Modulator, optical transmitter component, silicon photonics module and operating point locking method thereof

Abstract

The present invention discloses a modulator, an optical transmitter assembly, a silicon photonics module, and an operating point locking method therefor. The modulator includes at least one optical channel, each equipped with two parallel modulation arms. The combined light from the two modulation arms on each optical channel passes through a 2-to-2 MMI structure, outputting two light channels with different phases. Each optical channel corresponds to two MPD detection units, which respectively convert the first and second optical signals output by the MMI structure into current signals for output. The modulator is electrically connected to a control unit and a DSP unit. The modulation arms of the modulator receive electrical signals from the DSP unit and modulate the optical signals. The two MPD detection units in each optical channel of the modulator transmit the output photocurrents MPDXB and MPDXD, respectively, to the control unit. The present invention ensures the constant values ​​of MPDXB+MPDXD in each optical channel of the silicon photonics modulator, and the equality of the MPDXB photocurrent and MPDXD photocurrent values ​​in each optical channel, thereby ensuring stable operation of the optical module under various ambient temperatures.

Description

Technical Field

[0001] The present invention belongs to the field of optical communication technology, and in particular relates to a modulator, an optical transmitting component, a silicon photonic module and an operating point locking method thereof. Background Art

[0002] 5G transport and data center construction are placing strong demands on optical modules with high speeds, small size, low cost, and low power consumption. Single-wavelength 100Gb / s technology can effectively leverage the bandwidth improvements and iterative evolution of optoelectronic chips, as well as highly integrated processes and packaging, to achieve higher interface density and lower costs while meeting equivalent bandwidth requirements and reducing optical complexity. Regarding packaging, the QSFP-DD MSA and OSFP MSA have respectively released specifications for 400Gb / s QSFP-DD and OSFP, utilizing an 8×56Gb / s electrical interface. In 2021, the QSFP-DD MSA further updated and released version 6.01 of the specification, including the 400Gb / s QSFP112. The QSFP112 MSA, spearheaded by Alibaba and Baidu, also released relevant specifications to promote domestic data center interconnect applications. The applicant designed the first generation of 400Gb / s optical modules based on a single-wavelength 100Gb / s optical module, primarily based on an 8×56Gb / s electrical interface, requiring the use of a DSP to implement 8:4G earbox rate conversion. The applicant has also designed a second-generation 400Gb / s optical module using a 4×112Gb / s electrical interface, which can simplify the connection between the switch chip and the optical module, thereby reducing power consumption and cost.

[0003] In terms of optical interface technology, 400Gb / s 500m DR4 optical modules based on single-mode fiber have entered commercial use. Three solutions are available: EML, DML, and silicon photonics. The EML solution is the most mature traditional solution. At the end of 2020, Lumentum released a 100Gb / s PAM4 DML chip, providing strong support for the DML solution. This solution requires temperature control to ensure bandwidth performance at commercial temperatures (0-70°C). Silicon photonics solutions are fragmented and inconsistent across the industry, posing challenges to achieving scale advantages. Currently, 400Gbps optical modules on the market primarily utilize EML+TEC / DML+TEC solutions. Silicon photonics modules, however, eliminate the need for TEC and achieve high speeds, low costs, and low power consumption to meet market demand. However, silicon photonics modules can experience operating point drift when the operating environment changes. Therefore, it is necessary to design a 400G silicon photonics module with a single-channel transmission rate of 100Gbps that meets the required performance, as well as its silicon photonics modulator. Summary of the Invention

[0004] The purpose of the present invention is to overcome at least one defect in the prior art and provide a modulator, an optical transmission component, a silicon photonic module and an operating point locking method thereof.

[0005] The technical solution of the present invention is implemented as follows: The present invention discloses a modulator, including at least one optical channel, each optical channel is provided with two parallel modulation arms, the combined light of the two modulation arms on each optical channel passes through a 2-to-2 MMI structure, and two light paths are output according to different phases, each optical channel corresponds to two MPD detection units, wherein the first MPD detection unit is used to convert the first optical signal output by the MMI structure into a current signal output, and the second MPD detection unit is used to convert the second optical signal output by the MMI structure into a current signal output.

