circuit drives the magneto-optical switches to synchronously perform switching actions. When the OEO amplifier detects an interruption in the optical signal in any direction, all magneto-optical switches complete synchronous switching within less than 100 microseconds, with an end-to-end optical signal switching time difference of less than 2 picoseconds. This application is applicable to single-fiber bidirectional optical communication environments requiring high frequency, high precision, and high stability.

Description

Technical Field

[0001] This application relates to the field of optical amplifier technology, and in particular to an OEO amplifier with high-speed hard switching function and an optical transmission system. Background Technology

[0002] In modern high-speed fiber optic communication systems, especially in scenarios such as data center interconnect (DCI), 5G fronthaul / backhaul, and metropolitan area optical networks, extremely high demands are placed on the reliability of optical signal transmission, link redundancy, and fault recovery speed. Optical amplifiers, as key components for compensating fiber loss and extending transmission distance, are often deployed in optical network nodes. However, in a single-fiber bidirectional (BiDi) architecture, the same fiber must simultaneously carry optical signals in two directions, posing unique challenges to the amplifier's path management and switching mechanisms.

[0003] Currently, commonly used optical path switching solutions in optical networks mainly rely on mechanical optical switches, microelectromechanical systems (MEMS) optical switches, or electro-optic modulation switches. Among them, mechanical optical switches have advantages such as low insertion loss and high isolation, but their typical switching time is on the order of 10 milliseconds, and their mechanical life is usually less than 10 million cycles, making it difficult to meet the requirements of high-frequency fault switching or dynamic scheduling. Although MEMS optical switches can shorten the switching time to a few milliseconds, their structure is susceptible to vibration and temperature drift, raising questions about their long-term operational reliability. While solid-state switches based on electro-optic or thermo-optic effects have a fast response, they are often accompanied by high power consumption, complex driving circuits, and sensitivity to ambient temperature, and are also expensive.

[0004] Furthermore, in traditional OEO (Optical-Electrical-Optical) amplification architectures, link protection or primary / backup switching typically relies on external network management systems or embedded microcontrollers (MCUs) for status monitoring and decision control. Such "soft switching" solutions involve multiple stages, including photoelectric conversion, analog-to-digital sampling, software judgment, and command issuance, with an overall response latency typically exceeding tens of milliseconds. During this period, service signals may be interrupted, failing to meet the stringent requirements of sub-millisecond recovery capabilities in applications such as 5G URLLC (Ultra-Reliable Low-Latency Communication) or financial transactions.

[0005] In summary, current technologies lack an integrated OEO amplification solution that can achieve fast, reliable, and synchronous reconfiguration of bidirectional optical paths without introducing significant time delay deviations. There is an urgent need for a novel OEO amplifier structure that can overcome the shortcomings of existing switching technologies in terms of speed, lifespan, synchronization, and reliability while retaining the optical signal amplification function. Summary of the Invention

[0006] To address the shortcomings of existing technologies, this application provides a novel OEO amplifier structure that can overcome the deficiencies of existing switching technologies in terms of speed, lifespan, synchronization, and reliability while retaining the optical signal amplification function. It also provides an OEO amplifier and optical transmission system with high-speed hard switching functionality.

[0007] Firstly, the objective of this invention is achieved through the following technical solution:

[0008] An OEO amplifier with high-speed hard switching function includes: three magneto-optical switches, a beam splitter group, a photodetector group, a real-time comparison circuit, a logic gate control circuit, and a drive circuit.

[0009] The photodetector group collects optical signal power to generate an electrical signal; the beam splitter group includes at least two beam splitters, the first beam splitter splits the incident light into a main optical path and a first detection optical path according to a preset ratio, and the second beam splitter splits the output light of the main optical path into a working optical path and a second detection optical path again according to a preset ratio.

[0010] The real-time comparison circuit performs a voltage threshold judgment on the electrical signal; the logic gate control circuit is connected to the output of the real-time comparison circuit to synchronously control the switching state of the three magneto-optical switches according to the voltage threshold judgment result.

[0011] A driving circuit is connected to the output terminal of the logic gate control circuit and the control terminal of each magneto-optical switch, and is used to drive the magneto-optical switches to perform switching actions synchronously.

[0012] When the OEO amplifier detects an interruption in the optical signal in any direction, all magneto-optical switches complete synchronous switching within less than 100 microseconds, and the end-to-end optical signal switching time difference is less than 2 picoseconds in single-fiber bidirectional transmission.

