Method for testing microrings in a microring array

Abstract

The present application relates to the technical field of semiconductor, in particular to a kind of micro-ring testing method in micro-ring array, it includes the following steps: S1, at least one first test micro-ring is designated in advance, and testing is carried out to obtain the actual working voltage corresponding to different target working wavelengths of first test micro-ring respectively;S2, the deviation between actual working voltage and the theoretical working voltage corresponding to different target working wavelengths is calculated;S3, the test range of each second test micro-ring is determined based on the deviation and the theoretical working voltage of second test micro-ring in micro-ring array at different target working wavelengths;S4, testing is carried out based on the respective test range of each second test micro-ring, so as to obtain the target working voltage of second test micro-ring at corresponding target working wavelength.The test range in working micro-ring is shortened by preliminary testing, so that working micro-ring does not need traditional full scanning mode when testing, and test efficiency is improved to a certain extent.

Description

Technical Field

[0001] This invention relates to the field of semiconductor testing technology, and in particular to a testing method for microrings in a microring array. Background Technology

[0002] With the rapid development of large-scale artificial intelligence models (such as GPT and Gemini), the computing power requirements for AI training and inference are growing at a rate of 4.79 times per year. However, the bottlenecks of traditional electrical interconnect technologies in terms of bandwidth density, transmission distance, and energy efficiency are becoming increasingly prominent. The I / O power consumption of electrical interconnects has gradually exceeded the total power budget of the chip, and both training and inference in AI data centers are latency-sensitive workloads—gradient aggregation during training requires multiple GPUs to maintain strict synchronization, and any delay will lead to expensive GPUs idling and waiting, resulting in a serious waste of computing resources. Against this backdrop, optical input / output (OIO) based on silicon photonics technology has emerged. The core of OIO technology lies in abandoning traditional copper wire electrical I / O and integrating optical interconnects directly into the package of the computing chip or in a nearby location, enabling the chip to directly exchange data through optical signals.

[0003] Dense wavelength division multiplexing (DWDM) technology is a crucial means of achieving high bandwidth density in optical input / output (OIO). By multiplexing multiple wavelengths of optical signals in a single fiber, DWDM can expand throughput without increasing the single-channel rate, avoiding the sensitivity degradation and latency increases caused by single-channel speed increases. Microring resonators (MRRs), as the core device of DWDM systems, possess high Q-value resonance characteristics and wavelength selectivity, enabling simultaneous modulation, multiplexing / demultiplexing, and filtering functions. Furthermore, they are small in size, can be driven by CMOS circuits, and have extremely low power consumption. Based on these technological advantages, DWDM OIO (Wavelength Division Multiplexing Optical Input / Output) systems employing silicon photonic microring resonators have become a key path to overcome the bottleneck of AI computing power interconnection.

[0004] Microring resonators typically achieve their target operating wavelength through electrical or thermal tuning. However, in practical engineering applications, systems often integrate numerous microring arrays. Due to inherent precision limitations in semiconductor manufacturing processes, dimensional deviations are introduced during nanoscale fabrication processes such as photolithography, etching, deposition, and chemical mechanical polishing. For microring resonators, the actual values ​​of key geometric parameters such as waveguide width, waveguide thickness, microring radius, and sidewall roughness often deviate from the theoretical design values. Furthermore, due to process deviations, the actual operating voltage of each microring at the target operating wavelength differs from its theoretical value. In addition to manufacturing process deviations, chip packaging introduces further deviations. For example, packaging stress can cause slight changes in the waveguide's refractive index; differences in post-packaging heat dissipation can affect the temperature distribution of the microrings; and fiber coupling alignment errors can lead to optical power fluctuations, thus affecting the accurate determination of the resonant wavelength. These packaging-introduced deviations further increase the uncertainty between the theoretical and actual operating voltages. This means that before putting the microring array into practical use, each working microring must be tested individually to determine its actual operating voltage at the target wavelength.

[0005] However, for large-scale microring arrays (such as systems containing dozens or even hundreds of microrings), performing a full-range voltage scan on each working microring to find its resonant point will present the following problems: First, the testing time is too long. Each microring needs to be scanned with fine steps over a wide voltage range. The accumulated testing time increases linearly with the array size, which seriously restricts production efficiency and testing capacity.

[0006] Secondly, it affects the lifespan of the devices. The tuning elements of microring resonators (such as thermo-optical heaters or PN junctions) gradually age during repeated voltage scans, especially thermo-optical tuning devices, where the thermal stress cycle of the heater accelerates performance degradation. Performing a full-range scan on each working microring would significantly shorten the effective lifespan of the devices. Therefore, a more efficient testing method is urgently needed to determine the operating voltage of each working microring in a microring array. Summary of the Invention

[0007] The purpose of this invention is to provide a testing method for microrings in a microring array, which partially solves or alleviates the above-mentioned deficiencies in the prior art and can quickly find the operating voltage of the working microring in the microring array at the target operating wavelength.

[0008] To solve the aforementioned technical problems, the present invention specifically adopts the following technical solution: This invention provides a method for testing microrings in a microring array, comprising the following steps: S1, test at least one pre-specified first test microring to obtain the actual operating voltages V1, V2, ... VN of the first test microring at different target operating wavelengths λ1, λ2 ... λN; S2, calculate the deviation values ​​ΔV1, ΔV2, ..., ΔVN between the actual working voltage and the theoretical working voltages V11, V12, ..., V1N corresponding to different target working wavelengths λ1, λ2, ..., λN; S3, based on the deviation value and the theoretical operating voltages V21, V22, ... V2N of the second test microrings with different target operating wavelengths λ1, λ2 ... λN in the microring array, determine the test range of each second test microring; S4, perform tests based on the test range of each of the second test microrings to obtain the target operating voltage of the second test microrings at the corresponding target operating wavelength.

[0009] Furthermore, the step of specifying at least one first test microring specifically includes the following steps: S10, determine the target number G of the first test microring according to the preset projection coefficient K, and sequentially select the corresponding number of microrings as the first test microrings starting from the virtual microrings located at the boundary in the microring array.