[0006] Furthermore, the first optical signal output by the MMI structure of each optical channel is divided into detection light and signal light through the first output end splitter, and the first MPD detection unit is used to convert the detection light signal output by the first output end splitter into a current signal output. The second optical signal output by each MMI structure is divided into detection light and signal light through the second output end splitter, and the second MPD detection unit is used to convert the detection light signal output by the second output end splitter into a current signal output. The signal light output by the second output end splitter is output as the signal light of the optical channel.

[0007] Furthermore, the modulation arm is used to receive an electrical signal and modulate an optical signal;

[0008] The modulator is provided with a branching unit, which includes at least one input-end brancher. The branching unit is used to divide at least one optical input into at least two optical outputs, which correspond one-to-one to the multiple optical channels.

[0009] Furthermore, the modulator is provided with at least one optical input end and multiple optical output ends, the number of the optical output ends of the modulator is the same as the number of optical channels, when each input end splitter has one input end and at least two output ends, the number of the input end splitters is the same as the number of the optical input ends of the modulator, the input end of the input end splitter corresponds one-to-one to the optical input end of the modulator, each output end of the input end splitter corresponds one-to-one to the input end of each optical channel, and the output end of each optical channel corresponds one-to-one to the optical output end of each modulator.

[0010] The present invention discloses an optical transmission component, comprising at least one laser and the modulator as described above, wherein the optical input end of the modulator corresponds one-to-one with the laser, and the modulator is used to receive laser light output by at least one laser and output at least two modulated optical signals.

[0011] Furthermore, the optical transmission assembly of the present invention further comprises a transmission end assembly, wherein the transmission end assembly is used to receive the optical signal output from the optical output end of the modulator and couple it to the optical fiber.

[0012] The present invention discloses a silicon photonic module, comprising the light emitting component as described above. The modulator of the light emitting component is electrically connected to a control unit and a DSP processing unit. The modulation arm of the modulator is used to receive the electrical signal of the DSP processing unit and modulate the optical signal. The two MPD detection units of each optical channel of the modulator are used to transmit the output photocurrents MPDXB and MPDXD to the control unit respectively.

[0013] Furthermore, a switch selection circuit and an acquisition circuit are provided between the modulator and the control unit. The switch selection circuit has multiple input terminals and an output terminal. The multiple input terminals of the switch selection circuit are electrically connected to the multiple MPD detection units in a one-to-one correspondence, and are used to switch the photocurrents output by the multiple MPD detection units to any photocurrent output. The output terminal of the switch selection circuit is electrically connected to the input terminal of the acquisition circuit. The acquisition circuit is used to convert a selected photocurrent into a sampling voltage and then input it to the control unit through an operational amplifier.

[0014] Furthermore, the laser is used to receive a driving current, and by adjusting the driving current of the laser corresponding to each optical channel, the sum of MPDXB and MPDXD of each optical channel of the modulator is made equal to the target value of the optical channel or the difference is within the allowable error range, thereby realizing an automatic power control function;

[0015] Each optical channel of the modulator is used to receive a heater voltage to adjust the operating point of each optical channel of the modulator. By adjusting the heater voltage received by the Xth optical channel, the MPDXB photocurrent value and the MPDXD photocurrent value of the Xth optical channel are made equal or the difference between them is within the allowable error range, thereby locking the operating point of the Xth optical channel.

[0016] The present invention discloses a method for locking an operating point of a silicon photonic module, comprising the following steps:

[0017] At any operating temperature, the photocurrent values ​​MPDXB and MPDXD of each optical channel of the modulator are collected in real time, and the driving current of the laser is adjusted in real time to make the sum of MPDXB and MPDXD of each optical channel of the modulator equal to the target value corresponding to the optical channel or the difference is within the allowable error range;

[0018] At any operating temperature, the heater voltage of each optical channel of the modulator is adjusted in real time to make the MPDXB photocurrent value and the MPDXD photocurrent value of each optical channel equal or the difference between them is within the allowable error range.

