An adiabatic InP waveguide integration platform and its inverse design method

Abstract

This invention provides an adiabatic InP waveguide integrated platform and its reverse design method, belonging to the field of optical communication and millimeter-wave communication technology. It solves the problem of excessively large design size of current InP waveguide integrated platforms. The technical solution is as follows: an adiabatic InP waveguide integrated platform, including an InP-based grating waveguide structure and an InP-based ridge waveguide structure; and a reverse design method for the adiabatic InP waveguide integrated platform, including the following steps: Step 1, determining the variation trend of the silicon core; Step 2, refining the variation trend of the silicon core; Step 3, tilting the grating ends towards the central core grating; Step 4, determining the width division of the silicon core; Step 5, determining the length of each silicon core segment; and Step 6, assembling the adiabatic InP waveguide integrated platform. The beneficial effects of this invention are: it is versatile and efficient, suitable for designing adiabatic InP waveguide integrated platforms with complex geometries, boundaries, materials, and various types.

Description

Technical Field

[0001] This invention relates to the fields of optical communication and millimeter-wave communication technology, and in particular to an adiabatic InP waveguide integrated platform and its reverse design method. Background Technology

[0002] Currently, the Internet uses optical fiber cables to achieve high-speed information transmission. The energy information emitted by lasers made with InP-based materials can be transmitted efficiently in optical fibers, and can be applied to the big data centers of companies such as China Mobile, China Unicom, China Telecom, and Huawei.

[0003] Indium phosphide (InP) is crucial for both active and passive devices, and is widely used in optical and millimeter-wave communications because it allows for the integration of active devices with InP-based components. This is illustrated in the paper: R. Grover, P.P. Absil, V. Van, J.V. Hryniewicz, B.E. Little, O. King, L.C. Calhoun, F.G. Johnson, and P.-T. Ho, “Vertically coupled GaInAsP–InP microring resonators”, Opt. Lett., vol. 26, no. 8, pp. 506-508, Apr. 2001. InP-based photonic waveguides are well-suited for large-scale photonic integrated circuits (PICs). However, one of the drawbacks of traditional InP-based PICs is the weak light confinement in InP waveguides caused by the low refractive index difference between the core and cladding, as illustrated in the paper: M. Takenaka, and S. Takagi, “InP-based photonic integrated circuit platform on SiC wafer,” Opt. Express, vol. 25, no. 24, pp. 29993-30000, Nov. 2017. Therefore, the device and chip size of InP-based PICs is larger than that of Si-based PICs. The large refractive index difference between Si and SiO2 in Si-based PICs enables strong light confinement. Furthermore, for the design of Si-based thermal insulation devices, the paper: TLLiang, Y.Tu, X.Chen, Y.Huang, Q.Bai, Y.Zhao, J.Zhang, Y.Yuan, J.Li, F.Yi, W.Shao, and S.-T.Ho, “A Fully Numerical Method for Designing Efficient Adiabatic Mode Evolution Structures (Adiabatic Taper, Coupler, Splitter, Mode Converter) Applicable to Complex Geometries,” J. Lightw. Technol., vol.39, no.17, pp.5531-5547, Sept. 2021, proposes an SLA design algorithm. This algorithm has better versatility than existing technologies, but it cannot be directly applied to the design of InP-based waveguides.Therefore, this invention proposes a reverse design method for InP-based SiO2 / Si waveguide connectors, that is, a reverse design method for an integrated platform of thermally insulating InP waveguides.

[0004] The design of the thermally insulated InP waveguide integrated platform is too complex due to the involvement of "multi-degree-of-freedom" and "multi-scale problems". Analytical methods cannot be used for the design of this platform. The invention "An InP-based thermally insulated waveguide system suitable for optical communication and millimeter-wave communication" applied for on June 28, 2022, involves the design of this platform. However, this invention connects the input end directly to the output end through a straight segment, and the design size is large, requiring a total length of 750μm to achieve 90% power transmission efficiency.

[0005] Therefore, the purpose of this invention is to solve the above problems. Summary of the Invention

[0006] The purpose of this invention is to provide an adiabatic InP waveguide integration platform and its reverse design method. The method proposed in this invention is versatile and efficient. The reverse design method of the adiabatic InP waveguide integration platform proposed in this invention allows for a device structure with a total length of only 250μm to achieve 90% power transmission efficiency. The size is reduced by a factor of three compared to existing designs, enabling a higher level of integration.

[0007] To achieve the above-mentioned objectives, the present invention adopts the following technical solution:

[0008] An adiabatic InP waveguide integrated platform includes an InP-based grating waveguide structure and an InP-based ridge waveguide structure, wherein the InP-based grating waveguide structure is the input end and the InP-based ridge waveguide structure is the output end.

[0009] Both the InP-based grating waveguide structure and the InP-based ridge waveguide structure include a cladding and a silicon core. The cladding and silicon core, from bottom to top, are: lower silicon dioxide cladding, air cladding, lower InP cladding, middle InP cladding, upper InP cladding, and upper silicon dioxide cladding.