[0010] Specifically, the target quantity G = K * P, where P is the total number of working microrings in the microring array, and 0 < K < 1.

[0011] Furthermore, S20 includes the following steps: S20, dynamically adjust the projection coefficient K based on the number of microrings in the working microring array.

[0012] S201, Obtain the total number P of working microrings in the microring array; S202, determine whether the total number P of the working microrings is greater than or equal to the first preset number threshold M1 and less than the second preset number threshold M2; If the quantity is less than the first preset threshold M1, proceed to step S10; If the quantity is greater than or equal to the first preset quantity threshold M1, but less than the second preset quantity threshold M2, proceed to step S203. If it is greater than or equal to the second preset quantity threshold M2, proceed to step S204; S203, increase the initial projection coefficient K0 by the first preset increment, and execute step S10; S204, increase the initial projection coefficient K0 by a second preset increment, and execute step S10; the second preset increment is greater than the first preset increment.

[0013] Furthermore, step S10 specifically includes the following steps: S101, determine whether the number of targets of the first test microring determined based on the increased initial projection coefficient is greater than the number of virtual rings of the virtual microrings in the microring array. If yes, proceed to step S102; otherwise, proceed to step S103. S102, based on the difference between the target number G and the number of virtual rings, select a corresponding number of working microrings from the plurality of working microrings in the microring array as the first test microrings; S103, Select a plurality of the virtual microrings from all the virtual microrings as the first test microring.

[0014] Furthermore, it also includes the following steps: S5, obtain the test duration of each of the second test micro-rings that has been tested within the first time period; S6, perform linear fitting based on the test duration of multiple second test microrings within the first time period to obtain the slope and standard deviation; S7, determine whether the slope is greater than a first preset threshold and the standard deviation is less than a second preset threshold; If the slope is less than or equal to the first preset threshold and the standard deviation is less than the second preset threshold, continue to execute step S3; If the slope is greater than the first preset threshold, or the standard deviation is greater than or equal to the second preset threshold, the projection coefficient K is readjusted.

[0015] If the standard deviation is greater than or equal to the second preset threshold, and in step S202 it is determined that the total number P of working microrings in the microring array is greater than or equal to the second preset number threshold M2, all working microrings are divided into at least two groups, and each group is assigned a corresponding projection coefficient.

[0016] Furthermore, when there are multiple first test microrings, in step S2, for each target operating wavelength, the average deviation is calculated based on the deviation between the actual operating voltage and the theoretical operating voltage of all the first test microrings.

[0017] Furthermore, in step S3, the test range of the corresponding second test microring is determined based on the corresponding average deviation of the target working wavelength.

[0018] Beneficial Effects: In practical applications, due to limitations in manufacturing processes, the actual operating voltage of each working microring at the target operating wavelength will deviate from its theoretical voltage. Therefore, to find the actual operating voltage of each working microring at the target operating wavelength, this application sets virtual microrings at the boundaries of the microring array (the virtual microrings have the same attribute parameters as the working microrings, such as waveguide width and radius). Preliminary tests are performed on the virtual microrings to determine the deviation between their actual and theoretical operating voltages at different target operating wavelengths. Based on this deviation, the test range for each working microring is determined. In other words, the test range on the working microrings is narrowed by using virtual microrings, thus avoiding extensive testing on the working microrings and affecting their lifespan. At the same time, the testing cycle on the working microrings is shortened (compared to testing each working microring repeatedly without the aforementioned preliminary test), thereby improving testing efficiency.

[0019] As mentioned earlier, determining the test range of the working microring using the test results of the virtual microring essentially projects the test of the global microring onto the local microring. However, in actual testing, different batches or product designs result in varying sizes and numbers of working microrings. Therefore, to ensure the reliability of the test range applied to the working microrings obtained by this projection method, the number of microrings used for preliminary testing needs to be selected according to the different sizes and numbers of working microrings. Specifically, this application uses a projection coefficient to characterize the projection relationship between the number of first test microrings required for different sizes and numbers of working microrings. For example, if the size and number of working microrings are large, the projection coefficient is increased, and correspondingly, the number of first test microrings for preliminary testing is also increased. Furthermore, for each target operating voltage, the test range of the working microring is determined by the average deviation between the actual operating voltage and the theoretical operating voltage of multiple first test microrings.

[0020] Furthermore, since the number of virtual microrings is not necessarily better the more it is, but is limited by actual engineering needs, i.e., its number is finite, in this application, when the number of working microrings is very large, it is also necessary to determine whether the number of virtual microrings determined by the projection coefficient meets the required number of first test microrings. If it does not meet the requirement, the corresponding number of working microrings are used as the first test microrings for preliminary testing to determine the deviation. That is, based on all virtual microrings, a difference in the number of working microrings is selected from the working microring array as a supplement to jointly form the first test microring set and complete the deviation test. Thus, without increasing the chip area overhead, the reliability of deviation estimation under large-scale array is guaranteed.

[0021] Furthermore, when the number of working microrings is large, the test results of the working microrings, such as the trend of test duration changes, can be used to back-evaluate whether the test range determined based on the aforementioned deviations is reasonable. For example, does the test duration of each working microring tested sequentially decrease (e.g., the slope of the linear fit based on duration is less than 0), show almost no increase (e.g., the slope of the linear fit based on duration is 0), or increase very slowly? If it is unreasonable, for example, if the test duration of each working microring tested sequentially shows a large increasing trend (e.g., the slope is positive and greater than a preset threshold), then feedback indicates that the projection coefficient needs further adjustment. For example, group testing can be used, with different projection coefficients for different groups.

