Optical module

Abstract

The optical module provided by the invention comprises a circuit board, a photoelectric detector, a booster circuit, a sampling circuit and an MCU. The photoelectric detector is used for converting the optical signal into a photocurrent signal. The booster circuit is used for providing bias voltage for the photoelectric detector. The sampling circuit is used for sampling the light receiving intensity received by the photoelectric detector according to the trigger signal. And in the power-on process of the photoelectric detector, the MCU provides a trigger signal for the sampling circuit. A power-on large light protection mechanism is executed in the power-on process of the photoelectric detector: the sampled light receiving intensity is compared with the current intensity threshold value before the bias voltage is stepped every time, and if the sampled light receiving intensity is lower than the current intensity threshold value, the next step can be carried out; if the sampled light receiving intensity is higher than the current intensity threshold value, the output of the current bias voltage is maintained, stepping is not executed, and sampling is continuously triggered, so that the photoelectric detector is protected.

Description

Technical Field

[0001] The present disclosure relates to the field of optical communication technology, and in particular to an optical module. Background Art

[0002] With the development of new services and applications such as cloud computing, mobile internet, and video, advances in optical communication technology are becoming increasingly important. As a key component in optical communication equipment, optical modules enable photoelectric signal conversion. As optical communication technology evolves, the data transmission rate of these modules continues to increase.

[0003] As the transmission rate of optical modules increases, their ability to withstand strong light becomes worse. Abnormally strong light can easily damage the photodetector at the optical receiving end. Summary of the Invention

[0004] An embodiment of the present disclosure provides an optical module that provides a protection mechanism during the power-on process of a photodetector to prevent the photodetector from being damaged.

[0005] The optical module provided in the embodiment of the present disclosure includes:

[0006] circuit boards;

[0007] a photodetector electrically connected to the circuit board, configured to convert a received light signal into a photocurrent signal; wherein the photocurrent multiplication factor of the photodetector is positively correlated with the bias voltage received by the photodetector;

[0008] a boost circuit, electrically connected to the photodetector, and configured to provide a bias voltage for the photodetector;

[0009] a sampling circuit electrically connected to the photodetector, and configured to sample the light reception intensity of the photodetector according to a received trigger signal; when the boost circuit provides the bias voltage to the photodetector, the MCU provides the trigger signal when no trigger signal is received;

[0010] The MCU is electrically connected to the boost circuit and the sampling circuit respectively, and is configured as follows:

[0011] controlling the boost circuit to increase the bias voltage provided to the photodetector in a step-by-step manner;

[0012] before each step, sending a trigger signal to the sampling circuit to trigger the sampling circuit to sample the light receiving intensity of the photodetector;

[0013] If the sampled light receiving intensity is lower than the current intensity threshold, the next step is executed; if the sampled light receiving intensity is higher than the current intensity threshold, the current bias voltage is maintained and the sampling circuit is continuously triggered to sample the light receiving intensity of the photodetector.

[0014] The optical module provided herein includes a circuit board, a photodetector, a boost circuit, a sampling circuit, and an MCU. The photodetector is used to convert received optical signals into photocurrent signals. The boost circuit is used to provide a bias voltage for the photodetector. The sampling circuit is used to sample the received light intensity of the photodetector based on a received trigger signal. The sampling circuit feeds the sampled received light intensity back to the MCU, which controls the bias voltage provided to the photodetector by the boost circuit based on the received light intensity. When powering on the photodetector, if the photodetector is powered on quickly, sudden bursts of strong light during the rapid power-up process can easily damage the photodetector. Therefore, the present disclosure utilizes a step-by-step power-up method for the photodetector. To timely monitor the received light intensity of the photodetector, the received light intensity of the photodetector is sampled during the step-by-step power-up process. When the optical line terminal and the optical network unit are interconnected, the host computer system sends a trigger signal to the sampling circuit to trigger the sampling circuit to sample the received light intensity of the photodetector. If the interconnection between the optical line terminal and the optical network unit occurs after the initial power-up of the photodetector, the trigger signal may not be received during the power-up process. To this end, in the present disclosure, the MCU sends a trigger signal to the sampling circuit. And the photodetector power-on high light protection mechanism is executed during the photodetector power-on process. The photodetector power-on high light protection mechanism includes: before each step of the bias voltage, the sampled light reception intensity is compared with the current intensity threshold. If the sampled light reception intensity is lower than the current intensity threshold, the next step can be made; if the sampled light reception intensity is higher than the current intensity threshold, the output of the current bias voltage is maintained, no step is performed, and the sampling is continued to be triggered. In the present disclosure, when the sampled light reception intensity is higher than the current intensity threshold, it means that a burst of strong light is received, and the bias voltage provided to the photodetector is maintained at a relatively low bias voltage. Based on the fact that the photocurrent multiplication factor of the photodetector is positively correlated with the bias voltage received by the photodetector, the photocurrent multiplication factor of the photodetector is relatively small at this time. Even if there is a burst of strong light, the photocurrent generated at this time still does not exceed the maximum current allowed by the photodetector die, thereby protecting the photodetector. The photodetector power-on high-light protection mechanism disclosed in the present invention can ensure that there is no sudden strong light when each step of powering on the photodetector is performed, thereby protecting the photodetector. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] To more clearly illustrate the technical solutions of the present disclosure, the following briefly describes the drawings used in some embodiments of the present disclosure. Obviously, the drawings described below are merely illustrations of some embodiments of the present disclosure, and those skilled in the art can also derive other drawings based on these drawings. Furthermore, the drawings described below are schematic diagrams and are not intended to limit the actual dimensions of the products, actual processes of the methods, actual timing of signals, and the like involved in the embodiments of the present disclosure.

[0016] Figure 1 A partial architecture diagram of an optical communication system provided according to some embodiments of the present disclosure;

[0017] Figure 2 A partial structural diagram of a host computer provided according to some embodiments of the present disclosure;

[0018] Figure 3 A structural diagram of an optical module provided according to some embodiments of the present disclosure;

[0019] Figure 4 An exploded view of an optical module provided according to some embodiments of the present disclosure;

[0020] Figure 5 A schematic diagram of the connections among an MCU, a photodetector, a boost circuit, and a sampling circuit in a first power-on process of a photodetector in an optical module according to some embodiments of the present disclosure;

[0021] Figure 6 A schematic diagram of a connection between a boost circuit and a photodetector according to some embodiments of the present disclosure;

[0022] Figure 7 A schematic diagram of the interaction between an MCU, a photodetector, a boost circuit, and a sampling circuit in a first power-on process of a photodetector provided according to some embodiments of the present disclosure;

[0023] Figure 8 A schematic diagram of the interaction between an MCU, a photodetector, a boost circuit, and a sampling circuit in a second power-on process of a photodetector provided according to some embodiments of the present disclosure;

[0024] Figure 9 Schematic diagram of a light protection mechanism for a photodetector according to some embodiments of the present disclosure Figure 1 ;

[0025] Figure 10 Schematic diagram of a light protection mechanism for a photodetector according to some embodiments of the present disclosure Figure 2 . DETAILED DESCRIPTION

[0026] Some embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings. However, the embodiments described are only some of the embodiments of the present disclosure, not all of them. All other embodiments obtained by those of ordinary skill in the art based on the embodiments provided in the present disclosure are within the scope of protection of the present disclosure.

[0027] Unless the context requires otherwise, throughout the specification and claims, the term "including" is to be interpreted as open and inclusive, that is, "including, but not limited to"; the terms "first" and "second" are not to be understood as indicating or implying relative importance or indicating an upper limit on quantity; the term "plurality" means two or more; the term "connected" is to be understood in a broad sense, for example, "connected" can be a fixed connection, a detachable connection, or an integral connection, and can be directly connected or indirectly connected through an intermediate medium; the use of the terms "suitable for" or "configured to" means open and inclusive language, which does not exclude equipment that is suitable for or configured to perform additional tasks or steps; terms such as "parallel", "perpendicular", "same", "consistent", "level" and so on are not limited to absolute mathematical theoretical relationships, but also include acceptable error ranges generated in practice, and also include differences based on the same design concept but due to manufacturing reasons.

[0028] In optical communication technology, to establish information transmission between information processing devices, it is necessary to load the information onto light and use the propagation of light to achieve information transmission. Here, the light loaded with information is an optical signal. When transmitting optical signals within information transmission equipment, they can reduce optical power loss, thereby enabling high-speed, long-distance, and low-cost information transmission. The signals that information processing equipment can recognize and process are electrical signals. Information processing equipment typically includes optical network units (ONUs), gateways, routers, switches, mobile phones, computers, servers, tablets, televisions, etc., and information transmission equipment typically includes optical fibers and optical waveguides.

