Test system and method based on optical link simulation

Abstract

The application relates to the technical field of measurement and provides a test system and method based on optical link simulation. The test system comprises a test signal generator, a laser driver chip, a laser array, an optical device coupling structure, a photodetector array and a transimpedance amplifier array. The system and method restore the real application scene of the optical link as much as possible based on the optical link simulation, do not require a complex signal input link or a complex signal processing device, support precise tests of bit error rate, sensitivity, system performance and the like, support test requirements of a pluggable optical transceiver architecture and a linear pluggable optical module, and greatly shorten a test period and improve test efficiency.

Description

Technical Field

[0001] This application relates to the field of measurement technology, specifically to chip verification in high-speed photoelectric signal transmission scenarios, and particularly to a test system and method based on optical link simulation. Background Technology

[0002] With the development of technologies such as data centers and optical interconnects, there is a need to support high-speed optoelectronic signal transmission and pluggable optical transceiver architectures such as linear pluggable optical modules (LPOs). Therefore, before mass production of chips, chip verification for high-speed optoelectronic signal transmission scenarios is necessary. This involves replicating real-world application scenarios as closely as possible and performing precise tests such as bit error rate, sensitivity, and system performance, while also minimizing the overall testing cycle. Existing chip verification solutions for optoelectronic signal transmission scenarios utilize complex signal input links to input test signals to the electronic chip under test. Examples include US patents US20030034787A1 and US11680870B2, which use probe cards for wafer probe testing to couple test signals to the electronic component under test. However, probe cards for wafer probe testing are limited by space constraints and struggle to support pluggable optical transceiver architectures, making them unsuitable for the testing requirements of real-world LPO systems. In addition, existing testing solutions that can support LPO devices or LPO systems require complex signal processing equipment such as vector network analyzers (VNAs) and bit error rate testers (BERTs) to support system performance testing, such as Chinese patents with publication numbers CN121356673A and CN120454849A.

[0003] To this end, this application provides a test system and method based on optical link simulation. The optical link simulation restores the real application scenario of the optical link as much as possible. It does not require complex signal input links or complex signal processing equipment. It supports accurate testing of bit error rate, sensitivity, system performance, etc. It also supports the testing requirements of pluggable optical transceiver architecture and linear pluggable optical modules, and significantly shortens the test cycle and improves the test efficiency. Summary of the Invention

[0004] Firstly, this application provides a test system based on optical link simulation. The testing system includes: a test signal generator for providing a test electrical signal; a laser driver chip for providing a drive signal based on the test electrical signal; a laser array for being driven by the laser driver chip to provide a modulated optical signal, wherein the modulated optical signal is optically coupled to an optical device coupling structure through multiple optical channels, the optical device coupling structure including a multiplexer; the optical device coupling structure for selectively coupling the modulated optical signal to a multi-channel transmission optical fiber using the multiplexer; a photodetector array including at least one photodetector, wherein the multi-channel transmission optical fiber is non-contactly optically coupled to the photosensitive receiving surface of each of the at least one photodetector; and a transimpedance amplifier array including at least one transimpedance amplifier, wherein a first correspondence exists between the at least one photodetector and the at least one transimpedance amplifier, each of the at least one photodetector including a probe structure based on semiconductor growth technology for electrically coupling the current output terminal of the photodetector to the signal input terminal of the transimpedance amplifier corresponding to the photodetector as indicated by the first correspondence, and the signal output terminals of each of the at least one transimpedance amplifiers being connected back to the signal input terminal of the test signal generator for testing together with the test electrical signal.

[0005] Through the first aspect of this application, the optical link simulation restores the real application scenario of the optical link as much as possible. It does not require a complex signal input link or a complex signal processing device, supports accurate testing of bit error rate, sensitivity, system performance, etc., and also supports the testing requirements of pluggable optical transceiver architecture and linear pluggable optical modules. Furthermore, it significantly shortens the testing cycle and improves testing efficiency.

[0006] In one possible implementation of the first aspect of this application, the multiplexer is configured to optically couple the modulated optical signal through the multi-channel transmission optical fiber to the photosensitive receiving surfaces of the respective photodetectors of the at least one photodetector, so as to perform multi-channel parallel testing.

[0007] In one possible implementation of the first aspect of this application, the first correspondence indicates that a plurality of transimpedance amplifiers in the at least one transimpedance amplifier correspond to a plurality of photodetectors, and the multi-channel parallel test includes synchronous testing of the plurality of transimpedance amplifiers.

[0008] In one possible implementation of the first aspect of this application, the multiplexer is configured to sequentially turn on a plurality of photodetectors among the at least one photodetector, thereby sequentially testing the outputs of the plurality of transimpedance amplifiers corresponding to the plurality of photodetectors as indicated by the first correspondence, in order to perform crosstalk testing and alignment testing.

[0009] In one possible implementation of the first aspect of this application, the photodetector array or the transimpedance amplifier array is a linearly pluggable optical module.

[0010] In one possible implementation of the first aspect of this application, the photodetector array is detachably deployed on a first circuit board, and the transimpedance amplifier array is detachably deployed on a second circuit board.

[0011] In one possible implementation of the first aspect of this application, the laser array and the optical device coupling structure are deployed on the first circuit board, and the test signal generator and the laser driver chip are deployed on the third circuit board.

[0012] In one possible implementation of the first aspect of this application, the laser array and the optical device coupling structure are deployed on the first circuit board, and the test signal generator and the laser driver chip are deployed on the first circuit board.

[0013] In one possible implementation of the first aspect of this application, the optical device coupling structure is deployed on the first circuit board, and the laser array, the test signal generator, and the laser driver chip are deployed on the third circuit board. The multiplexer is a bidirectional multiplexer, and the plurality of optical channels correspond to a plurality of channel insertion losses respectively. The bidirectional multiplexer is used to select the multi-channel transmission optical fiber and to select the optical channel among the plurality of optical channels that corresponds to a given channel insertion loss among the plurality of channel insertion losses.

[0014] In one possible implementation of the first aspect of this application, the plurality of channel insertion losses are used to simulate different degrees of signal attenuation from the test signal generator to the laser driver chip, thereby testing the system performance under the different degrees of signal attenuation.