[0022] This application sets virtual microrings at the boundaries of the microring array at both ends. These virtual microrings not only provide boundary matching (i.e., offering the same or similar boundary environment to the working microrings at the boundaries as those in the middle), but also serve multiple functions such as process consistency and electrical shielding, thereby ensuring the consistency between the end channels (i.e., the working microrings at the boundaries) and the middle channels (i.e., the working microrings in the middle). For example, by setting virtual microrings, the photolithographic pattern density, etching load, and CMP polishing density at the boundary ends of the microring array are homogenized, allowing the waveguide width, coupling gap, and etching depth of the working microrings at the ends to be almost identical to those of the middle channels, thus eliminating density abrupt changes caused by "no neighbors." Since the resonant wavelength and coupling coefficient of the microrings are extremely sensitive to waveguide dimensions, even nanometer-level deviations can cause wavelength shifts far exceeding 5 pm. This measure directly ensures the relative accuracy of the wavelength.

[0023] In addition, the grounding metal or substrate contact structure of the virtual micro-ring at the end can also serve as the shielding boundary of the high-speed trace array, absorbing electrical coupling and substrate noise at the array edge.

[0024] Meanwhile, the virtual microrings at the ends can absorb or dissipate stray light at the array ends, reducing optical reflection and crosstalk of the working microrings at both ends of the microring array. In other words, by setting virtual microrings, the thermal boundary conditions of each working microring in the array are made almost identical, eliminating the thermal environment differences between the end channels (i.e., the working microrings located at the boundaries) and the middle channels (i.e., the working microrings located in the middle) caused by edge effects.

[0025] In addition, the virtual microring itself can serve as a channel, acting as a medium for transmitting clock signals. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. In all the drawings, similar elements or parts are generally identified by similar reference numerals. The elements or parts in the drawings are not necessarily drawn to scale. Obviously, the drawings described below are some embodiments of the present invention, and those skilled in the art can obtain other drawings based on these drawings without any creative effort.

[0027] Figure 1 This is a flowchart of the testing method for micro-rings in the micro-ring array of the present invention; Figure 2 This is a schematic diagram of the micro-ring array of the present invention; Figure 3 This is a schematic diagram of the wavelength division multiplexing optical input / output system of the present invention; Figure 4 This is a functional block diagram of the control module in the wavelength division multiplexing optical input / output system of the present invention. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0029] In this document, suffixes such as "module," "part," or "unit" used to denote elements are used only for the purpose of illustrative purposes and have no specific meaning in themselves. Therefore, "module," "part," or "unit" may be used interchangeably.

[0030] In this document, the terms "upper," "lower," "inner," "outer," "front," "rear," "one end," and "the other end," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the present invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0031] In this document, unless otherwise explicitly specified and limited, the terms "installed," "equipped with," "connected," etc., should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, a direct connection, or an indirect connection through an intermediate medium; it can be a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0032] In this document, "and / or" includes any and all combinations of one or more of the listed related items.

[0033] In this article, "multiple" means two or more, that is, it includes two, three, four, five, etc.

[0034] As used in this specification, the term "about" typically means + / -5% of the value, more typically + / -4% of the value, more typically + / -3% of the value, more typically + / -2% of the value, even more typically + / -1% of the value, and even more typically + / -0.5% of the value.

[0035] In this specification, certain embodiments may be disclosed in a range-bound format. It should be understood that this "range-bound" description is merely for convenience and brevity and should not be construed as a rigid limitation on the disclosed range. Therefore, the description of a range should be considered as having specifically disclosed all possible subranges and the individual numerical values ​​within those ranges. For example, a description of the range 1-6 should be considered as having specifically disclosed subranges such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., and the individual numbers within those ranges, such as 1, 2, 3, 4, 5, and 6. This rule applies regardless of the breadth of the range.

[0036] To avoid performing extensive full-scan testing on each working microring, which would affect its lifespan, this application pre-distributes corresponding virtual microrings along the boundaries on both sides of the working microring array. Then, by conducting preliminary tests on the virtual microrings, the deviation between the actual and theoretical operating voltages of the virtual microrings at each target operating wavelength is determined. Based on this deviation for each target operating wavelength, the test range for all working microrings at the corresponding operating wavelength is determined (the target operating wavelength is different for each working microring in the array). In other words, virtual microrings are used to quickly determine the test range for all working microrings, reducing the amount of testing required and improving testing efficiency to some extent.

[0037] Of course, furthermore, when the number of working microrings in the working microring array is relatively large, in order to ensure the reliability of the test, the number of virtual microrings for preliminary testing can be increased accordingly, or even some of the working microrings can be selected to be tested together with the virtual microrings, thereby determining the test range.

[0038] In this paper, virtual microrings and working microrings are collectively referred to as microrings. The microrings participating in the preliminary test, such as virtual microrings, or virtual microring 100 and working microring 200, are referred to as the first test microrings. Figure 2 As shown. Accordingly, the second test microring actually refers to the working microring 200 to be tested in the microring array.

[0039] The following detailed description is provided in conjunction with specific embodiments and accompanying drawings.

[0040] Example 1: See Figure 1 This invention provides a method for testing microrings in a microring array, comprising the following steps: S1, test at least one pre-specified first test microring to obtain the actual operating voltages V1, V2, ... VN of the first test microring at different target operating wavelengths λ1, λ2 ... λN.

[0041] In this embodiment, each microring can be modulated by applying a voltage to tune it from its initial resonant wavelength to different target operating wavelengths; that is, each microring can correspond to a different target operating wavelength. Typically, each target operating wavelength of a microring corresponds to a theoretical operating voltage. However, in practical applications, limitations such as manufacturing processes may cause a deviation between the actual operating voltage and the theoretical operating voltage for each microring to achieve its target operating wavelength. Therefore, during factory testing, it is usually necessary to determine the actual operating voltage corresponding to the target operating wavelength of each microring.

[0042] In some embodiments, testing the first test microring refers to sequentially applying test voltages to the first test microring based on a preset initial test voltage and a preset step size, and measuring the actual operating wavelength of the first test microring at the corresponding test voltage. When the difference between the actual operating wavelength and the target operating wavelength is less than a preset threshold, the test voltage is determined to be the actual operating voltage of the first test microring at the corresponding target operating wavelength. This testing process is prior art and is not the focus of this application, so it will not be described in detail here.

