A multi-channel semiconductor laser driving current calibration method, system and gate board

Abstract

The application is suitable for the field of automatic test calibration technology, and provides a multi-channel semiconductor laser drive current calibration method, system and gating board.The method comprises the following steps: connecting the to-be-calibrated drive channel with a current measuring device, and electrically connecting other drive channels except the to-be-calibrated drive channel with a laser; sequentially issuing each calibration voltage point corresponding to the to-be-calibrated drive channel as a set drive voltage value to the drive board, collecting the actual output current under each set drive voltage value by the current measuring device, obtaining the voltage-current measurement data of the to-be-calibrated drive channel, obtaining the voltage-current calibration relationship corresponding to each to-be-calibrated drive channel, and writing into the storage system, etc.The application has the advantages that the differences between different drive boards, different drive channels and different laser loads can be compensated, and compared with the traditional method, the precision of multi-channel laser drive current control can be improved.

Description

Technical Field

[0001] This invention belongs to the field of automated testing and calibration technology, and particularly relates to a method, system and gating board for calibrating the driving current of a multi-channel semiconductor laser. Background Technology

[0002] DBR-type wide-tunable semiconductor lasers typically include multiple current-driven channels that require independent control. The current applied to different drive channels will affect the laser's grating reflection conditions, resonant phase, gain state, and output power. Therefore, during laser operating point switching, wavelength tuning, and output power control, the driver board needs to output a relatively accurate drive current to each drive channel according to the target operating point.

[0003] In actual products, the driver board typically generates a corresponding drive voltage based on a set value, and then outputs drive current to the corresponding channel of the laser through a voltage-to-current output circuit. Theoretically, the drive voltage and output current can be converted into a relationship based on circuit parameters. However, during mass production and actual assembly, due to the influence of complex factors such as resistors, current source devices, operational amplifiers, digital-to-analog converter references, circuit board parasitic parameters, and the discreteness of laser load characteristics, the same drive voltage set value may correspond to different actual output currents under different driver boards, different drive channels, or different laser load conditions, thus affecting the output accuracy of the laser.

[0004] Existing methods for calibrating lasers mainly involve disconnecting and connecting each channel under test to a measuring instrument, or measuring the output characteristics of the driver board individually. However, when multiple driver channels work together on the same laser chip, if other channels are not properly connected or do not maintain their preset bias during calibration, the output state of the channel under test may not fully reflect the electrical connection conditions and load conditions during actual use, and the calibration results may still be inaccurate.

[0005] Therefore, it can be seen that the existing laser calibration process often relies only on a unified theoretical conversion relationship or only combines a small number of manual measurement results for simple correction. The calibration process is time-consuming, and the accuracy of the calibration results still needs to be improved. Summary of the Invention

[0006] The purpose of this application is to provide a method for calibrating the driving current of a multi-channel semiconductor laser, which aims to solve the problems that the existing laser calibration methods are time-consuming and the accuracy of the calibration results still needs to be improved.

[0007] This application provides a method for calibrating the driving current of a multi-channel semiconductor laser, the method comprising:

[0008] Determine the driving channel to be calibrated from the driving board with several driving channels, and obtain the calibration voltage point corresponding to each driving channel to be calibrated;

[0009] Connect the drive channel to be calibrated to the current measuring device, and electrically connect the other drive channels besides the drive channel to be calibrated to the laser;

[0010] Each calibration voltage point corresponding to the drive channel to be calibrated is sent to the drive board as a set drive voltage value in sequence. The current measuring device collects the actual output current under each set drive voltage value to obtain the voltage-current measurement data of the drive channel to be calibrated.

[0011] The next driving channel to be calibrated is connected to the current measurement device through the relay selection board to obtain the voltage-current measurement data of that channel. The process is repeated until the voltage-current measurement data of all driving channels to be calibrated are obtained.

[0012] Based on the voltage-current measurement data corresponding to each driving channel to be calibrated, the voltage-current calibration relationship corresponding to each driving channel to be calibrated is obtained, and the voltage-current calibration relationship is written into the non-volatile storage system of the driving board.

[0013] Preferably, the method for acquiring the actual output current under each set drive voltage value by the current measuring device is as follows:

[0014] After the driver board receives the set drive voltage value, it determines whether the output current of the drive channel to be calibrated has reached a stable state.

[0015] If and only if the output current reaches a stable state, the output current is sampled several times to obtain several current sample values, and the filtered average of the several current sample values ​​is used as the actual output current corresponding to the set drive voltage value.