[0029] Optical modules can convert optical signals into electrical signals between information processing devices and information transmission devices. For example, at least one of the optical signal input or output ends of an optical module is connected to an optical fiber, and at least one of the electrical signal input or output ends of the optical module is connected to an optical network terminal. A first optical signal from the optical fiber is transmitted to the optical module, which converts the first optical signal into a first electrical signal and transmits the first electrical signal to the optical network terminal. A second electrical signal from the optical network terminal is transmitted to the optical module, which converts the second electrical signal into a second optical signal and transmits the second optical signal to the optical fiber. Because multiple information processing devices can transmit information via electrical signals, at least one of the multiple information processing devices needs to be directly connected to the optical module, rather than all of them. Here, the information processing device directly connected to the optical module is referred to as the optical module's host computer. Furthermore, the optical signal input or output end of the optical module can be referred to as an optical port, and the electrical signal input or output end of the optical module can be referred to as an electrical port.

[0030] Figure 1 FIG. 1 is a partial structural diagram of an optical communication system according to some embodiments. Figure 1 As shown, the optical communication system mainly includes a remote information processing device 1000 , a local information processing device 2000 , a host computer 100 , an optical module 200 , an optical fiber 101 and a network cable 103 .

[0031] One end of optical fiber 101 extends toward remote information processing device 1000, and the other end of optical fiber 101 is connected to optical module 200 through the optical port of optical module 200. Optical signals can be totally reflected in optical fiber 101, and the propagation of the optical signal in the direction of total reflection can almost maintain the original optical power. The optical signal undergoes multiple total reflections in optical fiber 101 to transmit the optical signal from remote information processing device 1000 to optical module 200, and vice versa, thereby achieving long-distance, low-power information transmission.

[0032] The optical communication system may include one or more optical fibers 101, and the optical fibers 101 may be detachably connected or fixedly connected to the optical module 200. The host computer 100 is configured to provide data signals to the optical module 200, receive data signals from the optical module 200, or monitor or control the operating status of the optical module 200.

[0033] The host computer 100 includes a substantially rectangular housing and an optical module interface 102 disposed on the housing. The optical module interface 102 is configured to connect to the optical module 200 to establish a unidirectional or bidirectional electrical signal connection between the host computer 100 and the optical module 200.

[0034] The host computer 100 also includes an external electrical interface that can access an electrical signal network. For example, the external electrical interface includes a Universal Serial Bus (USB) interface or a network cable interface 104. The network cable interface 104 is configured to access a network cable 103 so that the host computer 100 establishes a unidirectional or bidirectional electrical signal connection with the network cable 103. One end of the network cable 103 is connected to the local information processing device 2000, and the other end of the network cable 103 is connected to the host computer 100, so that an electrical signal connection is established between the local information processing device 2000 and the host computer 100 via the network cable 103. For example, a third electrical signal emitted by the local information processing device 2000 is transmitted to the host computer 100 via the network cable 103. The host computer 100 generates a second electrical signal based on the third electrical signal. The second electrical signal from the host computer 100 is transmitted to the optical module 200. The optical module 200 converts the second electrical signal into a second optical signal and transmits the second optical signal to the optical fiber 101. The second optical signal is then transmitted to the remote information processing device 1000 via the optical fiber 101. For example, a first optical signal from the remote information processing device 1000 is transmitted through the optical fiber 101. The first optical signal from the optical fiber 101 is transmitted to the optical module 200. The optical module 200 converts the first optical signal into a first electrical signal. The optical module 200 transmits the first electrical signal to the host computer 100. The host computer 100 generates a fourth electrical signal based on the first electrical signal and transmits the fourth electrical signal to the local information processing device 2000. It should be noted that optical modules are tools for converting optical signals into electrical signals. During this conversion process, the information does not change, but the encoding and decoding methods of the information can change.

[0035] In addition to the optical network terminal, the host computer 100 also includes an optical line terminal (OLT), an optical network device (ONT), or a data center server.

[0036] Figure 2 FIG1 is a partial structural diagram of a host computer according to some embodiments. In order to clearly show the connection relationship between the optical module 200 and the host computer 100, Figure 2 Only the structure of the host computer 100 related to the optical module 200 is shown. Figure 2 As shown, the host computer 100 further includes a PCB 105 disposed within the housing, a cage 106 disposed on the surface of the PCB 105, a heat sink 107 disposed on the cage 106, and an electrical connector disposed within the cage 106. The electrical connector is configured to connect to the electrical port of the optical module 200; the heat sink 107 has protruding structures such as fins to increase the heat dissipation area.

[0037] The optical module 200 is inserted into the cage 106 of the host computer 100. The cage 106 secures the optical module 200. Heat generated by the optical module 200 is transferred to the cage 106 and then dissipated through the heat sink 107. After the optical module 200 is inserted into the cage 106, the electrical port of the optical module 200 connects with the electrical connector inside the cage 106, thereby establishing a bidirectional electrical signal connection between the optical module 200 and the host computer 100. Furthermore, the optical port of the optical module 200 connects to the optical fiber 101, thereby establishing a bidirectional optical signal connection between the optical module 200 and the optical fiber 101.

[0038] Figure 3 is a structural diagram of an optical module according to some embodiments. Figure 4 FIG. 1 is an exploded view of an optical module according to some embodiments. Figure 3 and Figure 4 As shown, the optical module 200 includes a housing, a circuit board 300 disposed in the housing, a light emitting component 400, and a light receiving component 500. However, the present disclosure is not limited thereto. In some embodiments, the optical module 200 includes one of the light emitting component 400 and the light receiving component 500.

[0039] The housing includes an upper housing 201 and a lower housing 202 . The upper housing 201 covers the lower housing 202 to form the housing having two openings 204 and 205 . The outer contour of the housing is generally a square.

[0040] In some embodiments, the lower shell 202 includes a base plate 2021 and two lower side plates 2022 located on both sides of the base plate 2021 and arranged perpendicular to the base plate 2021; the upper shell 201 includes a cover plate 2011, and the cover plate 2011 covers the two lower side plates 2022 of the lower shell 202 to form the above-mentioned shell.

[0041] In some embodiments, the lower shell 202 includes a base plate 2021 and two lower side plates 2022 located on both sides of the base plate 2021 and arranged perpendicularly to the base plate 2021; the upper shell 201 includes a cover plate 2011 and two upper side plates located on both sides of the cover plate 2011 and arranged perpendicularly to the cover plate 2011. The two upper side plates are combined with the two lower side plates 2022 to achieve the upper shell 201 covering the lower shell 202.

[0042] The direction of the line connecting the two openings 204 and 205 may be consistent with the length direction of the optical module 200, or may be inconsistent with the length direction of the optical module 200. For example, the opening 204 is located at the end of the optical module 200 ( Figure 3 The opening 205 is also located at the end of the optical module 200 ( Figure 3Alternatively, opening 204 is located at the end of optical module 200, while opening 205 is located on the side of optical module 200. Opening 204 is an electrical port, through which the gold finger 301 of circuit board 300 extends and is inserted into the electrical connector of host computer 100; opening 205 is an optical port, configured to receive an external optical fiber 101, thereby connecting optical fiber 101 to the light emitting component 400 and the light receiving component 500 in optical module 200.

[0043] The combined assembly of the upper housing 201 and the lower housing 202 facilitates the installation of the circuit board 300, the light emitting component 400, the light receiving component 500, and the like within the housing. The upper housing 201 and the lower housing 202 provide encapsulation and protection for these components. Furthermore, during assembly of the circuit board 300, the light emitting component 400, and the light receiving component 500, the positioning components, heat dissipation components, and electromagnetic shielding components of these components are easily positioned, facilitating automated production.

[0044] In some embodiments, the upper shell 201 and the lower shell 202 are made of metal materials, which facilitates electromagnetic shielding and heat dissipation.

[0045] In some embodiments, the optical module 200 further includes an unlocking component 600 located outside its housing. The unlocking component 600 is configured to achieve a fixed connection between the optical module 200 and the host computer, or to release the fixed connection between the optical module 200 and the host computer.

[0046] For example, the unlocking component 600 is located on the outside of the two lower side panels 2022 of the lower housing 202 and includes a snap-fit ​​component that mates with the cage 106 of the host computer 100. When the optical module 200 is inserted into the cage 106, the snap-fit ​​component of the unlocking component 600 secures the optical module 200 in the cage 106. When the unlocking component 600 is pulled, the snap-fit ​​component of the unlocking component 600 moves accordingly, thereby changing the connection between the snap-fit ​​component and the host computer, thereby releasing the optical module 200 from the cage 106 and allowing the optical module 200 to be removed from the cage 106.