[0043] In some embodiments, the number of first test rings can be one or more.

[0044] In some embodiments, the step of specifying at least one first test microring specifically includes the following steps: S10, determine the target number G of the first test microring according to the preset projection coefficient K, and sequentially select the corresponding number of microrings as the first test microrings starting from the virtual microrings located at the boundary in the microring array.

[0045] In some embodiments, the target number G = K * P, where P is the total number of working microrings in the microring array, and 0 < K < 1.

[0046] In some embodiments, the projection coefficient K is used to characterize the mapping relationship between all working microrings and the first test microring. Essentially, it is a scaling factor that projects all working microrings onto a “finite” first test microring. Specifically, this projection coefficient K can be pre-calibrated through numerous experiments.

[0047] For example, such as Figure 2 As shown, when there are 8 working micro-rings 200, and 2 virtual micro-rings 100 are set on each of their two side boundaries, since the number of working micro-rings 200 is 8, and the preset projection coefficient K is 0.2, the number of targets G = 0.2 * 8 = 1.6. Therefore, rounding up, we get 2 virtual micro-rings 100 as the first test micro-rings for preliminary testing. Of course, we can randomly select two virtual micro-rings 100 from any boundary, or randomly select one virtual micro-ring 100 from each side, for a total of two as the first test micro-rings.

[0048] S2, calculate the deviation values ​​ΔV1, ΔV2, ..., ΔVN between the actual working voltage and the theoretical working voltages V11, V12, ..., V1N corresponding to different target working wavelengths λ1, λ2, ..., λN.

[0049] In some embodiments, as described above, for each microring, different voltages or currents can be applied to tune it from the initial resonant wavelength to different target operating wavelengths λ1, λ2...λN. Naturally, for a single microring, different target operating wavelengths λ1, λ2...λN correspond to different theoretical operating voltage sets [V11, V12...V1N] and actual operating voltage sets [V1, V2...VN]. Therefore, for different target operating wavelengths of a single microring, a set of deviation values ​​[ΔV1, ΔV2...ΔVN] is obtained.

[0050] In some embodiments, each working microring 200 in the microring array may correspond to a different target operating wavelength, or some working microrings 200 may correspond to the same target operating wavelength. Therefore, in step S1, for a single first test microring, it is necessary to test the actual operating voltage at different target operating wavelengths to determine the set of deviation values, thereby enabling the test range of the working microrings operating at different target operating wavelengths to be quickly determined based on the set of deviation values.

[0051] S3. Based on the deviation value and the theoretical operating voltages V21, V22, ..., V2N of the second test microrings with different target operating wavelengths λ1, λ2...λN in the microring array, determine the test range of each second test microring.

[0052] In some embodiments, the second test microring here refers to each working microring in the microring array.

[0053] In some embodiments, as described above, since the deviation values ​​between the actual operating voltage and the theoretical operating voltage of the first test microring at different target operating wavelengths are obtained in advance, the test range of the corresponding working microring can be determined based on these deviation values ​​at the same target operating wavelength. Specifically, if there is only one first test microring, the test range of each working microring is directly determined based on the deviation value of the first test microring; if there are multiple first test microrings, the test range of each working microring is directly determined based on the average of the deviation values ​​of the multiple first test microrings. That is, when there are multiple first test microrings, in step S2, for each target operating wavelength, the average deviation value is calculated based on the deviation values ​​between the actual operating voltage and the theoretical operating voltage of all the first test microrings. Correspondingly, in step S3, for each target operating wavelength, the test range of the corresponding second test microring is determined based on its corresponding average deviation value.

[0054] For example, see Figure 2 If, in step S1, the first virtual microring 100 on the left boundary is specified as the first test microring, and after preliminary testing, the actual operating voltages V1, V2, ..., VN of the first virtual microring 100 under different target operating wavelengths λ1, λ2, ..., λN are obtained, and based on these actual operating voltages and the theoretical operating voltages V11, V12, ..., V1N of the first virtual microring 100 under different target operating wavelengths λ1, λ2, ..., λN, the corresponding set of deviation values ​​[ΔV11, ΔV12, ..., ΔV1N] is obtained; then accordingly; For the first working microring 200 from left to right, if its target working wavelength is λ1, then its test range is: [V21-ΔV11 to V21+ΔV11]; For the second working microring 200 from left to right, if its target working wavelength is λ2, then its test range is: [V21-ΔV12 to V21+ΔV12], and so on until the test range of the last working microring 200 is obtained.

[0055] For example, see also Figure 2 If, in step S1, two virtual micro-rings 100 on the left boundary are specified as the first test micro-rings, and after preliminary testing, the following is obtained: The theoretical operating voltages V11, V12, ..., V1N of the first virtual micro-ring 100 from left to right at different target operating wavelengths λ1, λ2...λN, and their corresponding set of deviation values ​​[ΔV11, ΔV12...ΔV1N]; The second virtual micro-ring 100 from left to right has theoretical operating voltages V11, V12, ..., V1N at different target operating wavelengths λ1, λ2...λN, and their corresponding deviation value sets [ΔV21, ΔV22...ΔV2N]. The mean deviation value is calculated. , ... ], then accordingly; For the first working microring 200 from left to right, if its target working wavelength is λ1, then its test range is: [ to ]; For the second working microring 200 from left to right, if its target working wavelength is λ2, then its test range is: [ to This process continues until the test range of the last working microring is obtained.

[0056] S4, perform tests based on the test range of each of the second test microrings to obtain the target operating voltage of the second test microrings at the corresponding target operating wavelength.

[0057] In some embodiments, testing is performed based on the test range of each working microring determined in step S3 to obtain the actual operating voltage of each working microring. For example, corresponding test voltages are applied sequentially according to a preset test step size, and the actual operating wavelength of the working microring under the corresponding test voltage is obtained. When the difference between the actual operating wavelength and the target operating wavelength is less than a preset threshold, the test voltage is determined to be the actual operating voltage of the working microring under the target operating wavelength. This testing process is prior art and is not the focus of this application, so it will not be described in detail here.