[0015] In one possible implementation of the first aspect of this application, the first correspondence indicates that an even number of photodetectors in the at least one photodetector non-repeatingly correspond to a single transimpedance amplifier in the at least one transimpedance amplifier.

[0016] In one possible implementation of the first aspect of this application, each of the at least one photodetector includes a probe structure comprising at least two probes for signal transmission and power supply, respectively.

[0017] In one possible implementation of the first aspect of this application, the test signal generator is a digital signal processor and the test electrical signal is a multi-frequency component signal, or the test signal generator is a network analyzer and the test electrical signal is a single-frequency component signal.

[0018] In one possible implementation of the first aspect of this application, the light output from the multi-channel transmission optical fiber illuminates the photosensitive receiving surface of each of the at least one photodetector at a fixed angle.

[0019] In one possible implementation of the first aspect of this application, the length of the probe structure is from 1 micrometer to 10 micrometers, and the length of the probe structure is set based on the soldering requirements of the electronic device under test.

[0020] In one possible implementation of the first aspect of this application, the semiconductor growth technology is molecular beam epitaxy, vapor phase epitaxy, chemical vapor deposition, or simulated alloying technology.

[0021] In one possible implementation of the first aspect of this application, the test system includes a closed-loop test link from the test electrical signal to the modulated optical signal and then to the signal input terminal of the test signal generator, and the test system supports bit error rate performance testing and sensitivity testing for any device on the closed-loop test link.

[0022] Secondly, this application provides a testing method based on optical link simulation. The testing method includes: providing a test electrical signal through a test signal generator; providing a driving signal based on the test electrical signal through a laser driver chip; providing a modulated optical signal through a laser array driven by the laser driver chip, wherein the modulated optical signal is optically coupled to an optical device coupling structure through multiple optical channels, the optical device coupling structure including a multiplexer; selectively coupling the modulated optical signal to a multi-channel transmission optical fiber using the multiplexer through the optical device coupling structure; and realizing a closed-loop test link through a photodetector array and a transimpedance amplifier array. The photodetector array includes at least one photodetector, and the multi-channel transmission optical fiber is non-contactly optically coupled to the photosensitive receiving surface of each of the at least one photodetector. The transimpedance amplifier array includes at least one transimpedance amplifier, and the at least one photodetector and the at least one transimpedance amplifier satisfy a first correspondence. Each of the at least one photodetector includes a probe structure based on semiconductor growth technology for electrically coupling the current output terminal of the photodetector to the signal input terminal of the transimpedance amplifier corresponding to the photodetector as indicated by the first correspondence. The signal output terminals of each of the at least one transimpedance amplifier are connected back to the signal input terminal of the test signal generator for use in testing together with the test electrical signal.

[0023] Through the second aspect of this application, the optical link simulation restores the real application scenario of the optical link as much as possible. It does not require a complex signal input link or a complex signal processing device, supports accurate testing of bit error rate, sensitivity, system performance, etc., and also supports the testing requirements of pluggable optical transceiver architecture and linear pluggable optical modules. Furthermore, it significantly shortens the testing cycle and improves testing efficiency.

[0024] In one possible implementation of the second aspect of this application, the photodetector array is detachably deployed on a first circuit board, and the transimpedance amplifier array is detachably deployed on a second circuit board.

[0025] In one possible implementation of the second aspect of this application, the test signal generator is a digital signal processor and the test electrical signal is a multi-frequency component signal, or the test signal generator is a network analyzer and the test electrical signal is a single-frequency component signal. Attached Figure Description

[0026] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0027] Figure 1 A schematic diagram of a test system based on optical link simulation according to a first embodiment of this application; Figure 2 A schematic diagram of a test system based on optical link simulation, provided as a second embodiment of this application; Figure 3 A schematic diagram of a test system based on optical link simulation according to a third embodiment of this application; Figure 4 This is a flowchart illustrating a test method based on optical link simulation provided in an embodiment of this application. Detailed Implementation

[0028] The embodiments of this application will now be described in further detail with reference to the accompanying drawings.

[0029] It should be understood that in the description of this application, "at least one" means one or more, and "multiple" means two or more. In addition, the words "first," "second," etc., unless otherwise stated, are used only for the purpose of distinguishing descriptions and should not be construed as indicating or implying relative importance or order.

[0030] Figure 1 This is a schematic diagram of a test system based on optical link simulation, provided as an embodiment of this application. Figure 1As shown, the test system includes: a test signal generator A132, a laser driver chip A134, a laser array A112, an optical device coupling structure A114 with a multiplexer, a photodetector array A116, and a transimpedance amplifier array A122. The test signal generator A132 provides a test electrical signal. The laser driver chip A134 provides a drive signal based on the test electrical signal. The laser array A112 is driven by the laser driver chip A134 to provide a modulated optical signal. The modulated optical signal is optically coupled to the optical device coupling structure A114 through multiple optical channels A170. The optical device coupling structure A114 includes a multiplexer. The optical device coupling structure A114 uses the multiplexer to selectively couple the modulated optical signal to a multi-channel transmission optical fiber A160. The photodetector array A116 includes at least one photodetector. The multi-channel transmission optical fiber A160 is non-contactly optically coupled to the photosensitive receiving surface of each of the at least one photodetector. The transimpedance amplifier array A122 includes at least one transimpedance amplifier (TIA). A first correspondence exists between the at least one photodetector and the at least one transimpedance amplifier. Each of the at least one photodetector includes a probe structure A150 based on semiconductor growth technology for electrically coupling the current output terminal of the photodetector to the signal input terminal of the transimpedance amplifier corresponding to that photodetector, as indicated by the first correspondence. The signal output terminals of each of the at least one transimpedance amplifier are connected back to the signal input terminal of the test signal generator A132 for use in conjunction with the test electrical signal for testing.

