A processing circuit, optical module, and chirp detection method

Abstract

The embodiment of the application discloses a processing circuit, an optical module and a chirp detection method, relates to the field of optical communication, and can quickly and accurately determine the chirp coefficient of a laser. The specific scheme is as follows: a processing circuit is applied to an optical module, the optical module comprises a chirp detection circuit and an optical transmitting module, and the processing circuit comprises a first optical coupler, an optical delay line, an optical filter and a second optical coupler. The first optical coupler receives an optical signal from the optical transmitting module, performs shunt processing on the optical signal, and obtains a first output signal and a second output signal. The optical delay line performs delay processing on the first output signal and obtains a delay signal. The optical filter performs filter processing on the second output signal and obtains a filter signal. The second optical coupler performs combination processing on the delay signal and the filter signal, obtains an output detection signal, and sends the output detection signal to the chirp detection circuit, so that the chirp detection circuit calculates the chirp coefficient of the optical transmitting module according to the output detection signal.

Description

Technical Field

[0001] This application relates to the field of optical communication, and more particularly to a processing circuit, an optical module, and a chirp detection method. Background Technology

[0002] With the continuous development of optical communication, short-to-medium distance optical communication based on intensity modulation direct detection (IM-DD) technology is being used more and more widely. Furthermore, the performance requirements for short-to-medium distance optical communication are also rapidly increasing.

[0003] Generally, the transmitting end can be equipped with an optical module, which can generate and transmit the optical signals required for optical communication. For example, a laser installed in the optical module can generate optical signals according to control signals issued by a processor installed in the optical module, and the information to be transmitted is loaded into the optical signals for transmission through intensity modulation.

[0004] Currently, the chirp-dispersion interaction (or chirp effect, where the laser's inherent dispersion broadens the spectrum at the leading and trailing edges of the optical pulse during intensity modulation) affects the signal quality of the acquired optical signal. As the performance requirements for short-to-medium-range optical communication increase, the laser's emission power inevitably increases, further exacerbating the chirp effect. The magnitude of the chirp effect is indicated by the chirp coefficient; a larger chirp coefficient indicates a greater impact on the optical signal, and vice versa.

[0005] Understandably, to compensate for the impact of chirp on optical signal quality, it is first necessary to determine the magnitude of the laser's chirp. In other words, to improve the signal quality of optical signals in optical communication, it is necessary to accurately and quickly measure the laser's chirp coefficient, and then perform flexible and rapid compensation accordingly. Summary of the Invention

[0006] This application provides a processing circuit, an optical module, and a chirp detection method, which can quickly and accurately determine the chirp coefficient of a laser, and thereby control the influence of chirp effect on the optical signal generated by the laser, thus improving the signal quality of optical communication.

[0007] To achieve the above objectives, the embodiments of this application adopt the following technical solutions:

[0008] In a first aspect, a processing circuit is provided for use in an optical module, which further includes a chirp detection circuit and an optical emitting module. The processing circuit includes: a first optical coupler, an optical delay line, an optical filter, and a second optical coupler. The first optical coupler receives an optical signal from the optical emitting module and performs splitting processing on the optical signal to obtain a first output signal and a second output signal. The optical delay line delays the first output signal to obtain a delayed signal. The optical filter filters the second output signal to obtain a filtered signal. The second optical coupler combines the delayed signal and the filtered signal to obtain an output detection signal and sends the output detection signal to the chirp detection circuit, so that the chirp detection circuit calculates the chirp coefficient of the optical emitting module based on the output detection signal.

[0009] Based on this scheme, the processing circuit can determine the chirp coefficient of the corresponding optical emitting module (such as a laser) by using the output detection signal obtained after processing by the optical delay line and optical filter. Since the optical delay line and optical filter are very small in size, they can be well integrated and thus placed within the optical circuit, reducing detection costs. Furthermore, since the input optical signal can be the full optical signal generated by the laser or a portion of it, in some implementations, chirp coefficient detection can be performed without affecting optical communication. It should be understood that the high integration of the chirp detection circuit and the optical circuit enables real-time chirp coefficient detection, making it possible to quickly and effectively adjust the optical signal to control the impact of chirp on the optical signal within a reasonable range.

[0010] In one possible design, the center wavelength of the rising or falling edge of the transmission spectrum of the optical filter is aligned with the center wavelength of the second output signal. Based on this scheme, the optical filter can effectively filter out spectral signals outside the center frequency range when filtering the optical signal of the corresponding input path, thereby obtaining a filtered signal that meets the requirements for chirp coefficient calculation. It should be understood that in other implementations, even if the center wavelength of the rising or falling edge of the transmission spectrum of the optical filter is not aligned with the center wavelength of the second output signal, the processing circuit provided in this application embodiment can still detect the chirp coefficient. However, its accuracy may be slightly lower than that of the scheme in this possible design.

[0011] In one possible design, the processing circuit also includes a microheater. This microheater is used to adjust the transmission spectrum of the optical filter by adjusting its temperature. Based on this approach, a method for actively adjusting the transmission spectrum of an optical filter is provided, namely, adjusting the temperature of the optical filter via a microheater. This allows alignment of the optical filter's center wavelength with the center wavelength of the second output signal to be achieved without adjusting the second output signal; alignment can be achieved simply by adjusting the optical filter. This also eliminates the need to adjust the laser's emission parameters during chirp detection.

[0012] In one possible design, the microheater is positioned around the optical filter, at a distance not exceeding a preset distance. Based on this approach, a possible method for adjusting the temperature of the optical filter using a microheater is provided, namely, placing the microheater close to the optical filter (e.g., positioning the microheater 1 to 2 μm around the optical filter), thereby achieving the purpose of adjusting the temperature of the optical filter via the microheater.

[0013] In one possible design, the time-domain distribution of the delayed signal does not overlap with the time-domain distribution of the filtered signal. Based on this scheme, the delayed signal after optical delay line processing does not overlap with the filtered signal in the time domain, thus facilitating subsequent combining of the two signals.

[0014] In one possible design, when the optical signal is a Gaussian pulse signal, the chirp detection circuit calculates the chirp coefficient of the optical transmitting module based on the time-domain distribution of the spectrum corresponding to the output detection signal, the peak value of the spectrum, the slope of the transmission spectrum of the optical filter, and the delay of the optical delay line. Based on this scheme, a possible method for a chirp detection circuit to determine the chirp coefficient based on the output detection signal is provided.

[0015] In one possible design, the chirp detection circuit obtains the chirp coefficient of the optical emitting module according to the following formula:

[0016] .

[0017] in, Let be the chirp coefficient of the optical emission module. The time of the previous pulse in the output detection signal. The time of the next pulse in the output detection signal. This is the peak power of the previous pulse in the output detection signal. This is the peak power of the next pulse in the output detection signal. Let be the slope of the optical filter. This is the time delay of the optical delay line. It is a constant. Based on this scheme, a possible specific method for calculating the chirp coefficient is provided.

[0018] In one possible design, the processing circuit also includes a photodetector. This photodetector converts the output detection signal into a corresponding analog electrical signal, which is then used as the output detection signal. Based on this scheme, the delayed optical signal and the filtered optical signal can be combined onto a single spectrum, allowing the chirp coefficient to be calculated based on the parameters of that spectrum. For example, when the chirp detection circuit cannot directly process the optical signal, the photodetector can convert the optical signal into an electrical signal for processing and calculation by the arithmetic module.

[0019] In one possible design, the processing circuit further includes a photodetector and an analog-to-digital converter (ADC). The photodetector converts the output detection signal into a corresponding analog electrical signal and transmits it to the ADC. The ADC converts the analog electrical signal into a digital electrical signal, and the output detection signal is this digital electrical signal. Based on this scheme, when the chirp detection circuit cannot directly process the optical signal or analog electrical signal, by setting up a photodetector and an ADC, the output detection signal can be converted into a digital electrical signal with corresponding characteristics, so that the chirp detection circuit can calculate and obtain the chirp coefficient based on the digital electrical signal.

[0020] In one possible design, the splitting ratio of the first optical coupler is 1:1 or 1:2. Based on this scheme, a possible characteristic of the first optical coupler is provided, namely, that it can split the input detection signal into an upper arm optical signal and a lower arm optical signal with optical power ratios of 1:1 or 1:2.

[0021] Secondly, an optical module is provided, comprising a first optical coupler, an optical delay line, an optical filter, a second optical coupler, a first optical transmitting module, and a chirp detection circuit. The optical communication branch incorporating the first optical transmitting module can be referred to as the first branch. The first optical transmitting module generates a first optical signal and transmits it to the first optical coupler. The first optical coupler performs splitting processing on the first optical signal to obtain a first output signal and a second output signal. The optical delay line delays the first output signal to obtain a first delayed signal. The optical filter filters the second output signal to obtain a first filtered signal. The second optical coupler combines the first delayed signal and the first filtered signal to obtain a first output detection signal and sends the first output detection signal to the chirp detection circuit. The chirp detection circuit calculates the chirp coefficient of the first optical transmitting module based on the first output detection signal.

[0022] Based on this scheme, a possible implementation of integrating processing circuitry into an optical module is provided. This enables the optical module to perform chirp detection based on the optical signal on the first branch and determine the chirp coefficient of the corresponding first optical emitting module. It should be noted that this scheme provides a processing mechanism for the first branch as a reference; the optical module may also include other branches, which can operate simultaneously with the first branch to generate optical signals with the same or different center wavelengths. Their specific operating mechanisms are similar to those of the first branch and will not be elaborated here. It should also be noted that in some implementations of this application, the optical signal received by the first optical coupler can be the full signal of the first optical signal. In other implementations, the signal received by the first optical coupler can be a portion of the first optical signal. In this example, a third optical coupler can be set on the first branch. This third optical coupler can be used to split the first optical signal. Of the two optical signals obtained, one is used to input to the first optical coupler for chirp coefficient detection, and the other can be directly transmitted to the transmission medium such as optical fiber for optical communication with the outside world. This allows the chirp coefficient to be measured in real time without interrupting the normal operation of optical communication.