[0058] In this application, by setting a first test microring to confirm the test range of the working microring in advance, the search range when testing the working microring is narrowed. This not only allows for the rapid determination of the actual working voltage of the working microring, but also avoids reducing the service life of the working microring due to multiple tests.

[0059] Example 2: The present invention also provides another testing method, which includes each step S1-S4 in Example 1 above. The difference is that in this example, a fixed projection coefficient is not used. Instead, the projection coefficient K is dynamically adjusted based on the total number of working microrings in the microring array (i.e., step S20).

[0060] Specifically, step S20 includes the following steps: S201, obtain the total number P of working microrings in the microring array.

[0061] In some embodiments, the size and number of working microrings in each microring array are different due to different computing requirements. Therefore, the total number P of working microrings in the microring array can be obtained through product layout design or product specifications.

[0062] S202, determine whether the total quantity P is greater than or equal to the first preset quantity threshold M1 and less than the second preset quantity threshold M2; if it is less than the first preset quantity threshold M1, execute step S10; if it is greater than or equal to the first preset quantity threshold M1 but less than the second preset quantity threshold M2, execute step S203; if it is greater than or equal to the second preset quantity threshold M2, execute step S204.

[0063] S203, increase the initial projection coefficient K0 by the first preset increment, and execute step S10.

[0064] S204, increase the initial projection coefficient K0 by a second preset increment, and execute step S10; the second preset increment is greater than the first preset increment.

[0065] In this embodiment, the projection coefficient K can be adjusted according to the size and number of working microrings. Specifically, when the size and number of working microrings are large, a larger projection coefficient K is set, thereby introducing more first test microrings for preliminary testing. Conversely, when the size and number of working microrings are small, a smaller projection coefficient K is set, thereby introducing fewer first test microrings for preliminary testing. That is, at a large scale, the "more time" spent on preliminary testing is exchanged for a "significant reduction in time" for testing the working microrings; while at a small scale, priority is given to protecting the lifespan of the working microrings, and working microrings are avoided as much as possible as the first test microrings. In other words, this embodiment dynamically adjusts the local microrings used for preliminary testing based on the size and number of working microrings, balancing test coverage and resource consumption.

[0066] For example, the preset initial projection coefficient K0 is 0.15, the number of virtual micro-rings 100 is 4, the first preset quantity threshold M1 is 12, the second preset quantity threshold M2 is 18, the first preset increment is 0.05, and the second preset increment is 0.1; accordingly, If the number of working microrings 200 in the microring array is 15, then 12 < 15 < 18. Therefore, the projection coefficient K = initial projection coefficient 0.15 + 0.05 = 0.2. Then the number of first test microrings = 15 * 0.2 = 3 < the number of virtual microrings 4. Therefore, three virtual microrings can be randomly selected as the first test microrings for preliminary testing.

[0067] If the number of working microrings 200 in the microring array is 8, then 8 < 12. Therefore, the projection coefficient K = the initial projection coefficient 0.15. Then the number of the first test microrings = 8 * 0.15 = 1.2, which is rounded up to 2. Two virtual microrings are randomly selected as the first test microrings for preliminary testing.

[0068] In some embodiments, since the number of working microrings is large and the number of pre-set virtual microrings is limited, the number of first test microrings required after adjusting the projection coefficient K may be greater than the number of virtual microrings. Therefore, before conducting the preliminary test, it is necessary to determine whether to include some working microrings as first test microrings. That is, step S10 in the test method of this embodiment specifically includes the following steps: S101, determine whether the number of targets of the first test microring determined based on the increased initial projection coefficient is greater than the number of virtual rings of the virtual microrings in the microring array. If yes, proceed to step S102; otherwise, proceed to step S103. S102, based on the difference between the target number and the number of virtual rings, select a corresponding number of working microrings from the plurality of working microrings in the microring array as the first test microrings; S103, Select a plurality of the virtual microrings from all the virtual microrings as the first test microring.

[0069] As mentioned earlier, since the attribute parameters of each virtual microring are actually the same or similar to those of the working microring (i.e., the deviation is small or within the tolerable range), the initial projection coefficient is calibrated based on a small-scale array of working microrings, which reduces the calibration test process and cycle; accordingly, the projection coefficient can be increased as the number of working microrings increases.

[0070] Continuing the previous example, if the number of working microrings 200 in a microring array is 20, which is greater than 18, then the projection coefficient = initial projection coefficient 0.15 + 0.1 = 0.25. Therefore, the number of first test microrings = 20 * 0.25 = 5, which is greater than the number of virtual microrings 100 (4). Thus, a working microring 200 needs to be selected as the first test microring in the initial test. Preferably, any working microring 200 located at the boundary is selected as the first test microring.

[0071] Example 3: The present invention also provides another testing method, which includes the steps in Example 1 or Example 2 above. The difference is that the testing method in this example further includes the following steps: S5, obtain the test duration of each of the second test micro-rings that has been tested within the first time period; S6, perform linear fitting based on the test duration of multiple second test microrings within the first time period to obtain the slope and standard deviation; S7, determine whether the slope is greater than a first preset threshold and the standard deviation is less than a second preset threshold; If the slope is less than or equal to the first preset threshold and the standard deviation is less than the second preset threshold, continue to execute step S3; If the slope is greater than the first preset threshold, or the standard deviation is greater than or equal to the second preset threshold, it indicates that the projection coefficient K needs to be readjusted.