[0013] By adopting the above technical solution, this invention provides a novel OEO amplifier structure that, while retaining the optical signal amplification function, overcomes the shortcomings of existing switching technologies in terms of speed, lifespan, synchronization, and reliability. It is particularly suitable for single-fiber bidirectional optical communication environments requiring high frequency, high precision, and high stability. The OEO amplifier with high-speed hard switching described in this invention significantly improves the speed and reliability of optical link switching by employing a pure hardware architecture of real-time comparison circuits and logic gate control circuits, combined with a high-lifespan, microsecond-level response magneto-optical switch. Compared to traditional solutions relying on MCU or software control, this invention avoids delays such as analog-to-digital conversion and program scheduling, compressing the overall switching response time to within 100 microseconds, meeting the stringent requirements of high-speed optical networks for sub-millisecond fault recovery. Meanwhile, the three magneto-optical switches achieve strictly synchronous switching under the control of logic gate circuits and drive circuits, ensuring highly consistent optical signal path reconstruction in both directions during single-fiber bidirectional transmission. End-to-end delay deviation is controlled within 2 picoseconds. This not only meets the needs of multiple long-distance point-to-point single-fiber bidirectional high-speed, high-frequency switching optical fiber OEO optical amplification services, but also ensures near-perfect synchronization between optical signal input and output, effectively guaranteeing the phase continuity of service signals and system synchronization performance. Furthermore, the closed-loop monitoring mechanism composed of the splitter group and photodetector group can detect optical power anomalies in any direction in real time and trigger seamless switching, significantly improving system availability. The magneto-optical switches' mechanical lifespan of up to hundreds of billions of cycles also solves the risk of equipment aging and failure in high-frequency switching scenarios, providing a new OEO amplification solution with both high performance and long lifespan for high-reliability optical communication systems such as data center interconnects and 5G bearer networks.

[0014] In a preferred embodiment of this application: the photodetector group includes a first photodetector disposed at the end of the first detection optical path and a second photodetector disposed at the end of the second detection optical path, the output terminals of the first photodetector and the second photodetector are both connected to the input terminal of the real-time comparison circuit; the driving circuit generates three sets of complementary control signals according to the high and low level combinations output by the real-time comparison circuit, which respectively drive the synchronous switching of the three magneto-optical switches.

[0015] By adopting the above technical solution, the present invention achieves independent sensing of the bidirectional optical link status by setting independent photodetectors at the ends of the first and second detection optical paths and connecting their outputs to a real-time comparison circuit. The three sets of complementary control signals generated by the driving circuit accurately drive the three magneto-optical switches to operate synchronously, effectively avoiding the risk of misjudgment caused by single-point detection, improving the accuracy of switching judgment, and ensuring that the three magneto-optical switches strictly achieve sub-microsecond synchronous switching operation at the physical level.

[0016] In a preferred embodiment of this application, the real-time comparison circuit includes a logarithmic amplifier and a high-speed voltage comparator, used to convert the weak current signal output by the photodetector group into a voltage signal and perform threshold comparison to distinguish between a light-emitting state and a light-free state.

[0017] By adopting the above technical solution, the optical power in the light-bearing state is ≥−36 dBm; the optical power in the dark state is ≥−40 dBm. The present invention uses a real-time comparison circuit composed of a logarithmic amplifier and a high-speed voltage comparator, which can efficiently convert the weak current output by the photodetector corresponding to the optical power range of −40 dBm to −36 dBm into a logarithmic voltage and perform rapid threshold discrimination. This not only improves the detection sensitivity of weak light signals, but also significantly shortens the signal conditioning time, so that the "light / dark" state judgment can be completed in nanoseconds.

[0018] In a preferred embodiment of this application: the first beam splitter splits the input optical signal at a ratio of 90%:10%, where 90% is used as the main signal of the main optical path and 10% is used as the first detection signal of the first detection optical path; the second beam splitter is disposed at the output end of the OEO optical module and splits the output optical signal of the OEO optical module at a ratio of 95%:5%, where 95% is used as the output main signal of the working optical path and 5% is used as the second detection signal of the second detection optical path, for real-time monitoring of the output light status of the OEO optical module, and participates in the switching decision between the main optical path and the detection optical path in conjunction with the first detection signal.

[0019] By adopting the above technical solution, this invention sets the first beam splitter to a splitting ratio of 90%:10% and the second beam splitter to a splitting ratio of 95%:5%. This ensures high-power transmission efficiency of the main optical path while providing a monitoring signal with sufficient signal-to-noise ratio for the probe optical path. 10% of the forward probe light is used to determine the input link status, and 5% of the backward probe light is used to verify the output link integrity. These two components work together to achieve bidirectional fault detection. The proportional design of this invention balances system gain and monitoring reliability.

[0020] In a preferred embodiment of this application: the three sets of complementary control signals are respectively: the first set controls the port selection of the magneto-optical switch near the input end, the second set controls the port selection of the magneto-optical switch before the intermediate amplification module, and the third set controls the port selection of the magneto-optical switch near the output end; the logic gate control circuit is a pure hardware combinational logic circuit, which does not rely on the main control microcontroller for switching decisions.

[0021] By adopting the above technical solution, the three sets of complementary control signals are respectively assigned to the magneto-optical switches at the input end, before the amplification module, and at the output end. The decision is made by pure hardware combinational logic circuit, which completely avoids the MCU processing delay. This ensures that the entire process from the change of optical state to the synchronous action of the three switches depends only on the gate circuit propagation delay, and the response speed can reach the nanosecond level. Thus, a true "hard switching" is achieved at the physical layer, meeting the stringent requirements of high-frequency and high-reliability optical networks for switching speed and determinism.