[0023] In one possible design, the center wavelength of the rising or falling edge of the transmission spectrum of the optical filter is aligned with the center wavelength of the second output signal. Based on this scheme, the optical filter can effectively filter out spectral signals outside the center frequency range when filtering the optical signal of the corresponding input path, thereby obtaining a filtered signal that meets the requirements for chirp coefficient calculation. It should be understood that in other implementations, even if the center wavelength of the rising or falling edge of the transmission spectrum of the optical filter is not aligned with the center wavelength of the second output signal, the processing circuit provided in this application embodiment can still detect the chirp coefficient. However, its accuracy may be slightly lower than that of the scheme in this possible design.

[0024] In one possible design, the optical module also includes a microheater. This microheater is used to adjust the transmission spectrum of the optical filter by adjusting its temperature. Based on this approach, a method for actively adjusting the transmission spectrum of an optical filter is provided, namely, adjusting the temperature of the optical filter via a microheater. This allows alignment of the optical filter's center wavelength with the center wavelength of the second output signal to be achieved without adjusting the second output signal; alignment can be achieved simply by adjusting the optical filter. This also eliminates the need to adjust the laser's emission parameters during chirp detection.

[0025] In one possible design, the microheater is positioned around the optical filter, at a distance not exceeding a preset distance. Based on this approach, a possible method for adjusting the temperature of the optical filter using a microheater is provided, namely, placing the microheater close to the optical filter (e.g., positioning the microheater 1 to 2 μm around the optical filter), thereby achieving the purpose of adjusting the temperature of the optical filter via the microheater.

[0026] In one possible design, the time-domain distribution of the first delayed signal does not overlap with the time-domain distribution of the first filtered signal. Based on this scheme, the first delayed signal after being delayed by the optical delay line does not overlap with the first filtered signal in the time domain, thereby facilitating the subsequent combining of the two signals.

[0027] In one possible design, when the first optical signal is a Gaussian pulse signal, the chirp detection circuit calculates the chirp coefficient of the first optical transmitting module based on the time-domain distribution and peak value of the spectrum corresponding to the first output detection signal, the slope of the transmission spectrum of the optical filter, and the delay of the optical delay line. Based on this scheme, a possible method for a chirp detection circuit to determine the chirp coefficient based on the output detection signal is provided.

[0028] In one possible design, the chirp detection circuit obtains the chirp coefficient of the first optical emitting module according to the following formula:

[0029] .

[0030] in, α Let be the chirp coefficient of the first optical emitting module. t 1 represents the time of the previous pulse in the first output detection signal. t 2 represents the duration of the next pulse in the first output detection signal. P 1 represents the peak power of the previous pulse in the first output detection signal. P 2 represents the peak power of the next pulse in the first output detection signal, S represents the slope of the optical filter, D represents the delay of the optical delay line, and C is a constant. Based on this scheme, a possible specific method for calculating the chirp coefficient is provided.

[0031] In one possible design, the optical module also includes an adjustment module. The chirp detection circuit is further used to instruct the adjustment module to adjust the chirp effect in the first optical transmitting module based on the chirp coefficient of the first optical transmitting module. Based on this scheme, a possible method is provided for an optical module to adjust the chirp effect of the first optical transmitting module according to real-time acquired chirp detection results (such as the chirp coefficient of the first optical transmitting module). This enables the optical module to actively manage the chirp effect, thereby ensuring signal quality during optical communication.

[0032] In one possible design, the chirp detection circuit is further used to determine that the chirp coefficient of the first optical emitting module is greater than a preset threshold, and to send an adjustment signal to the adjustment module based on the chirp coefficient of the first optical emitting module. The adjustment module is used to adjust the chirp effect in the first optical emitting module according to the adjustment signal. Based on this scheme, a specific method for actively managing the chirp effect of an optical module is provided. That is, by judging the relationship between the detected chirp coefficient and the preset threshold, it is determined whether the chirp effect needs to be adjusted, and then the adjustment module controls the chirp effect.

[0033] In one possible design, the adjustment signal includes a bias voltage / bias current adjustment signal and / or a temperature adjustment signal. Based on this scheme, a specific method for controlling the chirp effect is provided, namely, adjusting the chirp effect of the optical emitting module through the bias voltage / bias current adjustment signal and / or temperature adjustment signal.

[0034] In one possible design, the optical module further includes a second branch comprising a second optical emitting module for generating a second optical signal and transmitting it to the first optical coupler. The first optical coupler is further configured to perform splitting processing on the second optical signal to obtain a third output signal and a fourth output signal. The optical delay line is further configured to delay the third output signal to obtain a second delayed signal. The optical filter is further configured to filter the fourth output signal to obtain a second filtered signal. The second optical coupler is further configured to combine the second delayed signal and the second filtered signal to obtain a second output detection signal and send the second output detection signal to the chirp detection circuit. The chirp detection circuit is configured to calculate the chirp coefficient of the second optical emitting module based on the second output detection signal. Based on this scheme, an extended configuration of the optical module is provided. The optical module may include a second branch similar to the first branch provided in the second aspect, and the optical module can manage the chirp effect of other optical emitting modules through the second branch. It should be understood that the optical module may include more second branches. For example, in some implementations, the optical module may include a first branch and multiple second branches to manage the chirp effect of all lasers operating simultaneously. In other implementations, more lasers may be placed in the optical module in addition to the first and second branches, thereby expanding the working capability of the optical module (e.g., simultaneously providing more optical signals with different center wavelengths) while controlling the chirp effect of the entire optical signal emitted by the optical module through the chirp detection results of the first and second branches. It should be noted that, similar to the description in the solution provided in the second aspect above, in this example, an optical coupler may also be provided in the second branch to split the second optical signal so as to perform chirp detection on the branch without affecting the normal communication of the second optical signal.

[0035] In one possible design, the optical module also includes a photodetector. This photodetector converts the first output detection signal into a corresponding analog electrical signal, which is then the analog electrical signal. Based on this scheme, the delayed optical signal and the filtered optical signal can be combined onto a single spectrum, allowing the chirp coefficient to be calculated based on the parameters of that spectrum. For example, when the chirp detection circuit cannot directly process the optical signal, the photodetector can convert the optical signal into an electrical signal for processing and calculation by the computation module.

[0036] In one possible design, the optical module also includes a photodetector and an analog-to-digital converter (ADC). The photodetector converts the output detection signal into a corresponding analog electrical signal and transmits it to the ADC. The ADC converts the analog electrical signal into a digital electrical signal, and the output detection signal is this digital electrical signal. Based on this scheme, when the chirp detection circuit cannot directly process the optical signal or analog electrical signal, by setting up a photodetector and an ADC, the output detection signal can be converted into a digital electrical signal with corresponding characteristics, so that the chirp detection circuit can calculate and obtain the chirp coefficient based on the digital electrical signal.

[0037] In one possible design, the splitting ratio of the first optical coupler is 1:1 or 1:2. Based on this scheme, a possible characteristic of the first optical coupler is provided, namely, that it can split the input detection signal into an upper arm optical signal and a lower arm optical signal with optical power ratios of 1:1 or 1:2.

[0038] Thirdly, a chirp detection method is provided, applied in an optical module including a first optical coupler, an optical delay line, an optical filter, a second optical coupler, a first optical emitting module, and a chirp detection circuit. The method includes: the first optical emitting module generating a first optical signal and transmitting the first optical signal to the first optical coupler; the first optical coupler performing splitting processing on the first optical signal to obtain a first output signal and a second output signal; the optical delay line delaying the first output signal to obtain a first delayed signal; the optical filter filtering the second output signal to obtain a first filtered signal; and the second optical coupler combining the first delayed signal and the first filtered signal to obtain a first output detection signal, and sending the first output detection signal to the chirp detection circuit. The chirp detection circuit calculates the chirp coefficient of the first optical emitting module based on the first output detection signal.

[0039] In one possible design, the center wavelength of the rising or falling edge of the transmission spectrum of the optical filter is aligned with the center wavelength of the second output signal.

[0040] In one possible design, the optical module also includes a microheater. The method further includes: the microheater adjusting the transmission spectrum of the optical filter by adjusting the temperature of the optical filter.

[0041] In one possible design, the microheater is positioned around the optical filter at a distance not exceeding a preset distance.

[0042] In one possible design, the time-domain distribution of the first delayed signal does not overlap with the time-domain distribution of the first filtered signal.

[0043] In one possible design, when the first optical signal is a Gaussian pulse signal, the chirp detection circuit calculates the chirp coefficient of the first optical transmitting module based on the time-domain distribution of the spectrum corresponding to the first output detection signal, the peak value of the spectrum, the slope of the transmission spectrum of the optical filter, and the delay of the optical delay line.

[0044] In one possible design, the chirp detection circuit obtains the chirp coefficient of the first optical emitting module according to the following formula:

[0045] .

[0046] in, α Let be the chirp coefficient of the first optical emitting module. t 1 represents the time of the previous pulse in the first output detection signal. t 2 represents the duration of the next pulse in the first output detection signal. P 1 represents the peak power of the previous pulse in the first output detection signal. P 2 is the peak power of the next pulse in the first output detection signal, S is the slope of the optical filter, D is the delay of the optical delay line, and C is a constant.

[0047] In one possible design, the optical module further includes an adjustment module. The method also includes: the chirp detection circuit instructing the adjustment module to adjust the chirp effect in the first optical emitting module based on the chirp coefficient of the first optical emitting module.

[0048] In one possible design, the method further includes: the chirp detection circuit determines that the chirp coefficient of the first optical emitting module is greater than a preset threshold, and sends an adjustment signal to the adjustment module according to the chirp coefficient of the first optical emitting module, the adjustment module being used to adjust the chirp effect in the first optical emitting module according to the adjustment signal.