[0031] See Figure 1This testing system constructs a closed-loop test link from electrical signal to optical signal and back to electrical signal. Through optical link simulation, it can reproduce real application scenarios and perform tests on the device under test, such as bit error rate and sensitivity. The test signal generator A132 is used to generate the test electrical signal, which can be, for example, a Digital Signal Processor (DSP) or a Vector Network Analyzer (VNA), also called a network analyzer. A DSP can provide multi-frequency component signals, such as wave packet signals. A network analyzer can provide single-frequency component signals. The test signal generator A132 can be considered part of a higher-level control system, which provides various functions from bit error rate detection to frequency scanning. The signal output terminal of the test signal generator A132 is electrically connected to the signal input terminal of the laser driver chip A134, and the test electrical signal generated by the test signal generator A132 is transmitted to the laser driver chip A134. The output of laser driver chip A134 is electrically connected to the laser in laser array A112. Laser driver chip A134 amplifies, shapes, and drives the received electrical signal, thereby driving the laser to emit a modulated optical signal. The optical signal emitted by the laser in laser array A112 passes sequentially through multiple optical channels A170, then through a multi-channel optical coupling structure A114, and a multi-channel transmission fiber A160 for optical path transmission, finally incident on the photosensitive receiving surface of the photodetector in photodetector array A116. The photodetector receives the optical signal and completes the photoelectric conversion from optical signal to current signal. The current output of the photodetector is connected to the signal input of the transimpedance amplifier in transimpedance amplifier array A122, inputting the converted weak current signal to the transimpedance amplifier. The transimpedance amplifier performs impedance matching, current-to-voltage conversion, and signal amplification on the weak current signal. The signal output of the transimpedance amplifier is connected back to the signal input of test signal generator A132, forming a complete closed-loop test link of electrical-optical-electrical. By comparing the transceiver signals on the test signal generator A132 side, the bit error rate performance of the entire optical device, optical fiber and optoelectronic transceiver chip link can be detected, and the bit error rate and sensitivity can be accurately tested.

[0032] Continue reading Figure 1The photodetector can be, for example, a photodiode (PD) or other device capable of receiving optical signals and performing photoelectric conversion from optical signals to electrical signals. The transimpedance amplifier array A122 includes transimpedance amplifiers that represent subsequent circuitry after the photodetectors at the optical receiver, such as a high-speed current signal amplification circuit, whose analog circuit characteristics are embodied in the transimpedance amplifier. A first correspondence exists between the at least one photodetector and the at least one transimpedance amplifier. For example, two photodetectors correspond to one transimpedance amplifier, or four photodetectors correspond to one transimpedance amplifier; the specific correspondence and quantity can be determined according to the design specifications of the device under test. The device under test can be an optoelectronic transceiver chip, which is reflected in the combination of photodetectors and corresponding transimpedance amplifiers, or it can be limited to a high-speed electrical chip simulated by transimpedance amplifiers. Furthermore, each of the at least one photodetectors includes a probe structure A150 based on semiconductor growth technology for electrically coupling the current output terminal of the photodetector to the signal input terminal of the transimpedance amplifier corresponding to that photodetector, as indicated by the first correspondence. Each photodetector comes with a certain number of probes, for example, two probes. One probe is used for electrical coupling with the corresponding transimpedance amplifier, and the other probe is used for power supply. Therefore, the number of probes for each photodetector is pre-designed and pre-deployed, as are the number of photodetectors and their respective probes for each transimpedance amplifier. For example, four photodetectors correspond to one transimpedance amplifier, and each of these four photodetectors has two probes, so a total of 4 multiplied by 2 equals 8 probes corresponding to the transimpedance amplifier. Based on this first correspondence, it can be determined that each photodetector includes a semiconductor growth-based probe structure A150 and a corresponding transimpedance amplifier. Therefore, through a pre-designed and pre-deployed layout, test signals can be directly input to the electronic component under test via the probes. Thus, a complex signal input link is not required; probes of a certain length can simulate the soldering requirements of the product. For example, the probe length can be set from 1 micrometer to 10 micrometers to adapt to the actual soldering requirements of the device under test. The A150 probe structure, based on semiconductor growth technology, can simulate the testing requirements of actual linear pluggable optical modules (LPOs) or systems. It can perform bit error rate and sensitivity tests on LPOs or similar pluggable optical transceiver architectures, accurately reflecting the parameters in actual use of the module and avoiding test result deviations caused by the disconnect between the test scenario and the actual application scenario.This test system is based on optical link simulation. It provides a complete closed-loop test link from the test electrical signal to the modulated optical signal and then to the signal input of the test signal generator A132. Within this closed-loop test link, a combination of devices with known transmission characteristics and the device under test (DUT) whose transmission characteristics need to be measured is used. This allows any link in the closed-loop test link to be used as the DUT while other links are used as devices with known transmission characteristics, thus enabling the measurement of the DUT's transmission characteristics. For example, the laser driver chip A134 or the laser itself in the laser array A112 can be used as the DUT, and a measurement scheme can be implemented by deploying a photodetector and a transimpedance amplifier with known transmission characteristics. Alternatively, a photodetector or a transimpedance amplifier can be used as the DUT, or a combination of a photodetector and a transimpedance amplifier can be used. Different combinations of photodetectors and transimpedance amplifiers can represent various product design schemes. This allows for the reuse of the same test system to test different product design schemes, effectively improving overall development efficiency and shortening the development cycle. Photodetectors and transimpedance amplifiers with different selection combinations can be deployed in photodetector array A116 and transimpedance amplifier array A122, referring to the first correspondence. As long as the photodetectors and transimpedance amplifiers of the same selection combination are electrically coupled through probes, test signals can be directly input to the electronic component under test through probes using a pre-designed and deployed layout. Therefore, multiple photodetectors and transimpedance amplifiers with different selection combinations can be deployed simultaneously in photodetector array A116 and transimpedance amplifier array A122 to achieve comprehensive testing of various product design schemes, such as parallel or serial testing in a certain order.

