Optical module

Abstract

The invention provides an optical module which comprises a circuit board, a laser, a bias circuit, a power supply circuit, a voltage detection circuit and an MCU, the bias circuit, the power supply circuit, the voltage detection circuit and the MCU are located on the circuit board, the laser comprises a light-emitting area connected with the bias circuit and an electric absorption modulation area connected with the power supply circuit, and the bias circuit provides bias current for the light-emitting area. The power supply circuit supplies power to the electric absorption modulation area; the voltage detection circuit is connected with the electric absorption modulation area so as to detect the voltage of the electric absorption modulation area and convert the voltage into current; the MCU is connected with the first end of the power supply circuit, the MCU is connected with the voltage detection circuit, the MCU collects the current output by the voltage detection circuit, and the MCU adjusts the voltage output by the power supply circuit according to the current so as to reduce the voltage of the electric absorption modulation area. According to the invention, the output voltage of the power supply circuit is adjusted according to the change of the voltage of the electro-absorption modulation region, so that the emergent light power of the electro-absorption modulation region is adjusted, and the emergent light power loss caused by aging of the electro-absorption modulation region is compensated.

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 application models such as cloud computing, mobile Internet, and video, the development and progress of optical communication technology has become increasingly important. In optical communication technology, optical modules are tools for converting optical and electrical signals and are one of the key components in optical communication equipment.

[0003] The lasers inside the optical module include directly modulated lasers and externally modulated lasers. Since directly modulated lasers are not suitable for long-distance and high-speed communication transmission, externally modulated lasers are usually used in long-distance optical communication transmission or high-speed optical communication transmission. For example, the more common electro-absorption modulated laser (EML) is used. The optical power detection circuit of EML usually needs to add a monitor photodiode (Monitor PD Chip, MPD) in the optical transmitter optical subassembly (TOSA) to sample the backlight current, and then convert the current into a positive voltage through a conversion circuit to the MCU for voltage sampling. The MCU monitors the optical power by monitoring the voltage.

[0004] However, when using the MPD method to sample the backlight current, the relative position of the MPD and the distributed feedback laser diode (DFB LD) in the EML laser determines the ratio of the output light power after collection. Since these are two devices, their relative position is easily affected by parameters such as temperature and changes, which causes the ratio of the backlight collected by the MPD to change, resulting in inaccurate monitoring and affecting the monitoring accuracy of the output light power. Summary of the invention

[0005] The disclosed embodiment provides an optical module to realize automatic power control of an EML laser and improve the monitoring accuracy of the output optical power of the EML laser.

[0006] In a first aspect, the present disclosure provides an optical module, comprising:

[0007] Circuit boards;

[0008] A laser, electrically connected to the circuit board, the laser comprising a light emitting region and an electric absorption modulation region, and the laser is used to emit an optical signal;

[0009] A bias circuit is mounted on the circuit board, the bias circuit is connected to the light-emitting area, and the bias circuit is used to provide a bias current for the light-emitting area to make the light-emitting area emit light;

[0010] A power supply circuit is installed on the circuit board, the power supply circuit is connected to the electro-absorption modulation area, and the power supply circuit is used to supply power to the electro-absorption modulation area;

[0011] A voltage detection circuit is installed on the circuit board, the voltage detection circuit is connected to the electro-absorption modulation area, and the voltage detection circuit is used to detect the voltage of the electro-absorption modulation area and convert the voltage into current;

[0012] An MCU is installed on the circuit board, wherein a first end of the MCU is connected to a first end of the power supply circuit, and a second end of the MCU is connected to the voltage detection circuit. The MCU is used to collect the current output by the voltage detection circuit, and adjust the voltage output by the power supply circuit according to the current to reduce the voltage in the electro-absorption modulation area.

[0013] In a second aspect, the present disclosure provides an optical module, including:

[0014] Circuit boards;

[0015] A laser, electrically connected to the circuit board, the laser comprising a light emitting region and an electric absorption modulation region, and the laser is used to emit an optical signal;

[0016] A bias circuit is mounted on the circuit board, the bias circuit is connected to the light-emitting area, and the bias circuit is used to provide a bias current for the light-emitting area to make the light-emitting area emit light;

[0017] A power supply circuit is installed on the circuit board, the power supply circuit is connected to the electro-absorption modulation area, and the power supply circuit is used to supply power to the electro-absorption modulation area;

[0018] A voltage detection circuit is installed on the circuit board, the voltage detection circuit is connected to the electro-absorption modulation area, and the voltage detection circuit is used to detect the voltage of the electro-absorption modulation area;

[0019] An MCU is installed on the circuit board, a first end of the MCU is connected to a first end of the power supply circuit, a second end of the MCU is connected to the voltage detection circuit, and the MCU is used to collect the voltage output by the voltage detection circuit, and adjust the voltage output by the power supply circuit according to the voltage to reduce the voltage in the electro-absorption modulation area.

[0020] It can be seen from the above embodiments that the optical module provided by the embodiments of the present disclosure includes a circuit board, a laser, and a bias circuit, a power supply circuit, a voltage detection circuit and an MCU installed on the circuit board. The laser is electrically connected to the circuit board. The laser includes a light-emitting area and an electro-absorption modulation area. The bias circuit is connected to the light-emitting area. The bias circuit is used to provide a bias current to the light-emitting area so that the light-emitting area emits light; the power supply circuit is connected to the electro-absorption modulation area. The power supply circuit is used to supply power to the electro-absorption modulation area so that the electro-absorption modulation area modulates the light emitted by the light-emitting area according to the data signal to obtain a modulated light signal; the voltage detection circuit is connected to the electro-absorption modulation area. The voltage detection circuit is used to detect the voltage of the electro-absorption modulation area and convert the voltage into a current; the first end of the MCU is connected to the first end of the power supply circuit to control the voltage output by the power supply circuit through the MCU; the second end of the MCU is connected to the voltage detection circuit to monitor the voltage of the electro-absorption modulation area through the voltage detection circuit; the MCU is used to collect the current output by the voltage detection circuit, and the current is positively correlated with the voltage of the electro-absorption modulation area. When the electro-absorption modulation area of ​​the laser is not aged That is, when the internal resistance of the electro-absorption modulation zone does not increase, when the modulation voltage output by the power supply circuit remains unchanged, the voltage of the electro-absorption modulation zone remains unchanged, and the current output by the voltage detection circuit collected by the MCU is also stable and unchanged. When the electro-absorption modulation zone ages, that is, when the internal resistance of the electro-absorption modulation zone increases, the voltage division of the electro-absorption modulation zone increases, and the electro-absorption modulation zone absorbs more light emitted by the light-emitting zone. When the modulation voltage output by the power supply circuit remains unchanged, the light output power of the absorption modulation zone is less than the light output power of the light-emitting zone, resulting in the actual optical power of the laser being lower than the preset optical power. In order to maintain the stability of the light output power of the laser, the MCU adjusts the voltage output by the power supply circuit according to the collected current, such as reducing the voltage output by the power supply voltage, so that the absorption of the electro-absorption modulation zone becomes less, so as to increase the actual optical power of the laser. After the voltage output by the power supply voltage decreases, the voltage of the electro-absorption modulation zone decreases, so that the current output by the voltage detection circuit decreases. In this way, APC closed-loop control can be formed, thereby maintaining the relative stability of the absorption of the electro-absorption modulation zone and the relative stability of the light output power.