[0019] The present invention has at least the following beneficial effects: The silicon optical modulator employed in the present invention includes at least one optical channel, each equipped with two parallel modulation arms. The combined light from the two modulation arms passes through a 2-to-2 MMI structure, outputting two light paths according to different phases: Phase 1 light and Phase 2 light. 3% of Phase 1 light is detected by MPDXB, while 97% of Phase 1 light is useless. 3% of Phase 2 light is detected by MPDXD, while 97% of Phase 2 light is output as signal light. The modulation arm of the modulator receives electrical signals from a DSP processing unit and modulates the optical signal. The two MPD detection units in each optical channel transmit the output photocurrents MPDXB and MPDXD, respectively, to a control unit. The present invention implements automatic power control (APC) by locking the MPDXB+MPDXD values ​​of each optical channel of the silicon photomodulator (e.g., MPD1B+MPD1D and MPD3B+MPD3D), based on the photocurrents MPDXB and MPDXD corresponding to each optical channel monitored by the MPD detection unit. Furthermore, by locking the MPDXB photocurrent value of each optical channel to be equal to the MPDXD photocurrent value (i.e., MPD1B=MPD1D, MPD2B=MPD2D, MPD3B=MPD3D, and MPD4B=MPD4D), the operating point of each optical channel is locked. By using this solution, the present invention enables a 400G silicon photonics module with a single-channel transmission rate of 100Gbps to operate stably under different ambient temperatures, and the module performance meets the requirements of IEEE802.3. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0021] Figure 1 1 is a schematic diagram of the principle of a modulator provided by an embodiment of the present invention;

[0022] Figure 2 1 is a schematic diagram of a transmitting portion provided by an embodiment of the present invention;

[0023] Figure 3 A circuit diagram of a switch selection circuit and an acquisition circuit provided in an embodiment of the present invention;

[0024] Figure 4 A system block diagram of a silicon photonics module provided in an embodiment of the present invention;

[0025] Figure 5This is a flow chart of a method for locking an operating point of a silicon photonic module provided by an embodiment of the present invention;

[0026] Figure 6 This is a schematic diagram of a module provided by an embodiment of the present invention at a working point. DETAILED DESCRIPTION

[0027] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0028] The terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of the technical features indicated. Therefore, features specified as "first" or "second" may explicitly or implicitly include one or more of such features; in the description of the present invention, unless otherwise specified, "plurality" or "several" means two or more.

[0029] Example 1

[0030] See also Figure 1 An embodiment of the present invention provides a modulator including at least one optical channel, each optical channel being provided with two parallel modulation arms. The combined light from the two modulation arms on each optical channel passes through a 2-to-2 MMI structure, outputting two light paths according to different phases, namely, phase 1 light and phase 2 light. Each optical channel corresponds to two MPD detection units (similar to the function of a photodiode), wherein the first MPD detection unit is used to convert the first optical signal output by the MMI structure, namely, phase 1 light, into a current signal output, and the second MPD detection unit is used to convert the second optical signal output by the MMI structure, namely, phase 2 light, into a current signal output.

[0031] Furthermore, the first optical signal output by the MMI structure of each optical channel, namely, phase 1 light, is split into detection light (3% of phase 1 light) and signal light (97% of phase 1 light) by the first output end splitter. The first MPD detection unit is used to convert the detection light signal (3% of phase 1 light) output by the first output end splitter into a current signal MPDXB for output. The signal light signal (97% of phase 1 light) output by the first output end splitter is useless.

[0032] The second optical signal output by each MMI structure, namely the phase 2 light, is split into detection light (3% of the phase 2 light) and signal light (97% of the phase 2 light) by the second output end splitter. The second MPD detection unit is used to convert the detection light signal (3% of the phase 2 light) output by the second output end splitter into a current signal MPDXD for output. The signal light (97% of the phase 2 light) output by the second output end splitter is output as the signal light of this optical channel.

[0033] Each optical channel is provided with an MPD detection unit for detecting optical power, namely an MPD unit, which outputs a current related to the light intensity.

[0034] The phase modulation of the two branches of the MZM modulator of the present invention is related to the electro-optical characteristics of the substrate, and the phase change of each branch is converted into a change in the output optical power of the two-way combined light.