[0033] Continue reading Figure 1The multi-channel transmission fiber A160 is non-contactly optically coupled to the photosensitive receiving surface of each of the at least one photodetector. The optical device coupling structure A114 is used to selectively couple the modulated optical signal to the multi-channel transmission fiber A160 using the multiplexer. Generally, the photosensitive receiving surface of the photodetector and the current output terminal of the photodetector are not on the same plane. In some embodiments, the multi-channel transmission fiber A160 illuminates the photosensitive receiving surface of the photodetector at a fixed angle, which facilitates the deployment of the photodetector in a detachable manner and ensures non-contact optical coupling after the photodetector is replaced. Thus, the multi-channel transmission fiber A160 is non-contactly optically coupled to the photosensitive receiving surface of each of the at least one photodetector, which facilitates the replacement, removal, and installation of the photodetector, thereby enabling flexible testing of various product design schemes by combining different selection combinations of photodetectors and transimpedance amplifiers. In addition, as mentioned above, the optical device coupling structure A114 includes a multiplexer. The optical device coupling structure A114 is used to selectively couple the modulated optical signal to the multi-channel transmission optical fiber A160 using the multiplexer. Thus, by using the multiplexer on the optical device coupling structure A114, the modulated optical signal can be selectively coupled to a portion of the multi-channel transmission optical fiber A160 while not coupling to other portions. This allows control over which photodetectors are turned on (i.e., detecting the optical signal) and which are turned off (i.e., not detecting the optical signal), thereby enabling testing of the corresponding transimpedance amplifier output. Therefore, this test system supports multi-channel parallel testing, allowing simultaneous synchronous testing of multiple modules under test, significantly shortening the test cycle and improving test efficiency.

[0034] In short, Figure 1 The test system shown uses semiconductor growth technology to grow a probe at the output end of a photodetector. This probe directly inputs a test signal to the device under test (DUT), thus constructing a closed-loop test link from electrical signal to optical signal and back to electrical signal. This enables bit error rate (BER) and sensitivity testing. Based on optical link simulation, it recreates real-world application scenarios, improving testing efficiency and the authenticity of test results. Without the need for an additional complex signal input link, the system's structure is simplified, ensuring the stability and authenticity of the input signal and further improving the accuracy of BER and sensitivity test results. This system is suitable for testing the needs of practical pluggable optical transceiver architecture systems.

[0035] Continue reading Figure 1The photodetector array A116 is detachably deployed on the first circuit board A110, and the transimpedance amplifier array A122 is detachably deployed on the second circuit board A120. The laser array A112 and the optical device coupling structure A114 are deployed on the first circuit board A110, and the test signal generator A132 and the laser driver chip A134 are deployed on the third circuit board A130. Thus, through a detachable design, such as a linearly pluggable optical module, different selection combinations can be deployed on the same circuit board. This allows for the selection of different photodetectors and transimpedance amplifiers according to needs, and also facilitates parallel or serial testing schemes between different selection combinations. For example, the photodetector on the first circuit board A110 can remain unchanged, and different selection combinations can be achieved by removing and replacing the transimpedance amplifier on the second circuit board A120. Alternatively, different selection combinations can be achieved by replacing the entire second circuit board A120, as long as the corresponding photodetector and transimpedance amplifier are electrically coupled through probes based on semiconductor growth technology. In addition, different test signal generators A132 can be selected by replacing the entire third circuit board A130, thereby realizing different test modes. For example, mode switching between data processor, network analyzer or bit error rate tester (BERT) can be quickly realized by replacing the third circuit board A130.

[0036] Figure 2 This is a schematic diagram of a test system based on optical link simulation, provided as a second embodiment of this application. (See attached diagram.) Figure 2As shown, the test system includes: a test signal generator B232, a laser driver chip B234, a laser array B212, an optical device coupling structure B214 with a multiplexer, a photodetector array B216, and a transimpedance amplifier array B222. The test signal generator B232 provides a test electrical signal. The laser driver chip B234 provides a drive signal based on the test electrical signal. The laser array B212 is driven by the laser driver chip B234 to provide a modulated optical signal. The modulated optical signal is optically coupled to the optical device coupling structure B214 through multiple optical channels B270. The optical device coupling structure B214 includes a multiplexer. The optical device coupling structure B214 uses the multiplexer to selectively couple the modulated optical signal to a multi-channel transmission optical fiber B260. The photodetector array B216 includes at least one photodetector. The multi-channel transmission optical fiber B260 is non-contactly optically coupled to the photosensitive receiving surface of each of the at least one photodetector. The transimpedance amplifier array B222 includes at least one transimpedance amplifier. A first correspondence exists between the at least one photodetector and the at least one transimpedance amplifier. Each of the at least one photodetector includes a probe structure B250 based on semiconductor growth technology for electrically coupling the current output terminal of the photodetector to the signal input terminal of the transimpedance amplifier corresponding to that photodetector, as indicated by the first correspondence. The signal output terminals of each of the at least one transimpedance amplifier are connected back to the signal input terminal of the test signal generator B232 for use in conjunction with the test electrical signal for testing.

[0037] Figure 2 The test system shown is for reference. Figure 1 The test system shown utilizes semiconductor growth technology to grow a probe at the output end of a photodetector. This probe directly inputs a test signal to the device under test (DUT), thus constructing a closed-loop test link from electrical signal to optical signal and back to electrical signal. This enables bit error rate (BER) and sensitivity testing. Based on optical link simulation, it recreates real-world application scenarios, improving testing efficiency and the authenticity of test results. The system eliminates the need for a complex additional signal input link, simplifying the test system structure, ensuring the stability and authenticity of the input signal, and further improving the accuracy of BER and sensitivity test results. It is well-suited for the testing needs of practical pluggable optical transceiver architecture systems. About Figure 2 The basic principles and operating rules of the specific components in the test system shown can be found in the above information. Figure 1 The descriptions of the devices with the same names in the test system shown will not be repeated here.

[0038] Continue reading Figure 2The photodetector array B216 is detachably deployed on the first circuit board B210, and the transimpedance amplifier array B222 is detachably deployed on the second circuit board B220. The laser array B212 and the optical device coupling structure B214 are deployed on the first circuit board B210, and the test signal generator B232 and the laser driver chip B234 are deployed on the first circuit board B210. Thus, different combinations of photodetectors and transimpedance amplifiers can be selected as needed, and different combinations can be easily implemented. For example, the photodetector on the first circuit board B210 can remain unchanged, and different combinations can be achieved by removing and replacing the transimpedance amplifier on the second circuit board B220; or, different combinations can be achieved by replacing the entire second circuit board B220, as long as the corresponding photodetector and transimpedance amplifier are electrically coupled through a probe based on semiconductor growth technology.