[0022] In a preferred embodiment of this application, the switching states of the three magneto-optical switches remain consistent, and they operate synchronously according to the following logic:

[0023] When the first photodetector detects light and the second photodetector detects no light, switch to the IN1 path;

[0024] When the first photodetector detects no light and the second photodetector detects light, switch to the IN2 path;

[0025] When neither the first photodetector nor the second photodetector can clearly determine the light state, the current switching state remains unchanged.

[0026] By adopting the above technical solution, a clear switching logic is set based on the dual-path state combination of the first photodetector and the second photodetector—IN1 path, IN2 path, or hold—so that the system can automatically select the effective path in the face of typical fault scenarios such as unidirectional fiber breakage, and maintain the current connection when the state is ambiguous, thus avoiding erroneous switching.

[0027] In a preferred embodiment of this application: the logic gate control circuit includes at least one NAND gate chip and an inverter chip. The two input terminals of the NAND gate chip receive a first state signal and a second state signal from the real-time comparison circuit, respectively. The logic signal output by the NAND gate chip is shaped by the inverter chip to generate three sets of complementary high and low level combination signals, which are output from the output terminal of the logic gate control circuit as port selection instructions for the three magneto-optical switches.

[0028] By adopting the above technical solution, NAND gate chips such as MC14011BDG and inverter chips such as SN74HC04DR are used to form a logic gate control circuit through NAND gate chips and inverter chips to construct a fixed Boolean logic circuit, which directly maps two state signals into three sets of complementary control instructions. This invention uses standard logic chips to achieve deterministic output without programming or configuration, and has extremely high timing predictability and anti-interference capability.

[0029] In a preferred embodiment of this application, the driving circuit includes three sets of MOSFET push-pull driving units. The input terminal of each set of MOSFET push-pull driving units is connected to a set of complementary control signals output by the logic gate control circuit, and the output terminal is connected to the UP control terminal and DOWN control terminal of the corresponding magneto-optical switch, respectively, for completing the current commutation driving of the magneto-optical switch coil within less than 550 nanoseconds after receiving the switching command.

[0030] By adopting the above technical solution, the three sets of MOSFET push-pull drive units receive complementary control signals and drive the UP or DOWN terminals of the magneto-optical switch respectively, which can quickly complete the coil current commutation after receiving the command; the push-pull structure provides strong sink / pull current capability, ensuring that all magneto-optical switches complete the drive level establishment in less than 550 nanoseconds, overcoming the response hysteresis caused by coil inductance.

[0031] In a preferred embodiment, this application further includes a main control microcontroller, an auxiliary communication module, and a status indication circuit. The main control microcontroller uses an STM32F103VCT6 control chip and interacts with an external network management system through the auxiliary communication module to report the working status of the OEO optical module, optical power monitoring data, and switching event logs.

[0032] The status indication circuit includes a first LED and a second LED, which are respectively connected to the comparator output terminals of the first and second photodetectors through current-limiting resistors, for real-time display of the light-on or light-off state of their respective optical paths; wherein, the status indication circuit is connected in parallel with the logic gate control circuit.

[0033] By adopting the above technical solution, the status indication circuit and the logic gate control circuit are connected in parallel, which does not affect the signal transmission timing of the hard handover path. This invention, by introducing a STM32F103VCT6-based microcontroller and LED status indication circuit, achieves visualization and remote reporting of equipment operating status without affecting the core hard handover path. The LEDs directly reflect the detector comparison results, facilitating on-site debugging; the MCU uploads logs via RS485, supporting centralized network management monitoring. This invention enhances product usability while avoiding software delays, ensuring that core handover performance is not interfered with.

[0034] Secondly, the objective of this invention is achieved through the following technical solution:

[0035] A single-fiber bidirectional optical communication system with high-speed hard switching function includes a first node and a second node, each node being configured with an OEO amplifier with high-speed hard switching function as described above.

[0036] The first node and the second node are connected by a single optical fiber to form a bidirectional optical signal path;

[0037] When any node detects an interruption in the received optical signal, the local OEO amplifier triggers the magneto-optical switch switching through hardware logic and sends a switching synchronization signal to the peer through the peer optical signal detection branch in the single-fiber bidirectional link. This enables the peer OEO amplifier to synchronously adjust the magneto-optical switch state, maintain the continuity of the communication link, and achieve a full-link switching time of less than 100 microseconds and a bidirectional time delay deviation of less than 2 picoseconds.