[0035] The MZM modulator of this invention uses voltage-phase modulation. Different voltages produce different phases. The same phase increases the intensity of the combined light, while opposite phases cancel it out. A bias voltage is applied to one electrode in the modulator arm, while the other electrode in the modulator arm receives a high-speed electrical signal. A heater voltage is used to alter the phase of the light in the modulator arm. The heater voltage is equivalent to heating to alter the phase of light. When the phases of the two light paths output by the 2-by-2 MMI structure—Phase 1 and Phase 2—are equal, i.e., MPDXB = MPDXD—the module is at its operating point, which is approximately half of the maximum light intensity.

[0036] Furthermore, the modulation arm is used to receive electrical signals and modulate optical signals.

[0037] Furthermore, the modulator is provided with a branching unit, which includes at least one input-end splitter. The branching unit is used to split at least one optical input into at least two optical outputs, corresponding one-to-one to the multiple optical channels.

[0038] Furthermore, the modulator is provided with at least one optical input end and multiple optical output ends, the number of the optical output ends of the modulator is the same as the number of optical channels, when each input end splitter has one input end and at least two output ends, the number of the input end splitters is the same as the number of the optical input ends of the modulator, the input end of the input end splitter corresponds one-to-one to the optical input end of the modulator, each output end of the input end splitter corresponds one-to-one to the input end of each optical channel, and the output end of each optical channel corresponds one-to-one to the optical output end of each modulator.

[0039] When the optical module of the present invention has four optical channels, two lasers can be used. The optical signal emitted by the first laser enters the silicon optical modulator and is evenly divided into two optical channels by the first input end splitter, which are the first optical channel and the second optical channel. The optical signal emitted by the second laser enters the silicon optical modulator and is evenly divided into two optical channels by the second input end splitter, which are the third optical channel and the fourth optical channel. Each channel can transmit an optical signal of 100Gbps, so only two lasers are needed to achieve 4X100Gbps. Of course, one high-power laser can also be used, which is divided into four channels. Both methods can achieve 400G. If there is no optical splitting, four channels will require four lasers, which is more expensive. 800G can be achieved using four lasers and an MZ silicon optical modulator containing eight modulated optical channels.

[0040] The modulator includes four modulated optical channels, each consisting of two modulation arms. The combined light from the two modulation arms passes through a 2-to-2 MMI (Multi-Mode Multi-Integrated Multiplexing) to output two optical paths, phase 1 and phase 2, based on their phases. 3% of the phase 1 light is detected by MPDXB, while 97% of the phase 1 light is useless. 3% of the phase 2 light is detected by MPDXD, while 97% of the phase 2 light is output as signal light. The silicon photonics MZ modulator comprises eight MPD units: MPD1B, MPD1D, MPD2B, MPD2D, MPD3B, MPD3D, MPD4B, and MPD4D. The silicon photonics MZ modulator receives high-speed electrical signals and modulates them. The four modulated optical signals are then output from the silicon photonics MZ modulator.

[0041] When the first input end splitter splits light equally into the first channel and the second channel, the light in the first channel and the second channel is approximately equal, and controlling the optical power and current value of the first channel is equivalent to also controlling the optical power and current value of the second channel.

[0042] When the second input end splitter splits light equally into the third optical channel and the fourth optical channel, the light in the third optical channel and the fourth optical channel is approximately equal, and controlling the third optical channel is equivalent to controlling the optical power current value of the fourth optical channel.

[0043] Example 2

[0044] See also Figure 1 and Figure 2 An embodiment of the present invention discloses an optical transmission component, comprising at least one laser and a modulator as described in Example 1, wherein the optical input end of the modulator corresponds one-to-one with the laser, and the modulator is used to receive laser light output by at least one laser and output at least two modulated optical signals.

[0045] Furthermore, the optical transmission assembly of the present invention further includes a transmitting end assembly, which is used to receive the optical signal output from the optical output end of the modulator and couple it to the FA (fiber array).

[0046] Furthermore, the laser, modulator, and transmitter assembly are fixed on a substrate.