[0049] In one possible design, the adjustment signal includes a bias / current adjustment signal and / or a temperature adjustment signal.

[0050] In one possible design, the optical module further includes a second branch, which includes a second optical emitting module. The method further includes: the second optical emitting module generating a second optical signal and transmitting the second optical signal to the first optical coupler. The first optical coupler performs splitting processing on the second optical signal to obtain a third output signal and a fourth output signal. The optical delay line delays the third output signal to obtain a second delayed signal. The optical filter filters the fourth output signal to obtain a second filtered signal. The second optical coupler combines the second delayed signal and the second filtered signal to obtain a second output detection signal and sends the second output detection signal to the chirp detection circuit. The chirp detection circuit calculates the chirp coefficient of the second optical emitting module based on the second output detection signal.

[0051] In one possible design, the optical module further includes a photodetector. The method also includes: the photodetector converting the first output detection signal into a corresponding analog electrical signal, the output detection signal being the analog electrical signal.

[0052] In one possible design, the optical module further includes a photodetector and an analog-to-digital converter (ADC). The method also includes: the photodetector converting the output detection signal into a corresponding analog electrical signal and transmitting it to the ADC; the ADC converting the analog electrical signal into a digital electrical signal, and the output detection signal being the digital electrical signal.

[0053] In one possible design, the splitting ratio of the first optical coupler is 1:1 or 1:2.

[0054] It should be understood that the technical features of the chirp detection method provided in the third aspect above can all be mapped to the first / second aspect above, as well as their possible implementations, and therefore the beneficial effects obtained are similar, which will not be elaborated here. Attached Figure Description

[0055] Figure 1 This is a schematic diagram for determining the chirp coefficient;

[0056] Figure 2 This is another schematic diagram for determining the chirp coefficient;

[0057] Figure 3 This is a schematic diagram illustrating another method for determining the chirp coefficient.

[0058] Figure 4 A schematic diagram of a processing circuit provided in an embodiment of this application;

[0059] Figure 5 A schematic diagram illustrating the processing of upper arm optical signals by an optical delay line, provided as an embodiment of this application;

[0060] Figure 6 This is a schematic diagram illustrating the processing of lower arm optical signals by an optical filter according to an embodiment of this application.

[0061] Figure 7 A schematic diagram of another processing circuit provided in an embodiment of this application;

[0062] Figure 8 A schematic diagram of an optical signal obtained after processing by a second optical coupler, provided in an embodiment of this application;

[0063] Figure 9 A schematic diagram of the composition of a chirp detection circuit provided in an embodiment of this application;

[0064] Figure 10 A schematic diagram illustrating the composition of yet another chirp detection circuit provided in an embodiment of this application;

[0065] Figure 11 A schematic diagram of another processing circuit provided in an embodiment of this application;

[0066] Figure 12 A schematic diagram illustrating the composition of an optical module provided in an embodiment of this application;

[0067] Figure 13 A schematic diagram illustrating the composition of yet another optical module provided in an embodiment of this application;

[0068] Figure 14 A schematic diagram illustrating the composition of an adjustment module provided in an embodiment of this application;

[0069] Figure 15 A schematic flowchart illustrating a chirp detection method provided in an embodiment of this application;

[0070] Figure 16 A schematic flowchart illustrating another chirp detection method provided in this application embodiment;

[0071] Figure 17 A schematic diagram illustrating the composition of yet another optical module provided in an embodiment of this application;

[0072] Figure 18 This application provides a schematic diagram of another optical module composition;

[0073] Figure 19 This application provides a schematic diagram of another optical module configuration;

[0074] Figure 20 This application provides a schematic diagram of the composition of another optical module. Detailed Implementation

[0075] With the rise of 5G mobile communication technology and high-bandwidth services such as virtual reality, network traffic is increasingly concentrated in short- and medium-range communication networks such as metropolitan area networks, data centers, and content delivery networks. As a widely used short- and medium-range communication network, the role of short- and medium-range optical communication networks is becoming increasingly prominent.

[0076] It should be noted that in the evolution of optical communication technology, direct-modulation and direct-detection optical modules (hereinafter referred to as optical modules) based on non-return-to-zero (NRZ) code and 4-level pulse amplitude modulation (PAM4) modulation code have gradually become standard components of the transmitter / receiver in short-to-medium distance optical communication due to their advantages in cost, size and power consumption.

[0077] Currently, to improve the communication efficiency of short-to-medium distance optical communication, the transmission rate of optical modules can be increased through parallel fiber architecture or wavelength division multiplexing (WDM) technology during optical signal transmission. For example, by using parallel fiber architecture or WDM technology, the transmission rate of optical modules can be increased from 10 Gbps to 40 Gbps, 100 Gbps, or even 400 Gbps. Specifically, for a 400 Gbps 2km optical module, four wavelength channels can be selected, with a single channel rate of 100 Gbps, while simultaneously utilizing coarse wavelength division multiplexing (CWDM) technology.

[0078] Understandably, as business traffic continues to increase, the transmission rate of optical modules will inevitably increase further. For example, from the current 400 Gbps to 800 Gbps or higher. Currently, there are two methods to improve the transmission rate of optical modules: one is to increase the number of channels for optical signal transmission, such as from 4 channels to 8 channels. The other is to increase the data communication speed (i.e., baud rate) of a single channel for optical signal transmission, such as from 100 Gbps per channel at a baud rate of 50 Gaud PAM4 to 200 Gbps per channel at a baud rate of 100 Gaud PAM4. Among these, the solution of increasing the number of channels poses significant challenges to the layout, cost, and power consumption of optical modules. Therefore, the solution of increasing the baud rate of a single channel is considered a low-cost and low-power evolution path.

[0079] However, as the baud rate of a single channel increases, the signal spectrum further widens. When the laser in the optical module performs intensity modulation on the optical signal, the problem of ineffective spectral spread (or dispersion cost) caused by chirp becomes increasingly prominent. This has a significant impact on the signal quality of the optical signal and poses a huge challenge to the design of the optical module's link budget and optical port specifications. Therefore, accurately detecting the chirp coefficient of the laser in the optical module during optical communication and correcting the impact of chirp on the optical signal has become a key focus for improving the signal quality of optical communication.

[0080] Currently, the chirp factor of a laser can be determined using the following three methods.

[0081] Method 1: This method, also known as the frequency response method, involves measuring the frequency response spectrum of the optical signal generated by the laser using a network analyzer, and comparing it with the frequency response spectrum of the output optical signal after transmission through a dispersive medium (whose dispersive characteristics are known). By combining this with the location of the resonant peaks in the frequency response spectrum, the chirp coefficient corresponding to the laser's generation of the optical signal can be determined. For example, combining... Figure 1 In diagram (a), port 1 of the network analyzer is connected to the laser, and port 2 is connected to the optical signal receiver. The laser is connected to the optical signal receiver via a dispersive medium. During chirp measurement, the laser generates an optical signal that is transmitted to the network analyzer via port 1 and amplified by an amplifier in the dispersive medium. After transmission through the dispersive medium (such as standard optical fiber), the signal is received by the optical signal receiver. The received optical signal can be transmitted back to the network analyzer via port 2. The network analyzer can obtain the frequency response spectrum of the laser-generated optical signal sidebands and the optical signal transmitted through the standard optical fiber (or carrier beat frequency) based on the optical signal input from port 1 and the optical signal input from port 2. Figure 1 The frequency response spectrum shown in (b) is used as an example. By analyzing the parameters corresponding to this frequency response spectrum offline and combining them with the following formula (1), the chirp coefficient corresponding to the laser when generating the optical signal can be calculated.

[0082] ...Formula (1).

[0083] in, f μ denoted by , where L is the fiber length, c is the speed of light, and D is the fiber dispersion value. λ The center frequency of the optical signal. μ For a series, take integers such as 0, 1, 2, 3, etc. α chirp is the chirp factor of the laser.

[0084] Method 2: This method splits the optical signal emitted by the laser whose chirp coefficient is to be measured into two paths using an optical coupler. These paths are then transmitted into optical fibers with positive dispersion (+D) and negative dispersion (-D), respectively. The two fiber segments have known and opposite dispersion values ​​and are of equal length. The optical signals transmitted through the two fiber segments are then sent to two nonlinear detectors to obtain the corresponding electrical signals. It is understood that when the two optical signals are transmitted through fibers with different dispersions, the pulse width will change due to the chirp effect. For example,... Figure 2 As shown, the pulse width of the optical signal is compressed after passing through an optical fiber with positive dispersion (+D), while the pulse width of the optical signal is broadened after passing through an optical fiber with negative dispersion (-D). Therefore, the electrical signals converted from optical signals with different pulse widths will also have different characteristics. After obtaining the above two electrical signals, these two signals can be input into a subtractor to obtain the corresponding differential signals, and the chirp coefficient of the laser emitting the optical signal can be calculated using the following formula (2).

[0085] ...Formula (2).

[0086] in, V (C, △) ω B2) is the differential voltage signal output by the subtractor. E The average power of the optical signal input to the nonlinear detector, C Δ is the chirp coefficient. ω B2 is the spectral width of the optical signal input to the nonlinear detector, and B2 is the length of the positively dispersive fiber (or negatively dispersive fiber).

[0087] Method 3: This method can also be called the time-resolved method. The following combines... Figure 3 Please explain the proposed solution. Figure 3 As shown in (a), in this scheme, the device under test (i.e., the laser whose chirp coefficient is to be measured, referred to as DUT), a band-pass filter (BPF), and a photodetector (PD) constitute a single-path direct-through chirp detection system. During chirp coefficient measurement, the DUT is controlled to generate an input optical signal 1 (e.g., whose center wavelength is aligned with the center of the rising edge of the BPF's transmission spectrum)... Figure 3 (as shown in (b)). The PD detects signal 1 after it has been filtered by the BPF and obtains the power P1 of signal 1. The DUT adjusts the center wavelength of the input optical signal 2 (as shown in (b)) to align with the center of the falling edge of the BPF transmission spectrum. Figure 3(as shown in (c)). The PD detects signal 2 after it has been filtered by the BPF and obtains the power P2 of signal 2. In this scheme, the power and waveform of the electrical signal output by the PD can be determined by an oscilloscope (OSC) connected to the PD. The chirp coefficient of the DUT can be calculated by combining the following formula (3) based on P1, P2 and the rising and falling edge slopes of the filter transmission spectrum.

