Laser chip self-adaptive testing device and method based on light wave element analyzer

Abstract

The invention discloses a laser chip self-adaptive testing device and method based on a light wave element analyzer, and belongs to the technical field of photoelectric testing, the laser chip self-adaptive testing device comprises a microwave and master control module, the microwave and master control module is connected with a direct current bias device, the direct current bias device is connected with a laser chip, the laser chip is connected with a high-speed optical receiver module, and the high-speed optical receiver module is connected with a power supply. The high-speed optical receiver module is connected to the microwave and master control module; the high-speed optical receiver module comprises an optical coupler, the optical coupler is connected with a laser chip, the optical coupler is connected with an optical power meter and an optical amplifier, the optical power meter and the optical amplifier are both connected with a feedback controller, and the feedback controller is connected with a microwave and master control module; and the optical amplifier is connected with the high-speed photoelectric detector and then is connected to the microwave and master control module through an electric output end. According to the invention, the frequency response parameter of the low-power laser chip is accurately tested, and the frequency response parameter test requirements of various laser chips in the links of research and development verification, production detection and the like are met.

Description

Technical Field

[0001] The present invention relates to the technical field of photoelectric testing, and in particular to a laser chip adaptive testing device and method based on a lightwave component analyzer. Background Art

[0002] The statements in this section merely provide background information related to the present invention and do not necessarily constitute prior art.

[0003] High-speed laser chips, used to output high-frequency modulated optical signals, are core components in high-speed optical transmission systems. Frequency response parameters such as 3dB bandwidth and response flatness, as core technical specifications for high-speed lasers, require rigorous testing during product development and production.

[0004] In engineering, a test system can be built with separate instruments or a lightwave component analyzer can be used to test the laser chip. The use of separate instruments to build a test system has the disadvantages of complex methods, difficult calibration, and poor test accuracy. In the existing technology, the most widely used solution is to use a lightwave component analyzer to test the laser chip. However, the photoelectric conversion module of the lightwave component analyzer is limited by the performance of the internal high-speed photodetector, the test linear area is limited, and there are strict requirements on the input optical power. There are many types of lasers in engineering, and the laser chip will inevitably cause optical power loss during the coupling process of the chip test bench, resulting in the actual test optical power being too low, lower than the lower limit of the linear area of the photoelectric conversion module of the lightwave component analyzer, affecting the test accuracy and introducing too much random noise.

[0005] The existing laser chip test system based on a lightwave component analyzer connects the electrical output port of the lightwave component analyzer to a Biastee (DC bias device), which is then connected to the probe and laser chip. After the laser light output end face is fiber-coupled, it is tested with an optical power meter. When the optical power is too low, an external optical amplifier is used for optical amplification. The optical amplifier gain is appropriately adjusted according to the value tested by the optical power meter. After amplification, it is connected to the optical input interface of the lightwave component analyzer to begin testing. Each time the laser chip outputs an optical signal through optical fiber coupling, it is necessary to successively plug and unplug the optical power meter and optical amplifier, and manually adjust the optical amplifier gain according to the power value tested by the optical power meter. In addition, the stability of the probe station and the optical path must be ensured. Any slight jitter or vibration will change the coupling efficiency, and the optical power value will change accordingly. The only way to reset the optical amplifier gain is to switch the optical path again, which is a cumbersome operation. Moreover, the error caused by the optical amplifier cannot be accurately eliminated. After the optical amplifier amplifies the optical signal power, the amplitude of the transmission parameter measured by the lightwave component analyzer will increase. In addition, the wavelength response flatness of the optical amplifier will directly affect the shape of the transmission parameter S21 curve, affecting the test accuracy of characteristic parameters such as the laser chip bandwidth.

[0006] In summary, although the existing laser chip test system based on the lightwave component analyzer can realize the frequency response test of low-power laser chips, it has shortcomings such as complex system structure, inability to accurately compensate for optical amplifier parameters, and cumbersome operation steps, which affect the accuracy and efficiency of the test. Summary of the Invention

[0007] To address the above issues, the present invention proposes an adaptive testing device and method for laser chips based on a lightwave component analyzer. Functions and algorithms such as automatic optical power detection, adaptive optical amplifier amplification, and precise compensation of frequency response parameters are designed to achieve precise frequency response parameter testing of low-power laser chips. This device is suitable for frequency response parameter testing requirements of various laser chips in R&D verification, production testing, and other links.