[0038] By adopting the above technical solution

[0039] In summary, this application includes at least one of the following beneficial technical effects:

[0040] 1. This invention constructs a high-speed switching architecture with a fully hardware closed loop by integrating three magneto-optical switches, a beam splitter group, a photodetector group, a real-time comparison circuit, a logic gate control circuit, and a driving circuit. This structure can trigger synchronous switching without software intervention when the optical signal is interrupted in any direction, achieving an overall response time of less than 100 microseconds. At the same time, because the three magneto-optical switches are driven by the same logic source, their actions are highly synchronized, ensuring that the time delay deviation of the end-to-end optical signal path reconstruction in single-fiber bidirectional transmission is controlled within 2 picoseconds, significantly improving the reliability and synchronization performance of the high-speed optical communication system.

[0041] 2. A magneto-optical switch is adopted, with a rated switching frequency of no less than 10^11 times, avoiding the risk of insufficient equipment lifespan caused by high-frequency switching and ensuring the stability and reliability of conventional high-frequency switching optical networks; the logic gate control circuit controls the switching of the magneto-optical switch, making the high-speed switching response speed of the OEO amplifier far exceed the millisecond-level response speed of mechanical optical switches and MEMS optical switches, as well as the millisecond-level response speed of software-controlled magneto-optical switch technology, meeting the requirements of modern high-speed optical communication systems for optical amplifier switching speed. Attached Figure Description

[0042] Figure 1 This is a schematic diagram of the optical path connection of the optical amplifier in an OEO amplifier with high-speed hard switching function according to an embodiment of this application;

[0043] Figure 2 This is a circuit diagram of a PD amplification and comparison circuit based on a photodetector in an OEO amplifier with high-speed hard switching function according to one embodiment of this application;

[0044] Figure 3 This is a circuit diagram of a high-speed voltage comparator and logic gate control circuit in an OEO amplifier with high-speed hard switching function according to an embodiment of this application.

[0045] Figure 4 This is a circuit diagram of a drive circuit in an OEO amplifier with high-speed hard switching function according to an embodiment of this application;

[0046] Figure 5 This is a circuit diagram of the main control microcontroller in an OEO amplifier with high-speed hard switching function according to one embodiment of this application;

[0047] Figure 6 This is a diagram of the optical amplification module and the buck control circuit in an OEO amplifier with high-speed hard switching function according to one embodiment of this application;

[0048] Figure 7 This is a circuit diagram of a status indication circuit in an OEO amplifier with high-speed hard switching function according to an embodiment of this application. Detailed Implementation

[0049] The present application will be further described in detail below with reference to the accompanying drawings.

[0050] In one embodiment, such as Figure 1 As shown, this application discloses an OEO amplifier with high-speed hard switching function, including three magneto-optical switches, a beam splitter group, a photodetector group, a real-time comparison circuit, a logic gate control circuit, and a driving circuit. This embodiment uses three magneto-optical switches ( Figure 1 The following example illustrates the process (SW1, SW2, SW3 in sequence) (or can be expanded to N magneto-optical switches, N≥3). In practical applications, it is not limited to three magneto-optical switches. The photodetector group collects changes in the optical signal power to generate an electrical signal. The beam splitter group splits the optical signal. A real-time comparison circuit performs voltage threshold judgment on the electrical signal to obtain the voltage threshold judgment result. The logic gate control circuit then synchronously controls the switching state of the three magneto-optical switches based on the voltage threshold judgment result. The drive circuit drives the magneto-optical switches to synchronously execute the switching action. This achieves the beneficial effect that when an interruption of the optical signal is detected in any direction, all magneto-optical switches complete synchronous switching within less than 100 microseconds, and the end-to-end optical signal switching time difference is less than 2 picoseconds in single-fiber bidirectional transmission.

[0051] Because the components of the OEO amplifier with high-speed hard switching function work together, the photodetector rapidly acquires changes in the optical signal, the real-time comparison circuit and logic gate control circuit make rapid and accurate judgments and decisions, and the drive circuit drives the magneto-optical switch in a timely manner, thus achieving high-speed switching and signal synchronization. In a single-fiber bidirectional system, each node's OEO amplifier adds a "parallel optical signal detection branch" (couples the parallel optical signal from the bidirectional fiber through a beam splitter and connects it to a third photodetector).

[0052] Specifically, the photodetector group includes a first photodetector disposed at the end of the first detection optical path. Figure 2 The middle one is PD2) and the second photodetector at the end of the second detection optical path ( Figure 2(PD4 is shown in the image). The first photodetector is characterized by its ability to quickly respond to minute changes in optical signal power, converting the optical signal into a weak current signal. The photodetector can use a PIN photodiode or an avalanche photodiode, which offers higher sensitivity and can detect even weaker optical signals. The second photodetector is constructed similarly to the first, also requiring high sensitivity and a fast response. The output of the second photodetector is connected to the input of a real-time comparison circuit, allowing the circuit to acquire optical signal power information from both detection paths.