[0088] ...Formula (3).

[0089] Among them, α P0 is the chirp coefficient, P0 is the average optical power of the DUT output signal, and S is the absolute value of the rising / falling edge slope in the filter transmission spectrum.

[0090] Currently, the chirp coefficient of the corresponding laser can be obtained using any of the three methods mentioned above, which can be used to determine the extent to which the chirp effect affects the signal quality of the optical signal during the operation of the optical module, and thus compensate for it. However, all three methods have certain problems:

[0091] When measuring the chirp coefficient according to Method 1, a long optical fiber (typically several kilometers long) is required as the dispersion medium. Changes in external temperature, fiber stress, and other factors can easily interfere with the chirp coefficient measurement (or chirp detection), affecting the accuracy of the chirp detection. In addition, the offline calculation process according to the above formula (1) is quite complex, making it impossible to achieve rapid measurement of the chirp coefficient. At the same time, the need to use a network analyzer also puts considerable pressure on the measurement cost.

[0092] Similar to Method 1 above, Method 2 also uses relatively long positive and negative dispersion fibers (typically several kilometers long), which reduces the accuracy of chirp detection. Furthermore, the use of two nonlinear photodetectors increases measurement costs.

[0093] The chirp detection method provided in Method 3 requires locking the rising and falling edges of the filter's transmission spectrum twice, placing extremely high demands on the accuracy of the laser's wavelength locking function. Furthermore, the two locking processes during measurement are time-consuming. In addition, the linearity, consistency, and free spectral range of the filter's transmission spectrum's rising and falling edges all introduce measurement errors.

[0094] Understandably, the chirp detection methods provided in the above schemes, methods 1 and 2, both require the use of relatively long optical fibers, and therefore cannot be integrated into optical modules. Method 3, due to its high requirements for filters and lasers, is also unsuitable for integration into optical modules. This also leads to an increase in the layout cost of chirp detection.

[0095] Furthermore, in all three solutions described above, the laser needs to generate a separate optical signal for chirp detection. Therefore, chirp detection cannot be performed while the laser is operating normally. Consequently, it is impossible to adjust the optical signal generated by the laser in real time to address the chirp effect.

[0096] To address the aforementioned problems, embodiments of this application provide a processing circuit capable of rapid and accurate chirp detection. Furthermore, due to its simple composition, it can be integrated into the optical module while maintaining low cost for chirp detection, thereby enabling real-time reporting and adjustment of chirp effects. It is understood that because this processing circuit can perform accurate and rapid chirp detection, the chirp effect can be corrected based on the chirp detection results (such as the chirp coefficient), thereby improving the signal quality of the optical signal.

[0097] The solutions provided in the embodiments of this application will be described in detail below with reference to the accompanying drawings.

[0098] When using the processing circuit provided in the embodiments of this application to perform chirp detection, an optical signal can be transmitted to the processing circuit, and an output detection signal can be obtained after processing by the processing circuit. Then, the chirp coefficient of the corresponding laser can be calculated and determined based on the output detection signal.

[0099] Please refer to Figure 4 This is a schematic diagram of the composition of a processing circuit 400 provided in an embodiment of this application. Figure 4 As shown, the processing circuit 400 may include a first optical coupler 401, an optical delay line 402, an optical filter 403, and a second optical coupler 404. For ease of explanation, Figure 4 The diagram also shows a chirp detection circuit 405 that can process the output detection signal output by the processing circuit 400.

[0100] The first optocoupler 401 can be connected through its input terminal (e.g., Figure 4 The A1 terminal shown receives the optical signal generated by the laser (such as...). Figure 4 The input detection signal shown). The first output terminal of the first optocoupler 401 (as shown) Figure 4 The A2 terminal shown is connected to the input terminal of the optical delay line 402 (as shown). Figure 4 The B1 terminal shown is coupled to the second output terminal of the first optocoupler 401 (as shown). Figure 4 The A3 terminal shown is connected to the input terminal of the optical filter 403 (as shown). Figure 4 The C1 terminal shown is coupled to the output terminal of the optical delay line 402 (as shown). Figure 4 The B2 terminal shown is connected to the first input terminal of the second optocoupler 404 (as shown in the figure). Figure 4 The output terminal of the optical filter 403 (as shown in the D1 terminal) is coupled. Figure 4The C2 terminal shown is connected to the second input terminal of the second optocoupler 404 (as shown in the figure). Figure 4 The output of the second optocoupler 404 is coupled to the input of the chirp detection circuit 405. (D2 terminal shown).

[0101] The processing circuit 400 provided in this application embodiment can acquire the delayed signal corresponding to the detection signal and the filtered signal corresponding to the detection signal on the same time domain spectrum, and calculate the chirp coefficient of the laser by comparing the intensity and time domain difference of the two pulses.

[0102] As an example, when using such Figure 4 When the processing circuit 400 shown performs chirp detection, the first optical coupler 401 can be used to receive an input detection signal through its A1 terminal. This input detection signal is generated by the laser whose chirp coefficient is to be detected. In some embodiments, the input detection signal can be the detection optical signal obtained by inputting the full optical signal generated by the laser into the first coupler 401 for chirp detection. In other embodiments, the input detection signal can also be a detection optical signal obtained by the laser during normal operation by splitting the optical signal used for communication (e.g., by splitting it through an optical coupler).

[0103] Upon receiving the input detection signal, the first optical coupler 401 can be used to split (or branch) the signal. For example, the received input detection signal can be split at a splitting ratio of 1:1 to obtain two optical signals with the same power (such as an upper arm optical signal and a lower arm optical signal). The first optical coupler 401 can be used to transmit the upper arm optical signal to the optical delay line 402 for processing via terminal A2. The first optical coupler 401 can also be used to transmit the lower arm optical signal to the optical filter 403 for processing via terminal A3.

[0104] It should be noted that in some other embodiments, the first optical coupler 401 may also split the received input detection signal into two optical signals with different power levels according to other splitting ratios (such as 1:2), and transmit the corresponding optical signals to the optical delay line 402 through the A2 terminal and to the optical filter 403 through the A3 terminal for processing.

[0105] Optical delay line 402 can receive the upper arm optical signal through terminal B1. In this embodiment, optical delay line 402 can be used to adjust the delay of the upper arm optical signal (e.g., increase the delay of the upper arm optical signal) to achieve the purpose of shifting the spectrum of the upper arm optical signal backward in the time domain. For example, when the switching bandwidth of the upper arm optical signal is 1Gbps, optical delay line 402 can shift the spectrum of the upper arm optical signal backward by 1 bit in the time domain to obtain the delayed optical signal (e.g., optical signal 1). It should be noted that, in cases such as... Figure 4In the example shown, the delay adjustment of the upper arm optical signal is achieved through an optical delay line 402. In other embodiments, other devices may be used to adjust the delay of the upper arm optical signal, and this application does not limit this. The following examples illustrate this. Figure 4 The following example illustrates how the optical delay line 402 adjusts the delay of the upper arm optical signal.

[0106] As an example, Figure 5 (a) and Figure 5 Figure (b) shows a schematic diagram of the processing of upper arm optical signals by an optical delay line 402. The example uses a Gaussian pulse optical signal as the input detection signal. The optical delay line 402 can receive signals with characteristics such as... Figure 5 The upper arm optical signal with the spectral distribution shown in (a) is processed by delaying it. The time-delayed optical signal 1 can then be obtained. For example, optical signal 1 can have the following characteristics: Figure 5 The spectral distribution shown in (b) is shown in the figure.

[0107] After acquiring optical signal 1, optical delay line 402 can also be used to transmit optical signal 1 to the second optical coupler 404 through B2 terminal.

[0108] Optical filter 403 can receive the lower arm optical signal through terminal C1. In this embodiment, optical filter 403 can be used to filter the lower arm optical signal. It should be noted that, in this example, the center frequency of the lower arm optical signal is aligned with the center of the rising edge or falling edge of the transmission spectrum of optical filter 403, so that the chirp coefficient of the laser can be accurately determined based on the filtered signal (such as optical signal 2). Taking the alignment of the center frequency of the lower arm optical signal with the center of the rising edge of the transmission spectrum of optical filter 403 as an example.

[0109] It is understandable that the instantaneous frequency of an optical signal increases over time. Therefore, when the center frequency of the lower arm optical signal aligns with the center of the rising edge of the optical filter 403, the rising edge instantaneous frequency is low, corresponding to the low-frequency portion of the transmission spectrum of the optical filter 403, thus this portion of the optical signal is significantly attenuated. Conversely, the falling edge instantaneous frequency is low, corresponding to the high-frequency portion of the transmission spectrum of the optical filter 403, thus the attenuation of this portion of the optical signal is smaller. Therefore, after the lower arm optical signal is processed by the optical filter 403, the output optical signal 2, compared to the lower arm optical signal before processing, shows attenuation in intensity in the time domain, and the pulse peak value undergoes a time-domain shift.

[0110] As an example, Figure 6 (a) and Figure 6Figure (b) shows a schematic diagram of optical filter 403 processing the lower arm optical signal. It exemplifies this by using a Gaussian pulse optical signal as the input processing circuit 400, with the lower arm optical signal being the same as the upper arm optical signal, and the rising edge of the transmission spectrum of optical filter 403 aligned with the center frequency of the optical signal. Optical filter 403 can receive signals with the following characteristics through its C1 terminal: Figure 6 The lower arm optical signal with the spectral distribution shown in (a) is analyzed, and this lower arm optical signal is filtered to obtain the following: Figure 6 The optical signal 2 shown in (b) is shown in the figure. It can be seen that after filtering, the spectrum of optical signal 2 is still within the time domain distribution range of the spectrum of the lower arm optical signal, but the amplitude and peak phase have changed.

