An optical module

Abstract

The optical module provided in this application includes an optical receiving component and a circuit board. The optical receiving component includes a MCU, a variable optical attenuator, a photodetector, and a TIA. The MCU monitors the voltage output amplitude of the TIA and sends a control signal to the current source based on the voltage output amplitude. The current source responds to the control signal and adjusts the power supply to the variable optical attenuator. The variable optical attenuator adjusts the attenuation value of the photocurrent signal under different driving currents. The MCU also adjusts the gain voltage output to the TIA based on the voltage output amplitude. Under different gain voltages, the TIA gain is adjustable. In this application embodiment, by adjusting the attenuation value of the variable optical attenuator and the adjustable gain of the TIA, the output voltage amplitude of the TIA is maintained within a certain range, thereby ensuring good performance of the optical module receiver.

Description

Technical Field

[0001] This application relates to the field of optical communication technology, and in particular to an optical module. Background Technology

[0002] In optical communication, optical modules are tools for converting photoelectric signals to and from each other, and are one of the key components in optical communication equipment. Furthermore, with the rapid development of 5G networks, optical modules, which occupy a core position in optical communication, have seen significant advancements.

[0003] Optical modules include receivers, and to ensure the normal operation of optical modules, good receiver performance must be guaranteed. Summary of the Invention

[0004] This application provides an optical module that achieves better receiver performance by adjusting the operation of the device.

[0005] The optical module provided in this application embodiment includes:

[0006] Circuit board;

[0007] An optical receiving component, electrically connected to the circuit board, is used to receive optical signals, including:

[0008] A variable optical attenuator is used to attenuate the optical signal;

[0009] A photodetector is used to convert the attenuated optical signal into a photocurrent signal.

[0010] TIA, electrically connected to the photodetector, is used to convert the photocurrent signal into a photovoltage signal and amplify the photovoltage signal.

[0011] A current source is mounted on the circuit board, and its output terminal is electrically connected to the variable optical attenuator to supply power to the variable optical attenuator.

[0012] An MCU, mounted on the circuit board, is used to monitor the voltage output amplitude of the TIA and send a control signal to the current source according to the voltage output amplitude to adjust the power supply to the variable optical attenuator. By adjusting the power supply, the attenuation of the optical signal by the variable optical attenuator is adjusted.

[0013] It is also used to adjust the gain voltage output to the TIA according to the voltage output amplitude, and adjust the gain amplification of the optical voltage signal by the TIA by adjusting the gain voltage;

[0014] Furthermore, the voltage output amplitude can be adjusted by adjusting the attenuation of the optical signal by the variable optical attenuator and by adjusting the gain amplification of the optical voltage signal by the TIA.

[0015] In the optical module provided in this application embodiment, the MCU monitors the voltage output amplitude of the TIA and sends a control signal to the current source based on the voltage output amplitude. The current source responds to the control signal and adjusts the power supply to the variable optical attenuator. The variable optical attenuator adjusts the attenuation value of the photocurrent signal under different driving currents. The MCU also adjusts the gain voltage output to the TIA based on the voltage output amplitude. Under different gain voltages, the TIA gain is adjustable. In this application embodiment, by adjusting the attenuation value of the variable optical attenuator and the adjustable gain of the TIA, the output voltage amplitude of the TIA is maintained within a certain range, thereby ensuring good performance of the optical module receiver. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in this disclosure, the accompanying drawings used in some embodiments of this disclosure will be briefly described below. Obviously, the drawings described below are only drawings of some embodiments of this disclosure, and those skilled in the art can obtain other drawings 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, the actual flow of the method, the actual timing of the signals, etc. involved in the embodiments of this disclosure.

[0017] Figure 1 This is a connection diagram of an optical communication system according to some embodiments;

[0018] Figure 2 This is a structural diagram of an optical network terminal according to some embodiments;

[0019] Figure 3 This is a structural diagram of an optical module according to some embodiments;

[0020] Figure 4 An exploded view of an optical module according to some embodiments;

[0021] Figure 5 This is a schematic diagram of a specific device for an optical receiving component of an optical module according to some embodiments;

[0022] Figure 6 This is a schematic diagram illustrating the interaction between optical receiving components according to some embodiments. Detailed Implementation

[0023] The technical solutions in some embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this disclosure, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments provided in this disclosure are within the scope of protection of this disclosure.

[0024] Unless the context otherwise requires, throughout the specification and claims, the term "comprise" and its other forms, such as the third-person singular "comprises" and the present participle "comprising," are interpreted as open-ended and encompassing, meaning "including, but not limited to." In the description of the specification, terms such as "one embodiment," "some embodiments," "exemplary embodiments," "example," "specific example," or "some examples," etc., are intended to indicate that a particular feature, structure, material, or characteristic associated with that embodiment or example is included in at least one embodiment or example of this disclosure. The illustrative representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics mentioned may be included in any suitable manner in any one or more embodiments or examples.