[0053] The beam splitter assembly comprises at least two beam splitters. The first beam splitter divides the incident light into a main optical path and a first detection optical path according to a preset ratio. The first beam splitter is characterized by its precise splitting ratio control capability, enabling it to stably separate the input optical signal proportionally. For example, a fused biconical taper beam splitter can be used, which splits the optical signal by twisting two or more optical fibers together, heating and melting them, and then stretching them to form a coupling region; alternatively, a planar waveguide beam splitter can be used, which offers good splitting uniformity and low insertion loss. The second beam splitter further divides the output light from the main optical path into a working optical path and a second detection optical path according to a preset ratio. Its working principle and construction are similar to the first beam splitter, but the splitting ratio may differ. In this embodiment, the first beam splitter splits the input optical signal in a 90%:10% ratio, with 90% serving as the main signal of the main optical path and 10% serving as the first detection signal of the first detection optical path. The second beam splitter is located at the output end of the OEO optical module and splits the output optical signal of the OEO optical module in a 95%:5% ratio, with 95% serving as the main output signal of the working optical path and 5% serving as the second detection signal of the second detection optical path for monitoring or switching judgment.

[0054] Furthermore, in Figure 1 In this system, an optical amplifier node has two sets of splitter groups. Splitter 1 and splitter 2 form one set, and splitter 3 and splitter 4 form another set. The two sets of splitter groups are respectively set in the single-fiber bidirectional optical channel.

[0055] Real-time comparison circuits include logarithmic amplifiers and high-speed voltage comparators. Logarithmic amplifiers, such as the LOG114, are designed to convert the weak current signal output from the photodetector array into a voltage signal and amplify it logarithmically. Logarithmic amplifiers can be integrated logarithmic amplifier chips or constructed using discrete components, depending on specific requirements. High-speed voltage comparators, such as the LM393, compare the amplified voltage signal with a preset threshold to distinguish between a lit state (≥−36 dBm) and a dark state. They feature fast response and high comparison accuracy, enabling accurate judgments in a short time.

[0056] The logic gate control circuit is connected to the output of the real-time comparison circuit to synchronously control the switching state of the three magneto-optical switches based on the voltage threshold judgment result. The logic gate control circuit is a purely hardware combinational logic circuit, independent of the microcontroller for switching decisions. This design avoids the latency introduced by software control and improves switching speed. The logic gate control circuit can be composed of basic logic gates such as AND gates, OR gates, and NOT gates, achieving control of the magneto-optical switches through appropriate logic combinations. For example, the logic gate control circuit consists of NAND gates (such as MC14011) and NOT gates (such as SN74HC04).

[0057] The drive circuit connects the logic gate control circuit to the control terminals of each magneto-optical switch, and is used to drive the magneto-optical switches to perform switching actions synchronously. The characteristic of the drive circuit is that it can generate sufficient drive current and voltage according to the signal output by the logic gate control circuit, so that the magneto-optical switches can perform switching actions quickly and accurately.

[0058] The three magneto-optical switches maintain a consistent switching state, operating synchronously according to the following logic: when the first photodetector detects light and the second photodetector detects no light, the switch moves to path IN1; when the first photodetector detects no light and the second photodetector detects light, the switch moves to path IN2; when neither the first nor the second photodetector can definitively determine the light state, the current switching state remains unchanged. The magneto-optical switches possess rapid switching capabilities, capable of up to 100 billion switching cycles, meeting the demands of high-frequency switching. Their working principle utilizes the magneto-optical effect, changing the direction of light propagation by controlling the direction and intensity of the magnetic field.

[0059] Specifically, with Figures 2 to 7 Taking the circuit diagram shown as an example, the core of the OEO amplifier's control circuit consists of a photodetector group circuit, a logic gate control circuit, a MOSFET driver circuit, a main control microcontroller, and a status indicator circuit, all constructed entirely of hardware. The logic gate control circuit includes at least one NAND gate chip and one inverter chip. The input terminals of the NAND gate chip receive the first and second status signals from the real-time comparison circuit, respectively. After being shaped by the inverter chip, the output terminal generates three sets of complementary high and low level combination signals, which serve as port selection commands for the three magneto-optical switches.

[0060] Reference Figure 2 ,by Figure 2 Taking the circuit diagram shown as an example, Figure 2This is a circuit diagram of a PD amplification and comparison system based on a photodetector. It includes two sets of photodetector (PD) signal amplification and comparison modules, corresponding to two photodetector branches (PD2+ and PD4+). Taking the PD2+ branch as an example, the PD4+ branch has a symmetrical structure. Each PD amplification and comparison module includes a photodiode: receiving the probe light (e.g., PD2+) output from the beam splitter and generating a weak photocurrent; a logarithmic transimpedance amplifier, for... Figure 2 U5 (LOG114) or U61 (LOG114) converts nA~μA level photocurrent into logarithmic voltage; the negative voltage generation circuit generates it through U6 (TPS60400DBVR), providing a -5V power supply (VOA2_-5V) to LOG114; the reference voltage source generates a stable threshold through a precision reference D11 (LM4040) combined with voltage divider resistors (R81 / R84 or R123 / R126); and BAT54 Schottky diodes (D6 / D13) provide filtering and protection functions.