[0047] Furthermore, a first lens, an isolator, and a second lens are positioned between each laser and the modulator's optical input. The optical signal emitted by the laser is coupled into the modulator's optical input via the first lens, isolator, and second lens, or the first lens, second lens, and isolator, in sequence. The first lens diverges the optical signal emitted by the laser, the isolator reduces reflections, and the second lens focuses the optical signal. The first lens, isolator, and second lens increase coupling tolerance and improve coupling efficiency. Arranging the first lens, second lens, and isolator in this order shortens the optical path by 1 mm.

[0048] Furthermore, the first lens, the isolator, and the second lens are also fixed on the substrate.

[0049] Example 3

[0050] See also Figures 1 to 4 The present invention discloses a 400G silicon photonic module with low power consumption and low cost, a transmission distance of up to 2 km, and a single-channel transmission rate of 100Gbps, suitable for data center applications. The silicon photonic module includes a power management circuit, an electrical interface circuit, an optical receiving component, a control unit, a DSP processing unit, and the optical transmitting component described in Example 2. The modulator of the optical transmitting component is electrically connected to the control unit and the DSP processing unit. The modulator arm of the modulator is used to receive electrical signals from the DSP processing unit and modulate the optical signal. The two MPD detection units in each optical channel of the modulator are used to transmit the output photocurrents MPDXB and MPDXD to the control unit, respectively.

[0051] The power management circuit is used to supply power to the entire optical module. The electrical interface circuit, optical transmitting component, optical receiving component are electrically connected to the DSP processing unit. The control unit is electrically connected to the DSP processing unit. The control unit adopts an MCU.

[0052] The optical receiving assembly includes a photodetector and a TIA. The photodetector is used to convert the optical signal into an electrical signal and transmit it to the TIA. The TIA is used to amplify the electrical signal and output it to the DSP processing unit. The optical receiving assembly also includes a receiving end assembly, which is used to couple the received optical signal into the photodetector.

[0053] A silicon lens is located between the receiving assembly and the photodetector. The receiving assembly couples the received optical signal into the photodetector through the silicon lens. The silicon lens is fixed to a silicon spacer. The silicon lens focuses light. The transmitting and receiving assemblies can utilize existing technologies.

[0054] Furthermore, a switch selection circuit and an acquisition circuit are provided between the modulator and the control unit. The switch selection circuit has multiple input terminals and an output terminal. The multiple input terminals of the switch selection circuit are electrically connected to the multiple MPD detection units in a one-to-one correspondence, and are used to switch the photocurrents output by the multiple MPD detection units to any one photocurrent output. The output terminal of the switch selection circuit is electrically connected to the input terminal of the acquisition circuit. The acquisition circuit is used to convert the selected photocurrent into a sampling voltage and then input it to the control unit through an op amp. The acquisition circuit includes an op amp and a sampling circuit for converting a current signal into a voltage signal. The input terminal of the sampling circuit is connected to the output terminal of the switch selection circuit, the output terminal of the voltage sampling circuit is connected to the input terminal of the op amp, and the output terminal of the op amp (outputting the ADC value) is electrically connected to the control unit.

[0055] The switch selection circuit uses a switching chip U15. Multiple input terminals of the switching chip U15 are electrically connected to the multiple MPD detection units of the modulator in a one-to-one correspondence. The output terminal of the switching chip U15 is electrically connected to the input terminal of the acquisition circuit. The control terminal of the switching chip U15 is electrically connected to the control unit, which controls the conduction or disconnection of each channel of the switching chip.

[0056] The acquisition circuit includes an op amp U13. The non-inverting output terminal of the op amp U13 is connected to one end of a resistor R34 and one end of a resistor R33. The other end of the resistor R33 is grounded. The other end of the resistor R34 is connected to a voltage VEEF, one end of a resistor R35, and one end of a capacitor C174. The other end of the capacitor C174 is grounded. The other end of the resistor R35 is connected to the output terminal of the switching chip. The inverting output terminal of the op amp U13 is respectively connected to one end of a resistor R36, one end of a resistor R60, one end of a resistor R37, and one end of a capacitor C234. The other end of the resistor R36 is connected to the P4 terminal. The output terminal of the switching chip is connected to the P4 terminal. The other end of the resistor R60 is grounded. The other end of the resistor R37 and the other end of the capacitor C234 are both connected to the output terminal of the op amp U13. The P4 terminal is a reserved detection point that can be measured with a probe for easy detection.