[0025] Hereinafter, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of embodiments of this disclosure, unless otherwise stated, "a plurality of" means two or more.

[0026] In describing some embodiments, the terms "coupled" and "connected," and their derivative expressions, may be used. For example, the term "connected" may be used in describing some embodiments to indicate that two or more components have direct physical or electrical contact with each other. Similarly, the term "coupled" may be used in describing some embodiments to indicate that two or more components have direct physical or electrical contact. However, the terms "coupled" or "communicatively coupled" may also refer to two or more components that do not have direct contact with each other but still cooperate or interact with each other. The embodiments disclosed herein are not necessarily limited to the content of this document.

[0027] "At least one of A, B and C" has the same meaning as "at least one of A, B or C", both including the following combinations of A, B and C: only A, only B, only C, combinations of A and B, combinations of A and C, combinations of B and C, and combinations of A, B and C.

[0028] "A and / or B" includes the following three combinations: A only, B only, and a combination of A and B.

[0029] The use of “applies to” or “configured to” in this article implies an open and inclusive language that does not preclude applicability to or configuration to devices that perform additional tasks or steps.

[0030] As used herein, “about,” “approximately,” or “approximately” includes the stated value and the average value within an acceptable range of deviation from the given value, wherein the acceptable range of deviation is determined by a person skilled in the art taking into account the measurement under discussion and the error associated with the measurement of the given quantity (i.e., the limitations of the measurement system).

[0031] In optical communication technology, light carries the information to be transmitted, and the information-carrying optical signal is transmitted to information processing equipment such as computers through information transmission equipment such as optical fibers or optical waveguides to complete the information transmission. Because optical signals have passive transmission characteristics when transmitted through optical fibers or optical waveguides, low-cost and low-loss information transmission can be achieved. However, the signals transmitted by information transmission equipment such as optical fibers or optical waveguides are optical signals, while the signals that information processing equipment such as computers can recognize and process are electrical signals. Therefore, in order to establish an information connection between information transmission equipment such as optical fibers or optical waveguides and information processing equipment such as computers, it is necessary to realize the mutual conversion between electrical signals and optical signals.

[0032] In the field of optical fiber communication technology, optical modules realize the aforementioned functions of converting between optical signals and electrical signals. An optical module includes an optical port and an electrical port. The optical port enables optical communication with information transmission devices such as optical fibers or optical waveguides, while the electrical port enables electrical connection with optical network terminals (e.g., optical modems). The electrical connection is mainly used for power supply, I2C signal transmission, data signal transmission, and grounding. The optical network terminal transmits electrical signals to information processing devices such as computers via network cables or Wi-Fi.

[0033] Figure 1 This is a connection diagram of an optical communication system according to some embodiments. Figure 1 As shown, the optical communication system mainly includes a remote server 1000, a local information processing device 2000, an optical network terminal 100, an optical module 200, an optical fiber 101, and a network cable 103.

[0034] One end of optical fiber 101 is connected to the remote server 1000, and the other end is connected to the optical network terminal 100 via optical module 200. Optical fiber itself can support long-distance signal transmission, such as signal transmission over several kilometers (6 to 8 kilometers). Theoretically, ultra-long-distance transmission can be achieved by using repeaters. Therefore, in typical optical communication systems, the distance between the remote server 1000 and the optical network terminal 100 can usually reach several kilometers, tens of kilometers, or hundreds of kilometers.

[0035] One end of the network cable 103 is connected to the local information processing device 2000, and the other end is connected to the optical network terminal 100. The local information processing device 2000 can be any one or more of the following devices: router, switch, computer, mobile phone, tablet computer, television, etc.

[0036] The physical distance between the remote server 1000 and the optical network terminal 100 is greater than the physical distance between the local information processing device 2000 and the optical network terminal 100. The connection between the local information processing device 2000 and the remote server 1000 is completed by optical fiber 101 and network cable 103; while the connection between optical fiber 101 and network cable 103 is completed by optical module 200 and optical network terminal 100.

[0037] The optical module 200 includes an optical port and an electrical port. The optical port is configured to connect to the optical fiber 101, thereby establishing a bidirectional optical signal connection between the optical module 200 and the optical fiber 101. The electrical port is configured to connect to the optical network terminal 100, thereby establishing a bidirectional electrical signal connection between the optical module 200 and the optical network terminal 100. The optical module 200 performs mutual conversion between optical and electrical signals, thereby establishing a connection between the optical fiber 101 and the optical network terminal 100. For example, optical signals from the optical fiber 101 are converted into electrical signals by the optical module 200 and then input to the optical network terminal 100, while electrical signals from the optical network terminal 100 are converted into optical signals by the optical module 200 and then input to the optical fiber 101.