[0016] Preferably, the method for obtaining the voltage-current calibration relationship of each driving channel to be calibrated based on the voltage-current measurement data of each driving channel to be calibrated is as follows:

[0017] Multiple sets of voltage-current measurement data for the same drive channel to be calibrated are screened for validity to obtain valid measurement data;

[0018] Based on the correspondence between the set drive voltage value and the actual output current in the effective measurement data, the linear calibration parameters of the drive channel to be calibrated are determined;

[0019] Based on the linear calibration parameters, a piecewise linear calibration model of voltage-current for the drive channel to be calibrated is constructed, and the piecewise linear calibration model is set as a voltage-current calibration relationship.

[0020] Preferably, the drive channel to be calibrated includes multiple channels selected from the following: right rating channel, left rating channel, phase channel, gain channel, and SOA channel.

[0021] When calibrating the drive channel to be calibrated, other drive channels besides the drive channel to be calibrated are not connected to the current measuring device.

[0022] Preferably, the method for connecting the next drive channel to be calibrated to the current measuring device via a relay selector board is as follows:

[0023] The driving board, the current measuring device, and the laser are all connected to the relay gating board, which includes multiple gating units, each gating unit being connected to a driving channel.

[0024] When a drive channel is identified as the drive channel to be calibrated, the gating unit corresponding to that drive channel opens the measurement path between it and the current measuring device, and closes the connection path between it and the laser.

[0025] Another objective of this application is to provide a multi-channel semiconductor laser drive current calibration system, the system comprising:

[0026] Driver board, relay gate board, current measuring device, and laser;

[0027] The driver board includes multiple driving channels and a voltage-to-current output circuit corresponding to each driving channel. The driving channels are used to output driving current to the laser.

[0028] The relay selection board is connected to the driver board, the current measuring device and the laser respectively. The relay selection board includes multiple selection units, and each selection unit is connected to a corresponding driver channel.

[0029] When a driving channel is identified as the driving channel to be calibrated, the gating unit corresponding to the driving channel to be calibrated opens the measurement path between the driving channel to be calibrated and the current measuring device, and disconnects the connection path between the driving channel to be calibrated and the laser.

[0030] The gating unit corresponding to the other drive channels (excluding the drive channel to be calibrated) disconnects the measurement path between the other drive channels and the current measuring device, and connects the other drive channels to the laser.

[0031] Preferably, the system further includes a host computer;

[0032] The host computer is used to sequentially send the calibration voltage points corresponding to the drive channel to be calibrated to the drive board as set drive voltage values.

[0033] It is also used to read the actual output current collected by the current measuring device under each set drive voltage value, and to generate the voltage-current calibration relationship of the drive channel to be calibrated based on the set drive voltage value and the corresponding actual output current.

[0034] Preferably, the relay gate board includes a gate array, a channel interface, a measurement interface, a laser interface, and a communication interface;

[0035] The channel interface is used to connect multiple drive channels of the driver board, the measurement interface is used to connect the current measurement device, the laser interface is used to connect multiple drive terminals of the laser, and the communication interface is used to receive strobe commands sent by the host computer.

[0036] Preferably, the gating array is a relay array, used to change the conduction state of each relay according to the gating command, so that one drive channel to be calibrated is connected to the current measuring device, and other drive channels are connected to the laser.

[0037] Another objective of this application is to provide a relay gating board, including a communication interface, a control unit, a gating array, a channel interface, a measurement interface, and a laser interface;

[0038] The channel interface is used to connect multiple drive channels of the driver board, the measurement interface is used to connect a current measuring device, the laser interface is used to connect a laser, and the communication interface is used to receive external strobe commands.

[0039] The gating array includes multiple gating units, and each gating unit is connected to a driving channel.

[0040] The control unit is used to control the gating unit corresponding to the driving channel to be calibrated to open the measurement path between the driving channel to be calibrated and the measurement interface according to the external gating command, and to disconnect the connection path between the driving channel to be calibrated and the laser interface.

[0041] The control unit is also used to control the gating unit corresponding to other drive channels besides the drive channel to be calibrated to disconnect the measurement path between the other drive channels and the measurement interface, and to connect the other drive channels and the laser interface.