[0008] In order to achieve the above object, the present invention adopts the following technical solutions: A first aspect of the present invention provides an adaptive test device for a laser chip based on a lightwave component analyzer, comprising a microwave and master control module, the microwave and master control module being connected to the input of a DC bias device, the output of the DC bias device being connected to the input of a laser chip, the output of the laser chip being connected to the optical input of a high-speed optical receiver module, and the electrical output of the high-speed optical receiver module being connected to the microwave and master control module; The high-speed optical receiver module includes an optical coupler. The input end of the optical coupler is connected to the laser chip. The optical coupler has two output ends, wherein the first output end is connected to the optical power meter and the second output end is connected to the optical amplifier. The optical power meter and the optical amplifier are both connected to the feedback controller, which is connected to the microwave and master control module. The output end of the optical amplifier is connected to the high-speed photodetector and then connected to the microwave and master control module through the electrical output end of the high-speed optical receiver module. The feedback controller controls the optical amplifier in real time according to the monitoring value of the optical power meter, so that the output power of the optical amplifier is within the linear region of the high-speed photodetector.

[0009] As a further implementation, the DC bias device is also connected to the digital source meter.

[0010] As a further implementation method, the light beam at the output end of the laser chip is coupled with an optical fiber and then input into an optical coupler.

[0011] As a further implementation, the optical coupler is a 1 / 99 optical coupler, wherein the first output end is a 1% end and the second output end is a 99% end.

[0012] As a further implementation, the microwave and master control module includes a microwave signal generating unit, a frequency mixing receiving unit and a master control unit.

[0013] As a further implementation method, the optical power meter monitors the input optical signal in real time and transmits the monitoring result to the feedback controller. The feedback controller controls the gain of the optical amplifier in real time according to the monitoring result.

[0014] As a further implementation, the gain of the optical amplifier is controlled in real time. Specifically, a feedback controller adjusts the input current of the optical amplifier, thereby controlling the gain of the optical amplifier so that the output power of the optical amplifier is within the linear region of the high-speed photodetector.

[0015] As a further implementation method, after the optical amplifier is set up, the feedback control unit feeds back the setting parameters of the optical amplifier to the microwave and master control module of the optical wave component analyzer, and the microwave and master control module de-embeds and compensates the frequency response parameters corresponding to the operating parameters of the optical amplifier.

[0016] A second aspect of the present invention provides a laser chip adaptive testing method based on a lightwave component analyzer. The laser chip adaptive testing device based on a lightwave component analyzer according to the first aspect of the present invention comprises the following steps: Connect the laser chip test device and set the test parameters of the lightwave component analyzer; Use an optical power meter to monitor the input optical signal in real time and transmit the monitoring results to the feedback controller; The feedback controller sets the driving current of the optical amplifier according to the monitoring results, realizes the gain adjustment of the optical amplifier, and makes the output power of the optical amplifier within the linear region of the high-speed photodetector; When the optical amplifier is set up, the feedback control unit feeds back the optical amplifier setting parameters to the microwave and master control module of the lightwave component analyzer. The microwave and master control module then de-embeds and compensates the frequency response parameters corresponding to the optical amplifier operating parameters. Start scanning the S21 curve and S11 curve to complete the test of the laser bandwidth, reflection and other frequency response characteristic parameters.

[0017] As a further implementation method, the lightwave component analyzer calibrates the parameters of the optical amplifier in the high-speed optical receiver module before leaving the factory, and the calibration data is stored in the microwave and master control module.

[0018] Compared with the prior art, the present invention has the following beneficial effects: The present invention's adaptive laser chip testing device and method, based on a lightwave component analyzer, addresses the complex scenarios of laser chip testing. This method integrates an optical power meter unit, an optical amplifier unit, a feedback control unit, and related optical paths into the lightwave component analyzer's high-speed optical receiver module. Automatic monitoring and control are achieved through the feedback control unit, eliminating the need for manual configuration. This allows for one-click testing of laser chip parameters, significantly improving testing efficiency. Furthermore, precise calibration and compensation are performed for errors introduced by the optical amplifier, avoiding test errors introduced by the uneven wavelength response of the optical amplifier, which can affect laser chip testing accuracy.

