Method for testing silicon photonic chip, testing device, storage medium and program product thereof

Abstract

The application relates to a silicon optical chip testing method and device, a storage medium and a program product, wherein the silicon optical chip comprises a plurality of electro-optical modulators; the electro-optical modulator is a Mach-Zehnder modulator; the electro-optical modulator comprises a first modulation arm and a second modulation arm; the testing method comprises the following steps: detecting a loop resistance value of each electro-optical modulator corresponding to a preset loop; the preset loop is formed by the first modulation arm, the second modulation arm, the electro-optical modulator and a connecting cable between the electro-optical modulator and a resistance detection device; selecting an electro-optical modulator with the minimum loop resistance value as a reference modulator; determining a reference resistance value according to the difference between the loop resistance value of the reference modulator and the resistance value of the connecting cable; calculating the ratio of the loop resistance value of each electro-optical modulator to the reference resistance value to obtain an electro-optical modulator correction coefficient; and calculating the product of the correction coefficient and a preset modulation voltage to obtain a differential modulation voltage of the electro-optical modulator. The testing method can reduce the interference of contact resistance voltage division on half-wave voltage testing and improve testing accuracy.

Description

Technical Field

[0001] This application relates to the field of optical modulator technology, and in particular to a testing method, testing apparatus, storage medium, and program product for silicon photonic chips. Background Technology

[0002] In silicon photonics chips, electro-optic modulators are one of the core components for converting electrical signals to optical signals. Among them, the Mach-Zehnder modulator is a commonly used electro-optic modulator structure. During the wafer testing phase of silicon photonics chips, it is necessary to test the half-wave voltage of the Mach-Zehnder modulator to characterize its modulation efficiency. In traditional testing methods, this test typically involves contacting test probes with aluminum pads on the chip and applying the same differential modulation voltage to multiple electro-optic modulators on the chip to obtain the half-wave voltage of multiple electro-optic modulators.

[0003] However, during wafer fabrication, storage, transportation, and testing, an aluminum oxide layer easily forms on the surface of the chip's aluminum pads. Simultaneously, repeated contact between the test probes and the pads also leads to the adhesion of aluminum oxide debris, causing changes in the contact resistance between the test probes and the pads. Therefore, in testing multiple electro-optic modulators, the inconsistent contact resistance of different modulators results in a decrease in the actual voltage applied to each modulator due to voltage division caused by the contact resistance. This leads to varying degrees of deviation between the measured half-wave voltage of each modulator and the true value, resulting in poor test accuracy. Summary of the Invention

[0004] Based on this, this application provides a testing method for silicon photonic chips, which can reduce the interference of contact resistance voltage division on half-wave voltage testing and improve the accuracy of testing.

[0005] On one hand, this application provides a testing method for a silicon photonic chip, the silicon photonic chip including multiple electro-optic modulators; the electro-optic modulators are Mach-Zehnder type modulators; the electro-optic modulators include a first modulation arm and a second modulation arm; the first modulation arm includes a first electrode pad, a first traveling wave electrode and a first terminating resistor connected in sequence; the second modulation arm includes a second electrode pad, a second traveling wave electrode and a second terminating resistor connected in sequence; the first terminating resistor and the second terminating resistor are electrically connected; the testing method includes: based on a preset resistance detection device, detecting the loop resistance value of a preset loop corresponding to each electro-optic modulator; the preset loop is composed of the first modulation arm, the second modulation arm and the connecting cable between the electro-optic modulator and the resistance detection device; selecting the electro-optic modulator with the smallest loop resistance value as the reference modulator; determining the reference resistance value according to the difference between the loop resistance value of the reference modulator and the resistance value of the connecting cable; calculating the ratio of the loop resistance value of each electro-optic modulator to the reference resistance value to obtain the correction coefficient corresponding to each electro-optic modulator; calculating the product of the correction coefficient and the preset modulation voltage to obtain the differential modulation voltage corresponding to each electro-optic modulator; the differential modulation voltage is used to test the half-wave voltage of the electro-optic modulator.

[0006] Optionally, the voltage output terminal of the resistance detection device is connected to the first electrode pad and the second electrode pad respectively via connecting cables; the step of detecting the loop resistance value of the preset circuit corresponding to each electro-optic modulator based on the preset resistance detection device includes: controlling the resistance detection device to output a preset voltage through the voltage output terminal; detecting the first circuit current of each preset circuit; and determining the circuit resistance value based on the preset voltage and the first circuit current.

[0007] Optionally, the electro-optic modulator further includes a reference ground pad; the reference ground pad includes a first ground electrode and a second ground electrode; the voltage output terminal includes a first port, a second port, a third port, and a fourth port; wherein, the first port is connected to the first electrode pad; the second port is connected to the second electrode pad; the third port is connected to the first ground electrode via a connecting cable; and the fourth port is connected to the second ground electrode via a connecting cable; the step of controlling the resistance detection device to output a preset voltage through the voltage output terminal includes: controlling the resistance detection device to output a first positive voltage to the first port, the first positive voltage being equal to half of the preset voltage; controlling the resistance detection device to output a first negative voltage to the second port, the first negative voltage being equal to half of the negative preset voltage; and controlling the resistance detection device to output zero voltage to the third port and the fourth port.