[0038] The optical network terminal 100 includes a generally rectangular housing, and an optical module interface 102 and a network cable interface 104 disposed on the housing. The optical module interface 102 is configured to connect to an optical module 200, thereby establishing a bidirectional electrical signal connection between the optical network terminal 100 and the optical module 200; the network cable interface 104 is configured to connect to a network cable 103, thereby establishing a bidirectional electrical signal connection between the optical network terminal 100 and the network cable 103. The optical module 200 and the network cable 103 are connected through the optical network terminal 100. For example, the optical network terminal 100 transmits electrical signals from the optical module 200 to the network cable 103, and transmits signals from the network cable 103 to the optical module 200. Therefore, the optical network terminal 100 acts as a host computer for the optical module 200, monitoring the operation of the optical module 200. Besides the optical network terminal 100, the host computer for the optical module 200 may also include an optical line terminal (OLT), etc.

[0039] The remote server 1000 establishes a bidirectional signal transmission channel with the local information processing equipment 2000 through optical fiber 101, optical module 200, optical network terminal 100 and network cable 103.

[0040] Figure 2This is a structural diagram of an optical network terminal according to some embodiments, to clearly show the connection relationship between the optical module 200 and the optical network terminal 100. Figure 2 Only the structure of the optical network terminal 100 related to the optical module 200 is shown. For example... Figure 2 As shown, the optical network terminal 100 also includes a PCB circuit board 105 disposed within a housing, a cage 106 disposed on the surface of the PCB circuit board 105, and an electrical connector disposed inside the cage 106. The electrical connector is configured to connect to the electrical port of the optical module 200; the heat sink 107 has protrusions such as fins to increase the heat dissipation area.

[0041] The optical module 200 is inserted into the cage 106 of the optical network terminal 100, where it is secured. Heat generated by the optical module 200 is conducted to the cage 106 and then dissipated through the heat sink 107. After insertion into the cage 106, the optical module 200's electrical port connects to an electrical connector inside the cage 106, establishing a bidirectional electrical signal connection between the optical module 200 and the optical network terminal 100. Furthermore, the optical port of the optical module 200 connects to the optical fiber 101, establishing a bidirectional electrical signal connection between the optical module 200 and the optical fiber 101.

[0042] Figure 3 This is a structural diagram of an optical module according to some embodiments. Figure 4 This 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 105 disposed in the housing, and an optical transceiver assembly.

[0043] The housing includes an upper housing 201 and a lower housing 202, with the upper housing 201 covering the lower housing 202 to form the aforementioned housing having two openings 204 and 205; the outer contour of the housing is generally square.

[0044] In some embodiments of this disclosure, the lower housing 202 includes a bottom plate and two lower side plates located on both sides of the bottom plate and arranged perpendicularly to the bottom plate; the upper housing 201 includes a cover plate and two upper side plates located on both sides of the cover plate and arranged perpendicularly to the cover plate, and the two side walls are combined with the two side plates to realize that the upper housing 201 covers the lower housing 202.

[0045] The direction of the line connecting the two openings 204 and 205 can be consistent with or inconsistent with the length direction of the optical module 200. For example, 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 (left end). Figure 3(The right end). Alternatively, 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 fingers of circuit board 105 extend and are inserted into a host computer (such as optical network terminal 100); opening 205 is an optical port, configured to connect to an external optical fiber 101, so that the optical fiber 101 can connect to the optical transceiver components inside optical module 200.

[0046] The assembly method using an upper housing 201 and a lower housing 202 facilitates the installation of components such as the circuit board 105 and optical transceiver modules into the housing, which provides encapsulation and protection for these components. Furthermore, the assembly of components such as the circuit board 105 facilitates the deployment of positioning, heat dissipation, and electromagnetic shielding components, promoting automated production.

[0047] In some embodiments, the upper housing 201 and the lower housing 202 are generally made of metal materials, which facilitates electromagnetic shielding and heat dissipation.

[0048] In some embodiments, the optical module 200 further includes an unlocking component 203 located on the outer wall of its housing. The unlocking component 203 is configured to establish 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.

[0049] For example, the unlocking component 203 is located on the outer wall of the two lower side plates of the lower housing 202, and includes a locking component that matches the cage of the host computer (e.g., the cage 106 of the optical network terminal 100). When the optical module 200 is inserted into the cage of the host computer, the locking component of the unlocking component 203 fixes the optical module 200 in the cage of the host computer; when the unlocking component 203 is pulled, the locking component of the unlocking component 203 moves accordingly, thereby changing the connection relationship between the locking component and the host computer, so as to release the locking relationship between the optical module 200 and the host computer, thereby allowing the optical module 200 to be pulled out of the cage of the host computer.