[0039] Figure 3 This is a schematic diagram of a test system based on optical link simulation, provided as a third embodiment of this application. Figure 3 As shown, the test system includes: a test signal generator C332, a laser driver chip C334, a laser array C312, an optical device coupling structure C314 with a bidirectional multiplexer, a photodetector array C316, and a transimpedance amplifier array C322. The test signal generator C332 provides a test electrical signal. The laser driver chip C334 provides a drive signal based on the test electrical signal. The laser array C312 is driven by the laser driver chip C334 to provide a modulated optical signal. The modulated optical signal is optically coupled to the optical device coupling structure C314 through multiple optical channels C370. The optical device coupling structure C314 includes a multiplexer. The optical device coupling structure C314 uses the multiplexer to selectively couple the modulated optical signal to a multi-channel transmission optical fiber C360. The photodetector array C316 includes at least one photodetector. The multi-channel transmission optical fiber C360 is non-contactly optically coupled to the photosensitive receiving surface of each of the at least one photodetector. The transimpedance amplifier array C322 includes at least one transimpedance amplifier. A first correspondence exists between the at least one photodetector and the at least one transimpedance amplifier. Each of the at least one photodetector includes a probe structure C350 based on semiconductor growth technology for electrically coupling the current output terminal of the photodetector to the signal input terminal of the transimpedance amplifier corresponding to that photodetector, as indicated by the first correspondence. The signal output terminals of each of the at least one transimpedance amplifier are connected back to the signal input terminal of the test signal generator C332 for use in conjunction with the test electrical signal for testing.

[0040] Figure 3 The test system shown is for reference. Figure 1 The test system shown utilizes semiconductor growth technology to grow a probe at the output end of a photodetector. This probe directly inputs a test signal to the device under test (DUT), thus constructing a closed-loop test link from electrical signal to optical signal and back to electrical signal. This enables bit error rate (BER) and sensitivity testing. Based on optical link simulation, it recreates real-world application scenarios, improving testing efficiency and the authenticity of test results. The system eliminates the need for a complex additional signal input link, simplifying the test system structure, ensuring the stability and authenticity of the input signal, and further improving the accuracy of BER and sensitivity test results. It is well-suited for the testing needs of practical pluggable optical transceiver architecture systems. About Figure 3 The basic principles and operating rules of the specific components in the test system shown can be found in the above information. Figure 1 The descriptions of the devices with the same names in the test system shown will not be repeated here.

[0041] Continue reading Figure 3The photodetector array C316 is detachably deployed on the first circuit board C310, and the transimpedance amplifier array C322 is detachably deployed on the second circuit board C320. The optical device coupling structure C314 is deployed on the first circuit board C310, and the laser array C312, the test signal generator C332, and the laser driver chip C334 are deployed on the third circuit board C330. The multiplexer is a bidirectional multiplexer. The multiple optical channels C370 correspond to multiple channel insertion losses, that is, multiple optical channels C370 with different insertion losses. The bidirectional multiplexer is used to select the multi-channel transmission fiber C360 and to select the optical channel among the multiple optical channels C370 that corresponds to a given channel insertion loss among the multiple channel insertion losses. In this way, different combinations of photodetectors and transimpedance amplifiers can be selected as needed, and different selection combinations can be conveniently implemented. For example, the photodetector on the first circuit board C310 can be kept unchanged, and different selection combinations can be achieved by disassembling and replacing the transimpedance amplifier on the second circuit board C320. Alternatively, different selection combinations can be achieved by replacing the entire second circuit board C320, as long as the corresponding photodetector and transimpedance amplifier are electrically coupled through probes based on semiconductor growth technology. Furthermore, multiple optical channels C370 corresponding to different insertion losses are provided between the laser output of the laser array C312 and the photodetector array C316 to simulate different levels of insertion loss that may exist in actual applications. This allows for testing the performance of the entire system under different levels of insertion loss. In practical applications, insertion loss mainly originates between the test signal generator C332 and the laser driver chip C334. For example, different trace lengths on the finished chip cause different levels of single-channel loss. By providing multiple optical channels C370 corresponding to different insertion losses, the bidirectional multiplexer of the optical device coupling structure C314 can be used to select not only the multi-channel transmission fiber C360, but also the optical channel among the multiple optical channels C370 that corresponds to a given insertion loss among the multiple channel insertion losses. For example, assuming that the multiple optical channels C370 correspond to four different insertion loss values, selecting a given optical channel by using the bidirectional multiplexer selects the corresponding insertion loss, thus allowing testing of system performance under the selected insertion loss. In this way, based on optical link simulation and closed-loop test links, when it is necessary to test system performance under different insertion losses, no additional parameter configuration is required. By providing multiple optical channels C370 corresponding to different insertion losses and using the bidirectional multiplexer to select the optical channel corresponding to a given insertion loss, system performance testing under a specified insertion loss can be achieved, improving testing efficiency and simplifying the testing scheme.

[0042] See Figure 1 , Figure 2 and Figure 3 These optical link simulation-based test systems, through multiple circuit boards and a detachable design, enable flexible selection and combination. As long as the corresponding photodetectors and transimpedance amplifiers are electrically coupled via probes based on semiconductor growth technology, the photodetectors and transimpedance amplifiers can be conveniently located on different circuit boards. This allows for easy selection of different combinations of photodetectors and transimpedance amplifiers by utilizing the detachable design or replacing the entire circuit board. It also facilitates parallel or serial testing schemes between different combinations. Furthermore, by combining multiplexer selection control functions, it is possible to control which photodetectors receive the optical signal, enabling parallel testing, crosstalk testing, or alignment testing. Semiconductor growth technology can utilize any suitable technique, such as molecular beam epitaxy (MBE), vapor phase epitaxy (VPE), chemical vapor deposition (CVD), or simulated alloying techniques.