[0008] Optionally, the method further includes setting the differential modulation voltage of the electro-optic modulator to the preset voltage threshold when the differential modulation voltage corresponding to a single electro-optic modulator is greater than or equal to a preset voltage threshold.

[0009] Optionally, the method further includes: if, among the multiple electro-optic modulators, at least a preset number of electro-optic modulators have differential modulation voltages equal to a preset voltage threshold, an alarm command is sent.

[0010] Optionally, the method further includes: performing a probe cleaning operation on the test probes of the silicon photonics chip in response to an alarm command.

[0011] Optionally, after obtaining the differential modulation voltage corresponding to each electro-optic modulator, the method further includes: based on the resistance detection device, testing the half-wave voltage of multiple electro-optic modulators according to the obtained multiple differential modulation voltages.

[0012] Optionally, the method further includes: during the testing of the half-wave voltage of the reference modulator, obtaining the second loop current of the reference modulator; calculating the quotient of the differential modulation voltage and the second loop current corresponding to the reference modulator to obtain the second resistance value of the reference modulator; and determining that the half-wave voltage test results of multiple electro-optic modulators are invalid when the difference between the loop resistance value and the second resistance value of the reference modulator is greater than a preset resistance threshold.

[0013] On the other hand, this application also provides a testing device for a silicon photonic chip, the silicon photonic chip including multiple electro-optic modulators; the electro-optic modulators are Mach-Zehnder type modulators; the electro-optic modulators include a first modulation arm and a second modulation arm; the first modulation arm includes a first electrode pad, a first traveling wave electrode and a first terminating resistor connected in sequence; the second modulation arm includes a second electrode pad, a second traveling wave electrode and a second terminating resistor connected in sequence; the first terminating resistor and the second terminating resistor are electrically connected; the testing device includes: a detection module, used to detect the loop resistance value of a preset loop corresponding to each electro-optic modulator based on a preset resistance detection device; the preset loop is composed of the first modulation arm, the second modulation arm and the connecting cable between the electro-optic modulator and the resistance detection device; a selection module, used to select the electro-optic modulator with the smallest loop resistance value as a reference modulator; a determination module, used to determine a reference resistance value based on the difference between the loop resistance value of the reference modulator and the resistance value of the connecting cable; and a first calculation module, used to calculate the ratio of the loop resistance value of each electro-optic modulator to the reference resistance value to obtain a correction coefficient corresponding to each electro-optic modulator;

[0014] The second calculation module is used to calculate the product of the correction coefficient and the preset modulation voltage to obtain the differential modulation voltage corresponding to each electro-optic modulator; the differential modulation voltage is used to test the half-wave voltage of the electro-optic modulator.

[0015] In another aspect, this application also provides another testing device for silicon photonics chips, including a memory and a processor, wherein the memory stores a computer program and the processor is configured to run the computer program to perform the aforementioned method.

[0016] In another aspect, this application also provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the aforementioned method.

[0017] In another aspect, this application also provides a computer program product, including a computer program that, when executed by a processor, implements the steps of the aforementioned method.

[0018] The embodiments provided in this application select the electro-optic modulator with the smallest loop resistance as the reference modulator. A reference resistance value is then determined based on the difference between the loop resistance value of the reference modulator and the resistance value of the connecting cable. Subsequently, a correction coefficient for each electro-optic modulator is obtained based on the ratio of its loop resistance value to the reference resistance value. Finally, the product of the correction coefficient and a preset modulation voltage is calculated to obtain the differential modulation voltage corresponding to each electro-optic modulator. This allows the obtained differential modulation voltage to compensate for the voltage drop caused by contact resistance, thereby reducing the interference of contact resistance voltage division on half-wave voltage testing and improving test accuracy. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the structure of an electro-optic modulator according to an embodiment of this application;

[0020] Figure 2 This is a schematic flowchart of a testing method for a silicon photonic chip according to an embodiment of this application;

[0021] Figure 3 This is a structural block diagram of a testing apparatus for a silicon photonic chip according to an embodiment of this application;

[0022] Figure 4 This is a structural block diagram of a testing apparatus for a silicon photonic chip according to another embodiment of this application.

[0023] Explanation of reference numerals in the attached figures

[0024] 100. Electro-optic modulator; 110. First modulation arm; 111. First electrode pad; 112. First traveling wave electrode; 113. First terminating resistor; 120. Second modulation arm; 121. Second electrode pad; 122. Second traveling wave electrode; 123. Second terminating resistor; 130. One-to-two beam splitter; 140. Two-to-one beam combiner; 150. First waveguide; 160. Second waveguide; 170. Thermo-optic modulator; 180. Reference ground pad; 181. First ground electrode; 182. Second ground electrode; 200. Test device; 210. Detection module; 220. Selection module; 230. Determination module; 240. First calculation module; 250. Second calculation module. Detailed Implementation

[0025] To make the technical solution and beneficial effects of this application more apparent and understandable, a detailed description is provided below by listing specific embodiments. Unless otherwise defined, the technical and scientific terms used in this application have the same meaning as those in the technical field to which this application pertains. The terminology used in the specification of this application is for the purpose of describing specific embodiments only and is not intended to limit this application.