[0021] In the optical module provided by the present invention, the voltage of the electro-absorption modulation zone in the laser is collected by a voltage detection circuit, and the reduction in output optical power caused by aging of the electro-absorption modulation zone is fed back according to the change in the voltage of the electro-absorption modulation zone. The output voltage of the power supply circuit is adjusted to compensate for the loss in output optical power caused by aging of the electro-absorption modulation zone, thereby maintaining the output optical power of the laser. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions in the present disclosure, the following briefly introduces the drawings required to be used in some embodiments of the present disclosure. Obviously, the drawings described below are only drawings of some embodiments of the present disclosure. For ordinary technicians in this field, other drawings can also be obtained based on these drawings. In addition, the drawings described below can be regarded as schematic diagrams, and are not intended to limit the actual size of the product involved in the embodiments of the present disclosure, the actual process of the method, the actual timing of the signal, etc.

[0023] Figure 1 A partial structural diagram of an optical communication system provided according to some embodiments of the present disclosure;

[0024] Figure 2 A partial structural diagram of a host computer provided according to some embodiments of the present disclosure;

[0025] Figure 3 A structural diagram of an optical module provided according to some embodiments of the present disclosure;

[0026] Figure 4 An exploded view of an optical module provided according to some embodiments of the present disclosure;

[0027] Figure 5 This is the circuit diagram of the current traditional EML laser APC closed-loop control;

[0028] Figure 6 A structural diagram of a circuit board in an optical module provided according to some embodiments of the present disclosure;

[0029] Figure 7 A circuit block diagram of an APC closed-loop control of an EML laser in an optical module provided according to some embodiments of the present disclosure Figure 1 ;

[0030] Figure 8 A circuit schematic diagram of APC closed-loop control of an EML laser in an optical module provided according to some embodiments of the present disclosure;

[0031] Fig. 9 A power stabilization principle of an EML laser in an optical module according to some embodiments of the present disclosure Figure 1 ;

[0032] Fig.10 An enlarged diagram of a local circuit of an APC closed-loop control of an EML laser in an optical module provided according to some embodiments of the present disclosure;

[0033] Fig.11 A power stabilization principle of an EML laser in an optical module according to some embodiments of the present disclosure Figure 2 ;

[0034] Fig.12 A circuit block diagram of an APC closed-loop control of an EML laser in an optical module provided according to some embodiments of the present disclosure Figure 2 . DETAILED DESCRIPTION

[0035] Some embodiments of the present disclosure will be described in detail below in conjunction with the accompanying drawings. However, the described embodiments are only a part of the embodiments of the present disclosure, rather than all of the embodiments. Based on the embodiments provided by the present disclosure, all other embodiments obtained by ordinary technicians in this field are within the scope of protection of the present disclosure.

[0036] Unless the context requires otherwise, throughout the specification and claims, the term "comprising" is to be interpreted as having an open, inclusive meaning, 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" implies open and inclusive language, which does not exclude devices that are suitable for or configured to perform additional tasks or steps; descriptions such as "parallel", "perpendicular", "same", "consistent", and "flush" are not limited to absolute mathematical theoretical relationships, but also include an acceptable error range generated in practice, and also include differences based on the same design concept but due to manufacturing reasons.

[0037] In optical communication technology, in order to establish information transmission between information processing devices, it is necessary to load information onto light and use the propagation of light to achieve information transmission. Here, the light loaded with information is an optical signal. When optical signals are transmitted in information transmission equipment, the loss of optical power can be reduced, so high-speed, long-distance, and low-cost information transmission can be achieved. The signals that information processing equipment can recognize and process are electrical signals. Information processing equipment usually includes optical network terminals (Optical Network Unit, ONU), gateways, routers, switches, mobile phones, computers, servers, tablets, televisions, etc., and information transmission equipment usually includes optical fibers and optical waveguides.

[0038] The optical module can realize the mutual conversion between optical signals and electrical signals between information processing equipment and information transmission equipment. For example, at least one of the optical signal input end or the optical signal output end of the optical module is connected to an optical fiber, and at least one of the electrical signal input end or the electrical signal output end of the optical module is connected to an optical network terminal; the first optical signal from the optical fiber is transmitted to the optical module, and the optical module converts the first optical signal into a first electrical signal, and transmits the first electrical signal to the optical network terminal; the second electrical signal from the optical network terminal is transmitted to the optical module, and the optical module converts the second electrical signal into a second optical signal, and transmits the second optical signal to the optical fiber. Since multiple information processing devices can transmit information through electrical signals, at least one of the multiple information processing devices needs to be directly connected to the optical module, and all information processing devices do not need to be directly connected to the optical module. Here, the information processing device directly connected to the optical module is called the upper computer of the optical module. In addition, the optical signal input end or the optical signal output end of the optical module can be called an optical port, and the electrical signal input end or the electrical signal output end of the optical module can be called an electrical port.

[0039] Figure 1 FIG. 1 is a partial structural diagram of an optical communication system provided according to some embodiments of the present disclosure. 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 .

[0040] One end of the optical fiber 101 extends toward the remote information processing device 1000, and the other end of the optical fiber 101 is connected to the optical module 200 through the optical port of the optical module 200. The optical signal can be totally reflected in the optical fiber 101, and the propagation of the optical signal in the total reflection direction can almost maintain the original optical power. The optical signal undergoes multiple total reflections in the optical fiber 101 to transmit the optical signal from the remote information processing device 1000 to the optical module 200, or to transmit the optical signal from the optical module 200 to the remote information processing device 1000, thereby realizing long-distance, low-power loss information transmission.

[0041] The optical communication system may include one or more optical fibers 101, and the optical fibers 101 are 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 working state of the optical module 200.

[0042] 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 so that the host computer 100 and the optical module 200 establish a unidirectional or bidirectional electrical signal connection.