[0111] After acquiring the filtered optical signal 2, the optical filter 403 can be used as follows: Figure 4 The C2 terminal shown transmits the optical signal to the second optical coupler 404.

[0112] Based on the above description, the rising or falling edge of the transmission spectrum of the optical filter 403 involved in this application embodiment needs to be aligned with the center frequency of the optical signal (such as the lower arm optical signal) input to the optical filter 403. It is understood that the center frequency of the optical signal generated by the same laser will be different in different application scenarios. Furthermore, the chirp coefficient of the laser may also differ due to differences in the corresponding optical power and other factors when generating different optical signals. Therefore, in order to ensure that chirp detection can be covered when the laser operates in different scenarios (i.e., the laser generates optical signals with different center frequencies), in some implementations of this application embodiment, the transmission spectrum of the optical filter 403 can be actively adjusted to align with the center frequency of the corresponding input optical signal.

[0113] For example, Figure 7 A schematic diagram of another processing circuit 400 provided in an embodiment of this application is shown. Figure 7 As shown, a microheater 406 can be placed near the optical filter 403. It should be understood that due to the thermo-optical effect, the transmission spectrum of the optical filter will shift in the frequency domain with temperature changes. Therefore, in this example, the temperature of the optical filter 403 can be adjusted by setting the microheater 406, thereby adjusting the position of the transmission spectrum of the optical filter 403 in the frequency domain, so that the center of the rising / falling edge of the transmission spectrum of the optical filter 403 is aligned with the center frequency of the input optical signal. In some implementations, the microheater 406 can be placed close to the optical filter 403 to more effectively control the transmission spectrum of the optical filter 403. For example, the microheater 406 can be placed within a distance of 1 to 2 μm around the optical filter 403 so that the microheater 406 can effectively adjust the optical filter 403.

[0114] In specific implementations, the optical filter 403 can be flexibly selected according to different cost requirements and selection requirements. For example, when the optical filter 403 needs to be implemented through an on-chip structure, it can be integrated into the processing circuit 400 through a Mach-Zehnder interferometer structure or a micro-ring resonator structure.

[0115] The second optical coupler 404 can be used to receive optical signal 1, processed by optical delay line 402, through terminal D1, and optical signal 2, processed by optical filter 403, through terminal D2. The second optical coupler 404 can also be used to combine the two optical signals received from terminals D1 and D2. It is understood that, since the upper arm optical signal is delayed by optical delay line 402, its spectral position in the time domain does not overlap with that of the lower arm optical signal. Simultaneously, the optical filter 403 only performs filtering on the lower arm optical signal, and the resulting optical signal's spectrum in the time domain still falls within the time domain range of the lower arm optical signal's spectrum. Since the upper arm and lower arm optical signals are in the same time domain, after combining optical signals 1 and 2, the second optical coupler 404 can obtain complete and non-overlapping optical signal spectra of the two pulses processed by delay and filtering in the time domain.

[0116] For example, Figure 8 A schematic diagram of an optical signal obtained after processing by a second optical coupler 404 is shown. Continuing with the example of an input processing circuit 400 optical signal being a Gaussian pulse optical signal, with the lower arm optical signal being the same as the upper arm optical signal, and the rising edge of the transmission spectrum of the optical filter 403 aligned with the center frequency of the optical signal. Referring to the above description, the optical signal input to the second optical coupler 404 may include, for example: Figure 5 The optical signal 1 shown in (b) and as shown in Figure 6 The optical signal 2 is shown in (b) above. After the second optical coupler 404 performs combining processing on the two received optical signals, it can obtain the optical signal 2 shown in (b). Figure 8 The output detection signal is shown. As you can see, as... Figure 8 The output detection signal shown includes the spectrum of two pulse signals: the spectrum of optical signal 1 obtained after filtering by optical filter 403 and the spectrum of optical signal 2 obtained after delay processing by optical delay line 402.

[0117] Based on the above explanation, through, as follows Figure 4 or Figure 7 The processing circuit 400 shown can process the input detection signal and then output a detection signal that includes two pulses (for example, the time-domain spectrum of the output detection signal can have the following characteristics). Figure 8 (as shown in the distribution). This output detection signal can be transmitted to, for example, Figure 4 or Figure 7 The chirp detection circuit 405 shown is used to determine the chirp coefficient of the laser that generates the input detection signal based on the output detection signal.

[0118] For example, such as Figure 9 As shown, the chirp detection circuit 405 may include a photodetector 901 and a processing module 902. The input terminal of the photodetector 901 can serve as the input terminal of the chirp detection circuit 405 to receive the output detection signal. The output terminal of the photodetector 901 is coupled to the processing module 902.

[0119] Understandably, the output detection signal obtained after processing by the processing circuit 400 is an optical signal, which generally cannot be directly processed or calculated. Therefore, in this example, the photodetector 901 can be used to convert the output detection signal into a corresponding electrical signal for subsequent processing.

[0120] It should be noted that, as described above, since the electrical signal output by the photodetector 901 is generally an analog electrical signal, the processing module 902 needs to be capable of processing analog signals. To reduce the requirements on the processing module 902, such as... Figure 10 As shown, in some other embodiments of this application, an analog-to-digital converter (ADC) 903 can be provided before the analog signal is input to the arithmetic module 902. The input terminal of the ADC 903 is coupled to the output terminal of the photodetector 901, and the output terminal of the ADC 903 is coupled to the arithmetic module 902. The ADC 903 can be used to convert the analog electrical signal output by the photodetector 901 into a digital signal to obtain the corresponding digital electrical signal, so that the arithmetic module 903 can perform calculations quickly and accurately.

[0121] Furthermore, in the above example, the photodetector 901 and / or analog-to-digital converter 903 are described as being located in the chirp detection circuit 405. In other implementations, the photodetector 901 and / or analog-to-digital converter 903 may also be located in the processing circuit 400. For example, please refer to... Figure 11 This is a schematic diagram illustrating the composition of another processing circuit 400 provided in an embodiment of this application. Figure 11 As shown, a photodetector 901 coupled to the output of the second optocoupler 404 can be provided in this processing circuit. The output of the photodetector 901 is coupled to the input of the analog-to-digital converter 903, and the output of the analog-to-digital converter 903 can be the output of the processing circuit 400. Figure 11When performing chirp detection, the processing circuit shown obtains a digital signal (i.e., the output detection signal) that can be directly used by the arithmetic module. Of course, in some other embodiments of this application, the photodetector 901 and / or the analog-to-digital converter 903 can also be arranged in the serial path between the processing circuit 400 and the chirp detection circuit 405.

[0122] In the chirp detection circuit 405, the arithmetic module 902 can be a component with computational capabilities. For example, the arithmetic module 902 can implement its corresponding function using a component with logic operation capabilities, such as a Field-Programmable Gate Array (FPGA). Alternatively, the arithmetic module 902 can also implement its corresponding function using a component with processing capabilities, such as a Central Processing Unit (CPU) or a Microcontroller Unit (MCU). In specific implementations, the appropriate component can be flexibly selected based on product characteristics and related requirements; this application embodiment does not impose any limitations on this. The arithmetic module 902 can calculate the chirp coefficient by comparing the intensity and time-domain difference of two pulses corresponding to the output detection signal in the electrical signal output by the photodetector 901. It should be noted that the method by which the arithmetic module 902 calculates the chirp coefficient is related to the spectral type of the optical signal generated by the laser. Generally speaking, in optical communication, the optical signals generated by lasers mostly conform to a Gaussian pulse distribution. Therefore, here we take the optical signal generated by the laser with the chirp coefficient to be measured as a Gaussian pulse as an example.

[0123] For example, the calculation module can calculate the chirp coefficient of the corresponding laser according to the following formula (4).

[0124] ...Formula (4).

[0125] in, α The chirp coefficient, t 1 represents the time of the previous pulse in the output detection signal. t 2 represents the time of the next pulse in the output detection signal. P 1 represents the peak power of the previous pulse in the output detection signal. P2 To output the peak power of the next pulse in the detection signal, S The slope of the rising (or falling) edge spectrum aligned with the center wavelength of the input detection signal. D The time delay of the optical delay line, C It is a constant. It should be noted that the specific value varies depending on the model or type of laser used to measure the chirp coefficient. C It can take different values. For example, C can take the value 0.1.

[0126] Therefore, based on the above explanation, those skilled in the art should understand that when it is necessary to measure the chirp coefficient of a laser, the optical signal generated by the laser can be split to obtain the input detection signal without affecting the current optical communication. This input detection signal can then be input as follows: Figure 4 or Figure 7 or Figure 11 The processing circuit shown can acquire the corresponding output detection signal. Based on this output detection signal, the chirp detection circuit can determine the chirp coefficient of the laser currently in operation. This enables real-time and rapid chirp coefficient measurement without affecting optical communication.

[0127] It is understandable that when using, such as Figure 4 or Figure 7 or Figure 11 When the processing circuit shown performs chirp detection, the optical couplers (such as the first optical coupler 401 and the second optical coupler 404), optical delay line 402, optical filter 403, and microheater 406 involved are all commonly used components in optical communication. Each component occupies a very small area on the board, thus allowing the processing circuit to be well integrated into the optical module, greatly reducing the cost and implementation difficulty of chirp detection.

[0128] As an example, please refer to Figure 12 This is a schematic diagram illustrating the composition of an optical module 1200 provided in an embodiment of this application. The optical module 1200 may be equipped with any of the processing circuits 400 described above. It can perform real-time chirp detection without affecting normal optical communication, and adjust the optical signal based on the detection result to reduce the impact of chirp on the quality of the output optical signal. For ease of explanation, Figure 12 The processing circuit 1205 has the following features: Figure 11 The processing circuit 400 shown is an example.