[0026] Figure 1 The electro-optic modulator shown is one type of electro-optic modulator in a silicon photonic chip to which the test methods of this application can be applied. (Reference) Figure 1 The electro-optic modulator 100 includes a first modulation arm 110, a second modulation arm 120, a beam splitter 130, a beam combiner 140, a first waveguide 150, a second waveguide 160, two thermo-optic modulators 170, and a reference ground pad 180. The first modulation arm 110 includes a first electrode pad 111, a first traveling wave electrode 112, and a first terminating resistor 113 connected in sequence. The second modulation arm 120 includes a second electrode pad 121, a second traveling wave electrode 122, and a second terminating resistor 123 connected in sequence. The reference ground pad 180 includes a first ground electrode 181 and a second ground electrode 182. The first terminating resistor 113 and the second terminating resistor 123 are electrically connected (the connection wire is...). Figure 1 (Thick solid line in the diagram). The first waveguide 150 is disposed between the first modulation arm 110 and the first ground electrode 181. The second waveguide 160 is disposed between the second modulation arm 120 and the second ground electrode 182. The two branches of the 1-to-2 beam splitter 130 are respectively connected to the two branches of the 2-to-1 beam combiner 140 through the first waveguide 150 and the second waveguide 160. The two thermo-optic modulators 170 are connected to an external control circuit (not shown) through leads. The external control circuit is also connected to the first electrode pad 111 and the second electrode pad 121 through leads.

[0027] Specifically, the first modulation arm 110, the second modulation arm 120, the beam splitter 130, the beam combiner 140, the first waveguide 150, and the second waveguide 160 in the electro-optic modulator 100 constitute a typical Mach-Zehnder modulator. During normal operation of the electro-optic modulator 100, the input light is split into two paths by the beam splitter 130, entering the first waveguide 150 and the second waveguide 160 respectively, and then output through the beam combiner 140 to obtain the output light. During optical transmission, the external control circuit applies differential electrical signals to the first modulation arm 110 and the second modulation arm 120 through two electrode pads (111, 121), the first ground electrode 181, and the second ground electrode 182, respectively. The first ground electrode 181 and the second ground electrode 182 are mainly used to provide a signal reference ground. The differential electrical signal is transmitted through two traveling-wave electrodes (112, 122). The electro-optic effect is used to change the refractive index of the first waveguide 150 and the second waveguide 160, causing the phase of the light in the two waveguides (150, 160) to change with the phase difference of the differential electrical signal. Consequently, the intensity of the light output from the two-in-one beam combiner 140 also changes with the phase difference of the differential electrical signal. This achieves the conversion from an electrical signal to an optical signal.

[0028] In addition, the first terminating resistor 113 and the second terminating resistor 123 are connected to form a loop, mainly used for impedance matching and absorption of electrical signals. The two thermo-optic modulators 170 are mainly used, under the control of an external control circuit, to adjust and stabilize the operating point of the electro-optic modulator using the thermo-optic effect; the specific adjustment principle of the operating point is not elaborated here. Furthermore, the first ground electrode 181 and the second ground electrode 182 also serve to optimize the high-frequency performance of the electro-optic modulator 100.

[0029] It should be noted that, Figure 1 The electro-optic modulator 100 structure described herein is exemplary. Silicon photonic chips capable of applying the test methods of this application may also have Mach-Zehnder type modulators with other structures. For example, the electro-optic modulator of a silicon photonic chip may not include a thermo-optic modulator.

[0030] In addition, it should be noted that in this application, the reference ground pad 180 refers to a pad that has the function of an equivalent reference ground. Figure 1 In the electro-optic modulator 100 shown, the reference ground pad 180 includes a first ground electrode 181 and a second ground electrode 182, and this configuration is exemplary. In other embodiments, the reference ground pad 180 may be configured with other structures. For example, the two ground electrodes (181, 182) of the reference ground pad 180 may be combined into a single ground electrode.

[0031] See Figure 2 This application provides a testing method for silicon photonics chips in some embodiments, the testing method including:

[0032] S101, based on a preset resistance detection device, detects the loop resistance value of a preset circuit corresponding to each electro-optic modulator; the preset circuit consists of a first modulation arm, a second modulation arm, and a connecting cable between the electro-optic modulator and the resistance detection device.

[0033] S102, select the electro-optic modulator with the smallest loop resistance value as the reference modulator.

[0034] S103, determine the reference resistance value based on the difference between the loop resistance value of the reference modulator and the resistance value of the connecting cable.

[0035] S104, calculate the ratio of the loop resistance value to the reference resistance value for each electro-optic modulator to obtain the correction coefficient corresponding to each electro-optic modulator.