[0043] The host computer 100 also includes an external electrical interface, which can be connected to an electrical signal network. For example, the external electrical interface includes a Universal Serial Bus (USB) interface or a network cable interface 104, and the network cable interface 104 is configured to access the 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 as to establish an electrical signal connection between the local information processing device 2000 and the host computer 100 through the network cable 103. For example, the third electrical signal sent by the local information processing device 2000 is transmitted to the host computer 100 through the network cable 103, and the host computer 100 generates a second electrical signal according to the third electrical signal. The second electrical signal from the host computer 100 is transmitted to the optical module 200, and 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, and the second optical signal is transmitted to the remote information processing device 1000 in the optical fiber 101. For example, the first optical signal from the remote information processing device 1000 is transmitted through the optical fiber 101, and the first optical signal from the optical fiber 101 is transmitted to the optical module 200, and the optical module 200 converts the first optical signal into a first electrical signal, and the optical module 200 transmits the first electrical signal to the host computer 100, and the host computer 100 generates a fourth electrical signal according to the first electrical signal, and transmits the fourth electrical signal to the local information processing device 2000. It should be noted that the optical module is a tool for realizing the mutual conversion between optical signals and electrical signals. During the conversion process between the optical signals and electrical signals, the information does not change, but the encoding and decoding methods of the information can change.

[0044] 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.

[0045] Figure 2 1 is a partial structural diagram of a host computer provided according to some embodiments of the present disclosure. 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 circuit board 105 disposed in the housing, a cage 106 disposed on the surface of the PCB circuit board 105, a heat sink 107 disposed on the cage 106, and an electrical connector disposed inside the cage 106. The electrical connector is configured to access the electrical port of the optical module 200; the heat sink 107 has a protruding structure such as fins to increase the heat dissipation area.

[0046] The optical module 200 is inserted into the cage 106 of the host computer 100, and the cage 106 fixes the optical module 200. The heat generated by the optical module 200 is transferred to the cage 106 and then diffused through the heat sink 107. After the optical module 200 is inserted into the cage 106, the electrical port of the optical module 200 is connected to the electrical connector inside the cage 106, so that the optical module 200 establishes a bidirectional electrical signal connection with the host computer 100. In addition, the optical port of the optical module 200 is connected to the optical fiber 101, so that the optical module 200 establishes a bidirectional optical signal connection with the optical fiber 101.

[0047] Figure 3 is a structural diagram of an optical module provided according to some embodiments of the present disclosure, Figure 4 FIG. 1 is an exploded view of an optical module provided according to some embodiments of the present disclosure. Figure 3 and Figure 4 As shown, the optical module 200 includes a shell, a circuit board 300 disposed in the shell, 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.

[0048] The housing comprises 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 body.

[0049] In some embodiments, the lower shell 202 includes a bottom plate 2021 and two lower side plates 2022 located on both sides of the bottom plate 2021 and arranged perpendicular to the bottom 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.

[0050] In some embodiments, the lower shell 202 includes a bottom plate 2021 and two lower side plates 2022 located on both sides of the bottom plate 2021 and vertically arranged with the bottom 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 vertically arranged with the cover plate 2011, and the two upper side plates are combined with the two lower side plates 2022 to realize that the upper shell 201 covers the lower shell 202.

[0051] 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, the opening 204 is located at the end of the optical module 200, and the opening 205 is located at the side of the optical module 200. The opening 204 is an electrical port, and the gold finger 301 of the circuit board 300 extends from the electrical port and is inserted into the electrical connector of the host computer 100; the opening 205 is an optical port, which is configured to access the external optical fiber 101, so that the optical fiber 101 connects the optical emitting component 400 and the optical receiving component 500 in the optical module 200.

[0052] The assembly method of combining the upper shell 201 and the lower shell 202 is adopted, which facilitates the installation of the circuit board 300, the light emitting component 400, the light receiving component 500, etc. into the above shell, and the upper shell 201 and the lower shell 202 can encapsulate and protect the above components. In addition, when assembling the circuit board 300, the light emitting component 400 and the light receiving component 500, etc., it is convenient to deploy the positioning components, heat dissipation components and electromagnetic shielding components of these components, which is conducive to the automated production.

[0053] In some embodiments, the upper shell 201 and the lower shell 202 are made of metal materials to facilitate electromagnetic shielding and heat dissipation.

[0054] 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.

[0055] For example, the unlocking component 600 is located on the outside of the two lower side plates 2022 of the lower housing 202, and includes a snap-fit ​​component that matches 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 fixes 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 relationship between the snap-fit ​​component and the host computer, so as to release the fixation of the optical module 200 and the host computer, so that the optical module 200 can be pulled out of the cage 106.

[0056] The circuit board 300 includes circuit traces, electronic components and chips, etc. The electronic components and chips are connected according to the circuit design through the circuit traces to realize the functions of power supply, electrical signal transmission and grounding. The electronic components may include capacitors, resistors, transistors, metal-oxide-semiconductor field-effect transistors (Metal-Oxide-Semiconductor Field-Effect Transistor, MOSFET). The chip may include a microcontroller unit (Microcontroller Unit, MCU), a laser driver chip, a transimpedance amplifier (Transimpedance Amplifier, TIA), a limiting amplifier (Limiting Amplifier, LA), a clock and data recovery chip (Clock and Data Recovery, CDR), a power management chip, and a digital signal processing (Digital Signal Processing, DSP) chip.

[0057] 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.

[0058] The circuit board 300 also 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 upper surface shown in the figure) can also be set on the upper and lower surfaces of the circuit board 300 to provide more pins, so as to adapt to occasions where the number of pins is large. The gold finger 301 is configured to establish an electrical connection with the host computer to achieve power supply, grounding, two-wire synchronous serial (Inter-Integrated Circuit, I2C) signal transmission, data signal transmission, etc. Of course, flexible circuit boards are also used in some optical modules. Flexible circuit boards are generally used in conjunction with rigid circuit boards to supplement rigid circuit boards.

[0059] 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 .

[0060] 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.

[0061] In some embodiments, at least one of the light emitting component 400 or the light receiving component 500 may be directly disposed on the circuit board 300. For example, at least one of the light emitting component 400 or the light receiving component 500 may be disposed on a surface of the circuit board 300 or a side of the circuit board 300.

[0062] The optical transmission component 400 is used to transmit an optical signal. Specifically, the optical transmission component 400 includes a laser. The laser generally includes a directly modulated laser and an externally modulated laser. Since the directly modulated laser is not suitable for long-distance and high-speed communication transmission, an externally modulated laser is usually used in long-distance optical communication transmission or high-speed optical communication transmission, such as the more common electro-absorption modulated laser (EML).

[0063] When the EML laser is working, its threshold current and other characteristics generally change with parameters such as temperature. Due to the change of the threshold current and other characteristics, the output optical power of the EML laser will inevitably change. In order to maintain the stability of the output optical power of the EML laser, the working current of the EML laser needs to be adjusted accordingly.

[0064] Figure 5 The following is the circuit diagram of the current traditional EML laser APC closed-loop control. Figure 5 As shown, the optical module includes an EML laser, a monitor photo detector (mPD), a driving circuit and an MCU, etc. A light-emitting area (Distributed Feedback Laser Diode, DFB LD) and an electro-absorption modulation area (Electro-absorption, EA) are provided in the EML laser. The light-emitting area emits light under the action of a bias current, and the electro-absorption modulation area converts a part of the light emitted by the light-emitting area into current under the action of a power supply signal, and modulates the other part of the light to obtain an optical signal, and then emits the optical signal.