[0072] In some embodiments, although the attribute parameters of each virtual microring are the same as or similar to those of the working microring, some deviations are introduced during the actual packaging process in addition to the deviations caused by processing. Therefore, in this embodiment, the actual test results of the completed working microrings, such as the test duration, are used as an evaluation index to preliminarily assess whether the test range determined in step S3 is reasonable, or in other words, whether the number of first test microrings determined based on the preset projection coefficient is reasonable. Generally speaking, if the number of first test microrings is reasonable, the test range is also reasonable. Therefore, during the sequential testing of each working microring, the test duration of each working microring should not differ significantly. However, if the test range is unreasonable, the test duration of the working microrings will either fluctuate greatly (e.g., the standard deviation is greater than or equal to the second preset threshold) or the change in test duration will show an increasing trend (e.g., the slope is greater than or equal to the first preset threshold). If there is a large fluctuation or an increasing trend, it indicates that the projection coefficient needs to be readjusted.

[0073] Generally speaking, the theoretical test duration for each working microring can be estimated in advance through the test range. This first test period is less than or equal to the total test duration for all working microrings.

[0074] For example, a microring array contains 30 working microrings (numbered W01-W30). Following the testing method described above, the test range for each working microring is determined. Then, based on each microring's test range, tests are performed one by one. The test times for the first 10 working microrings that complete the test within 10 minutes are: W01: 50ms, W02: 51ms, W03: 49ms... W10: 50ms. Linear fitting yields a standard deviation of 1.42 ms < the second preset threshold of 2.0 ms, with a slope almost zero. Therefore, the test times of each working microring are very similar, and most working microrings can quickly find the actual operating voltage corresponding to the target operating wavelength within the currently set test range. In other words, the current projection coefficient K value is set reasonably and does not require adjustment; the remaining working microrings can continue to be tested.

[0075] For example, a microring array contains 30 working microrings (numbered W01-W30). The test range of each working microring is obtained according to the above testing method. Then, based on the test range of each working microring, tests are performed one by one. The test times of the first 10 working microrings that complete the test within 10 minutes are as follows: W01: 50ms, W02: 210ms, W03: 49ms... W9: 195ms; W10: 50ms. Then, linear fitting is performed to obtain the standard deviation: 61.5 ms > the second preset threshold of 2.0 ms. Therefore, it is indicated that the projection coefficient needs to be readjusted.

[0076] In some other embodiments, the testing method includes the steps in Embodiment 1 or 2, but the method in this embodiment further includes the following steps: obtaining the testing time of each of the second test microrings that has been tested, which has at least a preset threshold (e.g., Q, where Q is greater than M2 and Q is greater than or equal to 1 / 3 of the total number of working microrings; if Q is less than M2, Q is greater than or equal to 1 / 2 of the total number of working microrings); performing linear fitting on the testing time of each of the second test microrings according to the preset threshold to obtain the slope and standard deviation; determining whether the slope is greater than a first preset threshold (e.g., 0) and the standard deviation is less than a second preset threshold; if the slope is less than or equal to the first preset threshold and the standard deviation is less than the second preset threshold, continuing to execute step S3; if the slope is greater than the first preset threshold or the standard deviation is greater than or equal to the second preset threshold, readjusting the projection coefficient K.

[0077] In other embodiments, if the standard deviation is greater than or equal to the second preset threshold, and in step S202 it is determined that the total number P of working microrings in the microring array is greater than or equal to the second preset number threshold M2, all working microrings are divided into at least two groups, and each group is assigned a corresponding projection coefficient.

[0078] In some embodiments, since the size and number of working microrings are greater than the second preset number threshold M2, virtual microrings are usually included in the initial test. Considering that the virtual microrings are located at the two boundaries of the microring array, all working microrings are divided into three groups, namely two boundary groups G1 and G2 and an intermediate group G3. Accordingly, the projection coefficients are adjusted according to a preset adjustment strategy.

[0079] Specifically, in some embodiments, the adjustment strategy includes: adjusting the initial projection coefficients for the boundary group G1 near the input end so that preliminary testing is performed on multiple virtual microrings at the input end; adjusting the initial projection coefficients for the boundary group G2 near the output end so that preliminary testing is performed on all virtual microrings; and adjusting the initial projection coefficients for the intermediate group G3 so that preliminary testing is performed on all virtual microrings and at least one working microring (randomly selected).

[0080] For example, the total number of working microrings is 30 (numbered W01~W30), arranged at equal intervals along the straight waveguide. Four virtual microrings are symmetrically set on both sides of the boundary (two virtual microrings at the input end are numbered D1 and D2, and two virtual microrings at the output end are numbered D3 and D4). The grouping method is as follows: three groups are evenly divided, with 10 microrings in each group: G1 (left boundary / input end): W01~W10; G3 (middle group): W11~W20; G2 (right boundary / output end): W21~W30; the initial projection coefficient is 0.15.

[0081] For group G1, one or two virtual microrings at the input end are sufficient for initial testing. Because of the support provided by virtual microrings D1 and D2 at the input end, and because the process deviation at the input end is usually small, the projection coefficient can be lowered, requiring only one or two virtual microrings at the input end as the first test microring, achieving zero loss of working microrings.

[0082] For group G2, due to the potential for significant deviations caused by process accumulation, the projection coefficient can be increased, i.e., using all four virtual microrings for the initial test, where resources are sufficient. Although supported by output-end virtual microrings D3 and D4, the cumulative effect of process deviations at the output end is significant. Therefore, increasing the projection coefficient, for example, by using all four virtual microrings as the first test microrings, eliminates the need for sacrificing any working microrings.

[0083] For group G3, since it is far from the boundary, at least one working microring needs to be selected for preliminary testing. Preferably, the selected working microring comes from this intermediate group. Because there are no virtual microrings directly covering the area, the projection coefficient is further increased. Based on all four virtual microrings, one or more randomly selected working microrings are used together as the first test microrings for preliminary testing. This sacrifices only a small number of working microrings but effectively covers the uncertainty of the intermediate region.

[0084] Through the above-mentioned differential adjustments, the three sets of projection coefficients satisfy the relationship that the projection coefficient of the input boundary group G1 < the projection coefficient of the output group G2 < the projection coefficient of the intermediate group G3, thus realizing the full reuse of virtual micro-ring resources and minimizing the cost of requisitioning working micro-rings.