[0050] Circuit board 105 includes circuit traces, electronic components, and chips. The circuit traces connect the electronic components and chips together according to the circuit design 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), limiting amplifiers, clock and data recovery chips (CDRs), power management chips, and digital signal processing (DSP) chips.

[0051] Circuit board 105 is generally a rigid circuit board. Due to its relatively hard material, the rigid circuit board can also perform a load-bearing function. For example, the rigid circuit board can stably support the chip; the rigid circuit board can also be inserted into the electrical connector in the host computer cage.

[0052] The circuit board 105 also includes gold fingers formed on its end surfaces, each gold finger consisting of a plurality of independent pins. The circuit board 105 is inserted into a cage 106 and is electrically connected to an electrical connector within the cage 106 by the gold fingers. The gold fingers may be located only on one side of the surface of the circuit board 105 (e.g., ...). Figure 4 The upper surface shown can also be located on the upper and lower surfaces of the circuit board 105 to accommodate applications with a large number of pins. The gold fingers are configured to establish an electrical connection with the host computer for power supply, grounding, I2C signal transmission, and data signal transmission. Of course, flexible circuit boards are also used in some optical modules. Flexible circuit boards are generally used in conjunction with rigid circuit boards as a supplement to rigid circuit boards.

[0053] The optical transceiver assembly includes an optical transmitter 206 and an optical receiver 207, which are used to transmit and receive optical signals, respectively. In this embodiment, the optical transmitter 206 can be coaxial TO packaged and physically separated from the circuit board, with electrical connection achieved through a flexible board; the optical receiver 207 also adopts a coaxial TO package, is physically separated from the circuit board, and is electrically connected through a flexible board. In another common implementation, it can be disposed on the surface of the circuit board 105; in addition, the optical transmitter 206 and the optical receiver 207 can also be combined to form an integrated optical transceiver structure.

[0054] Figure 5 This is a partial structural diagram of an optical module provided in an embodiment of the present invention. Figure 5As shown, in the optical module provided in this embodiment, a row of gold fingers is arranged on the surface of one end of the circuit board 105. An MCU is arranged on the circuit board 105. The row of gold fingers is composed of independent gold fingers. The circuit board 105 is inserted into the electrical connector in the cage, and an electrical connection is established between the gold fingers and the host computer. The MCU is electrically connected to the gold fingers. The optical receiving component 207 includes a variable optical attenuator (VOA) 301, a photodetector 302, and a TIA 303. The essence of a chip is the integration of circuits. Circuits can be integrated into a chip, and some functions of the chip can also be implemented by circuits on the circuit board. The functions of the chip can be implemented by the chip, by circuits, or by the main chip combined with peripheral circuits. Different functions can also be integrated into the same chip. Changes in the circuit integration form are still within the protection scope of this invention. Specifically, in this application embodiment, the photodetector can be an avalanche photodiode or a PIN photodiode, in addition to an avalanche photodiode. The function of the photodetector is to linearly convert the received optical signal into an electrical signal and introduce as little additional noise as possible. The main types of photodetectors that are reliable in fiber optic communication systems and whose wavelengths are in the low-loss region of the optical fiber are PIN photodiodes and avalanche photodiodes (APDs). PIN photodiodes are less sensitive to optical power overload, while APDs require a bias circuit and have a larger reverse operating voltage.

[0055] During optical signal reception, the variable optical attenuator 301 attenuates the optical power of the received optical signal to prevent excessive optical power from saturating the TIA303 and ensuring that the TIA operates within the linear region. The photodetector 302 converts the attenuated optical signal into a weak current signal. The TIA303 converts the weak current signal into a voltage signal and amplifies the voltage signal.

[0056] The MCU adjusts the drive current supplied to the variable optical attenuator 301 to attenuate the optical signal power, thereby supporting the TIA to operate within the linear region. Specifically, in the implementation, a current source is provided on the surface of the circuit board. The MCU controls the current source to output current, which is applied to the variable optical attenuator 301. The current source output terminal has a current output pin, and the variable optical attenuator 301 input terminal has a current input pin. Drive current is provided to the variable optical attenuator 301 through the current output pin and the current input pin. Under the action of different magnitudes of drive current, the variable optical attenuator 301 attenuates the optical power of the optical signal to different degrees. The MCU has a first register to store the DAC value of the drive current output by the current source to the variable optical attenuator 301, denoted as I. DAC The MCU writes the corresponding I to the first register. DACThe system sends a control signal to adjust the power supply to the variable optical attenuator 301. The first register has a control signal output pin, and the current source input terminal has a control signal input pin. The control signal is sent to the current source through the first control signal output pin and the control signal input pin. Upon receiving the control signal, the current source adjusts the magnitude of the driving current applied to the variable optical attenuator 301 in response to the control signal, thereby adjusting the attenuation value of the variable optical attenuator 301. It can be seen that in this embodiment, by writing the corresponding I value into the first register... DAC The system sends a control signal to the current source, and upon receiving the control signal, the current source outputs a corresponding I value. DAC A driving current of a certain value is applied to the variable optical attenuator 301, which, under the action of the corresponding driving current, attenuates the optical power of the received optical signal.