[0065] In order to compensate for the changes in the characteristics of the EML laser and stabilize the output optical power, the automatic power control (APC) technology is generally used. The principle of APC closed-loop control is: the laser driving circuit or the external power supply provides the bias current required for the DFB LD to emit light, so that the DFB LD emits light; the modulation driving circuit 307 outputs a differential electrical signal. Since the EA modulator is a single-ended driving device, TXN is generally terminated in the form of "capacitor + 5lohm resistor", and TXP drives the EA modulator. The EA modulator modulates part of the light emitted by the light-emitting area under the action of the electrical signal to obtain a modulated optical signal.

[0066] The mPD is placed in the backlight direction of the DFB LD. The light output of the DFB LD and the light intensity collected by the mPD are in a certain proportional relationship and remain relatively stable. The mPD collects a certain proportion of the DFB LD light and converts it into a detection current. The MCU can collect the detection current to monitor the DFB emission light power.

[0067] Since the cathode of the mPD is grounded, in order to make the mPD work in reverse bias in the detection state, it needs to be connected to an external negative voltage. However, the laser driving circuit cannot receive negative voltage input. Therefore, between the output of the MCU and the mPD, a mirror current source or an integrated operational amplifier is often used to convert the detection current output by the mPD into a current or voltage signal that can be collected by the MCU.

[0068] The MCU monitors the current signal output by the mPD and adjusts the bias current output to the DFB LD to maintain the relative stability of the LD light emission and the stability of the light output power of the EML laser.

[0069] However, the relative position of the mPD and the DFB LD determines the ratio of the light output power after collection. Since the mPD and the DFBLD are two devices, their relative position is easily affected by parameters such as temperature and changes, which causes the ratio of the light output after the mPD collects the LD to change, resulting in inaccurate optical power monitoring and errors in the APC closed loop. In addition, since the EA is in the front light output direction of the DFB LD, it will cause the light output power to change when the EA ages. When the mPD is used to detect the light output power of the EML laser, it is impossible to achieve optical power compensation when the EA ages, resulting in inaccurate monitoring of the laser's light output power.

[0070] In view of the above problems, an embodiment of the present disclosure provides an optical module, which adopts EA forward monitoring and a dual closed-loop control circuit of EA current monitoring and EA voltage monitoring to realize automatic optical power control of the EML laser.

[0071] Figure 6 is a structural diagram of a circuit board in an optical module provided according to some embodiments of the present disclosure, Figure 7 A circuit block diagram of an APC closed-loop control of an EML laser in an optical module provided according to some embodiments of the present disclosure Figure 1 , Figure 8 The schematic diagram of the circuit for APC closed-loop control of an EML laser in an optical module according to some embodiments of the present disclosure is shown in FIG. Figure 6 , Figure 7 and Figure 8 As shown, the circuit board 300 is equipped with an MCU 302, a bias circuit 303, a power supply circuit 304 and a modulation drive circuit 307, wherein:

[0072] MCU302 is respectively connected to the bias circuit 303 and the power supply circuit 304. Specifically, the first end of MCU302 is connected to the power supply circuit 304, and MCU302 is used to control the power supply circuit 304 to output a modulation voltage to supply power to the electro-absorption modulation area; the third end of MCU302 is connected to the bias circuit 303, and MCU302 is used to control the bias circuit 303 to generate a bias current.

[0073] The first end of the bias circuit 303 is connected to the third end of the MCU 302, and the second end of the bias circuit 303 is connected to the light-emitting area of ​​the EML laser. The bias circuit 303 is used to provide a bias current to the light-emitting area so that the light-emitting area emits light. That is, the bias circuit 303 generates a bias current under the action of the MCU 302, and transmits the bias current to the light-emitting area, and the light-emitting area emits light under the action of the bias current.

[0074] In some embodiments, the bias circuit 303 may also be a power supply, which is electrically connected to the light-emitting area. The power supply provides a bias current for the light-emitting area to make the light-emitting area emit light. The power supply receives a control instruction sent by MCU302, and the power supply adjusts the output bias current according to the control instruction to adjust the output optical power of the EML laser.

[0075] The first end of the power supply circuit 304 is connected to the first end of the MCU302, and the second end of the power supply circuit 304 is connected to the first end of the electric absorption modulation area. The power supply circuit 304 is used to supply power to the electric absorption modulation area. The electric absorption modulation area modulates part of the light emitted by the light-emitting area under the action of the electric signal output by the modulation drive circuit 307 to obtain a modulated light signal.

[0076] In some embodiments, the second end of the electro-absorption modulation region is grounded, and the modulation voltage output by the power supply circuit 304 is a negative voltage, so that the electro-absorption modulation region generates a modulation current under the action of the negative voltage. The working principle of the power supply circuit 304 is: the first end of the MCU 302 generates a positive voltage DAC_VEA control signal, and the power supply circuit 304 generates a negative voltage VEA according to the DAC_VEA control signal.

[0077] Specifically, the first terminal of the MCU 302 is a voltage output digital-to-analog converter VDAC, and VDAC outputs a positive voltage DAC_VEA.

[0078] In some embodiments, the power supply circuit 304 may include an operational amplifier having an inverting effect. The positive voltage DAC_VEA generated by the MCU302 is converted into a negative voltage VEA through the inverting effect of the operational amplifier, so that the power supply circuit 304 provides a negative voltage VEA to the electro-absorption modulation area.

[0079] Under the action of negative voltage, the electro-absorption modulation zone absorbs a part of the light emitted by the luminescent zone to generate current, and the other part of the light emitted by the luminescent zone is modulated with the electrical signal output by the modulation drive circuit 307 to obtain a modulated light signal. The greater the absolute value of the negative voltage output by the power supply circuit 304, the more light is absorbed by the electro-absorption modulation zone, and the greater the current generated in the electro-absorption modulation zone. Because part of the light emitted by the luminescent zone is absorbed by the electro-absorption modulation zone, the light modulated by the electro-absorption modulation zone is reduced, resulting in a decrease in the output optical power of the EML laser. Therefore, the current in the electro-absorption modulation zone is negatively correlated with the output optical power of the EML laser, and the output optical power of the EML laser can be monitored by detecting the current in the electro-absorption modulation zone.

[0080] The electro-absorption modulation area generates a current IEA under the negative voltage output by the power supply circuit 304. The IEA is transmitted from the electro-absorption modulation area to the power supply circuit 304. The MCU302 can collect the current IEA flowing through the power supply circuit 304. The MCU302 can calibrate the output optical power of the EML laser according to the collected current IEA.