[0042] The multi-channel semiconductor laser drive current calibration method provided in this application has the following advantages: It places the drive board, relay selection board, current measurement device, and laser in the same actual connection environment for channel-level calibration, which helps improve calibration accuracy. When calibrating a drive channel, that channel is included in the measurement path while other drive channels remain connected to the laser. The resulting voltage-current measurement data more closely approximates the output characteristics under actual operating conditions. The voltage-current calibration relationship formed by each channel is written into the non-volatile storage system of the drive board, allowing the calibration results to be directly retrieved during subsequent laser driving. It can compensate for differences between different drive boards, different drive channels, and different laser loads, improving the accuracy of drive current control. Attached Figure Description

[0043] Figure 1 A flowchart illustrating a method for calibrating the driving current of a multi-channel semiconductor laser, as provided in this application embodiment;

[0044] Figure 2 This is a flowchart illustrating the automated execution steps of a drive current calibration method provided in this application embodiment. Detailed Implementation

[0045] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0046] It is understood that the terms "first," "second," etc., used in this application may be used herein to describe various elements, but unless otherwise specified, these elements are not limited by these terms. These terms are used only to distinguish the first unit or module from another unit or module. For example, without departing from the scope of this application, the first unit may be referred to as the second unit, and similarly, the second module may be referred to as the first module.

[0047] like Figure 1 As shown, this embodiment provides a method for calibrating the driving current of a multi-channel semiconductor laser, which may specifically include the following steps:

[0048] Step S10: Determine the driving channel to be calibrated from the driving board with several driving channels, and obtain the calibration voltage point corresponding to each driving channel to be calibrated.

[0049] In this embodiment, before calibration, the driver board, relay gating board, and current measuring device can be connected to a host computer (e.g., a computer) to establish a communication connection between these devices. The host computer can be a computer, industrial control computer, or other control device capable of executing calibration programs. The current measuring device can be a digital multimeter, source meter, current acquisition module, or other instrument capable of measuring the output current of the drive channel. The driver board can include multiple drive channels and voltage-to-current output circuits corresponding to each drive channel. The voltage-to-current output circuits can be used to convert the set drive voltage value received by the driver board into the corresponding drive current and output it through the corresponding drive channel. For example, if the laser is a DBR-type wide-tunable semiconductor laser, the drive channels can include multiple channels selected from RIGHT GRATING, LEFT GRATING, PHASE, GAIN, and SOA channels.

[0050] The calibration voltage point refers to the discrete voltage setting values ​​that are pre-selected and sequentially sent to the driver board during the calibration process. Different drive channels can have different calibration voltage points. For example, the calibration voltage points for the GAIN channel can be selected as 0.2V, 0.4V, 0.6V, 0.8V, and 1.0V according to its operating current range; when the SOA channel has a larger operating current range, more or higher calibration voltage points can be selected. By measuring multiple calibration voltage points, the actual output current variation of the drive channel under different set drive voltage values ​​can be obtained.

[0051] Step S20: Connect the drive channel to be calibrated to the current measuring device, and electrically connect the other drive channels besides the drive channel to be calibrated to the laser.

[0052] In this embodiment, all channels in non-test state are normally connected to the laser. The laser can be a DBR-type wide-tunable semiconductor laser, etc., and this application does not limit this. When calibrating a certain driving channel, the uncalibrated channels are still connected to the laser in a manner close to the actual working state. If necessary, the driving board can also apply a preset bias current or preset bias voltage to these channels. Here, other uncalibrated channels are not disconnected from the laser, nor are they switched to the current measurement device. This can minimize the influence of complex factors such as current source devices, operational amplifiers, digital-to-analog converter references, circuit board parasitic parameters, and laser load characteristic dispersion, thereby improving the final calibration accuracy.

[0053] Electrical connection refers to the conductive connection established between the drive channel and the corresponding drive terminal of the laser, enabling the drive channel to maintain its original connection state. Depending on specific calibration requirements, other drive channels can be maintained by the drive board for normal operation bias, safety bias, or output shutdown while maintaining connection. The purpose is to avoid calibrating a particular drive channel without removing other drive channels from the laser or connecting them to the current measurement device, thus preventing significant discrepancies between the calibration connection state and the actual assembly state.

[0054] For example, when calibrating the PHASE channel, the relay selector board connects the PHASE channel to a current measuring device to measure the actual output current of the PHASE channel at each set drive voltage value; the RIGHT GRATING, LEFT GRATING, GAIN, and SOA channels remain connected to their corresponding drive terminals on the laser. Thus, multiple drive channels can be calibrated sequentially without frequent disconnection and reconnection of the circuitry, simulating actual conditions and improving calibration accuracy.