[0019] The present invention's adaptive laser chip testing device and method based on a lightwave component analyzer incorporates functions and algorithms such as automatic optical power detection, adaptive optical amplifier amplification, and precise compensation of frequency response parameters. These functions enable precise frequency response parameter testing of low-power laser chips, making them more suitable for frequency response parameter testing requirements of various laser chips in R&D verification, production testing, and other stages. This reduces the complexity of the test system, enables one-click testing of chip bandwidth, and significantly improves the efficiency and accuracy of laser chip frequency response parameter testing. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The accompanying drawings, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0021] Figure 1 The figure is a schematic diagram of the overall structure of a conventional laser chip testing device based on a lightwave component analyzer; Figure 2 The figure is a schematic diagram of the overall structure of the laser chip adaptive testing device based on the lightwave component analyzer of the present invention. DETAILED DESCRIPTION

[0022] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0023] It should be noted that the following detailed descriptions are illustrative and intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which the present invention belongs.

[0024] In the absence of conflict, the embodiments of the present invention and the features thereof may be combined with each other.

[0025] Example 1 like Figure 2As shown, this embodiment provides a laser chip adaptive test device based on a lightwave component analyzer, including a microwave and master control module, the microwave and master control module is connected to the input end of a DC bias device, the output end of the DC bias device is connected to the input end of the laser chip, the output end of the laser chip is connected to the optical input end of a high-speed optical receiver module, and the electrical output end of the high-speed optical receiver module is connected to the microwave and master control module.

[0026] The high-speed optical receiver module includes an optical coupler, the input end of the optical coupler is connected to the laser chip, and the output end is provided with two, wherein the first output end is connected to the optical power meter, and the second output end is connected to the optical amplifier. The optical power meter and the optical amplifier are both connected to the feedback controller, and the feedback controller is connected to the microwave and master control module.

[0027] The output end of the optical amplifier is connected to the high-speed photodetector and then to the microwave and master control module through the electrical output end of the high-speed optical receiver module. The feedback controller controls the optical amplifier in real time according to the monitoring value of the optical power meter, so that the output power of the optical amplifier is within the linear region of the high-speed photodetector.

[0028] Figure 1 The present invention aims to improve the existing laser chip testing system based on the lightwave component analyzer.

[0029] The device, comprising a lightwave component analyzer, a Biastee (DC bias device), and a digital source meter, boasts a simple overall structure, ingenious design, and ease of operation. The lightwave component analyzer's high-speed optical receiver module integrates a 1 / 99 optical coupler, an optical power meter unit, a feedback controller unit, an optical amplifier unit, and a high-speed photodetector unit, enabling low-power adaptive amplification and testing of optical signals.

[0030] In this embodiment, the DC bias device is also connected to a digital source meter, which can measure relevant electrical parameters.

[0031] The light beam at the output end of the laser chip is coupled by optical fiber and then input into an optical coupler. The optical coupler in the present invention is a 1 / 99 optical coupler, wherein the first output end is the 1% end and the second output end is the 99% end.

[0032] The optical power meter monitors the input optical signal in real time and transmits the monitoring results to the feedback controller, which then controls the gain of the optical amplifier in real time based on the monitoring results. Specifically, the feedback controller adjusts the input current of the optical amplifier to control the gain of the optical amplifier, keeping the output power within the linear region of the high-speed photodetector. Once the optical amplifier is set up, the feedback control unit feeds the settings back to the microwave and master control module of the lightwave component analyzer. The microwave and master control module then de-embeds and compensates the frequency response parameters corresponding to the optical amplifier operating parameters.

[0033] The microwave and master control module includes a microwave signal generating unit, a mixing receiving unit and a master control unit. The microwave signal generator outputs an electrical signal, which is connected to a Biastee (DC bias device) and a digital source meter. This DC signal is then biased and input to the laser chip's RF interface, completing the laser chip drive and RF input. Once the chip is operating normally, the output optical signal is coupled through a lensed fiber and connected to the optical input interface of the lightwave component analyzer's high-speed optical receiver module. In the high-speed optical receiver module, the optical signal passes through a 1 / 99 optical coupler. The 99% end is connected to the optical amplifier unit for optical amplification, and the 1% end is connected to the optical power meter unit. This monitors the input optical signal in real time. The feedback controller monitors and controls the optical power meter unit and the optical amplifier unit in real time. Based on the input optical power, the input current of the optical amplifier is adjusted, thereby controlling the amplifier's gain to keep the amplifier's output power within the linear region of the high-speed photodetector. Once the optical amplifier is set up, the high-speed optical receiver module's feedback control unit feeds back the amplifier's settings to the lightwave component analyzer's master control module. The master control module then de-embeds and compensates the frequency response parameters corresponding to the amplifier's operating parameters, allowing the sweep test to begin.