[0081] Fig. 9 A power stabilization principle of an EML laser in an optical module according to some embodiments of the present disclosure Figure 1 .like Fig. 9 As shown, the first terminal VDAC1 of MCU302 provides a positive power supply voltage DAC_VEA to the power supply circuit 304, and the power supply circuit 304 inverts DAC_VEA to output a negative voltage VEA. The negative voltage VEA acts on the electro-absorption modulation area, and the electro-absorption modulation area generates a modulation current IEA under the action of the negative voltage VEA. The first terminal of MCU302 collects the modulation current IEA.

[0082] Since the modulation current IEA of the electro-absorption modulation zone is negatively correlated with the output optical power of the EML laser, a lookup table of the current IEA and the output optical power can be stored in MCU302. MCU302 obtains the value of the output optical power according to the collected current IEA, and compares the value of the output optical power with the preset optical power (average optical power). When the output optical power exceeds or does not reach the preset optical power, MCU302 adjusts the bias current output by the bias circuit 303 to adjust the output optical power of the DFB LD, so that the adjusted output optical power of the EML laser reaches the preset optical power, thereby forming an APC closed-loop control, so that the output optical power of the EML laser remains relatively stable.

[0083] In some embodiments, the MCU302 may also store a functional relationship between the current IEA and the output optical power. The MCU302 calculates the value of the output optical power based on the collected current IEA and the functional relationship, and compares the value of the output optical power with the preset optical power. When the output optical power exceeds or does not reach the preset optical power, the MCU302 adjusts the bias current output by the bias circuit 303 to adjust the output optical power of the DFB LD, so that the output optical power of the EML laser remains relatively stable.

[0084] For example, when the output optical power P obtained by MCU302 according to the current IEA is greater than the preset optical power P0, MCU302 controls to reduce the bias current output by the bias circuit 303 to reduce the output optical power P of the DFB LD, so that the adjusted output optical power P′ of the EML laser is equal to the preset optical power P0.

[0085] When the output optical power P obtained by MCU302 according to current IEA is less than the preset optical power P0, MCU302 controls to increase the bias current output by bias circuit 303 to increase the output optical power P of DFB LD, so that the adjusted output optical power P′ of EML laser is equal to the preset optical power P0.

[0086] In some embodiments, since the current IEA of the electro-absorption modulation zone is negatively correlated with the output optical power of the EML laser, when the output optical power of the EML laser is the preset optical power P0, the current IEA of the electro-absorption modulation zone has a preset modulation current I0. Therefore, the preset modulation current I0 may be stored in the MCU302. After the MCU302 acquires the current IEA, it compares the current IEA with the preset modulation current I0. When the current IEA is different from the preset modulation current I0, the MCU302 adjusts the bias current output by the bias circuit 303 to adjust the output optical power of the DFB LD, so that the adjusted output optical power of the EML laser reaches the preset optical power, so as to keep the output optical power of the EML laser relatively stable.

[0087] For example, after MCU302 collects the current IEA, if the current IEA is greater than the preset modulation current I0, MCU302 controls to reduce the bias current output by the bias circuit 303 to reduce the output optical power of the DFB LD, so that the adjusted output optical power of the EML laser is equal to the preset optical power.

[0088] If the current IEA is less than the preset modulation current I0, the MCU 302 controls to increase the bias current output by the bias circuit 303 to increase the output optical power of the DFB LD, so that the adjusted output optical power of the EML laser is equal to the preset optical power.

[0089] Since the DFB LD and the electro-absorption modulation area EA are located in the same EML laser, the relative positions of the DFB LD and the electro-absorption modulation area EA are fixed, and the electro-absorption modulation area EA is located in the front light-emitting direction of the LD, there is no error caused by coupling or TE, and the light-emitting condition of the DFB LD can be obtained more accurately. The MCU302, the power supply circuit 304, the electro-absorption modulation area EA, the bias circuit 303 and the DFB LD constitute an APC closed-loop control. The MCU302 collects the current generated by the electro-absorption modulation area EA under the modulation voltage output by the power supply circuit 304. The MCU302 controls the bias current according to the collected current feedback to provide the bias current size of the DFB LD to adjust the light-emitting optical power of the EML laser, thereby automatically controlling the light-emitting optical power of the EML laser and keeping the light-emitting optical power of the EML laser relatively stable.

[0090] In some embodiments, when the optical module has been running for a certain period of time, the electro-absorption modulation region of the EML laser may have aging problems. When the electro-absorption modulation region has aging problems, the current generated by the electro-absorption modulation region under the action of the modulation voltage will change, thereby causing the output optical power of the EML laser to fluctuate. Therefore, it is necessary to compensate for the loss of output optical power caused by the aging of the electro-absorption modulation region.

[0091] When MCU302 adopts the APC closed-loop control circuit of EA current monitoring to maintain the stability of the output optical power of the EML laser, the aging problem of the electro-absorption modulation area EA is not considered, and it is assumed that the electro-absorption modulation area EA is not aged. After the APC closed-loop control circuit of EA current monitoring is adopted to achieve the stability of the output optical power of the EML laser, the voltage change of the electro-absorption modulation area EA can be monitored to detect whether the electro-absorption modulation area EA is aged. When the electro-absorption modulation area EA is aged, MCU302 compensates for the loss of output optical power caused by EA aging by adjusting the negative voltage VEA output by the power supply circuit 304.

[0092] Fig.10 This is an enlarged diagram of a local circuit of an APC closed-loop control of an EML laser in an optical module provided according to some embodiments of the present disclosure. Fig.11 A power stabilization principle of an EML laser in an optical module according to some embodiments of the present disclosure Figure 2 .like Fig.10 and Fig.11As shown, the electro-absorption modulation area EA generates a current IEA under the action of the negative voltage output by the power supply circuit 304. When the electro-absorption modulation area EA ages, the internal resistance of the electro-absorption modulation area EA increases. When the negative voltage output by the power supply circuit 304 remains unchanged, the internal resistance of the electro-absorption modulation area EA increases, resulting in a decrease in the current IEA generated under the action of the power supply circuit 304. The voltage divider of the device in series with the electro-absorption modulation area EA decreases, causing the voltage of the electro-absorption modulation area EA to increase. Therefore, the aging of EA can be determined after monitoring the increase in the voltage of the electro-absorption modulation area EA.

[0093] In order to monitor the voltage of the electro-absorption modulation area EA, a voltage detection circuit 305 is also installed on the circuit board 300. The first end of the voltage detection circuit 305 can be connected to the first end of the electro-absorption modulation area, the second end of the voltage detection circuit 305 can be connected to the second end of the electro-absorption modulation area, and the third end of the voltage detection circuit 305 is connected to the second end of the MCU302, so as to collect the voltage of the electro-absorption modulation area through the voltage detection circuit 305, and transmit the collected voltage to the MCU302.

[0094] In some embodiments, since the second end of the electro-absorption modulation zone is grounded, the voltage detection circuit 305 can be connected only to the first end of the electro-absorption modulation zone, that is, the first end of the voltage detection circuit 305 is connected to the first end of the electro-absorption modulation zone, and the second end of the voltage detection circuit 305 is connected to the second end of the MCU302, and the voltage detection circuit 305 is used to detect the voltage of the first end of the electro-absorption modulation zone.