[0055] Step S30: The calibration voltage points corresponding to the drive channel to be calibrated are sequentially sent to the drive board as set drive voltage values. The current measuring device collects the actual output current under each set drive voltage value to obtain the voltage-current measurement data of the drive channel to be calibrated.

[0056] In this embodiment, the set drive voltage value refers to the target voltage setting sent by the host computer to the drive board. After receiving the set drive voltage value, the drive board generates an output current through the corresponding voltage-to-current output circuit. The actual output current refers to the real output current of the drive channel collected by the current measuring device under the set drive voltage value.

[0057] Voltage-current measurement data can include one or more sets of corresponding data between set drive voltage values ​​and actual output currents. For example, if three set drive voltage values ​​of 0.2V, 0.4V, and 0.6V are sequentially sent to a certain drive channel, and the current measuring device collects three actual output currents of 3.1mA, 6.4mA, and 9.8mA respectively, then the drive channel generates three sets of voltage-current measurement data: 0.2V corresponds to 3.1mA, 0.4V corresponds to 6.4mA, and 0.6V corresponds to 9.8mA.

[0058] Step S40: Connect the next drive channel to be calibrated to the current measuring device through the relay gate, and obtain the voltage-current measurement data of the channel. Switch sequentially until the voltage-current measurement data corresponding to all drive channels to be calibrated are obtained.

[0059] In this embodiment, the relay selector board is used to switch measurement paths between different drive channels. After all calibration voltage points of a drive channel to be calibrated have been collected, the relay selector board disconnects the measurement path between that drive channel and the current measuring device, and connects the next drive channel to be calibrated to the current measuring device. Subsequently, step S30 is repeated for the next drive channel to be calibrated to obtain the voltage-current measurement data of that channel.

[0060] Step S50: Based on the voltage-current measurement data corresponding to each driving channel to be calibrated, obtain the voltage-current calibration relationship corresponding to each driving channel to be calibrated, and write the voltage-current calibration relationship into the non-volatile storage system of the driving board.

[0061] In this embodiment, the purpose of writing the voltage-current calibration relationship into the non-volatile storage system of the driver board is to enable the driver board to read the voltage-current calibration relationship of the corresponding drive channel based on the target current when driving the laser in subsequent use, thereby obtaining the set value of the drive voltage corresponding to the target current. This reduces the deviation between the unified theoretical conversion relationship and the actual output characteristics. After writing the voltage-current calibration relationship into the non-volatile storage system of the driver board, the driver board can read the voltage-current calibration relationship of the corresponding drive channel based on the target current when driving the laser in subsequent use, and obtain the set value of the drive voltage corresponding to the target current without relying on an external current measuring device to remeasure. This solution can reduce the error caused by the unified theoretical conversion relationship, enabling each driver board, each drive channel, and the corresponding laser combination to use its own calibration data for drive control.

[0062] For example, after a channel is calibrated, a mapping relationship between the drive voltage and the output current is established. This mapping relationship can be a continuous function mapping, a piecewise function mapping, etc. If the channel subsequently needs to output a target current, the driver board can retrieve the pre-stored calibration mapping relationship and directly match the drive voltage corresponding to the target current, avoiding the use of traditional interpolation methods and improving output accuracy.

[0063] The advantages of this application are: by placing the driver board, relay selection board, current measurement device, and laser in the same actual connection environment for channel-level calibration, it is beneficial to improve calibration accuracy; when calibrating a driver channel, the channel is included in the measurement path, while other driver channels remain connected to the laser, thereby obtaining voltage-current measurement data that is closer to the output characteristics under actual use conditions; the voltage-current calibration relationship formed by each channel is written into the driver board's non-volatile storage system, allowing the calibration results to be directly retrieved during subsequent laser driving; and it can compensate for differences between different driver boards, different driver channels, and different laser loads, improving the accuracy of drive current control.

[0064] In a preferred embodiment, the method for the current measuring device to collect the actual output current under each set drive voltage value is as follows:

[0065] After the driver board receives the set drive voltage value, it determines whether the output current of the drive channel to be calibrated has reached a stable state.

[0066] If and only if the output current reaches a stable state, the output current is sampled several times to obtain several current sample values, and the filtered average of the several current sample values ​​is used as the actual output current corresponding to the set drive voltage value.

[0067] In this embodiment of the application, the output current of the drive channel to be calibrated can be determined to be stable by waiting for a preset stabilization time or by continuously reading the measured values ​​of the current measuring device and by determining the amount of change between the continuous measured values.