[0043] See Figure 1 , Figure 2 and Figure 3 In one possible implementation, the multiplexer is configured to optically couple the modulated optical signal through the multi-channel transmission fiber to the photosensitive receiving surfaces of each of the at least one photodetector, enabling multi-channel parallel testing. In some embodiments, the first correspondence indicates that multiple transimpedance amplifiers in the at least one transimpedance amplifier correspond to the multiple photodetectors, and the multi-channel parallel testing includes synchronous testing of the multiple transimpedance amplifiers. Thus, multi-channel parallel testing is supported, allowing simultaneous synchronous testing of multiple modules under test, significantly shortening the testing cycle and improving testing efficiency.

[0044] See Figure 1 , Figure 2 and Figure 3 In one possible implementation, the multiplexer is configured to sequentially activate multiple photodetectors among the at least one photodetector, thereby sequentially testing the outputs of the multiple transimpedance amplifiers corresponding to the multiple photodetectors as indicated by the first correspondence, in order to perform crosstalk testing and alignment testing. Thus, crosstalk testing and alignment testing are supported, allowing testing of whether the circuit boards are correctly aligned.

[0045] See Figure 1 , Figure 2 and Figure 3In one possible implementation, the photodetector array or the transimpedance amplifier array is a linearly pluggable optical module. This supports a linearly pluggable architecture.

[0046] See Figure 1 , Figure 2 and Figure 3 In one possible implementation, the photodetector array is detachably deployed on a first circuit board, and the transimpedance amplifier array is detachably deployed on a second circuit board. Thus, through a detachable design, such as a linearly pluggable optical module, different combinations of options can be deployed on the same circuit board. This allows for the selection of different combinations of photodetectors and transimpedance amplifiers as needed, and also facilitates parallel or serial testing schemes between different combinations.

[0047] See Figure 1 In one possible implementation, the laser array and the optical device coupling structure are deployed on the first circuit board, and the test signal generator and the laser driver chip are deployed on a third circuit board. This supports the implementation of different test modes.

[0048] See Figure 2 In one possible implementation, the laser array and the optical device coupling structure are deployed on the first circuit board, and the test signal generator and the laser driver chip are also deployed on the first circuit board. This supports different combinations of options.

[0049] See Figure 3 In one possible implementation, the optical device coupling structure is deployed on the first circuit board, and the laser array, the test signal generator, and the laser driver chip are deployed on a third circuit board. The multiplexer is a bidirectional multiplexer, and the multiple optical channels correspond to multiple channel insertion losses. The bidirectional multiplexer is used to select the multi-channel transmission fiber and to select the optical channel among the multiple optical channels that corresponds to a given channel insertion loss among the multiple channel insertion losses. In some embodiments, the multiple channel insertion losses are used to simulate different degrees of signal attenuation from the test signal generator to the laser driver chip, thereby testing the system performance under the different degrees of signal attenuation. Thus, based on optical link simulation and closed-loop test link, when it is necessary to test the system performance under different insertion losses, no additional parameter configuration is required. By providing multiple optical channels corresponding to different insertion losses and using a bidirectional multiplexer to select the optical channel corresponding to a given channel insertion loss, system performance testing under a specified insertion loss can be achieved, improving testing efficiency and simplifying the testing scheme.

[0050] See Figure 1 , Figure 2 and Figure 3 In one possible implementation, the first correspondence indicates that an even number of photodetectors in the at least one photodetector non-repeatingly correspond to a single transimpedance amplifier in the at least one transimpedance amplifier. This allows for flexible adaptation to the design specifications of actual products.

[0051] See Figure 1 , Figure 2 and Figure 3 In one possible implementation, each photodetector in the at least one photodetector includes a probe structure comprising at least two probes, one for signal transmission and the other for power supply. This supports design specifications for various detection structures.

[0052] See Figure 1 , Figure 2 and Figure 3 In one possible implementation, the test signal generator is a digital signal processor and the test electrical signal is a multi-frequency component signal; alternatively, the test signal generator is a network analyzer and the test electrical signal is a single-frequency component signal. This provides multiple functions from bit error rate detection to frequency scanning.

[0053] See Figure 1 , Figure 2 and Figure 3 In one possible implementation, the light output from the multi-channel transmission fiber illuminates the photosensitive receiving surfaces of each of the at least one photodetector at a fixed angle. This fixed angle illumination of the photodetector's receiving surface by the multi-channel transmission fiber facilitates detachable deployment of the photodetector and ensures non-contact optical coupling after replacement. Thus, the multi-channel transmission fiber is non-contactly optically coupled to the photosensitive receiving surfaces of each of the at least one photodetector, facilitating the replacement, removal, and installation of the photodetectors. This allows for flexible testing of various product design schemes by combining different selections of photodetectors and transimpedance amplifiers.

[0054] See Figure 1 , Figure 2 and Figure 3In one possible implementation, the probe structure has a length of 1 to 10 micrometers, and the length is set based on the soldering requirements of the electronic device under test. The probe structure based on semiconductor growth technology can simulate the testing requirements of actual linear pluggable optical modules (LPOs) or systems, performing bit error rate and sensitivity tests on LPOs or similar pluggable optical transceiver architectures. This accurately reflects the parameters used in actual module operation, avoiding test result deviations caused by a disconnect between the test scenario and the actual application scenario.

[0055] See Figure 1 , Figure 2 and Figure 3 In one possible implementation, the semiconductor growth technique is molecular beam epitaxy, vapor phase epitaxy, chemical vapor deposition, or simulated alloying. Thus, any suitable semiconductor growth technique can be used.

[0056] See Figure 1 , Figure 2 and Figure 3 In one possible implementation, the test system includes a closed-loop test link from the test electrical signal to the modulated optical signal and then to the signal input terminal of the test signal generator. Furthermore, the test system supports bit error rate performance testing and sensitivity testing for any device on the closed-loop test link. Thus, based on optical link simulation, by providing a complete closed-loop test link from the test electrical signal to the modulated optical signal and then to the signal input terminal of the test signal generator, and employing a combination of devices with known transmission characteristics and the device under test (DUT) whose transmission characteristics need to be measured within this closed-loop test link, any link in the closed-loop test link can be used as the DUT while other links are used as devices with known transmission characteristics, thereby enabling the measurement of the transmission characteristics of the DUT.

[0057] Figure 4 This is a flowchart illustrating a testing method based on optical link simulation, provided as an embodiment of this application. The testing method includes the following steps.