[0095] Since the second end of the electro-absorption modulation zone is grounded, the voltage at the first end of the electro-absorption modulation zone is a negative voltage, and the MCU302 generally cannot collect negative voltages, so the negative voltage at the first end of the electro-absorption modulation zone can be converted into a positive current through the voltage detection circuit 305.

[0096] After MCU302 collects the current I2 output by the voltage detection circuit 305, it determines whether EA is aged based on the change of current I2. For example, if current I2 is the preset current I0 and does not change, it means that the voltage of the electric absorption modulation area has not changed, and the electric absorption modulation area has not aged; if current I2 is greater than the preset current I0, it means that the voltage of the electric absorption modulation area has increased, and the internal resistance of the electric absorption modulation area has increased, and the electric absorption modulation area has aged.

[0097] After MCU302 determines that the electro-absorption modulation area is aged, in order to compensate for the loss of light output power caused by the aging of the electro-absorption modulation area, MCU302 controls to reduce the negative voltage output by the power supply circuit 304 (reduce the absolute value of the negative voltage) to reduce the voltage divider applied to the electro-absorption modulation area, so as to reduce the absorption of the light emitted by the light-emitting area by the electro-absorption modulation area. When the light output power of the DFB LD remains unchanged, the less light is absorbed by the electro-absorption modulation area, the more modulated light signals are output by the electro-absorption modulation area, and the actual light output power of the EML laser is closer to the light output power of the DFB LD.

[0098] In this way, MCU302, voltage detection circuit 305, power supply circuit 304 and electro-absorption modulation area EA constitute APC closed-loop control, and the APC closed-loop control circuit using EA voltage monitoring compensates for the optical power loss caused by EA aging to maintain the stability of the output optical power of the EML laser.

[0099] Reference Fig.10 In some embodiments, if the second end of the power supply circuit 304 is directly connected to the first end of the electric absorption modulation zone, when the negative voltage output by the power supply circuit 304 remains unchanged, even if the electric absorption modulation zone ages, due to the small resistance of the wire, the voltage change in the electric absorption modulation zone is small, and the MCU302 may not be able to monitor the voltage change in the electric absorption modulation zone according to the voltage detection circuit 305. Therefore, in order for the MCU302 to be able to monitor the voltage change in the electric absorption modulation zone when the electric absorption modulation zone ages, a first resistor R6 is also installed on the circuit board 300, and the first end of the first resistor R6 is connected to the second end of the power supply circuit 304, the second end of the first resistor R6 is connected to the first end of the electric absorption modulation zone, and the first end of the voltage detection circuit 305 is connected to the second end of the first resistor R6, so that the first resistor R6 is connected in series with the electric absorption modulation zone, and the first resistor R6 is used for voltage division.

[0100] Due to the voltage division of the first resistor R6, when the negative voltage output by the power supply circuit 304 remains unchanged, if the electro-absorption modulation area ages (internal resistance increases), the current IEA generated by the electro-absorption modulation area under the action of the negative voltage will decrease, causing the voltage of the first resistor R6 to decrease, and the voltage of the electro-absorption modulation area will increase. In this way, the voltage of the second end of the first resistor R6 (the first end of the first electro-absorption modulation area) will increase.

[0101] Because the voltage detection circuit 305 inputs the voltage at the second end of the first resistor R6 and outputs the current I2, when the electro-absorption modulation region ages, the voltage at the second end of the first resistor R6 increases, causing the current I2 output by the voltage detection circuit 305 to increase. For example, when the electro-absorption modulation region has not aged, the current I2 output by the voltage detection circuit 305 may be 5mA; when the electro-absorption modulation region ages, the current I2 output by the voltage detection circuit 305 may be 7mA.

[0102] Reference Fig.10 In order to monitor the voltage change of the second end of the first resistor R6 by the change of the current I2 output by the voltage detection circuit 305, the voltage detection circuit 305 includes a second resistor R5, a third resistor R7, a fourth resistor R8, a fifth resistor R9, a sixth resistor R10 and an operational amplifier Q1, wherein,

[0103] A first end of the second resistor R5 is connected to a second end of the first resistor R6 , and a second end of the second resistor R5 is connected to an inverting input end of the operational amplifier Q1 .

[0104] The first end of the third resistor R7 is connected to the inverting input end of the operational amplifier Q1 , so that the first end of the third resistor R7 is connected to the second end of the second resistor R5 .

[0105] A first end of the fourth resistor R8 is connected to the positive input end of the operational amplifier Q1 , and a second end of the fourth resistor R8 may be connected to a negative power supply.

[0106] A first end of the fifth resistor R9 is connected to the positive input end of the operational amplifier Q1 , and a second end of the fifth resistor R9 is connected to the second end of the third resistor R7 , so that a first end of the fourth resistor R8 is connected to a first end of the fifth resistor R9 .

[0107] The reverse input terminal of the operational amplifier Q1 is connected to the second end of the second resistor R5 and the first end of the third resistor R7, the forward input terminal of the operational amplifier Q1 is connected to the first end of the fourth resistor R8 and the first end of the fifth resistor R9, and the output terminal of the operational amplifier Q1 is connected to the second end of the third resistor R7.

[0108] A first end of the sixth resistor R10 is connected to a second end of the third resistor R7 , and a second end of the sixth resistor R10 is connected to a second end of the MCU 302 .

[0109] The working principle of the voltage detection circuit 305 is: sampling the voltage Ui at the second end of the first resistor R6, converting it into current I2 after differential amplification by the operational amplifier Q1, and then collecting the current I2 through the MCU302. When the voltage output by the power supply circuit 304 remains unchanged, if the electro-absorption modulation area ages, the voltage at both ends of the electro-absorption modulation area increases, so that the voltage Ui at the second end of the first resistor R6 increases, and the current I2 output by the voltage detection circuit 305 also increases. The current I2 collected by the MCU302 changes (increases), and the MCU302 adjusts the output optical power of the EML laser by adjusting the voltage output by the power supply circuit 304 to compensate for the loss of output optical power caused by the aging of the electro-absorption modulation area.

[0110] Due to the "virtual short and virtual open" of the positive input and reverse input of the operational amplifier, the voltages at the positive input and reverse input of the operational amplifier are equal, that is, V3=V4, and the currents at the positive input and reverse input of the operational amplifier are both 0, that is, I3=I4.

[0111] Since the currents at the positive input terminal and the negative input terminal of the operational amplifier are both 0, the second resistor R5 is connected in series with the third resistor R7, and the fourth resistor R8 is connected in series with the fifth resistor R9. Since the second resistor R5 is connected in series with the third resistor R7, and the fourth resistor R8 is connected in series with the fifth resistor R9, the current flowing through the second resistor R5 is equal to the current flowing through the third resistor R7, and the current flowing through the fourth resistor R8 is equal to the current flowing through the fifth resistor R9.