[0057] It is understandable that when 1mA of current is supplied to the variable optical attenuator 301, the corresponding optical signal power attenuation is 0.15dB. Therefore, based on the required optical signal power attenuation, the current supplied to the variable optical attenuator 301 can be determined. For example, if the optical signal power needs to be attenuated by 1.5dB, then 10mA of current needs to be supplied to the variable optical attenuator 301. If the address bits of the first register are 14 bits, then its maximum DAC value is 2. 14 The value is 16384, and the maximum current is 150mA. The correspondence between the DAC value in the first register and the response current is 16384:150. Therefore, if 10mA of current is supplied to the variable optical attenuator 301, the MCU can write the DAC value of 1638 into the first register.

[0058] The TIA303, as a core component of the optical receiver link, converts and amplifies the photocurrent signal into a voltage signal for subsequent circuitry. Since the optical receiver ultimately needs to output a constant amplitude signal to the subsequent circuitry, the TIA303 needs to amplify photocurrent signals of varying intensities to different degrees. Therefore, the TIA303 incorporates a gain control unit to achieve adjustable gain. The gain control unit controls the gain of the TIA303, ensuring that the TIA operates within its linear region while maximizing the signal output amplitude. The MCU achieves adjustable gain control by outputting different gain voltages to the TIA303. The MCU has a second register that stores the DAC value (denoted as U) of the gain voltage applied to the TIA303. DAC Write the corresponding U into the second register DAC MCU output U DACA gain voltage of varying magnitude is fed to the TIA303. The MCU has a gain voltage output pin, and the TIA303 has a gain voltage input pin. Through these pins, the MCU outputs a gain voltage to the TIA303. Furthermore, by writing different values ​​of U into the second register... DAC This allows the MCU to output different gain voltages to the TIA303, thus achieving adjustable gain control. It can be seen that in this embodiment, by writing the corresponding U value into the second register... DAC The MCU then outputs a corresponding gain voltage to the TIA303. Under the action of the corresponding gain voltage, the TIA303 achieves gain control, which ensures that the TIA operates in the linear region and improves the signal output amplitude of the TIA.

[0059] It is understandable that the MCU's maximum output voltage is 2.5V, and the address of the second register is 12 bits, therefore its maximum DAC value is 2. 12 The value is 4096. Therefore, the relationship between the address of the second register and the external output voltage is 4096:2.5. If the gain voltage of TIA needs to be adjusted to 1.25V, then write the value 2048 into the second register. When the DAC value 2048 is written into the second register, the gain voltage output by the MCU to TIA is 1.25V.

[0060] The TIA303 output terminal also has an output voltage monitoring pin. The MCU collects the output voltage of the TIA303 through the output voltage monitoring pin. In this embodiment, this can be the output voltage amplitude of the TIA303, denoted as TIA-PKD. The received bit error rate (BER) can be used to characterize and reflect the performance of the receiver. The TIA303 output voltage amplitude TIA-PKD is related to the received BER. Therefore, in this embodiment, the receiver performance can be characterized and reflected by monitoring TIA-PKD. To achieve optimal performance of the optical module receiver, the TIA303 output voltage amplitude TIA-PKD should be within its optimal range. That is, in this embodiment, by keeping the TIA303 output voltage amplitude TIA-PKD within its optimal range, the received BER is optimized, thereby ensuring a high level of receiver performance.

[0061] Based on this, specific implementation methods are also provided in this application embodiment to ensure that the TIA-PKD parameter is within the optimal range. The MCU acquires the TIA-PKD value through the output voltage monitoring pin and stores it in the third register inside the MCU. That is, the MCU has a third register for storing the TIA-PKD value acquired through the output voltage monitoring pin.

[0062] Understandably, since TIA-PKD is the output voltage amplitude of TIA303, this value cannot be modified. In this embodiment, the attenuation level of the variable optical attenuator 301 and the gain adjustable control of TIA303 are used to bring the TIA-PKD parameter within the optimal range. Because the MCU can write different I values ​​into the first register... DAC The value controls the current source to output a corresponding drive current to the variable optical attenuator 301, thereby adjusting the attenuation level of the variable optical attenuator 301. Therefore, in this embodiment, the attenuation level can be adjusted by changing I. DAC The value keeps the TIA-PKD parameter within its optimal range; because the MCU can write different values ​​into the second register... DAC Output the corresponding U to TIA303 DAC The gain voltage is adjusted to achieve adjustable gain for the TIA303. Therefore, in this application, the gain can be adjusted by adjusting U. DAC The value is adjusted to keep the TIA-PKD parameter within its optimal range. It can be seen that in this embodiment, by adjusting I... DAC Value and U DAC The value keeps TIA-PKD within its optimal range.