[0068] In this embodiment, the current can be determined to be stable by waiting for a preset stabilization time or by continuously reading the measured values ​​from the current measuring device. For example, by continuously reading the current value multiple times under the same set drive voltage value, the output current can be considered stable when the change between consecutive readings is less than a preset allowable range. The filtered mean can be obtained by averaging after removing significantly deviating sample values ​​to reduce the impact of instantaneous noise on the actual output current. Preferably, the channel number, set drive voltage value, actual output current, drive board temperature, timestamp, drive board serial number, and laser serial number of the drive channel to be calibrated can also be acquired and recorded. The above information can be used to trace the drive board, laser, and test conditions corresponding to a certain set of calibration data.

[0069] In a preferred embodiment, the method for obtaining the voltage-current calibration relationship of each driving channel to be calibrated based on the voltage-current measurement data of each driving channel to be calibrated is as follows:

[0070] Multiple sets of voltage-current measurement data for the same drive channel to be calibrated are screened for validity to obtain valid measurement data;

[0071] Based on the correspondence between the set drive voltage value and the actual output current in the effective measurement data, the linear calibration parameters of the drive channel to be calibrated are determined;

[0072] Based on the linear calibration parameters, a piecewise linear calibration model of voltage-current for the drive channel to be calibrated is constructed, and the piecewise linear calibration model is set as a voltage-current calibration relationship.

[0073] In this embodiment, effective measurement data refers to the measurement data used to generate the voltage-current calibration relationship. Linear calibration parameters can be the local slope and offset between two adjacent calibration voltage points, such as the slope and intercept between two adjacent calibration voltage points. Since the actual voltage-to-current output circuit may not perfectly satisfy the same linear relationship throughout the entire output range, multiple calibration voltage points can be divided into multiple adjacent intervals, and a linear relationship can be used within each adjacent interval to describe the change between the set drive voltage value and the actual output current. The linear relationships of multiple adjacent intervals together constitute a piecewise linear calibration model. For example, if a channel measures 3.1mA, 6.4mA, and 9.8mA at 0.2V, 0.4V, and 0.6V respectively, then a linear interval is formed between 0.2V and 0.4V, and another linear interval is formed between 0.4V and 0.6V. When the subsequent target current falls within a certain linear interval, the set drive voltage value can be determined based on the voltage-current correspondence within that interval.

[0074] In a preferred embodiment, the drive channel to be calibrated includes multiple channels selected from the RIGHT GRATING channel, LEFT GRATING channel, PHASE channel, GAIN channel, and SOA channel;

[0075] When calibrating the drive channel to be calibrated, other drive channels besides the drive channel to be calibrated are not connected to the current measuring device.

[0076] In this embodiment, the RIGHT GRATING and LEFT GRATING channels can be used for grating tuning, the PHASE channel for phase tuning, the GAIN channel for gain control, and the SOA channel for semiconductor optical amplification output control. These channels can be calibrated sequentially according to a preset order or according to a calibration order configured by the host computer. Except for the selected drive channel to be calibrated, other drive channels do not enter the current measurement path to avoid confusion in measurement results caused by multiple channels being simultaneously connected to the current measurement device.

[0077] In a preferred embodiment, the method for connecting the next drive channel to be calibrated to the current measuring device via a relay gate is as follows:

[0078] The driving board, the current measuring device, and the laser are all connected to the relay gating board, which includes multiple gating units, each gating unit being connected to a driving channel.

[0079] When a drive channel is identified as the drive channel to be calibrated, the gating unit corresponding to that drive channel opens the measurement path between it and the current measuring device, and closes the connection path between it and the laser.

[0080] In this embodiment, the gating unit refers to a circuit unit in the relay gating board used to switch the connection direction of a drive channel. Each gating unit corresponds to one drive channel and can switch between the measurement path and the laser connection path. The measurement path refers to the path from the drive channel to the current measuring device via the relay gating board; the laser connection path refers to the path from the drive channel to the corresponding drive terminal of the laser via the relay gating board. The current measuring device can be a 6.5-digit multimeter.