[0036] S105 calculates the product of the correction coefficient and the preset modulation voltage to obtain the differential modulation voltage corresponding to each electro-optic modulator. The differential modulation voltage is used to test the half-wave voltage of the electro-optic modulator.

[0037] As can be understood, a resistance detection device refers to a testing device capable of detecting resistance, such as a dual-channel source meter. Differential modulation voltage refers to the AC voltage peak value set by the testing device when detecting the half-wave voltage of the electro-optic modulator, outputting it to the electro-optic modulator in a differential form (equal amplitude, opposite polarity). This differential modulation voltage is applied to the electro-optic modulator after being divided by the connecting cables and contact resistance. Preset modulation voltage refers to the reference voltage value pre-set for calculating the differential modulation voltage corresponding to each electro-optic modulator. Connecting cables refer to the collective term for one or more cables connecting the resistance detection device and the electro-optic modulator.

[0038] Furthermore, it should be noted that the connecting cable between the electro-optic modulator and the resistance detection device includes test probes for connecting to the two electrode pads (111, 121). Therefore, the resistance of the preset circuit includes the contact resistance generated when the test probes contact the two electrode pads (111, 121). Additionally, the resistance of the connecting cable is a fixed value and can be determined through pre-measurement. Alternatively, in some embodiments, the resistance of the connecting cable is small, and therefore can be considered zero.

[0039] The aforementioned testing method for silicon photonic chips selects the electro-optic modulator with the smallest loop resistance as the reference modulator. The reference resistance value is then determined based on the difference between the loop resistance of the reference modulator and the resistance of the connecting cable. Subsequently, a correction coefficient for each electro-optic modulator is obtained based on the ratio of its loop resistance to the reference resistance. Finally, the product of the correction coefficient and the preset modulation voltage is calculated to obtain the differential modulation voltage corresponding to each electro-optic modulator. This allows the obtained differential modulation voltage to compensate for the voltage drop caused by contact resistance, thereby reducing the interference of contact resistance voltage division on the half-wave voltage test and improving the accuracy of the test.

[0040] Specifically, refer to Figure 1 Each electro-optic modulator's preset circuit consists of a first modulation arm, a second modulation arm, and a connecting cable between the electro-optic modulator and the resistance detection device, all connected in series. This results in the detected circuit resistance value being composed of three parts: the resistance of each component within the first and second modulation arms (hereinafter referred to as the internal resistance of the electro-optic modulator), the resistance of the connecting cable, and the contact resistance generated by the test probe contacting the two electrode pads. The resistance of the connecting cable is a fixed value. Furthermore, in mature wafer manufacturing processes, the resistance of silicon photonic chips exhibits good consistency across the entire wafer, and the impact of intra-wafer variations on the half-wave voltage is negligible. Therefore, the internal resistance of each electro-optic modulator can be considered the same. Consequently, the difference in circuit resistance values ​​between multiple electro-optic modulators is primarily determined by the difference in contact resistance.

[0041] In the aforementioned testing method for silicon photonic chips, the electro-optic modulator with the smallest loop resistance is selected as the reference modulator. This means that the contact resistance of the reference modulator is ignored, and the reference resistance value is obtained by subtracting the resistance of the connecting cable from the loop resistance value of the reference modulator. This reference resistance value is the internal resistance of the reference modulator. Since the internal resistances of multiple electro-optic modulators can be considered to be the same, according to the voltage divider principle, the ratio between the reference resistance value and the loop resistance value of each electro-optic modulator is the voltage division ratio between the internal resistance voltage of the electro-optic modulator and the total voltage on the preset loop.

[0042] Therefore, in steps S104 and S105 above, the correction coefficient for each electro-optic modulator is obtained by calculating the ratio of the loop resistance value to the reference resistance value. Then, the differential modulation voltage for each electro-optic modulator is obtained by multiplying this correction coefficient by the preset modulation voltage. This causes the differential modulation voltage to increase according to the voltage division ratio, thereby enabling the obtained differential modulation voltage to compensate for the voltage drop caused by the contact resistance, thus reducing the interference of the contact resistance voltage division on the half-wave voltage test.

[0043] Furthermore, in related technologies, the differential modulation voltage corresponding to each electro-optic modulator is determined by separately measuring the resistance values ​​of the first and second modulation arms. However, the disadvantage of this method is that, to avoid the influence of contact resistance, the Kelvin four-wire method is required to measure the resistance values ​​of the two modulation arms, which makes the test relatively complex. In the aforementioned silicon photonics chip testing method, it is not necessary to measure the specific resistance value of each modulation arm; only the loop resistance values ​​of multiple electro-optic modulators need to be determined. Therefore, a simple two-channel source meter, or two single-channel source meters, can be used for testing, thereby reducing the testing cost and improving the convenience of the testing method.