[0085] Preferably, the number of working microrings in each boundary group accounts for 15% to 30% of the total number of working microrings, and each group has at least 3 working microrings to ensure that the calculation of the mean and standard deviation of the deviation is statistically significant. Accordingly, the working microrings between two boundary groups are the intermediate group G3. Of course, further, if the number of intermediate groups is still greater than the second preset threshold, the intermediate group is further divided into multiple subgroups, and each subgroup can be set with a corresponding projection coefficient according to the actual situation. For example, the intermediate group is divided into three subgroups: G3-1, G3-2, and G3-3. Based on the same principle, compared with the two subgroups G3-1 and G3-3 that are close to the boundary group G1 or G2, the subgroup G3-2 in the center is completely isolated and has the greatest uncertainty. Therefore, the projection coefficient of subgroup G3-2 is the largest, the projection coefficient of subgroup G3-3 is the second largest, and the projection coefficient of subgroup G3-1 is the smallest (preferably, the projection coefficient of subgroup G3-1 is greater than or equal to the projection coefficient of the output group G2).

[0086] Example 4: See Figure 2 The present invention also provides a silicon-based photonic microring array, comprising: a transmission waveguide, a plurality of working microrings 200 optically coupled to the transmission waveguide and spaced apart along the optical transmission direction, and at least one virtual microring 100 optically coupled to the transmission waveguide and respectively provided with the two side boundaries of the plurality of working microrings; The coupling distance between the virtual microring 100 and the transmission waveguide is greater than the coupling distance between the working microring 200 and the transmission waveguide.

[0087] In this embodiment, the virtual micro-rings 100 on each side boundary are in at least two groups, each group including at least one of the virtual micro-rings 100, and... Along a direction away from the working microring 200, the coupling distance between at least two sets of virtual microrings 100 and the transmission waveguide gradually increases.

[0088] In some embodiments, each of the working microrings 200 has a different target operating wavelength.

[0089] Example 5: See Figure 3 The present invention also provides a wavelength division multiplexing optical input / output system with a micro-ring array, comprising: a substrate, wherein an optical region, an electrical region, and a control region are disposed on the substrate, the optical region and the electrical region being arranged side by side and located on the same side of the control region; and an isolation band 300 is disposed between the optical region and the electrical region, and an isolation band 300 is disposed between the control region and the optical region and the electrical region; wherein, The optical region is provided with a variety of optical devices, including the silicon-based photonic micro-ring array described in Embodiment 4 above. The electrical area is equipped with a driver chip and a TIA; the control area is equipped with a control module and an analog-to-digital / digital-to-analog converter module.

[0090] For example, in a wavelength division multiplexing optical input / output transceiver module based on microrings, the silicon-based photonic microring array at the transmitter (Tx) includes 8 working microrings, i.e., 8 microring modulators. Correspondingly, 8 high-speed drivers are provided in the electrical region. The silicon-based photonic microring array at the receiver (Rx) includes 8 working microrings, i.e., multiple microring filters. Correspondingly, 8 high-speed TIAs are provided in the electrical region. Furthermore, a common thermal control unit (TCU) is used, which includes: MCU + multiple ADC / DAC + IDAC heater driver. That is, the microring array and all active circuits are monolithically integrated on the same silicon substrate.

[0091] In some embodiments, the aforementioned insulating strip 300 may be a heat-insulating groove pre-formed between two adjacent regions by an etching process. Of course, other structures or materials capable of achieving thermal or electrical isolation may also be used.

[0092] In this embodiment, see Figure 4 The control module (such as the MCU mentioned above) specifically includes: The initial range determination unit is configured to apply a voltage to at least one pre-specified first test microring for testing, so as to obtain the actual operating voltages V1, V2, ... VN of the first test microring at different target operating wavelengths λ1, λ2 ... λN respectively; The calculation unit is configured to calculate the deviation values ​​ΔV1, ΔV2, ..., ΔVN between the actual operating voltage and the theoretical operating voltages V11, V12, ..., V1N corresponding to different target operating wavelengths λ1, λ2, ..., λN; The test range determination unit is configured to determine the test range of each second test microring based on the deviation value and the theoretical operating voltages V21, V22, ... V2N of the second test microrings with different target operating wavelengths λ1, λ2 ... λN in the microring array; The target operating voltage determination unit is configured to perform tests based on the respective test range of each of the second test microrings, thereby obtaining the target operating voltage of the second test microrings at the corresponding target operating wavelength.

[0093] In other embodiments, the control module further includes: The first test microring determination unit is configured to determine the target number G of the first test microrings according to a preset projection coefficient K, and to sequentially select a corresponding number of microrings as the first test microrings, starting from the virtual microrings located at the boundary in the microring array.

[0094] In other embodiments, the control module further includes: The first projection coefficient dynamic adjustment unit is configured to dynamically adjust the projection coefficient K based on the number of working microrings in the microring array. Specifically, it obtains the total number P of working microrings in the microring array; determines whether the total number P of working microrings is greater than or equal to a first preset number threshold M1 and less than a second preset number threshold M2; if it is less than the first preset number threshold M1, it assigns an initial value to the projection coefficient to obtain an initial projection coefficient K0; if it is greater than or equal to the first preset number threshold M1 but less than the second preset number threshold M2, it increases the initial projection coefficient K0 by a first preset increment; if it is greater than or equal to the second preset number threshold M2, it increases the initial projection coefficient K by a second preset increment, determines the target number G of the first test microrings according to the preset projection coefficient K, and sequentially selects a corresponding number of microrings as the first test microrings starting from the virtual microrings located at the boundary in the microring array; the second preset increment is greater than the first preset increment.

[0095] In some embodiments, the control module further includes: The judgment unit is configured to determine whether the target number of the first test microrings determined based on the increased initial projection coefficient is greater than the number of virtual rings in the microring array. If so, it selects a corresponding number of working microrings from the plurality of working microrings in the microring array as the first test microrings based on the difference between the target number and the number of virtual rings; otherwise, it selects a plurality of virtual microrings from all virtual microrings as the first test microrings.