[0063] Combined with appendix Figure 6 The solution in this embodiment is as follows: the MCU monitors the voltage output amplitude of the TIA and sends a control signal to the current source based on the voltage output amplitude. The current source responds to the control signal and adjusts the power supply to the variable optical attenuator. The variable optical attenuator adjusts the attenuation value of the photocurrent signal under different driving currents. The MCU also adjusts the gain voltage output to the TIA based on the voltage output amplitude. Under different gain voltages, the TIA gain is adjustable. In this embodiment, by adjusting the attenuation value of the variable optical attenuator and the adjustable gain of the TIA, the output voltage amplitude of the TIA is maintained within a certain range, thereby ensuring good performance of the optical module receiver.

[0064] The following is in conjunction with the appendix Figure 6 This application describes in detail the specific implementation of a scheme that maintains the output voltage amplitude of the TIA within a certain range by adjusting the attenuation value of the variable optical attenuator and the adjustable gain of the TIA, thereby ensuring good performance of the optical module receiver.

[0065] TIA-PKD value, I DAC Value, U DAC The correspondence between the three values ​​is as follows: I DAC The value is negatively correlated with the TIA-PKD value and positively correlated with the TIA-PKD value, that is, I DAC When the value shows an increasing trend, TIA-PKD shows a decreasing trend, IDAC When the value shows a decreasing trend, TIA-PKD shows an increasing trend; U DAC When the value shows an increasing trend, TIA-PKD also shows an increasing trend, U DAC When the value shows a decreasing trend, TIA-PKD also shows a decreasing trend. Therefore, it can be understood that if the TIA-PKD value needs to be increased, then the corresponding I needs to be increased. DAC Decrease the value, and reduce U DAC Increase the value; if you need to decrease the TIA-PKD value, you need to correspondingly increase the I value. DAC Increase the value of U DAC Decrease the value.

[0066] In the embodiments of this application, the TIA-PKD value, I DAC Value, U DAC Each value has its own optimal setting range, I DAC How to obtain the optimal range of values: I DAC The optimal range for the value is relatively large, and can be (0, ∞), i.e., I DAC The value range can be from 0 to infinity. The optimal range for TIA-PKD values ​​is obtained by performing I... under different TIA-PKD values. DAC The curve of the value versus the received bit error rate was then used, and then I was plotted sequentially at other TIA-PKD values. DAC The curve represents the relationship between the received bit error rate (BER) and the received bit error rate (IRR). A lower BER indicates optimal receiver performance. Based on the optimal range for the BER, the optimal range for the TIA-PKD value is obtained, along with the I value corresponding to the minimum BER. DAC Value; U DAC Method for obtaining the optimal range of values: Under different TIA-PKD values, perform I... DAC Value and U DAC The curve of the value, corresponding to the minimum received bit error rate obtained above. DAC The value corresponding to the minimum received bit error rate (I). DAC Under the given value, draw a vertical line and obtain the corresponding U based on the optimal range of TIA-PKD values. DAC The optimal range of values.

[0067] In this embodiment of the application, the optimal range of TIA-PKD values ​​is denoted as (PKD). – MIN, PKD – MAX), I DAC The optimal range of values ​​is denoted as (0, ∞), U DAC The optimal range of values ​​is denoted as (U) DAC –MIN,U DAC–MAX). The three optimal ranges are stored in the corresponding registers inside the MCU. Specifically, the fourth register inside the MCU is used to store the first preset range, which indicates the range of the voltage output amplitude; the fifth register inside the MCU is used to store the second preset range, which indicates the range of the drive current DAC value; and the sixth register inside the MCU is used to store the third preset range, which indicates the range of the gain voltage DAC value.

[0068] It is understood that, in some embodiments, this can be achieved simply by adjusting I. DAC The value keeps TIA-PKD within its optimal range; in some embodiments, this can be achieved simply by adjusting U. DAC The value keeps TIA-PKD within its optimal range; in some embodiments, I needs to be adjusted simultaneously. DAC Value and U DAC The value is set to keep TIA-PKD within its optimal range.