[0058] Step S401: Provide a test electrical signal through the test signal generator.

[0059] Step S403: Provide a drive signal based on the test electrical signal using a laser driver chip.

[0060] Step S405: A modulated optical signal is provided by a laser array driven by the laser driver chip, wherein the modulated optical signal is optically coupled to an optical device coupling structure through multiple optical channels, and the optical device coupling structure includes a multiplexer.

[0061] Step S407: Using the optical device coupling structure, the modulated optical signal is selectively coupled to the multi-channel transmission optical fiber by means of the multiplexer.

[0062] Step S409: A closed-loop test link is achieved through a photodetector array and a transimpedance amplifier array.

[0063] The photodetector array includes at least one photodetector, and the multi-channel transmission optical fiber is non-contactly optically coupled to the photosensitive receiving surface of each of the at least one photodetector. The transimpedance amplifier array includes at least one transimpedance amplifier, and a first correspondence exists between the at least one photodetector and the at least one transimpedance amplifier. Each of the at least one photodetector includes a probe structure based on semiconductor growth technology for electrically coupling the current output terminal of the photodetector to the signal input terminal of the transimpedance amplifier corresponding to that photodetector, as indicated by the first correspondence. The signal output terminals of each of the at least one transimpedance amplifier are connected back to the signal input terminal of the test signal generator for use in conjunction with the test electrical signal for testing.

[0064] Figure 4 The test method shown utilizes semiconductor growth technology to grow a probe at the output end of a photodetector. This probe directly inputs a test signal to the device under test (DUT), thus constructing a closed-loop test link from electrical signal to optical signal and back to electrical signal. This enables bit error rate (BER) and sensitivity testing. By simulating the optical link, it recreates real-world application scenarios, improving testing efficiency and the accuracy of test results. It eliminates the need for a complex additional signal input link, simplifying the test system structure, ensuring the stability and accuracy of the input signal, and further improving the accuracy of BER and sensitivity test results. This method is suitable for the testing needs of practical pluggable optical transceiver architecture systems. (About...) Figure 4 The basic principles and operating rules of the specific devices used in the test method shown can be found in the above information. Figure 1 The descriptions of the devices with the same names in the test system shown will not be repeated here.

[0065] See Figure 4In one possible implementation, the photodetector array is detachably deployed on a first circuit board, and the transimpedance amplifier array is detachably deployed on a second circuit board. Thus, through a detachable design, such as a linearly pluggable optical module, different selection combinations can be deployed on the same circuit board. This allows for the selection of different photodetectors and transimpedance amplifiers according to needs, and also facilitates parallel or serial testing schemes between different selection combinations. For example, the photodetectors on the first circuit board can remain unchanged, and different selection combinations can be achieved by removing and replacing the transimpedance amplifiers on the second circuit board. Alternatively, different selection combinations can be achieved by replacing the entire second circuit board, as long as the corresponding photodetectors and transimpedance amplifiers are electrically coupled via probes based on semiconductor growth technology.

[0066] See Figure 4 In one possible implementation, the test signal generator is a digital signal processor and the test electrical signal is a multi-frequency component signal; alternatively, the test signal generator is a network analyzer and the test electrical signal is a single-frequency component signal. This provides multiple functions from bit error rate detection to frequency scanning.

[0067] The methods and devices provided in this application are based on the same inventive concept. Since the principles by which the methods and devices solve problems are similar, the embodiments, implementation methods, examples, or methods of implementation of the methods and devices can be referred to each other, and repeated details will not be repeated. This application also provides a system comprising multiple computer devices, the structure of each computer device of which can refer to the structure of the computer devices described above. The functions or operations achievable by this system can refer to the specific implementation steps in the above method embodiments and / or the specific functions described in the above device embodiments, and will not be repeated here.

[0068] This application also provides a computer-readable storage medium storing computer instructions. When these computer instructions are executed on a computer device (such as one or more processors), they can implement the method steps described in the above method embodiments. The specific implementation of the above method steps by the processor of the computer-readable storage medium can refer to the specific operations described in the above method embodiments and / or the specific functions described in the above device embodiments, and will not be repeated here.

[0069] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. This application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Embodiments of this application can be implemented wholly or partially by software, hardware, firmware, or any other combination. When implemented in software, the above embodiments can be implemented wholly or partially as a computer program product. This application can take the form of a computer program product embodied on one or more computer-usable storage media containing computer-usable program code. The computer program product includes one or more computer instructions. When the computer program instructions are loaded or executed on a computer, all or part of the processes or functions described in the embodiments of this application are generated. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, computer instructions can be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via wired (e.g., coaxial cable, fiber optic, digital subscriber line) or wireless (e.g., infrared, wireless network communication, microwave, etc.) means. Computer-readable storage media can be any available medium that a computer can access, or a data storage device such as a server or data center that contains one or more sets of available media. Available media can be magnetic media (such as floppy disks, hard disks, and magnetic tapes), optical media, or semiconductor media. Semiconductor media can be solid-state drives, random access memory, flash memory, read-only memory, erasable programmable read-only memory, electrically erasable programmable read-only memory, registers, or any other suitable form of storage medium.

[0070] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. Each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to operate in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The functions specified in one or more boxes. These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable apparatus for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0071] In the above embodiments, the descriptions of each embodiment have their own emphasis. Parts not described in detail in a certain embodiment can be referred to in the relevant descriptions of other embodiments. Obviously, those skilled in the art can make various modifications and variations to the embodiments of this application without departing from the spirit and scope of the embodiments of this application. The steps in the methods of the embodiments of this application can be adjusted in order, combined, or deleted according to actual needs; the modules in the systems of the embodiments of this application can be divided, combined, or deleted according to actual needs. If these modifications and variations of the embodiments of this application fall within the scope of the claims of this application and their equivalents, then this application also intends to include these modifications and variations.