[0096] In other embodiments, the control module further includes: The second projection coefficient dynamic adjustment unit is configured to: acquire the test duration of each second test microring that has been tested within a preset first time period; perform linear fitting based on the test duration of multiple second test microrings within the first time period to obtain the slope and standard deviation; determine whether the slope is greater than a first preset threshold (e.g., 0) and the standard deviation is less than a second preset threshold; if the slope is less than or equal to the first preset threshold and the standard deviation is less than the second preset threshold, continue testing; if the slope is greater than the first preset threshold or the standard deviation is greater than or equal to the second preset threshold, readjust the projection coefficient K, and trigger the first test microring determination unit to redetermine the first test microring based on the adjusted projection coefficient K.

[0097] In some embodiments, the second projection coefficient dynamic adjustment unit is further configured to divide all working microrings into at least two groups if the standard deviation is greater than or equal to the second preset threshold and it is determined that the number P of working microrings in the microring array is greater than or equal to the second preset number threshold M2, and assign a corresponding projection coefficient to each group.

[0098] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, 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, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0099] Through the above description of the embodiments, those skilled in the art can clearly understand that the methods of the above embodiments can be implemented by means of software plus necessary general-purpose hardware platforms. Of course, they can also be implemented by hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk) and includes several instructions to cause a computer terminal (which may be a mobile phone, computer, server, or network device, etc.) to execute the methods described in the various embodiments of the present invention.

[0100] The embodiments of the present invention have been described above with reference to the accompanying drawings. However, the present invention is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of the present invention without departing from the spirit and scope of the claims. All of these forms are within the protection scope of the present invention.

Claims

1. A method for testing microrings in a microring array, characterized in that, Including the following steps: S1, test at least one pre-specified first test microring to obtain the actual operating voltages V1, V2, ... VN of the first test microring at different target operating wavelengths λ1, λ2 ... λN; S2, calculate the deviation values ​​ΔV1, ΔV2, ..., ΔVN between the actual working voltage and the theoretical working voltages V11, V12, ..., V1N corresponding to different target working wavelengths λ1, λ2, ..., λN; S3, based on the deviation value and the theoretical operating voltages V21, V22, ... V2N of the second test microrings with different target operating wavelengths λ1, λ2 ... λN in the microring array, determine the test range of each second test microring; S4, perform tests based on the test range of each of the second test microrings to obtain the target operating voltage of the second test microrings at the corresponding target operating wavelength.

2. The method for testing micro-rings in a micro-ring array according to claim 1, characterized in that, The step of specifying at least one first test microring specifically includes the following steps: S10, determine the target number G of the first test microring according to the preset projection coefficient K, and sequentially select the corresponding number of microrings as the first test microrings starting from the virtual microrings located at the boundary in the microring array.

3. The method for testing micro-rings in a micro-ring array according to claim 2, characterized in that, The target quantity G = K * P, where P is the total number of working microrings in the microring array, and 0 < K < 1.

4. The method for testing micro-rings in a micro-ring array according to claim 2, characterized in that, It also includes the following steps: S20, dynamically adjust the projection coefficient K based on the number of microrings in the working microring array.

5. The method for testing micro-rings in a micro-ring array according to claim 4, characterized in that, Step S20 specifically includes the following steps: S201, Obtain the total number P of working microrings in the microring array; S202, determine whether the total number P of the working microrings is greater than or equal to the first preset number threshold M1 and less than the second preset number threshold M2; If the quantity is less than the first preset threshold M1, proceed to step S10; If the quantity is greater than or equal to the first preset quantity threshold M1, but less than the second preset quantity threshold M2, proceed to step S203. If it is greater than or equal to the second preset quantity threshold M2, proceed to step S204; S203, increase the initial projection coefficient K0 by the first preset increment, and execute step S10; S204, increase the initial projection coefficient K0 by a second preset increment, and execute step S10; the second preset increment is greater than the first preset increment.

6. The method for testing micro-rings in a micro-ring array according to claim 5, characterized in that, Step S10 specifically includes the following steps: S101, determine whether the target number G of the first test microring determined based on the increased initial projection coefficient is greater than the number of virtual rings of the virtual microrings in the microring array; if so, execute step S102. Otherwise, proceed to step S103; S102, based on the difference between the target number G and the number of virtual rings, select a corresponding number of working microrings from the plurality of working microrings in the microring array as the first test microrings; S103, Select a plurality of the virtual microrings from all the virtual microrings as the first test microring.

7. A method for testing microrings in a microring array according to any one of claims 2 to 6, characterized in that, Also includes: S5, obtain the test duration of each of the second test micro-rings that has been tested within the first time period; S6, perform linear fitting based on the test duration of multiple second test microrings within the first time period to obtain the slope and standard deviation; S7, determine whether the slope is greater than a first preset threshold and the standard deviation is less than a second preset threshold; If the slope is less than or equal to the first preset threshold and the standard deviation is less than the second preset threshold, continue to execute step S3; If the slope is greater than the first preset threshold, or the standard deviation is greater than or equal to the second preset threshold, the projection coefficient K is readjusted.

8. The method for testing micro-rings in a micro-ring array according to claim 7, characterized in that, If the standard deviation is greater than or equal to the second preset threshold, and in step S202 it is determined that the total number P of working microrings in the microring array is greater than or equal to the second preset number threshold M2, all working microrings are divided into at least two groups, and each group is assigned a corresponding projection coefficient.

9. The method for testing micro-rings in a micro-ring array according to claim 1, characterized in that, When there are multiple first test microrings, in step S2, for each target operating wavelength, the average deviation is calculated based on the deviation between the actual operating voltage and the theoretical operating voltage of all the first test microrings.

10. A method for testing microrings in a microring array according to claim 9, characterized in that, In step S3, the test range of the corresponding second test microring is determined based on the corresponding target working wavelength and its corresponding average deviation.

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