[0047] The circuit board 300 includes circuit traces, electronic components, and chips. The electronic components and chips are connected according to the circuit design through the circuit traces to achieve functions such as power supply, electrical signal transmission, and grounding. Electronic components may include, for example, capacitors, resistors, transistors, and metal-oxide-semiconductor field-effect transistors (MOSFETs). Chips may include, for example, microcontroller units (MCUs), laser driver chips, transimpedance amplifiers (TIAs), limiting amplifiers, clock and data recovery chips (CDRs), power management chips, and digital signal processing (DSP) chips.

[0048] The circuit board 300 is generally a rigid circuit board. Due to its relatively hard material, the rigid circuit board can also realize the load-bearing function. For example, the rigid circuit board can stably carry the above-mentioned electronic components and chips; the rigid circuit board can also be inserted into the electrical connector in the cage 106 of the host computer 100.

[0049] The circuit board 300 further includes a gold finger 301 formed on the end surface thereof. The gold finger 301 is composed of a plurality of independent pins. The circuit board 300 is inserted into the cage 106, and the gold finger 301 is connected to the electrical connector in the cage 106. The gold finger 301 can be provided on only one side of the circuit board 300 (e.g. Figure 4 The top surface shown in FIG300 can also be located on the upper and lower surfaces of the circuit board 300 to provide a greater number of pins, thus adapting to applications requiring a large number of pins. Gold fingers 301 are configured to establish an electrical connection with a host computer to facilitate power supply, grounding, two-wire synchronous serial (Inter-Integrated Circuit, I2C) signal transmission, data signal transmission, and more. Of course, some optical modules also use flexible circuit boards. Flexible circuit boards are generally used in conjunction with rigid circuit boards to supplement them.

[0050] At least one of the light emitting component 400 or the light receiving component 500 is located on a side of the circuit board 300 away from the gold finger 301 .

[0051] In some embodiments, the light emitting component 400 and the light receiving component 500 are physically separated from the circuit board 300 and then electrically connected to the circuit board 300 through corresponding flexible circuit boards or electrical connectors.

[0052] In some embodiments, at least one of the light emitting component or the light receiving component may be directly disposed on the circuit board 300. For example, at least one of the light emitting component or the light receiving component may be disposed on a surface of the circuit board 300 or a side of the circuit board 300.

[0053] Figure 5 This is a connection diagram of an MCU, a photodetector, a boost circuit, and a sampling circuit in the first power-on process of a photodetector in an optical module according to some embodiments of the present disclosure. Figure 5 As shown, the light receiving component 500 may include a photodetector 501. The photodetector 501 is used to convert a received light signal into a photocurrent signal.

[0054] The photodetector 510 is used to convert the received light signal into a photocurrent signal. This application does not limit the specific form of the photodetector. For example, an avalanche photodiode (APD) is a common type of photodetector. When a reverse bias voltage is applied to the PN junction of the APD, received photons are absorbed by the PN junction to form a photocurrent. Increasing the reverse bias voltage doubles the photocurrent, producing an "avalanche" phenomenon.

[0055] The surface of the circuit board 300 may include a boost circuit 303 . The boost circuit 303 is electrically connected to the MCU 302 . The boost circuit 303 is used to provide a bias voltage for the photodetector 501 .

[0056] The APD requires a relatively high bias voltage during operation. To this end, a boost circuit 303 is used to provide the APD with the required high bias voltage. Because a reverse bias voltage is required for the APD, the positive terminal of the boost circuit 303 is electrically connected to the negative terminal of the APD, and the negative terminal of the boost circuit is grounded. The positive terminal of the APD is electrically connected to the positive terminal of the transimpedance amplifier, and the negative terminal of the transimpedance amplifier is also grounded. The ground of the transimpedance amplifier is then connected to the ground of the boost circuit to increase the reverse bias voltage for the APD. Under the action of the reverse bias voltage, the APD converts the received light signal into a photocurrent signal.

[0057] Figure 6 FIG. 1 is a schematic diagram showing the connection between a boost circuit and a photodetector according to some embodiments of the present disclosure. Figure 6As shown, the microcontroller unit (MCU) 302 controls the boost circuit to output a high-voltage signal, which is supplied to the high-voltage pin of the APD, allowing the APD to obtain sufficient voltage to generate an avalanche, producing a photocurrent multiplication effect. After the APD obtains sufficient voltage, it converts the received optical signal into a photocurrent signal. This is then converted into a differential signal by a trans-impedance amplifier (TIA) and output to the limiting amplifier. The limiting amplifier then shapes the differential signal and outputs it through the electrical interface.

[0058] In some embodiments, the boost circuit 303 is electrically connected to a filter capacitor CH. Because the APD uses a boost switching circuit to boost the voltage, the switching back and forth will generate significant noise, so a filter capacitor CH with a high voltage resistance is required for filtering. In the embodiments of the present application, due to the high response rate of the trigger signal, the value of the filter capacitor CH can be set to a large value to ensure that the APD achieves a high signal-to-noise ratio and sensitivity. Exemplarily, the filter capacitor is greater than 1NF.

[0059] According to the illumination characteristics of an avalanche photodiode, the photocurrent it generates is proportional to the intensity of the received light signal. When the light signal received by the APD is a burst of strong light, the photocurrent generated is relatively large. At the same time, as the transmission rate of the optical module increases, the optical module's ability to withstand strong light becomes worse, making it more likely to damage the photodetector when receiving a burst of strong light. For example, when the photocurrent generated by the photodetector exceeds the maximum current allowed by the photodetector die, the photodetector is damaged.

[0060] The circuit board 300 may include a sampling circuit 304 on its surface. One end of the sampling circuit 304 is electrically connected to the MCU 302 to receive a trigger signal from the MCU 302 when the host computer system is unable to issue a trigger signal. The other end of the sampling circuit 304 is electrically connected to the photodetector 501 to sample the light intensity received by the photodetector 501 based on the trigger signal. The sampling circuit 304 feeds the sampled light intensity back to the MCU 302.

[0061] The sampling circuit 304 is used to sample the light intensity received by the photodetector 501 according to the received trigger signal. The sampling circuit 304 feeds the sampled light intensity back to the MCU 302 in the form of an ADC value. The MCU 302 controls the bias voltage provided by the boost circuit 303 to the photodetector 501 according to the light intensity received.

[0062] In some embodiments, the optical modules may have different interrupt priorities for the MAC_Triger signal. This means that the timing of the interrupt triggering upon receiving the MAC_Triger signal by MCU 302 is not fixed, resulting in time deviations in the MCU 302 reading, which may result in different voltage values ​​being read at different times, reducing reading accuracy. Furthermore, because the ADC conversion module of MCU 302 requires a certain amount of time to perform signal conversion, the sampling circuit 304 in the present disclosure may be a sample-and-hold circuit. When the MAC_Triger signal experiences a falling edge, the hold circuit maintains the value sampled by the sampling circuit 304, ensuring relative sampling stability and the accuracy of the MCU 302 reading.

[0063] Because the optical signal at photodetector 501 is in burst reception mode, the host computer system must send a trigger signal to sampling circuit 304 to sample and report the received optical intensity of photodetector 501. The host computer's MAC chip issues a trigger signal, MAC_Triger, to specify the monitoring of the received optical power of a specific ONU optical module arriving at the OLT. When the host computer needs to monitor the received optical power of a particular optical packet, the MAC chip sends a trigger signal, MAC_Triger, to sampling circuit 304 via a gold finger.

[0064] Passive optical networks (PONs) have been widely deployed as optical access systems. PONs typically consist of an optical line terminal (OLT) located in the central office, multiple optical network units (ONUs) located at the user end, and an optical distribution network (ODN) located between them. After the OLT and ONUs are interconnected, the host computer system typically injects trigger signals into the optical packets of different ONUs to sample the corresponding ONU light intensity. This makes it impossible to monitor the APD's received light intensity in real time during the power-up phase of the OLT optical module and the initial phase after power-up.

[0065] When the OLT and ONU are interconnected, the host computer system sends a trigger signal to the sampling circuit 304 to trigger the sampling circuit 304 to sample the light reception intensity of the photodetector 501. Before the OLT and ONU are interconnected, the host computer system cannot send a trigger signal, and thus the sampling circuit 304 cannot receive the trigger signal from the host computer system.

[0066] In the present disclosure, when the host computer system is unable to send a trigger signal, the MCU 302 automatically sends a trigger signal through a control pin to sample the light receiving intensity of the photodetector 501 .