Claims

1. A test system based on optical link simulation, characterized in that, The testing system includes: Test signal generator, used to provide test electrical signals; A laser driver chip is used to provide a drive signal based on the test electrical signal; A laser array, driven by the laser driver chip to provide a modulated optical signal, wherein the modulated optical signal is optically coupled to an optical device coupling structure through multiple optical channels, the optical device coupling structure including a multiplexer; The optical device coupling structure is used to selectively couple the modulated optical signal to a multi-channel transmission optical fiber using the multiplexer. A photodetector array, comprising at least one photodetector, wherein the multi-channel transmission optical fiber is non-contactly optically coupled to the photosensitive receiving surface of each of the at least one photodetector; A transimpedance amplifier array, comprising at least one transimpedance amplifier, wherein the at least one photodetector and the at least one transimpedance amplifier satisfy a first correspondence, each of the at least one photodetector includes a probe structure based on semiconductor growth technology for electrically coupling the current output terminal of the photodetector to the signal input terminal of the transimpedance amplifier corresponding to the photodetector as indicated by the first correspondence, and the signal output terminals of the at least one transimpedance amplifier are respectively connected back to the signal input terminal of the test signal generator for use in testing together with the test electrical signal.

2. The testing system according to claim 1, characterized in that, The multiplexer is configured to optically couple the modulated optical signal through the multi-channel transmission optical fiber to the photosensitive receiving surfaces of the multiple photodetectors in the at least one photodetector, so as to perform multi-channel parallel testing.

3. The testing system according to claim 2, characterized in that, The first correspondence indicates that multiple transimpedance amplifiers in the at least one transimpedance amplifier correspond to multiple photodetectors, and the multi-channel parallel test includes synchronous testing of the multiple transimpedance amplifiers.

4. The testing system according to claim 1, characterized in that, The multiplexer is configured to sequentially turn on multiple photodetectors among the at least one photodetector, thereby sequentially testing the outputs of the multiple transimpedance amplifiers corresponding to the multiple photodetectors indicated by the first correspondence, in order to perform crosstalk testing and alignment testing.

5. The testing system according to claim 1, characterized in that, The photodetector array or the transimpedance amplifier array is a linearly pluggable optical module.

6. The testing system according to claim 1, characterized in that, The photodetector array is detachably deployed on the first circuit board, and the transimpedance amplifier array is detachably deployed on the second circuit board.

7. The testing system according to claim 6, characterized in that, The laser array and the optical device coupling structure are deployed on the first circuit board, and the test signal generator and the laser driver chip are deployed on the third circuit board.

8. The testing system according to claim 6, characterized in that, The laser array and the optical device coupling structure are deployed on the first circuit board, and the test signal generator and the laser driver chip are also deployed on the first circuit board.

9. The testing system according to claim 6, characterized in that, The optical device coupling structure is deployed on the first circuit board, and the laser array, the test signal generator, and the laser driver chip are deployed on the third circuit board. The multiplexer is a bidirectional multiplexer, and the multiple optical channels correspond to multiple channel insertion losses respectively. The bidirectional multiplexer is used to select the multi-channel transmission fiber and to select the optical channel among the multiple optical channels that corresponds to a given channel insertion loss among the multiple channel insertion losses.

10. The testing system according to claim 9, characterized in that, The multiple channel insertion losses are used to simulate different degrees of signal attenuation from the test signal generator to the laser driver chip, thereby testing the system performance under these different degrees of signal attenuation.

11. The testing system according to claim 1, characterized in that, The first correspondence indicates that an even number of photodetectors in the at least one photodetector correspond non-repeatingly to a single transimpedance amplifier in the at least one transimpedance amplifier.

12. The testing system according to claim 1, characterized in that, Each of the at least one photodetectors includes a probe structure comprising at least two probes, one for signal transmission and the other for power supply.

13. The testing system according to claim 1, characterized in that, The test signal generator is a digital signal processor and the test electrical signal is a multi-frequency component signal, or the test signal generator is a network analyzer and the test electrical signal is a single-frequency component signal.

14. The testing system according to claim 1, characterized in that, The light output from the multi-channel transmission optical fiber illuminates the photosensitive receiving surface of each of the at least one photodetector at a fixed angle.

15. The testing system according to claim 1, characterized in that, The length of the probe structure is from 1 micrometer to 10 micrometers, and the length of the probe structure is set based on the soldering requirements of the electronic device under test.

16. The testing system according to claim 1, characterized in that, The semiconductor growth technology mentioned is molecular beam epitaxy, vapor phase epitaxy, chemical vapor deposition, or simulated alloying technology.

17. The testing system according to claim 1, characterized in that, The test system includes a closed-loop test link from the test electrical signal to the modulated optical signal and then to the signal input terminal of the test signal generator. Furthermore, the test system supports bit error rate performance testing and sensitivity testing for any device on the closed-loop test link.

18. A test method based on optical link simulation, characterized in that, The testing method includes: A test electrical signal is provided through a test signal generator; A drive signal is provided based on the test electrical signal through a laser driver chip; A modulated optical signal is provided by a laser array driven by the laser driver chip, wherein the modulated optical signal is optically coupled to an optical device coupling structure through multiple optical channels, and the optical device coupling structure includes a multiplexer. The modulated optical signal is selectively coupled to a multi-channel transmission optical fiber using the optical device coupling structure and the multiplexer. A closed-loop test link is achieved using a photodetector array and a transimpedance amplifier array. The photodetector array includes at least one photodetector, and the multi-channel transmission optical fiber is non-contactly optically coupled to the photosensitive receiving surface of each of the at least one photodetector. The transimpedance amplifier array includes at least one transimpedance amplifier. The at least one photodetector and the at least one transimpedance amplifier satisfy a first correspondence. Each of the at least one photodetector includes a probe structure based on semiconductor growth technology for electrically coupling the current output terminal of the photodetector to the signal input terminal of the transimpedance amplifier corresponding to the photodetector as indicated by the first correspondence. The signal output terminals of the at least one transimpedance amplifier are respectively connected back to the signal input terminal of the test signal generator so as to be used for testing together with the test electrical signal.

19. The test method according to claim 18, characterized in that, The photodetector array is detachably deployed on the first circuit board, and the transimpedance amplifier array is detachably deployed on the second circuit board.

20. The test method according to claim 18, characterized in that, The test signal generator is a digital signal processor and the test electrical signal is a multi-frequency component signal, or the test signal generator is a network analyzer and the test electrical signal is a single-frequency component signal.

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