[0057] Furthermore, the current source or control unit, or a DAC chip controlled by the control unit, outputs a laser drive current, LD BIAS, to the laser, thereby regulating the laser's luminous intensity. The present invention can use a DAC chip that outputs several hundred mA of current to output the laser drive current, LD BIAS, to the laser, or it can use an amplifier to build a current source circuit to output the laser drive current, LD BIAS, to the laser.

[0058] The control unit or the DAC chip controlled by the control unit outputs a DAC value as a heater voltage, thereby adjusting the operating point.

[0059] The power management circuit provides the modulator with the required bias voltage VB. The present invention can also use a voltage source constructed by a DAC chip + an amplifier to output the DAC value as the heater voltage.

[0060] Furthermore, the laser is used to receive a driving current, and by adjusting the driving current of the laser corresponding to each optical channel, the sum of MPDXB and MPDXD of each optical channel of the modulator is made equal to or differs from the target value corresponding to the optical channel within an allowable error range (the allowable error range is set as needed), thereby realizing an automatic power control function, wherein X is a positive integer greater than or equal to 1 and less than or equal to N, and N is the number of optical channels of the modulator.

[0061] Each optical channel of the modulator is used to receive a heater voltage to adjust the operating point of each optical channel of the modulator. By adjusting the heater voltage received by the Xth optical channel, the MPDXB photocurrent value and the MPDXD photocurrent value of the Xth optical channel are made equal or the difference is within the allowable error range (the allowable error range is set as needed), thereby locking the operating point of the Xth optical channel.

[0062] Theoretically, when the MPDXB photocurrent value of the Xth optical channel is equal to the MPDXD photocurrent value, the heater is considered to be in the normal working point state. Otherwise, the heater voltage needs to be adjusted to restore it to the normal working state.

[0063] Heaer voltage is equivalent to heating to change the phase of light. When the phases of the two lights output by the 2-way 2MMI are equal: Phase 1 light and Phase 2 light, that is, MPDXB=MPDXD, the module is at the working point, which is about half of the maximum light. Figure 6 shown.

[0064] Example 4

[0065] See also Figure 5 The embodiment of the present invention discloses a method for locking the working point of a silicon photonic module, comprising the following steps:

[0066] Determine the target value corresponding to each optical channel;

[0067] At any operating temperature, the photocurrent values ​​MPDXB and MPDXD of each optical channel of the modulator are collected in real time, and the driving current of the laser is adjusted in real time so that the sum of MPDXB and MPDXD of each optical channel of the modulator is equal to the target value corresponding to the optical channel (if the difference is within the allowable error range, it is also equal by default);

[0068] At any operating temperature, the heater voltage of each optical channel of the modulator is adjusted in real time to make the MPDXB photocurrent value and the MPDXD photocurrent value of each optical channel equal (if the difference is within the allowable error range, it is also equal by default).

[0069] The basic principle of operating point locking is to determine based on the MPDxB and MPDxD photocurrent values ​​of the monitoring channel. When the two are equal, the heater is considered to be in the normal operating point state. Otherwise, the heater voltage needs to be adjusted to restore it to the normal operating state.

[0070] The target value for each optical channel is determined as follows: the modulator heater voltages, laser drive currents, and DSP configuration are adjusted to ensure that the transmitter indicators are within acceptable ranges. The MPDXB+MPDXD values ​​for each optical channel are recorded as the target values.

[0071] The present invention provides a 400G silicon photonics module with low power consumption, low cost, and a single-channel transmission rate of 100Gbps, suitable for data center applications. The present invention uses the above solution to achieve stable operation of the optical module under different ambient temperatures.

[0072] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A modulator, characterized in that: The system comprises at least one optical channel, each of which is provided with two parallel modulation arms. The combined light of the two modulation arms on each optical channel passes through a 2-to-2 MMI structure, and two light paths are output according to different phases. Each optical channel corresponds to two MPD detection units, wherein the first MPD detection unit is used to convert the first optical signal output by the MMI structure into a current signal MPDXB for output, and the second MPD detection unit is used to convert the second optical signal output by the MMI structure into a current signal MPDXD for output; The first optical signal output by the MMI structure of each optical channel is divided into detection light and signal light by the first output end splitter. The first MPD detection unit is used to convert the detection light signal output by the first output end splitter into a current signal output. The second optical signal output by each MMI structure is divided into detection light and signal light by the second output end splitter. The second MPD detection unit is used to convert the detection light signal output by the second output end splitter into a current signal output. The signal light output by the second output end splitter is output as the signal light of the optical channel.