[0069] In this embodiment, the MCU reads the current TIA-PKD value from the third register and determines whether the current TIA-PKD value is within the optimal range of TIA-PKD values. If the current TIA-PKD value is within the optimal range of TIA-PKD values, then the current TIA-PKD value is maintained. DAC Value, U DAC The value is sufficient. If the current TIA-PKD value is greater than PKD... – If it is MAX, then TIA-PKD needs to be reduced by adjusting I. DAC Increase the value of U DAC Decreasing the value can bring TIA-PKD within its optimal range.

[0070] In some embodiments, U is read from the second register. DAC Current value, if U DAC The current value is greater than U DAC– MIN, then decreases U in certain steps. DAC The current value will be obtained by U in a step-by-step manner. DAC Write the value into the second register, then check if the current TIA-PKD value is within the optimal range for TIA-PKD. If it is, the process ends; otherwise, continue decreasing U in increments. DAC Current value, until U DAC The current value equals U DAC– MIN, if when U DAC The current value equals U DAC– At MIN, check if the current TIA-PKD value is within the optimal range for TIA-PKD values. If it is, the process ends; otherwise, read I from the first register.DAC The current value is increased by I in certain steps. DAC The current value is maintained until the current TIA-PKD value falls within the optimal range for TIA-PKD values.

[0071] Read U from the second register DAC Current value, if U DAC The current value equals U DAC –MIN, then read I from the first register. DAC The current value is increased by I in certain steps. DAC The current value is maintained until the current TIA-PKD value falls within the optimal range for TIA-PKD values.

[0072] In some embodiments, I is read from the first register. DAC The current value I can be increased in certain steps. DAC The current value is maintained until the current TIA-PKD value falls within the optimal range for TIA-PKD values.

[0073] In this embodiment, the MCU reads the current TIA-PKD value from the third register and determines whether the current TIA-PKD value is within the optimal range of TIA-PKD values. If the current TIA-PKD value is within the optimal range of TIA-PKD values, then the current TIA-PKD value is maintained. DAC Value, U DAC The value is sufficient. If the current TIA-PKD value is less than PKD–MIN, then TIA-PKD needs to be increased by adjusting I. DAC Decrease the value, and reduce U DAC Increasing the value can bring TIA-PKD within its optimal range.

[0074] In some embodiments, I is read from the first register. DAC Current value, if I DAC If the current value is greater than 0, then decrease I in increments of a certain amount. DAC The current value, I, will be obtained in a step-by-step manner. DAC Write the value into the register, then check if the current TIA-PKD value is within the optimal range for TIA-PKD. If it is, stop; otherwise, continue decreasing I. DAC Current value, until I DAC The current value is 0. Check if the current TIA-PKD value is within the optimal range for TIA-PKD. If it is, the process ends; otherwise, read U from the second register. DAC Current value, if U DAC The current value is less than U DAC –MAX, increases U in increments according to a set step size. DACCurrent value, up to U DAC The current value equals U DAC –MAX, at this point the current TIA-PKD value is within the optimal range for TIA-PKD values.

[0075] Read I from the first register DAC Current value, if I DAC If the current value is 0, then read U from the second register. DAC Current value, if U DAC The current value is less than U DAC –MAX, increases U in increments according to a set step size. DAC Current value, up to U DAC The current value equals U DAC –MAX, at this point the current TIA-PKD value is within the optimal range for TIA-PKD values.

[0076] In some embodiments, U is read from the second register. DAC Current value, if U DAC The current value is less than U DAC –MIN, then U can be increased in certain steps. DAC Current value, up to U DAC The current value equals U DAC –MAX determines whether the current TIA-PKD value is within the optimal range for TIA-PKD. If it is, the process ends; otherwise, I can be adjusted at this point. DAC The current value is read from the first register. DAC Current value, if I DAC If the current value is greater than 0, then decrease I in increments of a certain amount. DAC The current value, I, will be obtained in a step-by-step manner. DAC Write the value into the register, then determine whether the current TIA-PKD value is within the optimal range of TIA-PKD values. If it is, then end the process.

[0077] As can be seen, in the embodiments of this application, by adjusting adjustment I DAC Value and U DAC The value is set to keep TIA-PKD within its optimal range. When TIA-PKD is within its optimal range, it means that the receiver performance is at its best.

[0078] In this embodiment of the application, the MCU writes the corresponding I to the first register. DAC The MCU sends a control signal to the current source to adjust the output current, thereby adjusting the power supply to the variable optical attenuator and achieving different levels of optical power attenuation. The MCU writes the corresponding U value into the second register. DACThe value is then used to output different voltages to the TIA, thereby adjusting the gain voltage of the TIA and achieving adjustable gain of the TIA.