[0081] In one embodiment, such as Figure 2 The diagram illustrates the automated execution steps of a drive current calibration method. First, the host computer establishes a communication connection with the drive board, relay gating board, and current measuring device, and reads the list of drive channels to be calibrated, the corresponding calibration voltage points for each channel, the current limiting threshold, the allowable error range, and the anomaly criteria. The host computer controls the relay gating board to connect one drive channel to be calibrated to the current measuring device, while keeping other drive channels connected to the laser. For each drive channel connected to the current measuring device, the host computer sequentially sends multiple set drive voltage values ​​for that channel to the drive board. After each set drive voltage value is sent, a preset stabilization time can be waited for, or the output current can be judged based on the continuous reading changes of the current measuring device to determine whether a stable state has been reached. After the output current stabilizes, the current measuring device collects the actual output current and records the channel number, set drive voltage value, actual output current, temperature, timestamp, drive board serial number, laser serial number, and measurement status. By repeating the above process for multiple calibration voltage points of the same channel, multiple sets of voltage-current measurement data for that channel can be generated. After all calibration voltage points of one drive channel to be calibrated are collected, the relay selection board switches to the next drive channel to be calibrated and repeats the process of channel selection, voltage setting, stabilization waiting, current measurement, and data recording until all channels to be calibrated in the RIGHT GRATING, LEFT GRATING, PHASE, GAIN, and SOA channels have been calibrated. This allows for the sequential acquisition of voltage-current measurement data for multiple drive channels without manual disconnection or reconnection of the drive channel connections. After all drive channels to be calibrated have been measured, the host computer generates the corresponding voltage-current calibration relationship based on the multiple sets of voltage-current measurement data for each channel. The voltage-current calibration relationship may include a lookup table, piecewise linear interpolation information, fitted curve parameters, or a piecewise model containing slope and intercept.

[0082] Subsequently, the host computer writes the voltage-current calibration relationship of each channel into the non-volatile memory system of the driver board, and can simultaneously write the checksum, version number, channel identifier, and valid range. When the driver board drives the laser later, it can read the voltage-current calibration relationship of the corresponding channel from the non-volatile memory system based on the target current, and calculate the required set drive voltage value through interpolation or fitting to automatically output the target drive current.

[0083] In a preferred embodiment, a multi-channel semiconductor laser drive current calibration system includes:

[0084] Driver board, relay gate board, current measuring device, and laser;

[0085] The driver board includes multiple driving channels and a voltage-to-current output circuit corresponding to each driving channel. The driving channels are used to output driving current to the laser.

[0086] The relay selection board is connected to the driver board, the current measuring device and the laser respectively. The relay selection board includes multiple selection units, and each selection unit is connected to a corresponding driver channel.

[0087] When a driving channel is identified as the driving channel to be calibrated, the gating unit corresponding to the driving channel to be calibrated opens the measurement path between the driving channel to be calibrated and the current measuring device, and disconnects the connection path between the driving channel to be calibrated and the laser.

[0088] The gating unit corresponding to the other drive channels (excluding the drive channel to be calibrated) disconnects the measurement path between the other drive channels and the current measuring device, and connects the other drive channels to the laser.

[0089] In this embodiment, the system described above can be used to execute the multi-channel semiconductor laser drive current calibration method as described above. The system includes a drive board for generating the output current of each drive channel, a relay selection board for selecting the drive channel under test, a current measuring device for measuring the actual output current of the drive channel under test, and the laser as the actual connection object of the drive board. The system's connection relationship ensures that only one drive channel enters the measurement path at any given time, while drive channels not entering the measurement path remain connected to the laser.

[0090] In a preferred embodiment, the system further includes a host computer;

[0091] The host computer is used to sequentially send the calibration voltage points corresponding to the drive channel to be calibrated to the drive board as set drive voltage values.

[0092] It is also used to read the actual output current collected by the current measuring device under each set drive voltage value, and to generate the voltage-current calibration relationship of the drive channel to be calibrated based on the set drive voltage value and the corresponding actual output current.

[0093] In this embodiment, the host computer can run a calibration program and automatically complete the calibration according to a preset channel sequence and calibration voltage points. The host computer can also write the generated voltage-current calibration relationship into the driver board's non-volatile storage system. The calibration results can be directly retrieved by the driver board during subsequent operation.

[0094] In a preferred embodiment, the relay gating board includes a gating array, a channel interface, a measurement interface, a laser interface, and a communication interface;

[0095] The channel interface is used to connect multiple drive channels of the driver board, the measurement interface is used to connect the current measurement device, the laser interface is used to connect multiple drive terminals of the laser, and the communication interface is used to receive strobe commands sent by the host computer.

[0096] In this embodiment, the channel interface receives signals or output currents from each drive channel of the driver board, the measurement interface connects the selected drive channel to be calibrated to a current measuring device, and the laser interface is used to keep unselected drive channels connected to the laser. The communication interface can be a serial port, USB, CAN, or Ethernet interface, etc., used to receive channel selection commands sent by the host computer.