2. The modulator according to claim 1, wherein: The modulation arm is used to receive the electrical signal and modulate the optical signal; The modulator is provided with a branching unit, which includes at least one input-end brancher. The branching unit is used to divide at least one optical input into at least two optical outputs, which correspond one-to-one to the multiple optical channels.

3. The modulator according to claim 1, wherein: The modulator is provided with at least one optical input end and multiple optical output ends. The number of the optical output ends of the modulator is the same as the number of optical channels. When each input end splitter has one input end and at least two output ends, the number of the input end splitters is the same as the number of the optical input ends of the modulator. The input ends of the input end splitters correspond one-to-one with the optical input ends of the modulator, each output end of the input end splitters corresponds one-to-one with the input end of each optical channel, and the output end of each optical channel corresponds one-to-one with the optical output end of each modulator.

4. A light emitting assembly comprising at least one laser, characterized in that: It also includes the modulator according to any one of claims 1 to 3, wherein the optical input end of the modulator corresponds one-to-one with the laser, and the modulator is used to receive laser light output by at least one laser and output at least two modulated optical signals.

5. The light emitting assembly according to claim 4, wherein: The device also includes a transmitting end component, which is used to receive the optical signal output from the optical output end of the modulator and couple the optical signal to the optical fiber.

6. A silicon photonics module, characterized in that: The optical transmission component comprises the optical transmission component as described in claim 4 or 5, wherein the modulator of the optical transmission component is electrically connected to the control unit and the DSP processing unit, the modulation arm of the modulator is used to receive the electrical signal of the DSP processing unit and modulate the optical signal, and the two MPD detection units of each optical channel of the modulator are used to transmit the output photocurrents MPDXB and MPDXD to the control unit respectively.

7. The silicon photonic module according to claim 6, wherein: A switch selection circuit and an acquisition circuit are provided between the modulator and the control unit. The switch selection circuit has multiple input terminals and an output terminal. The multiple input terminals of the switch selection circuit are electrically connected to the multiple MPD detection units in a one-to-one correspondence, and are used to switch the photocurrents output by the multiple MPD detection units to any photocurrent output. The output terminal of the switch selection circuit is electrically connected to the input terminal of the acquisition circuit. The acquisition circuit is used to convert the selected photocurrent into a sampling voltage and then input it into the control unit through an operational amplifier.

8. The silicon photonic module according to claim 6, wherein: The laser is used to receive a driving current. By adjusting the driving current of the laser corresponding to each optical channel, the sum of MPDXB and MPDXD of each optical channel of the modulator is made equal to the target value of the optical channel or the difference is within the allowable error range, thereby realizing an automatic power control function. Each optical channel of the modulator is used to receive a heater voltage to adjust the operating point of each optical channel of the modulator. By adjusting the heater voltage received by the Xth optical channel, the MPDXB photocurrent value and the MPDXD photocurrent value of the Xth optical channel are made equal or the difference between them is within the allowable error range, thereby locking the operating point of the Xth optical channel.

9. A method for locking the working point of a silicon photonic module, characterized in that: The silicon photonics module adopts the modulator according to any one of claims 1 to 3; The method for locking the working point of a silicon photonic module includes the following steps: At any operating temperature, the photocurrents MPDXB and MPDXD of each optical channel of the modulator are collected in real time, and the driving current of the laser is adjusted in real time to ensure that the sum of MPDXB and MPDXD of each optical channel of the modulator is equal to the target value corresponding to the optical channel or the difference is within the allowable error range; At any operating temperature, the heater voltage of each optical channel of the modulator is adjusted in real time to make the MPDXB photocurrent value and the MPDXD photocurrent value of each optical channel equal or the difference between them is within the allowable error range.

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