[0067] In some embodiments of the present disclosure, the interconnection between the OLT and the ONU may occur after the power-on of the photodetector 501 is completed. During the entire power-on process of the photodetector 501, the MCU provides a trigger signal to the sampling circuit 304 to sample the light receiving intensity of the photodetector 501.

[0068] When the bias voltage received by the photodetector 501 reaches the target bias voltage, that is, the normal operating voltage, the photocurrent multiplication coefficient of the photodetector 501 is large. Exemplarily, the photocurrent multiplication coefficient corresponding to the target bias voltage of the photodetector is compared to when the bias voltage is lower than the target bias voltage, and there is a sudden increase in the photocurrent multiplication coefficient. In some embodiments, when the photodetector 501 is powered on, if the photodetector 501 is powered on quickly, if a burst of strong light is received during the fast power-on process, the burst of strong light is still present, and the bias voltage of the photodetector 501 reaches the target bias voltage in a very short time, then the multiplied photocurrent is very large at this time, which can easily cause damage to the photodetector 501. Therefore, in the present disclosure, the photodetector 501 is powered on in a step-by-step manner.

[0069] In the present disclosure, a power-on high light protection mechanism is executed during the power-on process of the photodetector 501 to protect the photodetector 501 .

[0070] The power-on high-light protection mechanism of the photodetector includes: during the power-on process of the photodetector 501, the sampled light reception intensity is compared with the current intensity threshold before each step of the bias voltage. If the sampled light reception intensity is lower than the current intensity threshold, it means that there is no burst of strong light at this time, and the next step can be made; if the sampled light reception intensity is higher than the current intensity threshold, it means that a burst of strong light is received at this time, then the output of the current bias voltage is maintained, and sampling is continued until the sampled light reception intensity is lower than the current intensity threshold. Exemplarily, maintaining the bias voltage provided by the photodetector 501 at a relatively low bias voltage can be achieved by not stepping, or by taking a step amplitude that is smaller than the previous step amplitude.

[0071] In the present disclosure, when a sudden strong light burst is received, the bias voltage provided to the photodetector 501 is maintained at a relatively low bias voltage. Since the photocurrent multiplication factor of the photodetector is positively correlated with the bias voltage received by the photodetector, the photocurrent multiplication factor of the photodetector is relatively small. Therefore, even in the presence of a sudden strong light burst, the photocurrent generated does not exceed the maximum current allowed by the photodetector die, thereby protecting the photodetector 501.

[0072] In the present disclosure, when the sampled received light intensity exceeds the current intensity threshold, the bias voltage provided by the photodetector 501 is maintained at a relatively low bias voltage, and sampling is triggered. If the sampled received light intensity is still greater than the current intensity threshold after multiple sampling attempts, the stepping and triggering of sampling are stopped, and the current bias voltage is used as the final bias voltage of the photodetector 501. In other words, the final bias voltage is not determined by the target bias voltage, but is flexibly determined based on actual conditions.

[0073] The photodetector power-on high-light protection mechanism disclosed in the present invention can ensure that there is no sudden strong light with a large light intensity when each step of powering on the photodetector 501 is performed, thereby protecting the photodetector 501.

[0074] In the present disclosure, the photocurrent multiplication coefficient of the photodetector is positively correlated with the bias voltage received by the photodetector. As the bias voltage gradually increases during the stepping process, the photocurrent multiplication coefficient gradually increases, and the possibility of the photodetector 501 being damaged by sudden strong light becomes greater. For example, as the stepping progresses, strong light with a lower intensity may cause certain damage to the photodetector 501.

[0075] To this end, in some embodiments, the intensity threshold corresponding to each step can be set to a different intensity threshold. As the bias voltage stepping process proceeds, the intensity threshold can be appropriately gradually reduced to reduce the impact of strong light on the photodetector 501.

[0076] For example, if the sampled light intensity is greater than the current intensity threshold, no stepping is performed, or a smaller stepping amplitude is used than the previous stepping amplitude to maintain the bias voltage at a lower bias voltage. If the sampled light intensity is less than the current intensity threshold, stepping is continued.

[0077] In some embodiments, the intensity threshold corresponding to each step may also be set to the same intensity threshold. As the bias voltage stepping process proceeds, the amplitude of each step is gradually reduced to reduce the impact of strong light on the photodetector 501.

[0078] For example, if the sampled light intensity is greater than the current intensity threshold, no stepping is performed, or a smaller stepping amplitude is used than the previous stepping amplitude to maintain the bias voltage at a lower bias voltage. If the sampled light intensity is less than the current intensity threshold, stepping is continued. In this process, the stepping amplitude of each step is smaller than the previous stepping amplitude.

[0079] In the present disclosure, in order to avoid large intensity leaps and ensure the stability and safety of the steps, the intensity threshold during the power-on process can be set as follows: as the bias voltage stepping process proceeds, the intensity threshold gradually increases to a preset intensity threshold. The preset intensity threshold can be set to the light intensity corresponding to damage to the photodetector 501. The intensity threshold corresponding to each step can be set to a different intensity threshold: as the stepping process proceeds, the intensity threshold gradually increases from a smaller value to a preset intensity threshold. Fine stepping is used to avoid large intensity leaps. For example, if the sampled light intensity is greater than the current intensity threshold, the step amplitude is reduced, and the step amplitude is smaller than the previous step amplitude. If the sampled light intensity is less than the current intensity threshold, the bias voltage is increased according to the previous step amplitude.

[0080] In the present disclosure, the intensity threshold during the stepping process can also be set as a gradient intensity threshold. For example, the entire stepping process is divided into various stages, and a corresponding intensity threshold is selected for each stage, with the intensity threshold selected for each stage being different. The intensity threshold selected for each stage can be gradually increased to ensure the stability of the stepping. The intensity threshold selected for each stage can also be gradually decreased to avoid damage to the photodetector 501.

[0081] In the present disclosure, in some embodiments, the interconnection between the OLT and the ONU may occur at a certain moment during the power-on process of the photodetector 501. Therefore, before this moment, the host computer system cannot provide a trigger signal to the sampling circuit 304, and thus cannot monitor the light receiving intensity.

[0082] Based on this, the power-on process of photodetector 501 includes a first power-on process and a second power-on process. During the first power-on process of photodetector 501, the host computer system cannot provide a trigger signal to sampling circuit 304. Instead, the MCU provides the trigger signal to sampling circuit 304. During the second power-on process, the host computer system provides the trigger signal to the sampling circuit. The dividing point between the first and second power-on processes is the moment when the OLT and ONU are interconnected.

[0083] In the present disclosure, the sources of the trigger signals received by the sampling circuit of the photodetector 501 during the first and second power-up processes are different: the trigger signal for the sampling circuit 304 during the first power-up process is provided by the MCU 302, while the trigger signal for the sampling circuit 304 during the second power-up process is provided by the host computer system. The priority of the trigger signal source during the second power-up process is higher than the priority of the trigger signal source during the first power-up process, that is, the priority of the host computer system is higher than the priority of the MCU 302.

[0084] In some embodiments, the trigger signal for sampling circuit 304 during the first power-on process of photodetector 501 is provided by MCU 302, and the trigger signal for sampling circuit 304 during the second power-on process of photodetector 501 is provided by the host computer system. For ease of description, the trigger signal provided by the MCU to sampling circuit 304 during the first power-on process is referred to as the first trigger signal; the trigger signal provided by the host computer system to sampling circuit 304 during the second power-on process is referred to as the second trigger signal.

[0085] The host computer system has a higher priority than MCU 302. To avoid signal confusion between the first and second trigger signals, the MCU stops sending the first trigger signal to sampling circuit 304 during the second power-up process. Simultaneously, during the second power-up process of photodetector 501, the voltage output by the boost circuit is controlled to increase from the corresponding bias voltage at the end of the first power-up process to the target bias voltage, thereby completing the power-up of the photodetector. For example, the target bias voltage is the normal operating voltage of the photodetector.

[0086] In some embodiments, the power-on high-light protection mechanism can be exited during the second power-on process of the photodetector 501 to shorten the duration of the protection mechanism. In some embodiments, the power-on high-light protection mechanism can also continue to be executed during the second power-on process.

[0087] In the present disclosure, the sources of the trigger signals received by the sampling circuit in the first power-on process and the second power-on process of the photodetector 501 can also be: the trigger signal of the sampling circuit 304 in the first power-on process is provided by the MCU302, and the trigger signal of the sampling circuit 304 in the second power-on process is provided by the host computer system or the MCU302.