[0112] The voltage at the first end of the second resistor R5 is Ui. If the resistance relationship is selected as the third resistor R7 / the second resistor R5=the fifth resistor R9 / the fourth resistor R8, the current I2 collected by the MCU302 is:

[0113]

[0114] When the electro-absorption modulation area EA ages, the voltage Ui input to the first end of the second resistor R5 changes, and the current I2 output by the voltage detection circuit 305 also changes. The MCU302 adjusts the output voltage of the power supply circuit 304 by monitoring the change of the current I2 to adjust the voltage applied to the electro-absorption modulation area, thereby adjusting the light output power of the EML laser.

[0115] Specifically, when the electro-absorption modulation area EA ages, the internal resistance of EA increases. When the output voltage of the power supply circuit 304 remains unchanged, the voltage Ui at the first end of the second resistor R5 becomes more negative (the absolute value of Ui becomes larger), and the voltage applied to the electro-absorption modulation area increases, resulting in an increase in the electro-absorption modulation area's absorption of the light emitted by the light-emitting area, and a decrease in the modulated light signal output by the electro-absorption modulation area, so that the actual output light power of the EML laser is less than the output light power of the DFB LD.

[0116] When the absolute value of the voltage Ui at the first end of the second resistor R5 becomes larger, the current I2 collected by the MCU302 also becomes larger. In order to stabilize the actual light output power of the EML laser, it is necessary to reduce the absorption of the light emitted by the light-emitting area by the electro-absorption modulation area. At this time, the MCU302 needs to control the reduction of the output negative voltage of the power supply circuit 304 to reduce the negative voltage applied to the electro-absorption modulation area, thereby reducing the absorption of the light emitted by the light-emitting area by the electro-absorption modulation area. In this way, the modulated light signal output by the electro-absorption modulation area increases, and the current I2 collected by the MCU302 will also decrease, maintaining the relative stability of the current I2, thereby maintaining the relative stability of the absorption of the electro-absorption modulation area and the relative stability of the light output power of the EML laser.

[0117] After MCU302 collects the current I2 output by the voltage detection circuit 305, in order to determine whether the electric absorption modulation area is aged through the current I2, a preset current can be stored in MCU302, and the collected current I2 is compared with the preset current. When the collected current I2 is greater than the preset current, it indicates that the electric absorption modulation area has aged. MCU302 controls the voltage output by the power supply circuit 304 to adjust the voltage applied to the electric absorption modulation area so that the adjusted light output power of the electric absorption modulation area reaches the preset light power.

[0118] Specifically, when the current I2 output by the voltage detection circuit 305 is greater than the preset current, it indicates that the electro-absorption modulation zone has an aging problem, and the light output power of the electro-absorption modulation zone is less than the light output power of the light-emitting zone (preset light power), resulting in light power loss. In order to reduce the light power loss caused by the aging of the electro-absorption modulation zone, the MCU302 controls the reduction of the voltage output by the power supply circuit 304 to reduce the negative pressure applied to the electro-absorption modulation zone, so that the electro-absorption modulation zone reduces the absorption of light emitted by the light-emitting zone. In this way, the modulated light signal output by the electro-absorption modulation zone increases, and the light output power of the electro-absorption modulation zone is close to the preset light power, thereby maintaining the relative stability of the absorption of the electro-absorption modulation zone and the relative stability of the light output power of the EML laser.

[0119] After reducing the negative voltage applied to the electro-absorption modulation area, the voltage at the second end of the first resistor R6 decreases, and the voltage input to the voltage detection circuit 305 decreases, so that the current I2 collected by the MCU302 decreases, thereby maintaining the relative stability of the current I2 output by the voltage detection circuit 305.

[0120] In some embodiments, since the voltage detection circuit 305 includes an operational amplifier, due to the "virtual disconnection" of the operational amplifier, the current IEA generated in the electro-absorption modulation area will not flow through the voltage detection circuit 305, and the voltage detection circuit 305 will not affect the current IEA in the electro-absorption modulation area. In this way, when the output voltage of the power supply circuit 304 remains unchanged, then when the electro-absorption modulation area ages, the current IEA in the electro-absorption modulation area will decrease, and the voltage in the electro-absorption modulation area will change, so that the APC closed-loop control circuit using EA voltage monitoring can compensate for the optical power loss caused by EA aging.

[0121] Reference Figure 8 In some embodiments, a matching circuit 306 is also installed on the circuit board 300, the first end of the matching circuit 306 is connected to the second end of the first resistor R6, the second end of the matching circuit 306 is connected to the first end of the electro-absorption modulation area, and the matching circuit 306 is used for filtering.

[0122] Specifically, the matching circuit 306 includes a seventh resistor R4, a first inductor L9, a second inductor L8 and a third inductor L7. The first end of the seventh resistor R4 is connected to the second end of the first resistor R6. The second end of the seventh resistor R4 is connected to the second end of the first inductor L9.

[0123] The first end of the first inductor L9 is connected to the second end of the first resistor R6, and the second end of the first inductor L9 is connected to the second end of the seventh resistor R4. The main function of the first inductor L9 is to prevent the power ripple on the first resistor R6 from entering the electro-absorption modulation area to affect the performance of the laser optical eye diagram, and to prevent it from entering the modulation drive circuit 307 to affect its working performance.

[0124] In some embodiments, the seventh resistor R4 is connected in parallel with the first inductor L9, which can increase the bandwidth of the matching circuit and better prevent the power ripple.

[0125] The first end of the second inductor L8 is connected to the second end of the first inductor L9, the second end of the second inductor L8 is connected to the first end of the third inductor L7, and the second end of the third inductor L7 is connected to the first end of the electric absorption modulation area. The second inductor L8 and the third inductor L7 are high-impedance inductors, which can be selected according to the actual data transmission rate of the optical module. The second inductor L8 and the third inductor L7 are connected in series to form a 2-level inductor network, which mainly prevents the high-speed data signal loaded in the electric absorption modulation area from flowing to the power supply circuit 304 through the high bandwidth and high impedance of the inductor, thereby reducing the bandwidth of the high-speed signal affecting the optical eye diagram.

[0126] In the above embodiment, the voltage Ui at the second end of the first resistor R6 is detected by the voltage detection circuit 305, and the voltage detection circuit 305 converts the negative voltage Ui into the current I2 to facilitate the collection by MCU302; because the voltage at the second end of the first resistor R6 is a negative voltage, MCU302 cannot accept negative voltage input, and an integrated operational amplifier method can also be used to convert the negative voltage into a positive voltage, so that MCU302 can monitor the voltage change at the second end of the first resistor R6.