[0129] like Figure 12 As shown, the optical module 1200 may include a processor 1201, a signal processing module 1202, an optical emitting module 1203, an optical coupler 1204, a processing circuit 1205, and an adjustment module 1206. The optical emitting module 1203 may also be referred to as a laser or a modulator.

[0130] Among them, the first output terminal of processor 1201 (such as Figure 12 The A1 terminal shown is connected to the first receiving terminal of the signal processing module 1202 (as shown in the diagram). Figure 12 The signal processing module 1202's first transmitter (as shown in the B1 terminal) is coupled to the B1 terminal. Figure 12 The B2 terminal shown is connected to the input terminal of the optical emission module 1203 (as shown). Figure 12 The C1 terminal shown is coupled to the output terminal of the optical emitting module 1203 (as shown). Figure 12 The C2 terminal shown is connected to the input terminal of the optocoupler 1204 (as shown). Figure 12 The first output terminal of the optocoupler 1204 (as shown in the D1 terminal) is coupled. Figure 12 The D2 terminal shown is connected to the input terminal of the chirp monitoring module (as shown). Figure 12 The E1 terminal shown is coupled to the second output terminal of the optocoupler 1204 (as shown). Figure 12 The D3 terminal shown is the output terminal of the optical module 1200. The output terminal of the processing circuit 1205 (as shown) Figure 12 The E2 terminal shown is connected to the first input terminal of the processor 1201 (as shown). Figure 12 (As shown at terminal A2) is coupled.

[0131] The second output terminal of processor 1201 (e.g.) Figure 12 The A3 terminal shown is connected to the input terminal of the adjustment module 1206 (as shown). Figure 12 The F1 terminal shown is coupled to the output terminal of the adjustment module 1206 (as shown). Figure 12 The F2 terminal shown is connected to the second input terminal of the optical emitting module 1203 (as shown in the figure). Figure 12 The C3 terminal shown is coupled.

[0132] The processor 1201 is responsible for generating control signals and processing feedback signals, and is typically implemented by a microcontroller unit (MCU). In this example, because the processor 1201 has computational capabilities, it can be used to implement, for example... Figure 10 The chirp detection circuit 405 shown illustrates the function of the arithmetic module 902. The following explanation uses an MCU as the processor.

[0133] The signal processing module 1202 can be used to generate, process, and recover electrical signals that meet different rate standards and modulation formats.

[0134] The optical emission module 1203 can be used to generate an optical signal with a specific wavelength according to a received instruction. In some embodiments, the optical emission module 1203 can be implemented using components such as a directly modulated semiconductor laser (DML) or an electroabsorption modulator (EML).

[0135] It should be noted that in some implementations, the electrical signals generated by the signal processing module 1202 under the control of the MCU 1201 may not be directly recognized by the optical emitting module 1203 to generate corresponding optical signals. Therefore, a driver module can be provided between the signal processing module 1202 and the optical emitting module 1203 to send instructions that can be recognized and applied by the optical emitting module 1203 according to the instructions of the signal processing module 1202. For an example, please refer to... Figure 13 This is a schematic diagram illustrating the composition of another optical module 1200 provided in an embodiment of this application. Figure 13 As shown, in this example, a driver module 1207 can also be provided between the signal processing module 1202 and the optical emission module 1203. The input terminal of this driver module 1207 (e.g., ...) Figure 13 The G1 terminal shown can be coupled to the B2 terminal of the signal processing module 1202, and the output terminal of the drive module 1207 (such as...) Figure 13 The G2 terminal shown can be coupled to the C1 terminal of the optical emitting module 1203. The driving module 1207 can be used to receive the electrical signal sent by the signal processing module 1202 through the G1 terminal, perform amplification / rectification and other operations on the electrical signal, obtain the corresponding electrical signal that can be recognized and processed by the optical emitting module 1203, and transmit it to the optical emitting module 1203 through the G2 terminal.

[0136] Generally, when the optical emitting module 1203 is operating, its bias current / voltage and the ambient temperature affect the chirp generated during the modulation of the optical signal. In other words, the chirp can be adjusted by changing the bias current / voltage and / or the ambient temperature of the optical emitting module 1203. In this embodiment, the adjustment module 1206 can be used to adjust the bias current / voltage and / or the ambient temperature of the optical emitting module 1203 to adjust the chirp of the generated optical signal when the optical emitting module 1203 is operating.

[0137] As an example, Figure 14 A schematic diagram of the composition of an adjustment module 1206 is shown. For example... Figure 14 As shown, the adjustment module 1206 may include a bias / bias current control module 1206-1 and a temperature control module 1206-2. The input terminal of the bias / bias current control module 1206-1 (e.g., ...) Figure 14 The F1-1 terminal in the diagram and the input terminal of the temperature control module 1206-2 (such as the F1-2 terminal shown in Figure 14) can correspond to, for example, the input terminal of the temperature control module 1206-2 (such as the F1-2 terminal shown in Figure 14). Figure 12The F1 terminal of the adjustment module 1206 shown is used to receive corresponding control signals from the MCU 1201. For example, the bias / bias current control module 1206-1 can receive instructions from the MCU 1201 to control the bias / bias current from the F1-1 terminal, so as to realize the adjustment of the bias / bias current of the light emitting module 1203 by the MCU 1201. As another example, the temperature control module 1206-2 can receive instructions from the MCU 1201 to control the temperature from the F1-2 terminal, so as to realize the adjustment of the ambient temperature of the light emitting module 1203 by the MCU 1201.

[0138] It should be noted that, Figure 14 The following description uses an adjustment module 1206 that includes both a bias / bias current control module 1206-1 and a temperature adjustment module 1206 as an example. In other embodiments of this application, the adjustment module 1206 may also include only one of the bias / bias current control module 1206-1 or the temperature adjustment module 1206. It is understood that since the chirp coefficient corresponding to the modulation of the optical signal by the optical emission module 1203 is affected by both bias / bias current and temperature, when the adjustment module 1206 includes only one of the bias / bias current control module 1206-1 or the temperature adjustment module 1206, the optical module 1200 can still control the chirp size through the MCU 1201 to adjust the chirp corresponding to the optical signal. For ease of explanation, the following description uses an adjustment module 1206 that includes both a bias / bias current control module 1206-1 and a temperature adjustment module 1206 as an example.

[0139] For example, when the optical module 1200 is operating, the MCU 1201 can send an indication message 1 to the signal processing module 1202 via its A1 terminal. This indication message 1 can instruct the signal processing module 1202 to generate a corresponding instruction, which in turn controls the optical transmitting module 1203 to generate a corresponding optical signal for optical communication. The signal processing module 1202 can generate an instruction (such as a control message 1) corresponding to the indication message 1 and send it to the optical transmitting module 1203 via its B2 terminal. The optical transmitting module 1203 can generate a corresponding optical signal 1 based on the control message 1 and transmit it to the optical coupler 1204 via its C2 terminal. The optical coupler 1204 can receive the optical signal 1 via its D1 terminal and perform splitting processing to obtain an output optical signal and an input detection signal for chirp detection. The optical coupler 1204 can also transmit the output optical signal from the optical module 1200 via its D3 terminal to enable external communication of the optical module 1200. Optical coupler 1204 can also be used to transmit the input detection signal to processing circuit 1205 via D2 terminal. Processing circuit 1205 can receive the input detection signal via E1 terminal, process the input detection signal, and obtain the output detection signal. As one possible implementation, taking the optical signal 1 generated by optical emission module 1203 having a Gaussian pulse spectrum distribution as an example, the chirp monitoring module can generate a signal with such a Gaussian pulse spectrum distribution. Figure 8 The output detection signal is shown in the spectral distribution diagram. The processing circuit 1205 can transmit this output detection signal to the MCU 1201 via the E2 terminal. The MCU 1201 can receive this output detection signal via the A2 terminal and calculate the corresponding chirp coefficient accordingly. This achieves real-time detection of the chirp coefficient without interrupting optical communication.

[0140] After obtaining the chirp coefficient, the optical module 1200 can adjust the optical signal currently in communication accordingly to control the impact of chirp on the optical signal within a reasonable range.

[0141] For example, MCU 1201 can also be used to acquire the output detection signal sent by processing circuit 1205, in conjunction with the chirp coefficient calculation method described above. After acquiring the current chirp coefficient of optical emitting module 1203, MCU 1201 can determine whether the current chirp coefficient is within a reasonable range. If it exceeds the reasonable range, it controls adjustment module 1206 (such as bias voltage / bias current control module 1206-1 and / or temperature control module 1206-2) to adjust the bias voltage / bias current of optical emitting module 1203 and the ambient temperature in order to adjust the chirp.

[0142] Specifically, by comparing the calculated chirp coefficient with a preset threshold, it can be determined whether the chirp coefficient needs adjustment. For example, MCU 1201 can determine that the chirp coefficient needs adjustment when it determines that the current chirp coefficient is greater than the preset threshold. Conversely, MCU 1201 can determine that the chirp coefficient does not need adjustment when it determines that the current chirp coefficient is less than the preset threshold. It should be noted that the preset threshold can be a threshold set within MCU 1201 or can be flexibly set during chirp detection. This application embodiment does not impose any limitations on this.

[0143] Please refer to Figure 15 This is a schematic flowchart illustrating a chirp detection method provided in an embodiment of this application. This method can be applied to the examples described above (such as...). Figure 12 or Figure 13 or Figure 14 The optical module 1200 is as described in any one of the following statements. For ease of explanation, the optical module is described below as having the following characteristics: Figure 14 The following example illustrates the composition. Furthermore, this method can be applied to chirp detection during normal operation of the optical module, as well as to chirp detection of the laser during non-operational periods. The following example demonstrates chirp detection of the laser during non-operational periods. Figure 15 As shown, the method may include S1501-S1506.