[0088] MCU 302 issues trigger signals more frequently than the host system, resulting in more uniform sampling intervals, thereby increasing sampling frequency and sampling uniformity. For example, if sampling circuit 304 receives trigger signals from both the host system and MCU 302 at the same moment, the trigger signals overlap, thereby enhancing the strength and sensitivity of the trigger signal. Alternatively, sampling circuit 304 selects a response to the trigger signal at this moment.

[0089] In the present disclosure, during the first power-on process of the photodetector 501, a high-light protection mechanism is implemented for the photodetector. The high-light protection mechanism for the photodetector includes the following steps: during the first power-on process of the photodetector 501, before each step of the bias voltage is made, the sampled received light intensity is compared with the current intensity threshold. If the sampled received light intensity is lower than the current intensity threshold, the next step can be made. If the sampled received light intensity is higher than the current intensity threshold, indicating that a burst of strong light has been received, the current bias voltage output is maintained, and no step is performed.

[0090] In the present disclosure, when a sudden strong light is received, the bias voltage provided to the photodetector is maintained at a relatively low bias voltage. Based on the fact that the photocurrent multiplication coefficient of the photodetector is positively correlated with the bias voltage received by the photodetector, the photocurrent multiplication coefficient of the photodetector is relatively small at this time. Even if there is a sudden strong light, the photocurrent generated at this time still does not exceed the maximum current allowed by the photodetector die, thereby protecting the photodetector.

[0091] The photodetector power-on high-light protection mechanism disclosed in the present invention can ensure that there is no sudden strong light when each step of powering on the photodetector is performed, thereby protecting the photodetector.

[0092] In the present disclosure, in the first power-on process, the photocurrent multiplication coefficient based on the photodetector is positively correlated with the bias voltage received by the photodetector. As the bias voltage gradually increases during the stepping process, the photocurrent multiplication coefficient gradually increases, and the possibility of the photodetector 501 being damaged by sudden strong light becomes greater. For example, as the stepping progresses, strong light with a lower intensity may cause certain damage to the photodetector 501.

[0093] To this end, in some embodiments, the intensity threshold corresponding to each step can be set to a different intensity threshold. As the bias voltage stepping process proceeds, the intensity threshold can be appropriately gradually reduced to reduce the impact of strong light on the photodetector 501.

[0094] For example, if the sampled light intensity is greater than the current intensity threshold, no stepping is performed, or a smaller stepping amplitude is used than the previous stepping amplitude to maintain the bias voltage at a lower bias voltage. If the sampled light intensity is less than the current intensity threshold, stepping is continued.

[0095] In some embodiments, the intensity threshold corresponding to each step may also be set to the same intensity threshold. As the bias voltage stepping process proceeds, the amplitude of each step is gradually reduced to reduce the impact of strong light on the photodetector 501.

[0096] For example, if the sampled light intensity is greater than the current intensity threshold, no stepping is performed, or a smaller stepping amplitude is used than the previous stepping amplitude to maintain the bias voltage at a lower bias voltage. If the sampled light intensity is less than the current intensity threshold, stepping is continued. In this process, the stepping amplitude of each step is smaller than the previous stepping amplitude.

[0097] In the present disclosure, in order to avoid a large intensity span and ensure the stability and safety of the step in the first power-on process, the intensity threshold in the power-on process can be set as follows: as the bias voltage step process proceeds, the intensity threshold gradually increases to a preset intensity threshold. The preset intensity threshold can be set to the light intensity corresponding to the damage to the photodetector 501. The intensity threshold corresponding to each step can be set to a different intensity threshold: as the step process proceeds, the intensity threshold gradually increases from a smaller value to a preset intensity threshold. Fine stepping is performed to avoid large intensity spans. For example, if the sampled light intensity is greater than the current intensity threshold, the step amplitude is reduced, and the step amplitude is smaller than the previous step amplitude. If the sampled light intensity is less than the current intensity threshold, the bias voltage is increased according to the previous step amplitude.

[0098] In the present disclosure, during the first power-on process, the intensity threshold during the stepping process can also be set as a gradient intensity threshold. For example, the entire stepping process is divided into various stages, each of which uses a corresponding intensity threshold, with the intensity thresholds selected for each stage being different. The intensity thresholds selected for each stage can be increased in a gradient to ensure the reliability of the stepping. The intensity thresholds used in each stage can also be decreased in a gradient to avoid damage to the photodetector 501.

[0099] Figure 7 Schematic diagram of the interaction between the MCU, photodetector, boost circuit, and sampling circuit in the first power-on process of a photodetector provided according to some embodiments of the present disclosure. Figure 7 As shown, in the first power-on process of the photodetector 501 , the sampling circuit 304 cannot receive the trigger signal sent by the host computer system.

[0100] In order to trigger the sampling circuit 304 to sample the light receiving intensity of the photodetector 501 during the first power-on process of the photodetector 501 , in the present disclosure, the MCU 302 automatically sends a trigger signal through a control pin.

[0101] The sampling circuit 304 samples the light receiving intensity of the photodetector 501 according to the trigger signal provided by the MCU, and determines whether to perform the next step of bias voltage stepping according to the relationship between the sampled light receiving intensity and the current intensity threshold.

[0102] During the first power-up process of the photodetector 501, a high-light protection mechanism is activated. This mechanism includes comparing the sampled received light intensity with a current intensity threshold before each bias voltage step. If the sampled received light intensity is lower than the current intensity threshold, indicating no strong light burst, the next step can be performed. If the sampled received light intensity is higher than the current intensity threshold, indicating a strong light burst, the current bias voltage output is maintained, no step is performed, and sampling continues.

[0103] In some embodiments, the sampling circuit 304 samples the light receiving intensity of the photodetector 501 according to the trigger signal provided by the MCU, and feeds the sampled light receiving intensity back to the MCU 302. The MCU 302 compares the current light receiving intensity with the current intensity threshold.

[0104] If the sampled light reception intensity is lower than the current intensity threshold, the MCU 302 controls the boost circuit 303 to step the bias voltage. For example, the MCU 302 controls the boost circuit 303 to output a first bias voltage to the photodetector 501 .

[0105] If the sampled received light intensity is higher than the current intensity threshold, the MCU 302 controls the boost circuit 303 to maintain the current bias voltage output without stepping, keeping it at a relatively low bias voltage. At the same time, the next sampling of the received light intensity is triggered. Until the sampled received light intensity is lower than the current intensity threshold, the MCU 302 controls the boost circuit 303 to step the bias voltage. For example, at this time, the MCU 302 controls the boost circuit 303 to output a second bias voltage to the photodetector 501. The second bias voltage is greater than the first bias voltage, i.e., the bias voltage is stepped from the first bias voltage to the second bias voltage.

[0106] The present disclosure starts the high-light protection mechanism for the photodetector during the first power-on process of the photodetector 501, and compares the sampled light reception intensity with the intensity threshold before each step of the bias voltage. This ensures that there is no sudden strong light when each step of the photodetector is powered on, thereby protecting the photodetector 501.

[0107] The photocurrent multiplication factor of the photodetector is positively correlated with the bias voltage received by the photodetector. When the bias voltage output to the photodetector 501 is maintained at a relatively low voltage, the photocurrent multiplication factor is relatively small. Even in the presence of a sudden strong light burst, the photocurrent generated at this time still does not exceed the maximum current allowed by the photodetector die, thereby protecting the photodetector. The photocurrent multiplication factor of the photodetector 501 in the first power-up process is smaller than the photocurrent multiplication factor of the photodetector 501 in the second power-up process. This also provides the possibility of activating the power-up high light protection mechanism in the first power-up process of the present disclosure. As mentioned above, when the bias voltage received by the photodetector 501 reaches the target bias voltage, that is, the normal operating voltage, the photocurrent multiplication factor of the photodetector 501 is large. For example, the photocurrent multiplication factor corresponding to the target bias voltage of the photodetector has a sudden increase in the photocurrent multiplication factor. When the bias voltage of the photodetector is lower than the target bias voltage, the photocurrent multiplication factor of the photodetector 501 is relatively low. For example, if the photocurrent multiplication factor corresponding to the target bias voltage of the photodetector is 10, and the photocurrent generated by photodetector 501 is 1 uA, based on the multiplication effect, the photocurrent ultimately generated by photodetector 501 is 10 uA. If the bias voltage of the photodetector is lower than the target bias voltage, the corresponding photocurrent multiplication factor is assumed to be 5. If the photocurrent generated by photodetector 501 is 1 uA, based on the multiplication effect, the photocurrent ultimately generated by photodetector 501 is 5 uA.

[0108] Exemplarily, when the first power-on process of the photodetector 501 ends, the corresponding bias voltage generates a larger photocurrent multiplication effect, and the photocurrent multiplication coefficient of the photodetector 501 is relatively low.