[0061] Reference Figure 3 , Figure 3 The high-speed voltage comparator in the circuit is U7 (LM393ADR), which compares the output of LOG114 with the threshold and outputs a TTL level. Figure 3 The system also includes a logic gate control circuit, which consists of U10 (model: MC14011BDG, quad 2-input NAND gate) and U11 (model: SN74HC04DR, hex inverter). Two digital status signals from the real-time comparator circuit—A_PD_OUT_A (indicating the presence or absence of light in the first detection optical path) and B_PD_OUT_B (indicating the presence or absence of light in the second detection optical path)—are respectively connected to the two NAND gate inputs of U10. U10 generates a preliminary control level according to preset Boolean logic. This level is then waveform-shaped and enhanced by the inverter in U11, outputting three sets of complementary high and low level combination signals, named 1OPS_UP / 1OPS_DOWN, 2OPS_UP / 2OPS_DOWN, and 3OPS_UP / 3OPS_DOWN, respectively, to obtain three sets of complementary high and low level combination signals (i.e., three sets of complementary control signals, which drive the synchronous switching of the three magneto-optical switches respectively). Preset Boolean logic, such as OUT=NOT(A AND B), etc. These three sets of signals serve as port selection commands for the three magneto-optical switches (SW1, SW2, SW3), ensuring that their switching actions are strictly synchronized.

[0062] Reference Figure 4 ,by Figure 4 Taking the circuit diagram shown as an example, Figure 4The circuit is a MOSFET drive circuit, which includes three sets of MOSFET push-pull drive units. The input of each MOSFET push-pull drive unit is connected to a set of complementary control signals output by the logic gate control circuit, and the output is connected to the UP control terminal and DOWN control terminal of the corresponding magneto-optical switch, respectively. It is used to complete the current commutation drive of the magneto-optical switch coil within less than 550 nanoseconds after receiving the switching command.

[0063] Specifically, the driving circuit includes three identical MOSFET driving units, and three magneto-optical switches, SW1, SW2, and SW3. 30PS UP and 30PS DOWN define pins A and B, respectively, that control the magneto-optical switches. High and low level signals on A and B are used to switch the direction of the magneto-optical switches. The control terminals of the magneto-optical switches (SW1-SW3) are synchronized: "10PS UP" and "10PS DOWN" control SW1, "20PS UP" and "20PS DOWN" control SW2, and "30PS UP" and "30PS DOWN" control SW3.

[0064] Each MOSFET drive unit includes a first N-channel MOSFET, a second N-channel MOSFET, a first P-channel MOSFET, a second P-channel MOSFET, and a corresponding freewheeling diode. Figure 5 The N-channel MOSFET is model SI2302, and the P-channel MOSFET is model SI2301. The first N-channel MOSFET and the first P-channel MOSFET form a first push-pull branch, used to drive the UP control terminal of the corresponding magneto-optical switch. The second N-channel MOSFET and the second P-channel MOSFET form a second push-pull branch, used to drive the DOWN control terminal of the corresponding magneto-optical switch. Taking the first group (controlling SW1) as an example: the 1OPS_UP signal is connected to the gate of the N-channel MOSFET D15 (model: SI2302), and simultaneously, after inversion, is connected to the gate of the P-channel MOSFET Q1 (model: SI2301). The drains of both are connected to the UP control terminal of the magneto-optical switch, and their sources are connected to GND and +5V_VCC respectively, forming the first push-pull branch. Similarly, the 1OPS_DOWN signal drives D16 (SI2302) and Q2 (SI2301), forming the second push-pull branch, and is output to the DOWN control terminal of the magneto-optical switch. Both the first N-channel MOSFET and the second N-channel MOSFET are model SI2302, and both the first P-channel MOSFET and the second P-channel MOSFET are model SI2301. Each MOSFET has a BAT54 Schottky freewheeling diode connected in parallel to its drain to suppress the back electromotive force generated when the magneto-optical switch coil is turned off.

[0065] Reference Figure 5,by Figure 5 Taking the circuit diagram shown as an example, it also includes a main control microcontroller, an auxiliary communication module, and a status indicator circuit. The main control microcontroller uses an STM32F103VCT6 control chip. Figure 5 The U31A and U31B modules in the OEO module use RS485 communication modules as auxiliary communication modules. The main control microcontroller connects to the external network management system via the RS485 communication module to periodically report the working status of the OEO module, the optical power data collected by the photodetector, and historical switching event logs.

[0066] Reference Figure 6 ,by Figure 6 Taking the circuit diagram shown as an example, Figure 6 OEO1 and OEO2 are optical amplifier modules, and the TPS51125 chip is a dual-channel synchronous buck controller. The TPS51125 provides a clean and stable +5V main power supply for the optical module. Specifically, the +12V input (VCC12V) is connected to the VIN pin of the TPS51125 after being filtered by the primary filter of L5 / C13. The internal reference (0.6V) of the chip and the external feedback resistor (such as R14 / R15) form a voltage divider network to sample the output voltage of VREG5. The dual-channel synchronous buck controller dynamically adjusts the duty cycle of the high-side (DRVH) and low-side (DRVL) drive signals through PWM comparison to control the external power stage.