[0144] S1501, the MCU sends a chirp detection command to the signal processing module.

[0145] Since the laser is not working, the MCU can send a chirp detection command to trigger the optical module to start working and generate a corresponding optical signal for chirp detection.

[0146] S1502, The signal processing module generates and sends a chirp detection signal according to the chirp detection instruction.

[0147] S1503 The driver module receives the chirp detection signal, amplifies the chirp detection signal, and sends the processed chirp detection signal to the optical emission module.

[0148] S1504, the optical transmitting module receives the chirp detection signal and generates a corresponding input detection signal based on the chirp detection signal. The optical transmitting module then sends the input detection signal to the processing circuit.

[0149] It should be noted that since the laser is not operational, in this application scenario, the optical emission module in this optical module can transmit the entire generated optical signal to the processing circuit. For example, combined with... Figure 14In this scenario, the optical module 1200 may also exclude the optical coupler 1204. After generating the optical signal, the optical emitting module 1203 can input the entire signal into the processing circuit 1205 for chirp detection.

[0150] S1505 The processing circuit obtains the output detection signal based on the input detection signal and sends the output detection signal to the MCU.

[0151] S1506: The MCU determines the chirp coefficient based on the output detection signal.

[0152] The processing circuit obtains the output detection signal based on the input detection signal, and the MCU determines the chirp coefficient based on the output detection signal, which is similar to the above description and will not be repeated here.

[0153] Generally, when the MCU determines the chirp coefficient based on the output detection signal, the stronger the output detection signal, the more accurate the determined chirp coefficient will be. Therefore, in some embodiments of this application, before determining the chirp coefficient (i.e., executing S1506 above), the MCU can first determine whether the signal strength of the acquired output detection signal meets a preset strength. Only if the preset strength is met will S1506 be executed. When the MCU determines that the signal strength of the output detection signal is insufficient to accurately determine the chirp coefficient, the MCU can stop executing S1506 above and instead adjust the relevant parameters of the processing circuit to obtain an output detection signal with sufficient signal strength for detection. For example, the MCU can send a wavelength adjustment instruction to the processing circuit to control the micro-heater to adjust the center frequency of the rising / falling edge of the optical filter, thereby obtaining a slightly sufficient output detection signal.

[0154] Understandably, after determining the chirp coefficient, the MCU can determine whether the chirp effect in the current laser state has an acceptable impact on the optical signal. If the chirp effect has an excessive impact on the optical signal, it can be corrected accordingly.

[0155] For example, such as Figure 16 As shown, in executing as Figure 15 Following S1506, the method may further include S1507-S1509.

[0156] S1507, the MCU determines whether chirp correction is needed.

[0157] For example, the MCU can determine whether chirp correction is needed based on the relationship between the acquired chirp coefficient and a preset threshold. For instance, if the chirp coefficient is greater than the preset threshold, chirp correction is determined to be necessary. The process continues to S1508. Conversely, if the chirp coefficient is less than the preset threshold, chirp correction is not necessary.

[0158] S1508, the MCU sends an adjustment instruction to the adjustment module.

[0159] S1509. The adjustment module receives the adjustment instruction and adjusts the chirp coefficient of the optical emission module according to the adjustment instruction.

[0160] Among them, when the adjustment module includes, for example Figure 14 When the bias / bias current control module and temperature control module are shown, the MCU can send corresponding adjustment instructions to the bias / bias current control module and temperature control module respectively, so that the adjustment module can adjust the bias / bias current of the light emitting module and the ambient temperature according to the adjustment instructions.

[0161] For example, the MCU can send an adjustment instruction 1 to the bias / bias current control module so that the bias / bias current control module can adjust the bias / bias current of the light emitting module according to the adjustment instruction 1.

[0162] For example, the MCU can send adjustment instruction 2 to the temperature control module so that the temperature control module can adjust the ambient temperature of the light emitting module according to the adjustment instruction 2.

[0163] It should be noted that, in this embodiment, the MCU can determine the corresponding adjustment instruction based on the relationship between the detected chirp coefficient and a preset threshold. As an example, the MCU can store the correspondence between adjustment instructions for different chirp coefficients. When it is determined that chirp adjustment is needed, the MCU can filter and determine the corresponding adjustment instruction based on this correspondence and send it to the adjustment module so that the adjustment module can perform accurate chirp adjustment accordingly.

[0164] It is understandable that, such as Figure 16 As shown, after chirp adjustment, the above S1501 can be repeated to re-detect the adjusted chirp coefficient until chirp adjustment is no longer required.

[0165] Based on the above solution, it can be seen that the processing circuit provided in this application embodiment can be conveniently and effectively integrated into the optical module. This enables the optical module to detect the chirp coefficient in real time without affecting the current communication. In addition, by setting an adjustment module in the optical module, the optical module can adjust the chirp coefficient in real time, so as to control the impact of the chirp effect on the optical signal within a reasonable range, thereby effectively improving the signal quality of optical communication.

[0166] Generally, an optical module is installed in a node of an optical communication system and may need to simultaneously receive and transmit optical signals. The optical module in the example above can effectively adjust the chirp coefficient of the output optical signal to ensure signal quality. Based on this, this application also provides an optical module capable of simultaneously receiving and processing optical signals. For examples, please refer to... Figure 17 The optical module 1200 may also include an optical receiver module 1208. The input terminal of the optical receiver module 1208 (e.g., Figure 17 The H1 terminal shown can be used to receive input optical signals. The output terminal of the optical receiver module 1208 (as shown) Figure 17 The H2 terminal shown is connected to the second input terminal of the signal processing module 1202 (as shown in the figure). Figure 17 The B3 terminal shown is coupled to the second output terminal of the signal processing module 1202 (as shown in the diagram). Figure 17 The B4 terminal shown is coupled to the MCU.

[0167] When the optical module 1200 receives an optical signal, the optical receiving module 1208 can receive the input optical signal through its H1 terminal, convert it into a corresponding electrical signal, and transmit it to the signal processing module 1202 through its H2 terminal. The signal processing module 1202 can process the received electrical signal, parse it to obtain the corresponding data, and transmit it to the MCU through its B3 terminal. This allows the MCU to process the data accordingly.

[0168] It should be noted that the optical module described above is based on the example of simultaneously performing chirp detection and adjustment on an optical signal of one wavelength. It is understood that currently, optical modules can generally perform communication for optical signals corresponding to multiple wavelengths simultaneously. For example, in common Coarse Wavelength Division Multiplexing (CWDM) communication, the optical module can operate simultaneously at 1270nm, 1290nm, 1310nm, and 1330nm (also known as CWDM 4-wavelength). To address the impact of chirp effects on the signal quality of optical signals in this situation, this application embodiment also provides an optical module that effectively controls the impact of chirp effects on the signal quality of optical signals when simultaneously performing optical communication for optical signals corresponding to multiple wavelengths.

[0169] For example, please refer to Figure 18 This application provides a schematic diagram illustrating the composition of another optical module 1200. (See attached diagram.) Figure 18As shown, the optical module may include multiple optical emitting modules (1203-1 to 1203-n as shown in the figure), and optical couplers (1204-1 to 1204-n as shown in the figure) corresponding to each of the multiple optical emitting modules. In this example, one optical emitting module and one optical coupler correspond to one wavelength of optical signal link. Each optical signal link operates at a different operating wavelength. It should be noted that... Figure 18 In this context, each optical signal link has such... Figure 12 The configuration shown is an example. In other embodiments, one or more optical signal links in the optical module 1200 may have, as shown in the example... Figure 13 or Figure 14 or Figure 17 The composition described in any of the embodiments herein is not limited thereto.

[0170] In such Figure 18 When the optical module shown performs chirp detection, the MCU 1201 can control the signal processing module 1202 to send an instruction to the optical emitting module 1203-1 to operate at wavelength 1, so that the optical emitting module 1203-1 generates an optical signal A with a center wavelength of wavelength 1. This optical signal A can be processed by the optocoupler 1204-1 to obtain an output optical signal 1 for optical communication and an input detection signal 1 for chirp detection. This input detection signal 1 can be input to the processing circuit 1205 to obtain the corresponding output detection signal 1, and then transmit this output detection signal 1 to the MCU 1201. The MCU 1201 can determine whether chirp adjustment of the optical emitting module 1203-1 is needed based on this output detection signal 1. If necessary, the chirp coefficient of the optical emitting module 1203-1 can be adjusted by the adjustment module. Similarly, MCU 1201 can control signal processing module 1202 to send an instruction to optical emitting module n 1203-n to operate at wavelength n, so that optical emitting module n 1203-n generates an optical signal N with a center wavelength of wavelength n. This optical signal N can be processed by optocoupler n 1204-n to obtain an output optical signal n for optical communication and an input detection signal n for chirp detection. This input detection signal n can be input to processing circuit 1205 to obtain the corresponding output detection signal n, and then transmit this output detection signal n to MCU 1201. MCU 1201 can determine whether chirp adjustment of optical emitting module n 1203-n is necessary based on this output detection signal n. If necessary, the chirp coefficient of optical emitting module n 1203-n can be adjusted via the adjustment module.

[0171] Please refer to Figure 19This diagram illustrates the composition of an optical module 1200 capable of supporting CWDM 4-wavelength optical communication. As an example, optical transmitter module 1, under the control of the signal processing module, generates an optical signal with a center wavelength of 1270nm. Optical transmitter module 2, under the control of the signal processing module, generates an optical signal with a center wavelength of 1290nm. Optical transmitter module 3, under the control of the signal processing module, generates an optical signal with a center wavelength of 1310nm. Optical transmitter module 4, under the control of the signal processing module, generates an optical signal with a center wavelength of 1330nm. The optical coupler corresponding to each optical transmitter module splits the corresponding wavelength optical signal into two paths: one path is emitted outward for optical communication, and the other path serves as the input processing circuit for the corresponding chirp detection signal, enabling chirp detection. After the MCU obtains the chirp coefficient corresponding to the optical transmitter module, it can then... Figure 16 The methods shown in S1507-S1509 are used to adjust the chirp in order to ensure that the influence of the chirp effect on optical signals of different center wavelengths is within a controllable range.