[0044] As a specific example, if the resistance of the connecting cable is negligible, the differential modulation voltage corresponding to each electro-optic modulator can be obtained by the following formula (1):

[0045] V1=V0*R1 / R2 (1)

[0046] Where V1 is the differential modulation voltage corresponding to each electro-optic modulator. V0 is the preset modulation voltage. R1 is the loop resistance value of each electro-optic modulator. R2 is the loop resistance value of the reference modulator. Since the resistance of the connecting cable is zero, the loop resistance value of the reference modulator can be directly used as the reference resistance value.

[0047] As another specific example, if the resistance of the connecting cable is not negligible, the differential modulation voltage corresponding to each electro-optic modulator can be obtained by the following formula (2):

[0048] V1=V0*R1 / (R2-R3) (2)

[0049] Where V1 is the differential modulation voltage corresponding to each electro-optic modulator, V0 is the preset modulation voltage, R1 is the loop resistance value of each electro-optic modulator, R2 is the loop resistance value of the reference modulator, and R3 is the resistance value of the connecting cable.

[0050] In some embodiments, the voltage output terminal of the resistance detection device is connected to the first electrode pad and the second electrode pad respectively via connecting cables. Step S101, based on the preset resistance detection device, is a step of detecting the loop resistance value of a preset loop corresponding to each electro-optic modulator, which includes: controlling the resistance detection device to output a preset voltage through the voltage output terminal; detecting the first loop current of each preset loop; and determining the loop resistance value based on the preset voltage and the first loop current. Thus, the testing method can realize the function of detecting the loop resistance value through the resistance detection device.

[0051] It is understood that the preset voltage refers to a pre-set voltage value, which may be the same as or different from the preset modulation voltage. Furthermore, in the above embodiment, the detection method of determining the loop resistance value by outputting the preset voltage and detecting the first loop current is exemplary. In other embodiments, the loop resistance value can also be determined by other methods. For example, a preset current can be output to a preset loop, and the loop voltage can be detected to determine the loop resistance value.

[0052] In some embodiments, the voltage output terminal includes a first port, a second port, a third port, and a fourth port. The first port is connected to a first electrode pad. The second port is connected to a second electrode pad. The third port is connected to a first ground electrode via a connecting cable. The fourth port is connected to a second ground electrode via a connecting cable. The step of controlling the resistance detection device to output a preset voltage through the voltage output terminal includes: controlling the resistance detection device to output a first positive voltage to the first port, the first positive voltage being equal to half of the preset voltage; controlling the resistance detection device to output a first negative voltage to the second port, the first negative voltage being equal to half of the negative preset voltage; and controlling the resistance detection device to output zero voltage to the third and fourth ports. This enables the resistance detection device to output a preset voltage to the electro-optic modulator through the voltage output terminal.

[0053] Furthermore, the aforementioned method has the advantage that when performing other tests on silicon photonics chips, such as detecting half-wave voltage, it is usually necessary to use connecting cables to output corresponding detection signals between the first electrode pad, the second electrode pad, the first ground electrode, and the second ground electrode. In the above testing method, the first to fourth ports of the resistance detection device are all connected to the corresponding ports of the electro-optic modulator via connecting cables. This allows the testing method of this application to share a set of connecting cables (including test probes) with other tests on the silicon photonics chip. When the tester switches test content, there is no need to adjust the connection relationship between the connecting cables and the silicon photonics chip, thus not changing the contact position between the test probe and the silicon photonics chip pad. This results in smaller fluctuations in the contact resistance between the silicon photonics chip pad and the test probe, and the test probe does not need to frequently penetrate the pad. The risk of alumina debris adhering to its surface due to penetrating the pad is also lower, thereby improving the reliability of the testing method.

[0054] In some embodiments, the method further includes setting the differential modulation voltage of the electro-optic modulator to the preset voltage threshold when the differential modulation voltage corresponding to a single electro-optic modulator is greater than or equal to a preset voltage threshold.

[0055] Specifically, the preset voltage threshold refers to the preset upper limit value of the differential modulation voltage. When the differential modulation voltage corresponding to a single electro-optic modulator is greater than or equal to the preset voltage threshold, it indicates that the differential modulation voltage is too high. If this differential modulation voltage is used for testing, it can easily cause malfunctions in the testing device or the silicon photonics chip. Therefore, in the aforementioned silicon photonics chip testing method, when the differential modulation voltage corresponding to a single electro-optic modulator is greater than or equal to the preset voltage threshold, the differential modulation voltage of that electro-optic modulator is set to the preset voltage threshold to reduce malfunctions caused by excessive differential modulation voltage and improve the reliability of the testing method.

[0056] In some embodiments, the method further includes: if, among the plurality of electro-optic modulators, at least a preset number of electro-optic modulators have differential modulation voltages equal to a preset voltage threshold, sending an alarm command.

[0057] Understandably, the preset quantity can be set in various ways. For example, the preset quantity can be set to 5, or it can be set to one percent of the total number of electro-optic modulators.

[0058] Specifically, when the differential modulation voltage corresponding to a certain electro-optic modulator is forcibly reduced to a preset voltage threshold, it indicates that the contact resistance of the electro-optic modulator is relatively large, which is prone to causing poor contact problems.