[0097] In one embodiment, the gating array is a relay array, used to change the conduction state of each relay according to the gating command, so that one drive channel to be calibrated is connected to the current measuring device, and other drive channels are connected to the laser.

[0098] In this embodiment, the relay array may include multiple relay selection branches, each corresponding to a driving channel. The relay selection branches can switch between the measurement path and the laser connection path using normally open contacts, normally closed contacts, or multiplexer contacts. When a driving channel is selected, the relay selection branch corresponding to that channel switches to the measurement path; the relay selection branches corresponding to other driving channels remain or switch to the laser connection path. The relays can also be replaced with solid-state relays, analog switches, optical MOS relays, or matrix switches, as long as they can achieve the path switching function of the selected channel connecting to the current measuring device and the unselected channel connecting to the laser.

[0099] In one embodiment, a relay gating board is provided, including a communication interface, a control unit, a gating array, a channel interface, a measurement interface, and a laser interface;

[0100] The channel interface is used to connect multiple drive channels of the driver board, the measurement interface is used to connect a current measuring device, the laser interface is used to connect a laser, and the communication interface is used to receive external strobe commands.

[0101] The gating array includes multiple gating units, and each gating unit is connected to a driving channel.

[0102] The control unit is used to control the gating unit corresponding to the driving channel to be calibrated to open the measurement path between the driving channel to be calibrated and the measurement interface according to the external gating command, and to disconnect the connection path between the driving channel to be calibrated and the laser interface.

[0103] The control unit is also used to control the gating unit corresponding to other drive channels besides the drive channel to be calibrated to disconnect the measurement path between the other drive channels and the measurement interface, and to connect the other drive channels and the laser interface.

[0104] In this embodiment, the gating board can be the relay gating board in the multi-channel semiconductor laser drive current calibration system described above, and can operate based on the multi-channel semiconductor laser drive current calibration method described above. The control unit can be a microcontroller, a programmable logic device, or other control circuit capable of controlling the gating array according to external gating commands. The external gating commands can include the channel identifier of the drive channel to be calibrated, such as RIGHT GRATING, LEFT GRATING, PHASE, GAIN, or SOA. The control unit changes the conduction state of the corresponding gating unit in the gating array according to the channel identifier, thereby allowing the relay gating board to switch measurement paths between different drive channels.

[0105] It should be understood that although the steps in the flowcharts of the various embodiments of this application are shown sequentially according to the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless explicitly stated herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least some steps in each embodiment may include multiple sub-steps or multiple stages. These sub-steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these sub-steps or stages is not necessarily sequential, but can be performed alternately or in turn with other steps or at least a portion of the sub-steps or stages of other steps.

[0106] Those skilled in the art will understand that all or part of the processes in the above embodiments can be implemented by a computer program instructing related hardware. The program can be stored in a non-volatile computer-readable storage medium, and when executed, it can include the processes of the embodiments of the above methods. Furthermore, any references to memory, storage, databases, or other media used in the embodiments provided in this application can include non-volatile and / or volatile memory.

[0107] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

Claims

1. A method for calibrating the driving current of a multi-channel semiconductor laser, characterized in that, The method includes the following steps: Determine the driving channel to be calibrated from the driving board with several driving channels, and obtain the calibration voltage point corresponding to each driving channel to be calibrated; Connect the drive channel to be calibrated to the current measuring device, and electrically connect the other drive channels besides the drive channel to be calibrated to the laser; Each calibration voltage point corresponding to the drive channel to be calibrated is sent to the drive board as a set drive voltage value in sequence. The current measuring device collects the actual output current under each set drive voltage value to obtain the voltage-current measurement data of the drive channel to be calibrated. The next driving channel to be calibrated is connected to the current measurement device through the relay selection board to obtain the voltage-current measurement data of that channel. The process is repeated until the voltage-current measurement data of all driving channels to be calibrated are obtained. Based on the voltage-current measurement data corresponding to each driving channel to be calibrated, the voltage-current calibration relationship corresponding to each driving channel to be calibrated is obtained, and the voltage-current calibration relationship is written into the non-volatile storage system of the driving board.

2. The method for calibrating the driving current of a multi-channel semiconductor laser according to claim 1, characterized in that, The method for acquiring the actual output current at each set drive voltage value by the current measuring device is as follows: After the driver board receives the set drive voltage value, it determines whether the output current of the drive channel to be calibrated has reached a stable state. If and only if the output current reaches a stable state, the output current is sampled several times to obtain several current sample values, and the filtered average of the several current sample values ​​is used as the actual output current corresponding to the set drive voltage value.