[0067] Reference Figure 7 ,by Figure 7 Taking the circuit diagram shown as an example, Figure 7 This is the circuit diagram for the status indicator circuit. Figure 7 LEDM1 indicates the state of the first optical path (PD2+), and LEDM2 indicates the state of the second optical path (PD4+). The driving signal sources are A_PD_OUT_A and B_PD_OUT_B, which come from the output of the LM393ADR comparator (U7 / U14). The anode of OEOM1 is connected to +5V, and the cathode is connected to A_PD_OUT_A via R120; the anode of OEOM2 is connected to +5V, and the cathode is connected to B_PD_OUT_B via R119. For example, when there is light in the first optical path, PD2+ generates sufficient photocurrent, LOG114 outputs high, then LM393 outputs a high level, so A_PD_OUT_A = +5V, making the cathode of LEDM1 = +5V, resulting in no voltage difference across LEDM1, and it is off. When there is no light in the first optical path, LM393 outputs a low level, so A_PD_OUT_A = 0V. At this time, the anode of LED = +5V, the cathode = 0V, causing LEDM1 to conduct and emit light.

[0068] The implementation principle of this embodiment is as follows: In an optical fiber communication system, when an optical signal enters the OEO amplifier, it first passes through a first beam splitter, which proportionally divides the optical signal into a main optical path and a first detection optical path. The first photodetector on the first detection optical path collects the power change of the optical signal and converts it into a weak current signal. This signal is then converted into a voltage signal by a logarithmic amplifier and compared against a threshold by a high-speed voltage comparator. Simultaneously, the optical signal in the main optical path passes through an intermediate amplification module and a second beam splitter, while the second photodetector on the second detection optical path performs the same signal acquisition and processing. The real-time comparison circuit outputs the processed signal to a logic gate control circuit, which generates a control signal according to preset logic rules. The drive circuit amplifies the control signal and drives the magneto-optical switches to switch. Due to the coordinated operation and rapid response of each component, when an interruption in the optical signal is detected in either direction, all magneto-optical switches can complete synchronous switching within less than 100 microseconds. Furthermore, in single-fiber bidirectional transmission, the end-to-end optical signal switching time difference is less than 2 picoseconds, meeting the requirements of high-speed, high-frequency switching optical fiber OEO optical amplification services and ensuring the stability and reliability of the optical network.

[0069] In one embodiment, a single-fiber bidirectional optical communication system with high-speed hard switching function is provided. The single-fiber bidirectional optical communication system with high-speed hard switching function includes a first node and a second node, and each node is configured with an OEO amplifier with high-speed hard switching function as described in the above embodiment.

[0070] A single-fiber bidirectional optical communication system with high-speed hard switching function includes a first node and a second node, each node being equipped with an OEO amplifier with high-speed hard switching function.

[0071] The first node and the second node are connected by a single optical fiber to form a bidirectional optical signal path;

[0072] When any node detects an interruption in the received optical signal, the local OEO amplifier triggers the magneto-optical switch switching through hardware logic and sends a switching synchronization signal to the peer through the peer optical signal detection branch in the single-fiber bidirectional link. This enables the peer OEO amplifier to synchronously adjust the magneto-optical switch state, maintain the continuity of the communication link, and achieve a full-link switching time of less than 100 microseconds and a bidirectional time delay deviation of less than 2 picoseconds.

[0073] In the above-mentioned single-fiber bidirectional optical communication system with high-speed hard switching function, each module can be implemented in whole or in part through software, hardware and their combination; each module can be embedded in the processor of the computer device in hardware form or independent of the processor, or it can be stored in the memory of the computer device in software form, so that the processor can call and execute the corresponding operations of each module.

[0074] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the above-described division of functional units and modules is used as an example. In practical applications, the above functions can be assigned to different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above.

[0075] The above-described embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be included within the protection scope of this application.

Claims

1. An OEO amplifier with high-speed hard switching function, characterized in that, include: Three magneto-optical switches, a beam splitter group, a photodetector group, a real-time comparison circuit, a logic gate control circuit, and a drive circuit; The photodetector group collects optical signal power to generate an electrical signal; the beam splitter group includes at least two beam splitters, the first beam splitter splits the incident light into a main optical path and a first detection optical path according to a preset ratio, and the second beam splitter splits the output light of the main optical path into a working optical path and a second detection optical path again according to a preset ratio. The real-time comparison circuit performs a voltage threshold judgment on the electrical signal; the logic gate control circuit is connected to the output of the real-time comparison circuit to synchronously control the switching state of the three magneto-optical switches according to the voltage threshold judgment result. A driving circuit is connected to the output terminal of the logic gate control circuit and the control terminal of each magneto-optical switch, and is used to drive the magneto-optical switches to perform switching actions synchronously. When the OEO amplifier detects an interruption in the optical signal in any direction, all magneto-optical switches complete synchronous switching within less than 100 microseconds, and the end-to-end optical signal switching time difference is less than 2 picoseconds in single-fiber bidirectional transmission.