[0109] During the first power-up of the photodetector 501, if the bias voltage of the photodetector 501 is increased in a step-by-step manner, i.e., if the power is turned on in a step-by-step manner, the photocurrent multiplication factor is relatively low. Therefore, even in the presence of a sudden strong light burst, the generated photocurrent does not exceed the maximum current allowed by the photodetector die, thereby preventing damage to the photodetector. This is also a self-protection mechanism of the photodetector 501. However, if the photodetector 501 is powered on quickly, the sudden strong light burst can easily damage the photodetector.

[0110] In the present disclosure, when the sampled light reception intensity is higher than an intensity threshold, an alarm mechanism may be activated.

[0111] In the present disclosure, the MCU 302 automatically sending the first trigger signal through the control pin may include:

[0112] The MCU 302 may include a trigger signal output pin, which is used to send a trigger signal to the sampling circuit 304 .

[0113] The MCU 302 sends a high-level trigger signal to the sampling circuit 304 through the trigger signal output pin to trigger the sampling circuit 304 to perform sampling.

[0114] The MCU 302 sends a low-level trigger signal to the sampling circuit 304 through the trigger signal output pin to trigger the sampling circuit 304 to stop sampling.

[0115] In some embodiments, the trigger signal output pin may be a multiplexed pin. MCU 302 assigns a multiplexed function to the multiplexed pin, namely, a function of issuing a first trigger signal, to send a first trigger signal to sampling circuit 304 to trigger sampling circuit 304 to sample the light receiving intensity of photodetector 501.

[0116] For example, the MCU 302 may control the pin to send the first trigger signal three times, and each triggering samples the current light receiving intensity, and averages the three samples to obtain the light receiving intensity.

[0117] Figure 8 Schematic diagram of the interaction between the MCU, photodetector, boost circuit, and sampling circuit in the second power-on process of a photodetector according to some embodiments of the present disclosure. Figure 8 As shown, in the second power-on process of the photodetector 501 , the trigger signal received by the sampling circuit 304 comes from the host computer system, that is, the trigger signal received by the sampling circuit 304 at this time is the second trigger signal.

[0118] In some embodiments, since the priority of the host computer system is higher than that of the MCU 302 , and in order to avoid signal confusion, the MCU 302 no longer sends a trigger signal to the sampling circuit 304 in the second power-on process.

[0119] In some embodiments, MCU 302 still sends a trigger signal to sampling circuit 304 during the second power-on process. During the second power-on process, sampling circuit 304 receives trigger signals from both the host system and MCU 302. MCU 302 sends trigger signals more frequently than the host system, resulting in more uniform sampling intervals, thereby increasing sampling frequency and sampling uniformity.

[0120] For example, if the sampling circuit 304 receives trigger signals from the host system and the MCU 302 at the same time, the trigger signals are superimposed at this moment, thereby enhancing the strength and sensitivity of the trigger signal. Alternatively, at this moment, the sampling circuit 304 responds to the trigger signal.

[0121] The sampling circuit 304 samples the light receiving intensity of the photodetector 501 according to the second trigger signal, and feeds the sampled light receiving intensity back to the MCU 302 .

[0122] MCU 302 controls the output of boost circuit 303 based on the received light intensity feedback. When the sampled received light intensity exceeds the intensity threshold, indicating the presence of a strong light burst, boost circuit 303 is controlled to maintain the current bias voltage output and temporarily stop boosting the voltage. The boost circuit 303 can be controlled to increase the voltage again when the strong light disappears.

[0123] In the present disclosure, during the second power-on process of the photodetector 501, the MCU 302 can control the boost circuit 303 to directly increase the bias voltage from the bias voltage corresponding to the first power-on process to the target bias voltage, that is, without stepping. Alternatively, the boost circuit 303 can be controlled to step the bias voltage from the bias voltage corresponding to the first power-on process to the target bias voltage. During the stepping process, the photodetector's power-on high-light protection mechanism can be disabled to shorten the protection mechanism's operation time. Of course, the photodetector's power-on high-light protection mechanism can also be activated during the stepping process.

[0124] In the present disclosure, based on the above embodiments, a method for protecting a photodetector from excessive light is further provided. In some embodiments, the method may include:

[0125] controlling the boost circuit to increase the bias voltage provided to the photodetector in a step-by-step manner;

[0126] Before each step, the MCU sends a trigger signal to the sampling circuit to trigger the sampling circuit to sample the light receiving intensity of the photodetector;

[0127] If the sampled light receiving intensity is lower than the current intensity threshold, the next step is executed; if the sampled light receiving intensity is higher than the current intensity threshold, the current bias voltage is maintained and the sampling circuit is continuously triggered to sample the light receiving intensity of the photodetector.

[0128] In some embodiments, during the entire power-on process of the photodetector 501 , the MCU provides a trigger signal to the sampling circuit 304 .

[0129] In some embodiments, the power-on process of the photodetector 501 includes a first power-on process and a second power-on process. During the first power-on process of the photodetector 501, the host computer system cannot provide a trigger signal to the sampling circuit 304. Instead, the trigger signal is provided to the sampling circuit 304 via the MCU. During the second power-on process, the host computer system provides a trigger signal to the sampling circuit 304. Of course, the MCU can also provide a trigger signal to the sampling circuit 304 during the second power-on process. The dividing point between the first and second power-on processes is the moment when the OLT and ONU are interconnected.

[0130] In the present disclosure, the sources of the trigger signals received by the sampling circuit in the first power-on process and the second power-on process of the photodetector 501 are different: the trigger signal of the sampling circuit 304 in the first power-on process is provided by the MCU302, and the trigger signal of the sampling circuit 304 in the second power-on process is provided by the host computer system.

[0131] In the present disclosure, the sources of the trigger signals received by the sampling circuit in the first power-on process and the second power-on process of the photodetector 501 are respectively: the trigger signal of the sampling circuit 304 in the first power-on process is provided by the MCU302, and the trigger signal of the sampling circuit 304 in the second power-on process is provided by the host computer system or the MCU302.

[0132] In some embodiments, when the power-on process of the photodetector 501 includes a first power-on process and a second power-on process, the photodetector power-on high-light protection method may include:

[0133] In a first power-on process, controlling the boost circuit to increase the bias voltage provided to the photodetector in a step-by-step manner;

[0134] Before each step, a trigger signal is sent to the sampling circuit to trigger the sampling circuit to sample the light receiving intensity of the photodetector;

[0135] If the sampled light receiving intensity is lower than the current intensity threshold, the next step is executed; if the sampled light receiving intensity is higher than the current intensity threshold, the current bias voltage is maintained and the sampling circuit is continuously triggered to sample the light receiving intensity of the photodetector;

[0136] In the second power-on process, the trigger signal is stopped from being provided to the sampling circuit, and the voltage output by the boost circuit is controlled to increase from the bias voltage corresponding to the end of the first power-on process to the target bias voltage.

[0137] Illustratively, in the second power-on process, the MCU may still provide a trigger signal to the sampling circuit.

[0138] Figure 9 Schematic diagram of a light protection mechanism for a photodetector according to some embodiments of the present disclosure Figure 1 . Figure 9 The embodiment shown is only one embodiment of the present disclosure. Figure 9 As shown, taking the power-on process of the photodetector including the first power-on process and the second power-on process as an example, the technical concepts of the power-on process of the photodetector can respectively include:

[0139] S110: In the first power-on process, controlling the boost circuit to increase the bias voltage provided to the photodetector in a step-by-step manner.

[0140] In the present disclosure, the power-on process of the photodetector 501 includes a first power-on process and a second power-on process. In the first power-on process of the photodetector 501, the host computer system cannot send a trigger signal to the sampling circuit.

[0141] In the present disclosure, during the first power-on process of the photodetector 501, the MCU sends a trigger signal to the sampling circuit. The trigger signals received by the sampling circuit during the first and second power-on processes of the photodetector 501 have different sources: the trigger signal during the first power-on process is sent by the MCU 302, while the trigger signal during the second power-on process is sent by the host computer system.

[0142] When the bias voltage received by the photodetector 501 reaches the target bias voltage, that is, the normal operating voltage, the photocurrent multiplication factor of the photodetector 501 is large. Exemplarily, the photocurrent multiplication factor corresponding to the target bias voltage of the photodetector has a sudden increase in the photocurrent multiplication factor compared to when it is lower than the target bias voltage. In some embodiments, when the photodetector 501 is powered on, if the photodetector 501 is powered on quickly, if a burst of strong light is received during the fast power-on process, the burst of strong light is still present, and the bias voltage of the photodetector 501 reaches the target bias voltage in a very short time, then the multiplied photocurrent is very large at this time, which can easily cause damage to the photodetector 501. Therefore, in the present disclosure, the photodetector 501 is powered on in a step-by-step manner.