[0034] When the optical power changes due to chip replacement or slight jitter in the coupled fiber, the high-speed optical receiver module feedback controller can also automatically adjust the optical amplifier gain according to the changes in the monitoring value of the optical power meter unit, eliminating the need for manual testing and settings by testers, greatly improving test efficiency and accuracy.

[0035] Example 2 This embodiment provides a laser chip adaptive testing method based on a lightwave component analyzer, based on the laser chip adaptive testing device based on a lightwave component analyzer of the first embodiment. The method includes the following steps: Connect the laser chip test device and set the test parameters of the lightwave component analyzer; Use an optical power meter to monitor the input optical signal in real time and transmit the monitoring results to the feedback controller; The feedback controller sets the driving current of the optical amplifier according to the monitoring results, realizes the gain adjustment of the optical amplifier, and makes the output power of the optical amplifier within the linear region of the high-speed photodetector; When the optical amplifier is set up, the feedback control unit feeds back the optical amplifier setting parameters to the microwave and master control module of the lightwave component analyzer. The microwave and master control module then de-embeds and compensates the frequency response parameters corresponding to the optical amplifier operating parameters. Start scanning the S21 curve and S11 curve to complete the test of the laser bandwidth, reflection and other frequency response characteristic parameters.

[0036] As a further implementation method, the lightwave component analyzer calibrates the parameters of the optical amplifier in the high-speed optical receiver module before leaving the factory, and the calibration data is stored in the microwave and master control module.

[0037] The specific implementation process of the present invention is as follows: Use the coaxial calibration kit lightwave component analyzer, according to Figure 2 Device structure diagram, connecting the Biastee (DC bias device), digital source meter, and laser chip. The laser chip's optical output end face is optically coupled with an optical fiber and then connected to the optical input port of the high-speed optical receiver module of the lightwave component analyzer. The electrical output port of the high-speed optical receiver module is connected to the microwave and master control module of the lightwave component analyzer using an RF cable.

[0038] In the dedicated software of the optical wave component analyzer host, set the wavelength parameters and click Start; set the optical input signal (dBm), after passing through a 1 / 99 optical coupler, the 1% end is connected to an optical power meter unit, and the signal power detected by the optical power meter unit 0.01× , that is, the 1% insertion loss (optical power meter end) after passing through the 1 / 99 optical coupler is:

[0039] Unit: dB; The optical power meter monitors the input optical signal in real time. The insertion loss after passing through the optical coupler is 20dB, that is, the actual power input to the optical power meter is In the dedicated software for the optical power meter unit, add a compensation factor of 20dB to the measured value of the optical power meter. The power value fed back by the power meter unit is the actual power input to the optical input interface of the high-speed optical receiver module.

[0040] The 99% end of the 1 / 99 optical coupler is connected to the optical amplifier. The optical power meter unit feeds back the optical power monitoring value of the optical input interface to the feedback controller. The feedback controller sets the driving current of the optical amplifier according to the monitoring value to adjust the gain of the optical amplifier. The specific gain value is set according to the boundary value of the linear region of the high-speed photodetector. Assume that the boundary of the linear region of the high-speed photodetector is 、 , respectively, are the minimum input optical power and the maximum input optical power in the linear region. The device of the present invention is designed for the case where the optical input signal is weak, that is, By setting the optical amplifier gain, the optical power of the input optical signal after amplification by the optical amplifier is , try to stay away from the two boundaries of the linear region to prevent the coupling fiber from being unstable and causing the optical power to change beyond the linear region. At this time, the gain of the optical amplifier is .

[0041] Since the S21 parameter amplitude is different under different gain working conditions of the optical amplifier, and the wavelength flatness of the optical amplifier will also lead to the flatness of the S21 curve, the optical wave component analyzer will calibrate the optical amplifier parameters in the high-speed optical receiver before leaving the factory, and the data is saved in the master control module. When calibrating the parameters, a reference gain value is set. S parameters under working conditions , in the actual test process, the actual working gain of the optical amplifier is , at this time the actual S parameter of the optical amplifier is , and They are all in the s2p file format dedicated to vector network analyzers, containing the S parameters of each frequency point. Since changing the gain of the optical amplifier will only affect the amplitude value of S21, it will not change the overall curve shape of S21. That is Based on the S21 amplitude value of each frequency point plus the compensation factor, the compensation factor is set to (dB):

[0042] The lightwave component analyzer master control module will De-embedding compensation is performed as an error term of the optical amplifier.