[0059] When the differential modulation voltage corresponding to a preset number of electro-optic modulators equals a preset voltage threshold, it indicates that a significant number of differential modulation voltages have been forcibly reduced to the preset voltage threshold. This, in turn, suggests that a large number of electro-optic modulators have high contact resistance, leading to a higher risk of accumulated contact defects. Therefore, in this situation, the aforementioned silicon photonics chip testing method also sends an alarm command to the system or user to alert them to the situation and prevent the accumulated risk of contact defects from causing larger failures, thereby improving the reliability of the testing method.

[0060] It is understandable that alarm commands can take one or more different forms, such as any combination of buzzer sounds, light signals, voice prompts, and pop-up messages, and there are no restrictions here.

[0061] Furthermore, the method also includes: in response to an alarm command, performing a probe cleaning operation on the test probes of the silicon photonics chip.

[0062] Specifically, the test probes have a large amount of alumina debris adhering to them, which can lead to increased contact resistance. Therefore, when an alarm command is received, the test method can perform a probe cleaning operation on the silicon photonics chip to remove the alumina debris from the test probe surface, eliminate potential contact problems, and thus improve the reliability of the test method.

[0063] In some embodiments, after obtaining the differential modulation voltage corresponding to each electro-optic modulator, the method further includes: based on the resistance detection device, testing the half-wave voltage of the multiple electro-optic modulators according to the obtained multiple differential modulation voltages.

[0064] Specifically, since the resistance detection device can output a specific voltage value to each electro-optic modulator, and after the differential modulation voltage corresponding to each electro-optic modulator is determined through step S105, the resistance detection device is already connected to multiple electrode pads of the electro-optic modulator. Therefore, the multiple differential modulation voltages determined in step S105 can be used as reference values ​​to change the output voltage of the resistance detection device, thereby testing the half-wave voltage of multiple electro-optic modulators. The advantage of this method is that it allows for the reuse of the resistance detection device, thereby reducing the hardware cost of the testing method.

[0065] In some embodiments, the method further includes: acquiring the second loop current of the reference modulator during the testing of the half-wave voltage of the reference modulator; calculating the quotient of the differential modulation voltage corresponding to the reference modulator and the second loop current to obtain the second resistance value of the reference modulator; and determining that the half-wave voltage test results of multiple electro-optic modulators are invalid when the difference between the loop resistance value and the second resistance value of the reference modulator is greater than a preset resistance threshold.

[0066] Specifically, during the half-wave voltage test, a sinking current is generated between the two modulation arms due to the differential modulation voltage. Therefore, if the second loop current of the reference modulator is obtained during the test, the second resistance value can be obtained based on the differential modulation voltage and the second loop current corresponding to the reference modulator. This second resistance value also represents the loop resistance value of the preset loop corresponding to the reference modulator.

[0067] Therefore, if the difference between the loop resistance value of the reference modulator measured in step S101 and the second resistance value is greater than the preset resistance threshold, it indicates that the contact resistance of the reference modulator changes significantly between the two detection processes, thus indicating that the contact resistance of the reference modulator is highly random. In steps S101-S105, the differential modulation voltage corresponding to each electro-optic modulator is obtained by ignoring the contact resistance of the reference modulator. If the contact resistance of the reference modulator is highly random, directly ignoring it may introduce a large error, resulting in low accuracy of the half-wave voltage. Therefore, in the above silicon photonics chip testing method, when the difference between the loop resistance value and the second resistance value of the reference modulator is greater than the preset resistance threshold, the half-wave voltage test results of multiple electro-optic modulators are determined to be invalid to exclude test results with low accuracy and improve the reliability of the testing method.

[0068] Some embodiments of this application provide a testing apparatus for silicon photonics chips. The silicon photonics chip includes multiple electro-optic modulators. The electro-optic modulators are Mach-Zehnder type modulators. (Reference) Figure 1 The electro-optic modulator 100 includes a first modulation arm 110 and a second modulation arm 120. The first modulation arm 110 includes a first electrode pad 111, a first traveling wave electrode 112, and a first terminating resistor 113 connected in sequence. The second modulation arm 120 includes a second electrode pad 121, a second traveling wave electrode 122, and a second terminating resistor 123 connected in sequence. The first terminating resistor 113 and the second terminating resistor 123 are electrically connected. (Reference) Figure 3 The testing device 200 includes a detection module 210, a selection module 220, a determination module 230, a first calculation module 240, and a second calculation module 250.

[0069] The detection module 210 detects the loop resistance value of a preset loop corresponding to each electro-optic modulator 100 based on a preset resistance detection device. The preset loop consists of a first modulation arm 110, a second modulation arm 120, and a connecting cable between the electro-optic modulator and the resistance detection device. The selection module 220 selects the electro-optic modulator 100 with the smallest loop resistance value as the reference modulator. The determination module 230 determines the reference resistance value based on the difference between the loop resistance value of the reference modulator and the resistance value of the connecting cable. The first calculation module 240 calculates the ratio of the loop resistance value of each electro-optic modulator 100 to the reference resistance value to obtain the correction coefficient corresponding to each electro-optic modulator 100. The second calculation module 250 calculates the product of the correction coefficient and the preset modulation voltage to obtain the differential modulation voltage corresponding to each electro-optic modulator 100. The differential modulation voltage is used to test the half-wave voltage of the electro-optic modulator 100.