[0143] S120: Sending a trigger signal to the sampling circuit before each step to trigger the sampling circuit to sample the light receiving intensity of the photodetector.

[0144] The photodetector power-on high-light protection mechanism provided in the present disclosure is a comprehensive mechanism. Before each step, it is judged whether there is a sudden strong light. The bias voltage is stepped only when there is no sudden strong light. In the present disclosure, there is a judgment on whether there is a sudden strong light between two adjacent steps, and the step is performed only when there is no sudden strong light. Whenever there is a sudden strong light, the step is not performed. The present disclosure is different from the judgment on whether there is a sudden strong light during the stepping process, because the stepping process may be a judgment on the sudden strong light after a certain step is completed, which is not equivalent to "each step" in the present disclosure.

[0145] In the present disclosure, after each step is completed, the next step is tentatively performed, that is, the bias voltage is stepped only when there is no sudden strong light; when there is a sudden strong light, the output of the current bias voltage is maintained without stepping, and the current bias voltage is maintained at a relatively low voltage.

[0146] The photodetector power-on high-light protection mechanism disclosed in the present invention can ensure that there is no sudden strong light when each step of powering on the photodetector is performed, thereby protecting the photodetector.

[0147] S130: If the sampled light receiving intensity is lower than the current intensity threshold, the next step is executed; if the sampled light receiving intensity is higher than the current intensity threshold, the current bias voltage is maintained and the sampling circuit is continuously triggered to sample the light receiving intensity of the photodetector.

[0148] In some embodiments, sampling circuit 304 samples the light reception intensity of photodetector 501 based on the first trigger signal and feeds the sampled light reception intensity back to MCU 302. MCU 302 compares the current light reception intensity with a threshold. If the sampled light reception intensity is lower than the current intensity threshold, MCU 302 controls boost circuit 303 to step the bias voltage. For example, MCU 302 controls boost circuit 303 to output a first bias voltage to photodetector 501.

[0149] If the sampled received light intensity is higher than the current intensity threshold, the MCU 302 controls the boost circuit 303 to maintain the current bias voltage output without stepping, keeping it at a relatively low bias voltage. At the same time, the next sampling of the received light intensity is triggered. Until the sampled received light intensity is lower than the current intensity threshold, the MCU 302 controls the boost circuit 303 to step the bias voltage. For example, at this time, the MCU 302 controls the boost circuit 303 to output a second bias voltage to the photodetector 501. The second bias voltage is greater than the first bias voltage, i.e., the bias voltage is stepped from the first bias voltage to the second bias voltage.

[0150] S140: In the second power-on process, stop sending the trigger signal to the sampling circuit, and control the voltage output by the boost circuit to increase from the bias voltage corresponding to the end of the first power-on process to the target bias voltage.

[0151] The host computer system has a higher priority than MCU 302. To avoid signal confusion between the first and second trigger signals, MCU 302 stops sending the first trigger signal to sampling circuit 304 during the second power-up process. Simultaneously, during the second power-up process of photodetector 501, the voltage output by the boost circuit is controlled to increase from the corresponding bias voltage at the end of the first power-up process to the target bias voltage, thereby completing the power-up of the photodetector. For example, the target bias voltage is the normal operating voltage of the photodetector.

[0152] In the present disclosure, the photodetector power-on high-light protection mechanism of the present disclosure can ensure that there is no sudden strong light when each step of powering on the photodetector is performed, thereby protecting the photodetector.

[0153] Figure 10 Schematic diagram of a light protection mechanism for a photodetector according to some embodiments of the present disclosure Figure 2 .like Figure 10 As shown, specific embodiments of the power-on process of the photodetector may include:

[0154] S210: In a first power-on process, controlling the boost circuit to output a first bias voltage to the photodetector, and sending a trigger signal to the sampling circuit to trigger the sampling circuit to sample the light receiving intensity of the photodetector.

[0155] Exemplarily, at this time, the first bias voltage is relatively low.

[0156] The MCU 302 sends a trigger signal to the sampling circuit 304 via a control pin to trigger the sampling circuit 304 to sample the light receiving intensity of the photodetector 501 .

[0157] MCU 302 may include a trigger signal output pin. The trigger signal output pin is used to send a trigger signal to sampling circuit 304. MCU 302 sends a high-level trigger signal to sampling circuit 304 via the trigger signal output pin to trigger sampling circuit 304 to start sampling. MCU 302 also sends a low-level trigger signal to sampling circuit 304 via the trigger signal output pin to trigger sampling circuit 304 to stop sampling.

[0158] In some embodiments, the trigger signal output pin may be a multiplexed pin. MCU 302 assigns a multiplexed function to the multiplexed pin, namely, a function of issuing a first trigger signal, to send a first trigger signal to sampling circuit 304 to trigger sampling circuit 304 to sample the light receiving intensity of photodetector 501.

[0159] S220: If the sampled light reception intensity is lower than the intensity threshold, control the boost circuit to output a second bias voltage to the photodetector; wherein the second bias voltage is greater than the first bias voltage.

[0160] Before each step of the bias voltage, the sampled received light intensity is compared with the current intensity threshold. If the sampled received light intensity is lower than the current intensity threshold, indicating that there is no burst of strong light, the next step can be performed: the boost circuit 303 is controlled to output a second bias voltage to the photodetector 501. The second bias voltage is obtained by stepping the first bias voltage by a certain step value. For example, the step value is a positive value.

[0161] S230: If the sampled light receiving intensity is higher than the intensity threshold, control the boost circuit to maintain outputting the first bias voltage, and trigger the sampling circuit again to sample the light receiving intensity of the photodetector.

[0162] If the sampled light receiving intensity is higher than the current intensity threshold, it means that a burst of strong light is received at this time, and the boost circuit is controlled to maintain the output of the first bias voltage, that is, maintain the output of the current bias voltage without performing stepping.

[0163] In the present disclosure, when a sudden strong light is received, the bias voltage provided to the photodetector is maintained at a relatively low bias voltage. Based on the fact that the photocurrent multiplication coefficient of the photodetector is positively correlated with the bias voltage received by the photodetector, the photocurrent multiplication coefficient of the photodetector is relatively small at this time. Even if there is a sudden strong light, the photocurrent generated at this time still does not exceed the maximum current allowed by the photodetector die, thereby protecting the photodetector.

[0164] S240: Continue to trigger the sampling circuit to sample the light receiving intensity of the photodetector until the boost circuit is controlled to output a preset voltage to the photodetector; the preset voltage is greater than the second bias voltage.

[0165] The sampling circuit 304 is continuously triggered to sample the light receiving intensity of the photodetector 501 until the boost circuit is controlled to output a preset voltage to the photodetector, which is greater than the second bias voltage.

[0166] When the photodetector's power-on protection mechanism runs for a long time, it affects the light-emitting time of the optical module. Therefore, in the present disclosure, when the boost circuit 303 outputs a preset voltage to the photodetector 501, the power-on protection mechanism of the photodetector is exited, thereby shortening the protection mechanism's operation time.

[0167] For example, the preset voltage is half of the target bias voltage, i.e., the normal operating voltage. If the normal operating voltage of the photodetector 501 needs to reach 40V, then when the boost circuit 303 is controlled to output a voltage of 20V to the photodetector 501, the photodetector power-on protection mechanism is no longer executed.

[0168] S250: In the second power-on process, stop sending the trigger signal to the sampling circuit, and control the voltage output by the boost circuit to increase from the preset voltage to the target bias voltage.

[0169] In the second power-on process of the photodetector 501 , the MCU 302 no longer sends the first trigger signal to the sampling circuit 304 .

[0170] The sampling circuit 304 receives a second trigger signal from the host computer system, samples the light reception intensity of the photodetector 501 according to the second trigger signal, and controls the boost circuit 303 to increase the voltage from a preset voltage to a target bias voltage.

[0171] For example, the preset voltage is half of the target bias voltage, that is, the normal operating voltage. If the normal operating voltage of the photodetector 501 needs to reach 40V, the preset voltage is 20V. The MCU 302 controls the boost circuit 303 to increase the voltage from 20V to 40V.

[0172] The boost circuit 303 can increase the bias voltage from 20V to 40V directly or in a step-by-step manner.

[0173] In the present disclosure, the photodetector power-on high-light protection mechanism of the present disclosure can ensure that there is no sudden strong light when each step of powering on the photodetector is performed, thereby protecting the photodetector.