[0172] This allows for chirp detection and adjustment of multiple optical emitting modules corresponding to different wavelengths within the optical module. It should be noted that, generally, when multiple optical signals of different wavelengths are output simultaneously, the chirp effect affects each wavelength differently. For example, the chirp effect has two extreme effects on the optical signals with the longest and shortest wavelengths: bandwidth expansion and compression. Therefore, in some embodiments of this application, chirp detection and adjustment can be performed only on the optical emitting modules that output the longest and shortest wavelengths, in order to simplify the optical module while effectively controlling the signal quality of the optical signal generated by the optical emitting module most affected by the chirp effect.

[0173] For example, combining Figure 19 Let's continue with the example of the 1200 optical module, which supports CWDM 4-wavelength optical communication. Figure 20 As shown, the optical module can be configured with corresponding optical couplers for optical emitting modules 1 and 4, while optical emitting modules 2 (for generating 1290nm wavelength) and 3 (for generating 1310nm wavelength) do not require corresponding optical couplers. Therefore, the MCU, in conjunction with the processing circuit, can perform chirp detection and adjustment on optical emitting modules 1 and 4, ensuring that the chirp effect on the output optical signal of the CWDM 4 wavelength is controlled within a reasonable range.

[0174] As can be seen, the optical module provided in this application embodiment can realize real-time detection of the chirp coefficient, and when the chirp effect has too great an impact on the signal quality of the optical signal, that is, when the chirp coefficient is greater than a preset threshold, the chirp effect is adjusted by the adjustment module so as to effectively control the impact of the chirp effect on the optical signal quality.

[0175] Although this application has been described in conjunction with specific features and embodiments, it is obvious that various modifications and combinations can be made thereto without departing from the spirit and scope of this application. Accordingly, this specification and drawings are merely exemplary illustrations of this application as defined by the appended claims, and are considered to cover any and all modifications, variations, combinations, or equivalents within the scope of this application. Clearly, those skilled in the art can make various alterations and modifications to this application without departing from the spirit and scope of this application. Thus, if such modifications and modifications of this application fall within the scope of the claims of this application and their equivalents, this application is also intended to include such modifications and modifications.

Claims

1. A processing circuit, characterized in that, The optical module is applied to an optical module, which also includes a chirp detection circuit and an optical emission module. The processing circuit includes a first optical coupler, an optical delay line, an optical filter, and a second optical coupler. The first optical coupler is used to receive optical signals from the optical emitting module and to perform splitting processing on the optical signals to obtain a first output signal and a second output signal; The optical delay line is used to delay the first output signal to obtain a delayed signal; The optical filter is used to filter the second output signal to obtain a filtered signal; The second optical coupler is used to combine the delayed signal and the filtered signal to obtain an output detection signal, and send the output detection signal to the chirp detection circuit so that the chirp detection circuit can calculate the chirp coefficient of the optical emitting module based on the output detection signal; wherein the output detection signal has two pulses; the optical signal is a Gaussian pulse signal, and the chirp coefficient of the optical emitting module is: ， in, α Let be the chirp coefficient of the optical emitting module. t 1 represents the time of the previous pulse in the output detection signal. t 2 represents the time of the next pulse in the output detection signal. P 1 represents the peak power of the previous pulse in the output detection signal. P 2 is the peak power of the next pulse in the output detection signal, S is the slope of the optical filter, D is the delay of the optical delay line, and C is a constant.

2. The processing circuit according to claim 1, characterized in that, The center wavelength of the rising or falling edge of the transmission spectrum of the optical filter is aligned with the center wavelength of the second output signal.

3. The processing circuit according to claim 2, characterized in that, The processing circuit also includes a micro heater; The microheater is used to adjust the transmission spectrum of the optical filter by adjusting the temperature of the optical filter.

4. The processing circuit according to claim 3, characterized in that, The micro heater is positioned around the optical filter, and the distance between it and the optical filter does not exceed a preset distance.

5. The processing circuit according to any one of claims 1-4, characterized in that, The time-domain distribution of the delayed signal does not overlap with the time-domain distribution of the filtered signal.

6. The processing circuit according to any one of claims 1-4, characterized in that, The processing circuit also includes a photodetector; The photodetector is used to convert the output detection signal into a corresponding analog electrical signal, and the output detection signal is the analog electrical signal.

7. The processing circuit according to any one of claims 1-4, characterized in that, The processing circuit also includes a photodetector and an analog-to-digital converter; The photodetector is used to convert the output detection signal into a corresponding analog electrical signal and transmit it to the analog-to-digital converter; The analog-to-digital converter is used to convert the analog electrical signal into a digital electrical signal, and the output detection signal is the digital electrical signal.

8. The processing circuit according to any one of claims 1-4, characterized in that, The splitting ratio of the first optical coupler is 1:1 or 1:

2.

9. An optical module, characterized in that, The optical module includes a first optical coupler, an optical delay line, an optical filter, a second optical coupler, a first optical emission module, and a chirp detection circuit. The first optical emitting module is used to generate a first optical signal and transmit the first optical signal to the first optical coupler; The first optical coupler is used to perform splitting processing based on the first optical signal to obtain a first output signal and a second output signal; The optical delay line is used to delay the first output signal to obtain a first delayed signal. The optical filter is used to filter the second output signal to obtain a first filtered signal; The second optical coupler is used to combine the first delayed signal and the first filtered signal to obtain a first output detection signal, and send the first output detection signal to the chirp detection circuit. The chirp detection circuit is used to calculate the chirp coefficient of the first optical emitting module based on the first output detection signal; wherein, the first output detection signal has two pulses; the optical signal is a Gaussian pulse signal, and the chirp coefficient of the first optical emitting module is: ， in, α Let be the chirp coefficient of the first optical emitting module. t 1 represents the time of the previous pulse in the first output detection signal. t 2 represents the duration of the next pulse in the first output detection signal. P 1 represents the peak power of the previous pulse in the first output detection signal. P 2 is the peak power of the next pulse in the first output detection signal, S is the slope of the optical filter, D is the delay of the optical delay line, and C is a constant.

10. The optical module according to claim 9, characterized in that, The center wavelength of the rising or falling edge of the transmission spectrum of the optical filter is aligned with the center wavelength of the second output signal.

11. The optical module according to claim 10, characterized in that, The optical module also includes a micro heater; The microheater is used to adjust the transmission spectrum of the optical filter by adjusting the temperature of the optical filter.

12. The optical module according to claim 11, characterized in that, The micro heater is positioned around the optical filter, and the distance between it and the optical filter does not exceed a preset distance.

13. The optical module according to any one of claims 9-12, characterized in that, The time-domain distribution of the first delayed signal does not overlap with the time-domain distribution of the first filtered signal.

14. The optical module according to any one of claims 9-12, characterized in that, The optical module also includes an adjustment module; The chirp detection circuit is also used to instruct the adjustment module to adjust the chirp effect in the first optical emitting module based on the chirp coefficient of the first optical emitting module.

15. The optical module according to claim 14, characterized in that, The chirp detection circuit is further configured to determine that the chirp coefficient of the first optical emitting module is greater than a preset threshold, and to send an adjustment signal to the adjustment module according to the chirp coefficient of the first optical emitting module. The adjustment module is configured to adjust the chirp effect in the first optical emitting module according to the adjustment signal.

16. The optical module according to claim 15, characterized in that, The adjustment signals include bias / bias current adjustment signals and / or temperature adjustment signals.

17. The optical module according to any one of claims 9-12, characterized in that, In the optical module, the optical communication branch where the first optical transmitting module is located is the first branch, and the optical module also includes a second branch equipped with a second optical transmitting module. The second optical emitting module is used to generate a second optical signal and transmit the second optical signal to the first optical coupler; The first optical coupler is also used to perform splitting processing based on the second optical signal to obtain a third output signal and a fourth output signal; The optical delay line is also used to delay the third output signal to obtain a second delayed signal; The optical filter is also used to filter the fourth output signal to obtain a second filtered signal; The second optocoupler is further configured to combine the second delayed signal and the second filtered signal to obtain a second output detection signal, and send the second output detection signal to the chirp detection circuit. The chirp detection circuit is used to calculate the chirp coefficient of the second optical emission module based on the second output detection signal.

18. A chirp detection method, characterized in that, The method is applied to an optical module, the optical module including a first optical coupler, an optical delay line, an optical filter, a second optical coupler, a first optical emission module, and a chirp detection circuit; the method includes: The first optical emitting module generates a first optical signal and transmits the first optical signal to the first optical coupler; The first optical coupler performs splitting processing based on the first optical signal to obtain a first output signal and a second output signal; The optical delay line delays the first output signal to obtain a first delayed signal. The optical filter filters the second output signal to obtain a first filtered signal; The second optocoupler performs a combining process on the first delayed signal and the first filtered signal to obtain a first output detection signal, and sends the first output detection signal to the chirp detection circuit. The chirp detection circuit calculates the chirp coefficient of the first optical emitting module based on the first output detection signal; wherein the first output detection signal has two pulses; the optical signal is a Gaussian pulse signal, and the chirp coefficient of the first optical emitting module is: ， in, α Let be the chirp coefficient of the first optical emitting module. t 1 represents the time of the previous pulse in the first output detection signal. t 2 represents the duration of the next pulse in the first output detection signal. P 1 represents the peak power of the previous pulse in the first output detection signal. P 2 is the peak power of the next pulse in the first output detection signal, S is the slope of the optical filter, D is the delay of the optical delay line, and C is a constant.

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