[0070] Each module in the aforementioned testing device 200 can be implemented entirely or partially through software, hardware, or a combination thereof. These modules can be embedded in or independent of the processor in a computer device, or stored in the memory of the testing device 200 as software, so that the processor can call and execute the operations corresponding to each module. It should be noted that the above module division is illustrative and represents only a logical functional division; in actual implementation, other division methods may be used.

[0071] Based on the aforementioned embodiments of the silicon photonics chip testing method, in some other embodiments provided in this application, another testing apparatus is provided, the internal structure of which can be shown in the diagram below. Figure 4As shown, the test device includes a processor, memory, input / output (I / O) interfaces, and a communication interface. The processor, memory, and I / O interfaces are connected via a system bus, and the communication interface is also connected to the system bus via the I / O interfaces. The processor provides computational and control capabilities. The memory includes non-volatile storage media and internal memory. The non-volatile storage media stores the operating system, computer programs, and a database. The internal memory provides the environment for the operation of the operating system and computer programs stored in the non-volatile storage media. The database stores data. The I / O interfaces are used for exchanging information between the processor and external devices. The communication interface is used for communication with external terminals via a network connection. When the computer program is executed by the processor, it implements a testing method for silicon photonics chips.

[0072] Those skilled in the art will understand that Figure 4 The structure shown is merely a block diagram of a portion of the structure related to the present application and does not constitute a limitation on the testing device to which the present application is applied. A specific testing device may include more or fewer components than those shown in the figure, or combine certain components, or have different component arrangements.

[0073] Based on the aforementioned embodiments of the silicon photonics chip testing method, in another embodiment provided in this application, a computer-readable storage medium is provided, on which a computer program is stored, and when the computer program is executed by a processor, it implements the steps in the above-described method embodiments.

[0074] Based on the aforementioned embodiments of the silicon photonics chip testing method, in another embodiment provided in this application, a computer program product is provided, including a computer program that, when executed by a processor, implements the steps in the above-described method embodiments.

[0075] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in orders other than those illustrated or described herein. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this application as detailed in the appended claims. The terms "comprising," "including," or any other variations thereof are intended to cover a non-exclusive inclusion, such that a process, method, product, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, product, or apparatus. Without further limitations, the presence of other identical or equivalent elements in a process, method, product, or apparatus that includes said elements is not excluded. For example, the use of terms such as "first," "second," etc., is to denote names and does not indicate any specific order.

[0076] When used herein, the singular forms of “a,” “an,” and “the” may also include the plural forms unless the context clearly indicates otherwise. It should also be understood that the terms “comprising / including” or “having,” etc., specify the presence of the stated features, wholes, steps, operations, components, parts, or combinations thereof, but do not preclude the possibility of the presence or addition of one or more other features, wholes, steps, operations, components, parts, or combinations thereof. Meanwhile, in this specification, the term “and / or” includes any and all combinations of the associated listed items.

[0077] In the description of this application, the references to terms such as "some embodiments," "other embodiments," "ideal embodiments," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present invention. In this specification, the illustrative descriptions of the above terms do not necessarily refer to the same embodiments or examples.

[0078] It is understood that the various embodiments of the methods described in this specification are presented in a progressive manner. Similar or identical parts between embodiments can be referred to mutually. Each embodiment focuses on its differences from other embodiments. Relevant details can be found in the descriptions of other method embodiments.

[0079] It should be understood that the above embodiments are exemplary and are not intended to encompass all possible implementations included in the claims. Various modifications and changes can be made to the above embodiments without departing from the scope of this application. Similarly, the various technical features of the above embodiments can be arbitrarily combined to form other embodiments of this application that may not be explicitly described. Therefore, the above embodiments only illustrate several implementations of this application and do not limit the scope of protection of this patent application.

Claims

1. A testing method for silicon photonic chips, characterized in that, The silicon photonic chip includes multiple electro-optic modulators; the electro-optic modulators are Mach-Zehnder type modulators; the electro-optic modulators include a first modulation arm and a second modulation arm; the first modulation arm includes a first electrode pad, a first traveling wave electrode and a first terminating resistor connected in sequence; the second modulation arm includes a second electrode pad, a second traveling wave electrode and a second terminating resistor connected in sequence. The first terminating resistor and the second terminating resistor are electrically connected; the test method includes: Based on a preset resistance detection device, the loop resistance value of a preset circuit corresponding to each electro-optic modulator is detected; the preset circuit consists of the first modulation arm, the second modulation arm, and the connecting cable between the electro-optic modulator and the resistance detection device; The electro-optic modulator with the smallest loop resistance value is selected as the reference modulator; The reference resistance value is determined based on the difference between the loop resistance value of the reference modulator and the resistance value of the connecting cable; Calculate the ratio of the loop resistance value of each electro-optic modulator to the reference resistance value to obtain the correction coefficient corresponding to each electro-optic modulator; The product of the correction coefficient and the preset modulation voltage is calculated to obtain the differential modulation voltage corresponding to each electro-optic modulator; the differential modulation voltage is used to test the half-wave voltage of the electro-optic modulator.