[0127] Fig.12 A circuit block diagram of an APC closed-loop control of an EML laser in an optical module provided according to some embodiments of the present disclosure Figure 2 .like Figure 6 and Fig.12 As shown, in order for MCU302 to collect the voltage at the second end of the first resistor R6, the voltage detection circuit 305 is used to detect the voltage of the electro-absorption modulation area. MCU302 collects the voltage output by the voltage detection circuit and adjusts the voltage output by the power supply circuit 304 according to the voltage change to maintain the light output power of the EML laser.

[0128] Specifically, the voltage detection circuit 305 may include an operational amplifier, and according to the inverting action of the operational amplifier, the negative voltage input to the voltage detection circuit 305 is converted into a positive voltage. A preset voltage may be stored in the MCU302. When the voltage output by the voltage detection circuit 305 is greater than the preset voltage, it indicates that an aging problem has occurred in the electro-absorption modulation area, resulting in the light output power of the electro-absorption modulation area being less than the light output power of the light-emitting area (preset light power). At this time, the MCU302 controls the reduction of the voltage output by the power supply circuit 304 to reduce the voltage applied to the electro-absorption modulation area, thereby reducing the absorption of the electro-absorption modulation area, thereby making the light output power of the electro-absorption modulation area close to the light output power of the light-emitting area, so as to maintain the stability of the light output power of the EML laser.

[0129] In the optical module provided by the present invention, the voltage of the first end of the electro-absorption modulation zone is collected by a voltage detection circuit, and the reduction of the output optical power caused by the aging of the electro-absorption modulation zone is fed back according to the change of the voltage of the first end of the electro-absorption modulation zone. The output voltage of the power supply circuit is adjusted to compensate for the loss of the output optical power caused by the aging of the electro-absorption modulation zone, thereby maintaining the output optical power of the EML laser.

[0130] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present disclosure, rather than to limit them. Although the present disclosure has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present disclosure.

Claims

1. An optical module, characterized in that: include: Circuit boards; A laser, electrically connected to the circuit board, comprising a light-emitting region and an electric absorption modulation region, and used for emitting an optical signal; A bias circuit is mounted on the circuit board, the bias circuit is connected to the light-emitting area, and the bias circuit is used to provide a bias current for the light-emitting area to make the light-emitting area emit light; A power supply circuit is installed on the circuit board, the power supply circuit is connected to the electro-absorption modulation area, and the power supply circuit is used to supply power to the electro-absorption modulation area; A voltage detection circuit is installed on the circuit board, the voltage detection circuit is connected to the electro-absorption modulation area, and the voltage detection circuit is used to detect the voltage of the electro-absorption modulation area and convert the voltage into current; An MCU is installed on the circuit board, wherein a first end of the MCU is connected to a first end of the power supply circuit, and a second end of the MCU is connected to the voltage detection circuit. The MCU is used to collect the current output by the voltage detection circuit, and adjust the voltage output by the power supply circuit according to the current to reduce the voltage in the electro-absorption modulation area.

2. The optical module according to claim 1, characterized in that: Also includes: A first resistor is mounted on the circuit board, wherein the first end of the first resistor is connected to the power supply circuit, the second end of the first resistor is connected to the first end of the electro-absorption modulation area, the first end of the voltage detection circuit is connected to the second end of the first resistor, and the first resistor is used for voltage division.

3. The optical module according to claim 2, characterized in that: The voltage detection circuit comprises: a second resistor, a first end of which is connected to the second end of the first resistor; a third resistor, a first end of which is connected to the second end of the second resistor; A fourth resistor, a second end of which is connected to a negative power supply; a fifth resistor, a first end of which is connected to the first end of the fourth resistor, and a second end of which is connected to the second end of the third resistor; a sixth resistor, a first end of which is connected to the second end of the third resistor, and a second end of which is connected to the second end of the MCU; An operational amplifier, wherein the inverting input terminal is connected to the second end of the second resistor, the positive input terminal of the operational amplifier is connected to the first end of the fourth resistor, and the output terminal of the operational amplifier is connected to the second end of the third resistor.

4. The optical module according to claim 3, characterized in that: The third resistor / the second resistor is equal to the fifth resistor / the fourth resistor.

5. The optical module according to claim 1, characterized in that: The MCU is also used to, When the current output by the voltage detection circuit is greater than a preset current, the output optical power of the laser is less than a preset optical power, and the MCU controls the reduction of the voltage output by the power supply circuit to reduce the modulation voltage provided to the electro-absorption modulation area.

6. The optical module according to claim 1, characterized in that: The third end of the MCU is connected to the bias circuit. The MCU is also used to collect the modulation current provided by the power supply circuit to the electric absorption modulation area, and judge whether the modulation current meets the preset modulation current according to the preset relationship between the modulation current and the output optical power of the laser. When the modulation current does not meet the preset modulation current, control and adjust the bias current output by the bias circuit to adjust the output optical power of the laser.

7. The optical module according to claim 6, characterized in that: The MCU is also used for controlling to increase the bias current output by the bias circuit when the collected modulation current is greater than the preset modulation current, so as to increase the output optical power of the laser; When the collected modulation current is less than the preset modulation current, the bias current output by the bias circuit is controlled to be reduced so as to reduce the output optical power of the laser.

8. The optical module according to claim 2, characterized in that: Also included is a matching circuit, the matching circuit is used for filtering; wherein the matching circuit includes: a seventh resistor, a first end of which is connected to the second end of the first resistor; a first inductor, a first end of which is connected to the second end of the first resistor, and a second end of the first inductor is connected to the second end of the seventh resistor; a second inductor, a first end of which is connected to the second end of the first inductor; A third inductor has a first end connected to the second end of the second inductor, and a second end of the third inductor is connected to the first end of the electric absorption modulation region.

9. An optical module, characterized in that: include: Circuit boards; A laser, electrically connected to the circuit board, comprising a light-emitting region and an electric absorption modulation region, and used for emitting an optical signal; A bias circuit is mounted on the circuit board, the bias circuit is connected to the light-emitting area, and the bias circuit is used to provide a bias current for the light-emitting area to make the light-emitting area emit light; A power supply circuit is installed on the circuit board, the power supply circuit is connected to the electro-absorption modulation area, and the power supply circuit is used to supply power to the electro-absorption modulation area; A voltage detection circuit is installed on the circuit board, the voltage detection circuit is connected to the electro-absorption modulation area, and the voltage detection circuit is used to detect the voltage of the electro-absorption modulation area; An MCU is installed on the circuit board, a first end of the MCU is connected to a first end of the power supply circuit, a second end of the MCU is connected to the voltage detection circuit, and the MCU is used to collect the voltage output by the voltage detection circuit, and adjust the voltage output by the power supply circuit according to the voltage to reduce the voltage in the electro-absorption modulation area.

10. The optical module according to claim 9, characterized in that: The MCU is also used to, When the voltage output by the voltage detection circuit is greater than a preset voltage, the output optical power of the laser is less than the preset optical power, and the MCU controls to reduce the voltage output by the power supply circuit to reduce the modulation voltage provided to the electro-absorption modulation area.

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