[0043] Start scanning the S21 and S11 curves to complete the test of the laser's bandwidth, reflection and other frequency response characteristic parameters.

[0044] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

[0045] Although the above describes the specific embodiments of the present invention in conjunction with the accompanying drawings, it is not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art on the basis of the technical solution of the present invention without any creative work are still within the scope of protection of the present invention.

Claims

1. A laser chip adaptive test device based on a lightwave component analyzer, characterized in that: The microwave and master control module is connected to the input of the DC bias device, the output of the DC bias device is connected to the input of the laser chip, the output of the laser chip is connected to the optical input of the high-speed optical receiver module, and the electrical output of the high-speed optical receiver module is connected to the microwave and master control module. The high-speed optical receiver module includes an optical coupler, the input end of the optical coupler is connected to the laser chip, and the output end is provided with two, wherein the first output end is connected to the optical power meter, and the second output end is connected to the optical amplifier. The optical power meter and the optical amplifier are both connected to the feedback controller, and the feedback controller is connected to the microwave and master control module; The output end of the optical amplifier is connected to a high-speed photodetector and then connected to a microwave and master control module through the electrical output end of a high-speed optical receiver module. The feedback controller controls the optical amplifier in real time according to the monitoring value of the optical power meter so that the output power of the optical amplifier is within the linear region of the high-speed photodetector.

2. The laser chip adaptive testing device based on a lightwave component analyzer according to claim 1, characterized in that: The DC bias device is also connected to a digital source meter.

3. The laser chip adaptive testing device based on a lightwave component analyzer according to claim 1, characterized in that: The light beam at the output end of the laser chip is coupled with an optical fiber and then input into an optical coupler.

4. The laser chip adaptive testing device based on a lightwave component analyzer according to claim 3, characterized in that: The optical coupler is a 1 / 99 optical coupler, wherein the first output end is a 1% end and the second output end is a 99% end.

5. The laser chip adaptive testing device based on a lightwave component analyzer according to claim 1, characterized in that: The microwave and master control module includes a microwave signal generating unit, a frequency mixing receiving unit and a master control unit.

6. The laser chip adaptive testing device based on a lightwave component analyzer according to claim 1, characterized in that: The optical power meter monitors the input optical signal in real time and transmits the monitoring result to the feedback controller. The feedback controller controls the gain of the optical amplifier in real time according to the monitoring result.

7. The laser chip adaptive testing device based on a lightwave component analyzer according to claim 6, characterized in that: The gain of the optical amplifier is controlled in real time. Specifically, the feedback controller adjusts the input current of the optical amplifier, thereby controlling the gain of the optical amplifier so that the output power of the optical amplifier is within the linear region of the high-speed photodetector.

8. The laser chip adaptive testing device based on a lightwave component analyzer according to claim 6, characterized in that: When the optical amplifier is set up, the feedback control unit feeds back the setting parameters of the optical amplifier to the microwave and master control module of the lightwave component analyzer, and the microwave and master control module de-embeds and compensates the frequency response parameters corresponding to the operating parameters of the optical amplifier.

9. A laser chip adaptive testing method based on a lightwave component analyzer, characterized in that: The laser chip adaptive testing device based on the lightwave component analyzer according to any one of claims 1 to 8 comprises the following steps: Connect the laser chip test device and set the test parameters of the lightwave component analyzer; Use an optical power meter to monitor the input optical signal in real time and transmit the monitoring results to the feedback controller; The feedback controller sets the driving current of the optical amplifier according to the monitoring results, realizes the gain adjustment of the optical amplifier, and makes the output power of the optical amplifier within the linear region of the high-speed photodetector; When the optical amplifier is set up, the feedback control unit feeds back the optical amplifier setting parameters to the microwave and master control module of the lightwave component analyzer. The microwave and master control module then de-embeds and compensates the frequency response parameters corresponding to the optical amplifier operating parameters. Start scanning the S21 curve and S11 curve to complete the test of the laser bandwidth, reflection and other frequency response characteristic parameters.

10. The laser chip adaptive testing method based on a lightwave component analyzer according to claim 9, characterized in that: The lightwave component analyzer calibrates the parameters of the optical amplifier in the high-speed optical receiver module before leaving the factory, and the calibration data is stored in the microwave and master control module.

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