2. The test method according to claim 1, characterized in that, The voltage output terminal of the resistance detection device is connected to the first electrode pad and the second electrode pad respectively via the connecting cable; the step of detecting the loop resistance value of the preset circuit corresponding to each electro-optic modulator based on the preset resistance detection device includes: The resistance detection device is controlled to output a preset voltage through the voltage output terminal; Detect the first loop current of each of the preset loops; The circuit resistance value is determined based on the preset voltage and the first circuit current.

3. The test method according to claim 2, characterized in that, The electro-optic modulator further includes a reference ground pad; the reference ground pad includes a first ground electrode and a second ground electrode; the voltage output terminal includes a first port, a second port, a third port, and a fourth port; wherein, the first port is connected to the first electrode pad; the second port is connected to the second electrode pad; the third port is connected to the first ground electrode via the connecting cable; the fourth port is connected to the second ground electrode via the connecting cable; the step of controlling the resistance detection device to output a preset voltage through the voltage output terminal includes: The resistance detection device is controlled to output a first positive voltage to the first port, and the first positive voltage is equal to half of the preset voltage; The resistance detection device is controlled to output a first negative voltage to the second port; the first negative voltage is equal to half of the negative preset voltage; The resistance detection device is controlled to output zero voltage to the third port and the fourth port.

4. The test method according to claim 1, characterized in that, The method further includes: When the differential modulation voltage corresponding to a single electro-optic modulator is greater than or equal to a preset voltage threshold, the differential modulation voltage of the electro-optic modulator is set to the preset voltage threshold.

5. The test method according to claim 4, characterized in that, The method further includes: If at least a preset number of the electro-optic modulators have a differential modulation voltage equal to the preset voltage threshold, an alarm command is sent.

6. The test method according to claim 5, characterized in that, The method further includes: In response to the alarm command, a probe cleaning operation is performed on the test probes of the silicon photonics chip.

7. The test method according to any one of claims 1-6, characterized in that, After obtaining the differential modulation voltage corresponding to each of the electro-optic modulators, the method further includes: Based on the resistance detection device, the half-wave voltage of the plurality of electro-optic modulators is tested according to the obtained plurality of differential modulation voltages.

8. The test method according to claim 7, characterized in that, The method further includes: During the testing of the half-wave voltage of the reference modulator, the second loop current of the reference modulator is obtained; The second resistance value of the reference modulator is obtained by calculating the quotient of the differential modulation voltage corresponding to the reference modulator and the second loop current. When the difference between the loop resistance value of the reference modulator and the second resistance value is greater than a preset resistance threshold, the half-wave voltage test results of the plurality of electro-optic modulators are determined to be invalid.

9. A testing device for silicon photonic chips, characterized in that, The silicon photonic chip includes multiple electro-optic modulators; the electro-optic modulators are Mach-Zehnder type modulators; the electro-optic modulators include a first modulation arm and a second modulation arm; the first modulation arm includes a first electrode pad, a first traveling wave electrode and a first terminating resistor connected in sequence; the second modulation arm includes a second electrode pad, a second traveling wave electrode and a second terminating resistor connected in sequence. The first terminating resistor and the second terminating resistor are electrically connected; The testing apparatus includes: The detection module is used to detect the loop resistance value of a preset circuit corresponding to each electro-optic modulator based on a preset resistance detection device; the preset circuit is composed of the first modulation arm, the second modulation arm, and the connecting cable between the electro-optic modulator and the resistance detection device. The selection module is used to select the electro-optic modulator with the smallest loop resistance value as the reference modulator. The determination module is used to determine the reference resistance value based on the difference between the loop resistance value of the reference modulator and the resistance value of the connecting cable; The first calculation module is used to calculate the ratio of the loop resistance value of each electro-optic modulator to the reference resistance value, and obtain the correction coefficient corresponding to each electro-optic modulator; The second calculation module is used to calculate the product of the correction coefficient and the preset modulation voltage to obtain the differential modulation voltage corresponding to each electro-optic modulator; the differential modulation voltage is used to test the half-wave voltage of the electro-optic modulator.

10. A testing apparatus for silicon photonic chips, comprising a memory and a processor, characterized in that, The memory stores a computer program, and the processor is configured to run the computer program to perform the method of any one of claims 1 to 8.

11. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it implements the steps of the method according to any one of claims 1 to 8.

12. A computer program product, comprising a computer program, characterized in that, When the computer program is executed by a processor, it implements the steps of the method according to any one of claims 1 to 8.

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