[0079] In this embodiment, based on the obtained current TIA-PKD value, the relationship between the current TIA-PKD value and PKD-MAX and PKD-MIN is determined, and different adjustment methods are adopted, or the I stored in the first register is adjusted. DAC The value, or by adjusting the U stored in the second register. DAC Value, or by adjusting I DAC Value and U DAC The value is then adjusted to adjust TIA-PKD; in this embodiment, the value stored in the first register is adjusted accordingly. DAC The value, U stored in the second register DAC The value is then adjusted to bring the TIA-PKD within its optimal range, thereby achieving the goal of optimal receiver performance.

[0080] In this embodiment, the control I is automatically adjusted by monitoring the voltage output amplitude TIA-PKD of TIA. DAC Value and U DAC The value is adjusted to control the attenuation level of the variable optical attenuator and the gain of the TIA. By adjusting the attenuation value of the variable optical attenuator and the gain of the TIA, the output voltage amplitude of the TIA is maintained within a certain range, thereby ensuring good performance of the optical module receiver.

[0081] The above description is merely a specific embodiment of this disclosure, but the scope of protection of this disclosure is not limited thereto. Any variations or substitutions conceived by those skilled in the art within the scope of the technology disclosed in this disclosure should be included within the scope of protection of this disclosure. Therefore, the scope of protection of this disclosure should be determined by the scope of the claims.

Claims

1. An optical module, characterized in that, include: Circuit board; An optical receiving component, electrically connected to the circuit board, is used to receive optical signals. The optical receiving component includes a variable optical attenuator, a photodetector, and a TIA. The variable optical attenuator is used to attenuate the optical signal. The photodetector is used to convert the attenuated optical signal into a photocurrent signal. The TIA is electrically connected to the photodetector and is used to convert the photocurrent signal into a photovoltage signal and amplify the photovoltage signal. A current source is mounted on the circuit board, and its output terminal is electrically connected to the variable optical attenuator to supply power to the variable optical attenuator. An MCU, mounted on the circuit board, is used to monitor the voltage output amplitude of the TIA and send a control signal to the current source according to the voltage output amplitude to adjust the power supply to the variable optical attenuator. By adjusting the power supply, the attenuation of the optical signal by the variable optical attenuator is adjusted. The MCU is also used to adjust the gain voltage output to the TIA according to the voltage output amplitude, and adjust the gain voltage to adjust the gain amplification of the photovoltage signal by the TIA; Furthermore, the voltage output amplitude is adjusted by adjusting the attenuation of the optical signal by the variable optical attenuator and the gain amplification of the optical voltage signal by the TIA. This includes: when the voltage output amplitude of the TIA needs to be reduced, first reducing the gain voltage output to the TIA until the voltage output amplitude is within the optimal range; if the voltage output amplitude is still not within the optimal range when the gain voltage output to the TIA is reduced to its minimum value, then increasing the power supply from the current source to the variable optical attenuator until the voltage output amplitude is within the optimal range; conversely, when the voltage output amplitude of the TIA needs to be increased, first reducing the power supply from the current source to the variable optical attenuator until the voltage output amplitude is within the optimal range; if the voltage output amplitude is still not within the optimal range when the power supply from the current source to the variable optical attenuator is reduced to its minimum value, then increasing the gain voltage output to the TIA until the voltage output amplitude is within the optimal range.

2. The optical module according to claim 1, characterized in that, The MCU includes: The first register is used to store the drive current output to the variable optical attenuator through the current source; The second register is used to store the gain voltage output to the TIA; The third register is used to store the monitored voltage output amplitude of the TIA.

3. The optical module according to claim 2, characterized in that, The MCU includes: The first register is used to store the DAC value of the drive current output to the variable optical attenuator through the current source; The second register is used to store the DAC value of the output gain voltage to the TIA; The third register is used to store the ADC value of the voltage output amplitude of the TIA as monitored.

4. The optical module according to claim 3, characterized in that, The MCU also includes: The fourth register is used to store a first preset range, which indicates the range of the voltage output amplitude. The fifth register is used to store a second preset range, which indicates the range of the drive current DAC value; The sixth register is used to store a third preset range, which indicates the range of the gain voltage DAC value.

5. The optical module according to claim 4, characterized in that, The control signal is issued based on the relationship between the voltage output amplitude and the first preset range.

6. The optical module according to claim 4, characterized in that, The first preset range is obtained based on the received bit error rate.

7. The optical module according to claim 1, characterized in that, The current source has a current output pin, and the variable optical attenuator has a current input pin. The current output pin is electrically connected to the current input pin.

8. The optical module according to claim 1, characterized in that... The MCU has a control signal output pin, and the current source has a control signal input pin. The control signal output pin is electrically connected to the control signal input pin.

9. The optical module according to claim 1, characterized in that, The MCU also has a gain voltage output pin, and the TIA has a gain voltage input pin. The gain voltage output pin is electrically connected to the gain voltage input pin.

10. The optical module according to claim 1, characterized in that, The TIA has a gain control unit inside.

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