3. The method for calibrating the driving current of a multi-channel semiconductor laser according to claim 1, characterized in that, The method for obtaining the voltage-current calibration relationship for each driving channel to be calibrated based on the voltage-current measurement data is as follows: Multiple sets of voltage-current measurement data for the same drive channel to be calibrated are screened for validity to obtain valid measurement data; Based on the correspondence between the set drive voltage value and the actual output current in the effective measurement data, the linear calibration parameters of the drive channel to be calibrated are determined; Based on the linear calibration parameters, a piecewise linear calibration model of voltage-current for the drive channel to be calibrated is constructed, and the piecewise linear calibration model is set as a voltage-current calibration relationship.

4. The method for calibrating the driving current of a multi-channel semiconductor laser according to claim 1, characterized in that, The drive channels to be calibrated include multiple channels from the RIGHT GRATING channel, LEFT GRATING channel, PHASE channel, GAIN channel, and SOA channel; When calibrating the drive channel to be calibrated, other drive channels besides the drive channel to be calibrated are not connected to the current measuring device.

5. The method for calibrating the driving current of a multi-channel semiconductor laser according to claim 1, characterized in that, The method for connecting the next drive channel to be calibrated to the current measuring device via the relay selector board is as follows: The driving board, the current measuring device, and the laser are all connected to the relay gating board, which includes multiple gating units, each gating unit being connected to a driving channel. When a drive channel is identified as the drive channel to be calibrated, the gating unit corresponding to that drive channel opens the measurement path between it and the current measuring device, and closes the connection path between it and the laser.

6. A multi-channel semiconductor laser drive current calibration system, characterized in that, The system includes: Driver board, relay gate board, current measuring device, and laser; The driver board includes multiple driving channels and a voltage-to-current output circuit corresponding to each driving channel. The driving channels are used to output driving current to the laser. The relay selection board is connected to the driver board, the current measuring device and the laser respectively. The relay selection board includes multiple selection units, and each selection unit is connected to a corresponding driver channel. When a driving channel is identified as the driving channel to be calibrated, the gating unit corresponding to the driving channel to be calibrated opens the measurement path between the driving channel to be calibrated and the current measuring device, and disconnects the connection path between the driving channel to be calibrated and the laser. The gating unit corresponding to the other drive channels (excluding the drive channel to be calibrated) disconnects the measurement path between the other drive channels and the current measuring device, and connects the other drive channels to the laser.

7. The multi-channel semiconductor laser drive current calibration system according to claim 6, characterized in that, The system also includes a host computer; The host computer is used to sequentially send the calibration voltage points corresponding to the drive channel to be calibrated to the drive board as set drive voltage values. It is also used to read the actual output current collected by the current measuring device under each set drive voltage value, and to generate the voltage-current calibration relationship of the drive channel to be calibrated based on the set drive voltage value and the corresponding actual output current.

8. The multi-channel semiconductor laser drive current calibration system according to claim 7, characterized in that, The relay gating board includes a gating array, channel interface, measurement interface, laser interface, and communication interface; The channel interface is used to connect multiple drive channels of the driver board, the measurement interface is used to connect the current measurement device, the laser interface is used to connect multiple drive terminals of the laser, and the communication interface is used to receive strobe commands sent by the host computer.

9. The multi-channel semiconductor laser drive current calibration system according to claim 8, characterized in that, The gating array is a relay array, used to change the conduction state of each relay according to the gating command, so that one drive channel to be calibrated is connected to the current measuring device, and other drive channels are connected to the laser.

10. A relay gate board, characterized in that, This includes communication interfaces, control units, gating arrays, channel interfaces, measurement interfaces, and laser interfaces; The channel interface is used to connect multiple drive channels of the driver board, the measurement interface is used to connect a current measuring device, the laser interface is used to connect a laser, and the communication interface is used to receive external strobe commands. The gating array includes multiple gating units, and each gating unit is connected to a corresponding driving channel; The control unit is used to control the gating unit corresponding to the driving channel to be calibrated to open the measurement path between the driving channel to be calibrated and the measurement interface according to the external gating command, and to disconnect the connection path between the driving channel to be calibrated and the laser interface. The control unit is also used to control the gating unit corresponding to other drive channels besides the drive channel to be calibrated to disconnect the measurement path between the other drive channels and the measurement interface, and to connect the other drive channels and the laser interface.

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