[0174] In some embodiments of the present disclosure, the MCU 302 controls the boost circuit 303 to output a minimum voltage value to the photodetector 501. For example, the minimum voltage value may be 0V.

[0175] The MCU 302 sends the first trigger signal three times to the sampling circuit 304 via the control pin, and each triggering samples the current light receiving intensity. The light receiving intensity is obtained by averaging the three samples.

[0176] If the sampled received light intensity exceeds the current intensity threshold, an alarm is reported, the current minimum voltage output is maintained, and the first trigger signal is sent three times to sampling circuit 304 via the control pin. Each triggering step samples the current received light intensity. The three samples are averaged to obtain the received light intensity. If the received light intensity falls below the current intensity threshold, the alarm is cleared and boost circuit 303 is controlled to step from the minimum voltage value to 1 / 3 of the target bias voltage.

[0177] If the sampled light reception intensity is directly lower than the current intensity threshold, the voltage boost circuit 303 is controlled to step from the minimum voltage value to 1 / 3 of the target bias voltage.

[0178] The MCU 302 continues to send the first trigger signal three times to the sampling circuit 304 via the control pin, and each triggering samples the current light receiving intensity. The light receiving intensity is obtained by averaging the three samples.

[0179] If the sampled received light intensity exceeds the current intensity threshold, an alarm is reported, and the boost circuit 303 is controlled to maintain the output at 1 / 3 of the target bias voltage. The first trigger signal is then sent three more times to the sampling circuit 304 via the control pin, with each trigger sampling the current received light intensity. The three samples are averaged to obtain the received light intensity. If the received light intensity falls below the current intensity threshold, the alarm is cleared, and the boost circuit 303 is controlled to step up from 1 / 3 to 1 / 2 of the target bias voltage.

[0180] If the sampled light reception intensity is directly lower than the current intensity threshold, the voltage boost circuit 303 is controlled to step from 1 / 3 of the target bias voltage to 1 / 2 of the target bias voltage.

[0181] When the bias voltage provided to the photodetector 501 reaches 1 / 2 of the target bias voltage, the current protection algorithm ends and the boost circuit 303 is controlled to increase the voltage from 1 / 2 of the target bias voltage to the target bias voltage. For example, the boost circuit 303 may be controlled to increase the voltage from 1 / 2 of the target bias voltage to the target bias voltage in one step, rather than in a stepwise manner.

[0182] As can be seen, in the present disclosure, the power-on process of the photodetector 501 includes a first power-on process and a second power-on process. During the first power-on process, a bias voltage corresponding to a preset voltage is provided to the photodetector 501 in steps from a minimum voltage value. At the end of the first power-on process, the bias voltage corresponding to the preset voltage provided to the photodetector 501 can provide the photodetector 501 with a voltage value corresponding to half of the target bias voltage. Furthermore, during the first power-on process, the photodetector power-on high-light protection mechanism is activated. During the second power-on process, the target bias voltage is provided to the photodetector 501 from the preset voltage. After the first and second power-on processes, the power-on of the photodetector 501 is complete.

[0183] In the present disclosure, during the power-on process of the photodetector, the MCU sends a trigger signal to the sampling circuit, and during the power-on process of the photodetector, a high-light protection mechanism for the photodetector is executed.

[0184] The high-light protection mechanism on the photodetector includes: before each step of the bias voltage, the sampled light reception intensity is compared with the current intensity threshold. If the sampled light reception intensity is lower than the current intensity threshold, the next step can be made; if the sampled light reception intensity is higher than the current intensity threshold, the output of the current bias voltage is maintained, no step is performed, and the sampling is continued. In the present disclosure, when the sampled light reception intensity is higher than the current intensity threshold, it means that a burst of strong light is received, and the bias voltage provided to the photodetector is maintained at a relatively low bias voltage. Based on the positive correlation between the photocurrent multiplication factor of the photodetector and the bias voltage received by the photodetector, the photocurrent multiplication factor of the photodetector is relatively small at this time. Even if there is a burst of strong light, the photocurrent generated at this time still does not exceed the maximum current allowed by the photodetector die, thereby protecting the photodetector.

[0185] The photodetector power-on high-light protection mechanism disclosed in the present invention can ensure that there is no sudden strong light when each step of powering on the photodetector is performed, thereby protecting the photodetector.

[0186] The above description is merely a specific embodiment of the present disclosure, but the scope of protection of the present disclosure is not limited thereto. Any changes or substitutions that a person skilled in the art can conceive within the technical scope disclosed in the present disclosure should be included within the scope of protection of the present disclosure. Therefore, the scope of protection of the present disclosure should be based on the scope of protection of the claims.

Claims

1. An optical module, characterized in that: include: circuit boards; a photodetector, electrically connected to the circuit board, and configured to convert a received light signal into a photocurrent signal; The photocurrent multiplication factor of the photodetector is positively correlated with the bias voltage received by the photodetector; a boost circuit, electrically connected to the photodetector, and configured to provide a bias voltage for the photodetector; a sampling circuit, electrically connected to the photodetector, and configured to sample the light receiving intensity of the photodetector according to a received trigger signal; When the boost circuit provides the bias voltage to the photodetector, the MCU provides the trigger signal when no trigger signal is received; The MCU is electrically connected to the boost circuit and the sampling circuit respectively, and is configured as follows: controlling the boost circuit to increase the bias voltage provided to the photodetector in a step-by-step manner; before each step, sending a trigger signal to the sampling circuit to trigger the sampling circuit to sample the light receiving intensity of the photodetector; If the sampled light receiving intensity is lower than the current intensity threshold, the next step is executed; if the sampled light receiving intensity is higher than the current intensity threshold, the current bias voltage is maintained and the sampling circuit is continuously triggered to sample the light receiving intensity of the photodetector.

2. The optical module according to claim 1, wherein During the power-on process of the photodetector, the trigger signal of the sampling circuit comes from the MCU.

3. The optical module according to claim 1, wherein: The power-on process of the photodetector includes a first power-on process and a second power-on process; the trigger signal sources in the first power-on process and the second power-on process are different; During the first power-on process, the sampling circuit receives a trigger signal from the MCU; In the second power-on process, the trigger signal received by the sampling circuit comes from a signal source with a higher priority than that of the MCU.

4. The optical module according to claim 1, wherein: The power-on process of the photodetector includes a first power-on process and a second power-on process; the trigger signal sources in the first power-on process and the second power-on process are different; During the first power-on process, the sampling circuit receives a trigger signal from the MCU; In the second power-on process, the trigger signal received by the sampling circuit comes from the MCU, or a signal source with a higher priority than that of the MCU.

5. The optical module according to claim 1, wherein: In the process of controlling the boost circuit to increase the bias voltage provided to the photodetector in a step-by-step manner, each step corresponds to a different intensity threshold.

6. An optical module, characterized in that: include: circuit boards; A photodetector electrically connected to the circuit board, configured to convert a received optical signal into a photocurrent signal; wherein the power-on process of the photodetector includes a first power-on process and a second power-on process; a boost circuit, electrically connected to the photodetector, and configured to provide a bias voltage for the photodetector; a sampling circuit electrically connected to the photodetector, and configured to sample the light reception intensity of the photodetector according to a received trigger signal; in the first power-on process, the trigger signal is derived from the MCU; The MCU is electrically connected to the boost circuit and the sampling circuit respectively, and is configured as follows: In the first power-on process, controlling the boost circuit to increase the bias voltage provided to the photodetector in a step-by-step manner; before each step, sending a trigger signal to the sampling circuit to trigger the sampling circuit to sample the light receiving intensity of the photodetector; If the sampled light receiving intensity is lower than the current intensity threshold, the next step is performed; if the sampled light receiving intensity is higher than the current intensity threshold, the current bias voltage is maintained and the sampling circuit is continuously triggered to sample the light receiving intensity of the photodetector; In the second power-on process, the voltage output by the boost circuit is controlled to increase from the bias voltage corresponding to the end of the first power-on process to the target bias voltage.

7. The optical module according to claim 6, wherein: In the second power-on process, the trigger signal received by the sampling circuit comes from the MCU, or a signal source with a higher priority than that of the MCU.

8. The optical module according to claim 6, wherein: The priority of the trigger signal source in the second power-on process is higher than the priority of the trigger signal source in the first power-on process.

9. The optical module according to claim 6, wherein: In the process of controlling the boost circuit to increase the bias voltage provided to the photodetector in a step-by-step manner, each step corresponds to a different intensity threshold.

10. The optical module according to claim 6, wherein: When the first power-on process ends, the corresponding bias voltage is set to half of the target bias voltage.

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