2. The OEO amplifier with high-speed hard switching function according to claim 1, characterized in that, The photodetector group includes a first photodetector disposed at the end of the first detection optical path and a second photodetector disposed at the end of the second detection optical path. The output terminals of the first photodetector and the second photodetector are both connected to the input terminal of the real-time comparison circuit. The driving circuit generates three sets of complementary control signals according to the high and low level combinations output by the real-time comparison circuit, which drive the synchronous switching of the three magneto-optical switches respectively.

3. The OEO amplifier with high-speed hard switching function according to claim 1, characterized in that, The real-time comparison circuit includes a logarithmic amplifier and a high-speed voltage comparator, which are used to convert the weak current signal output by the photodetector group into a voltage signal and perform threshold comparison to distinguish between the light state and the dark state.

4. An OEO amplifier with high-speed hard switching function according to claim 2, characterized in that, The first beam splitter splits the input optical signal in a 90%:10% ratio, with 90% serving as the main signal of the main optical path and 10% serving as the first detection signal of the first detection optical path. The second beam splitter is located at the output end of the OEO optical module and splits the output optical signal of the OEO optical module in a 95%:5% ratio, with 95% serving as the main output signal of the working optical path and 5% serving as the second detection signal of the second detection optical path. This is used to monitor the output light status of the OEO optical module in real time and to participate in the switching decision between the main optical path and the detection optical path in conjunction with the first detection signal.

5. An OEO amplifier with high-speed hard switching function according to claim 2, characterized in that, The three sets of complementary control signals are as follows: the first set controls the port selection of the magneto-optical switch near the input end, the second set controls the port selection of the magneto-optical switch before the intermediate amplification module, and the third set controls the port selection of the magneto-optical switch near the output end; the logic gate control circuit is a pure hardware combinational logic circuit, which does not rely on the main microcontroller for switching decisions.

6. An OEO amplifier with high-speed hard switching function according to claim 2, characterized in that, The switching states of the three magneto-optical switches remain consistent, and they operate synchronously according to the following logic: When the first photodetector detects light and the second photodetector detects no light, switch to the IN1 path; When the first photodetector detects no light and the second photodetector detects light, switch to the IN2 path; When neither the first photodetector nor the second photodetector can clearly determine the light state, the current switching state remains unchanged.

7. An OEO amplifier with high-speed hard switching function according to claim 5, characterized in that, The logic gate control circuit includes at least one NAND gate chip and one inverter chip. The two input terminals of the NAND gate chip receive a first state signal and a second state signal from the real-time comparison circuit, respectively. The logic signal output by the NAND gate chip is shaped by the inverter chip to generate three sets of complementary high and low level combination signals, which are output from the output terminal of the logic gate control circuit as port selection instructions for the three magneto-optical switches.

8. An OEO amplifier with high-speed hard switching function according to claim 7, characterized in that, The driving circuit includes three sets of MOSFET push-pull driving units. The input of each set of MOSFET push-pull driving units is connected to a set of complementary control signals output by the logic gate control circuit, and the output is connected to the UP control terminal and DOWN control terminal of the corresponding magneto-optical switch, respectively. It is used to complete the current commutation driving of the magneto-optical switch coil within less than 550 nanoseconds after receiving the switching command.

9. An OEO amplifier with high-speed hard switching function according to claim 2, characterized in that, It also includes a main control microcontroller, an auxiliary communication module and a status indication circuit. The main control microcontroller uses an STM32F103VCT6 control chip and interacts with an external network management system through the auxiliary communication module to report the working status of the OEO optical module, optical power monitoring data and switching event logs. The status indication circuit includes a first LED and a second LED, which are respectively connected to the comparator output terminals of the first and second photodetectors through current-limiting resistors, for real-time display of the light-on or light-off state of their respective optical paths; wherein, the status indication circuit is connected in parallel with the logic gate control circuit.

10. A single-fiber bidirectional optical communication system with high-speed hard switching function, characterized in that, It includes a first node and a second node, each node being configured with an OEO amplifier with high-speed hard switching function as described in any one of claims 1 to 9; The first node and the second node are connected by a single optical fiber to form a bidirectional optical signal path; When any node detects an interruption in the received optical signal, the local OEO amplifier triggers the magneto-optical switch switching through hardware logic and sends a switching synchronization signal to the peer through the peer optical signal detection branch in the single-fiber bidirectional link. This enables the peer OEO amplifier to synchronously adjust the magneto-optical switch state, maintain the continuity of the communication link, and achieve a full-link switching time of less than 100 microseconds and a bidirectional time delay deviation of less than 2 picoseconds.

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