[0010] The silicon dioxide lower cladding is connected to the silicon core, the silicon core is connected to the air cladding, the air cladding is connected to the InP lower cladding, the InP lower cladding is connected to the InP middle cladding, the InP middle cladding is connected to the InP upper cladding, and the InP upper cladding is connected to the silicon dioxide upper cladding.

[0011] The thickness of the silicon dioxide underlayer is h1 = 1 μm, and the refractive index is n. SiO2 =1.445; Silicon core refractive index n Si =3.455, silicon plate thickness h2 = 0.08 μm, silicon ridge thickness h3 = 0.42 μm; air cladding refractive index n Air=1. Thickness h3 = 0.42 μm; Refractive index n of the InP undercoat InP(4) =3.1825, thickness h4 = 0.15 μm; cladding refractive index n in InP InP(5) =3.4195, thickness h5=0.396μm; refractive index n of InP cladding InP(6) =3.1787, thickness h6 = 1.5 μm; the thickness of the cladding layer on the silicon dioxide is h1 = 0.5 μm, refractive index n SiO2 =1.445.

[0012] The silicon core of the InP-based grating waveguide structure has seven grating structures, including: two outer gratings, two sub-outer gratings inside the two outer gratings, two inner gratings inside the two sub-outer gratings, and a central core grating inside the two inner gratings. The width W of the seven gratings is... I =0.2μm, and the gap between gratings G =0.45μm.

[0013] InP-based ridge waveguide structures have only one ridge waveguide in the silicon core, with a width of W. O =1.5μm.

[0014] A reverse design method for an adiabatic InP waveguide integrated platform, comprising the following steps:

[0015] Step 1: Determine the variation trend of the silicon core in the beam propagation direction;

[0016] Because the waveguide structures at the input and output ends of this invention are completely different—the silicon core at the input end contains seven grating structures, while the silicon core at the output end is a conventional ridge waveguide structure, i.e., only one grating structure—this invention requires determining the variation trend of the silicon core in the beam propagation direction.

[0017] Step 2: Improve the variation trend of the silicon core in the beam propagation direction;

[0018] Step 3: Tilt the outer end of the silicon core grating towards the central core grating; at this time, the distance between the tip and the adjacent grating is 0.1μm, which is the minimum spacing, thereby realizing the design of the compact thermally adiabatic InP waveguide integrated platform of the present invention.

[0019] Step 4: Determine the width division of the silicon core;

[0020] Step 5: Determine the length of each silicon core segment;

[0021] Step 6: Assemble all the segments into an adiabatic InP waveguide integrated platform.

[0022] Step one uses a comparative method to determine the variation trend of the silicon core in the beam propagation direction, comparing two cases: the "slow change case" and the "slow change case". In the "slow change case", the six outer grating structures of the silicon core at the input end only change from width W to width W at the output end. L Reduce to 0;

[0023] "Rapidly Changing Situation": The six grating structures on the outer side of the input silicon chip extend only half the width from the output end to W. L Reduce to 0. Calculate the mode-field diameter and effective refractive index n for the TE0 mode in both cases. eff .

[0024] Using the information obtained in Step 1, in Step 2, determine the width of each of the six outer grating structures from W... L The conditions required to reduce it to 0.

[0025] In step four, the input end is defined as Region 1, the output end is defined as Region 3, and the intermediate transmission area to be designed is defined as Region 2. Region 2 is divided into eight segments along the beam propagation direction, and the width of each grating segment in Region 2 is determined.

[0026] Preferably, the width of the first segment of the central core grating increases from 0.2 μm to 0.2625 μm; the width of the second segment increases from 0.2625 μm to 0.325 μm; the width of the third segment increases from 0.325 μm to 0.4 μm; the width of the fourth segment increases from 0.4 μm to 0.45 μm; the width of the fifth segment increases from 0.45 μm to 0.525 μm; the width of the sixth segment increases from 0.525 μm to 0.75 μm; the width of the seventh segment increases from 0.75 μm to 1 μm; and the width of the eighth segment increases from 1 μm to 1.5 μm.

[0027] Preferably, the widths of the first to fourth segments of the two inner gratings and the middle core grating change in the same way; the width of the fifth segment decreases from 0.45μm to 0.2375μm; the width of the sixth segment decreases from 0.2375μm to 0.1μm; and the width of the seventh segment decreases from 0.1μm to 0.

[0028] Preferably, the width changes of the first and second segments of the two secondary outer gratings are consistent with the width changes of the middle core grating; the width of the third segment decreases from 0.325μm to 0.1625μm; and the width of the fourth segment decreases from 0.1625μm to 0.

[0029] Preferably, the width of the first segment of the two outer gratings is reduced from 0.2 μm to 0.1 μm; and the width of the second segment is reduced from 0.1 μm to 0.

[0030] The width of the gap can be calculated by those skilled in the art.

[0031] In step five, the SLA algorithm was used to calculate the lengths of the following segments: L1 = 916 μm; L2 = 455 μm; L3 = 213 μm; L4 = 161 μm; L5 = 45 μm; L6 = 285 μm; L7 = 105 μm; and L8 = 29 μm.

[0032] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0033] 1. Compared to the invention application "An InP-based thermally adiabatic waveguide system suitable for optical and millimeter-wave communication," which involves the design of such a platform by directly connecting the input end to the output end via a straight line segment, resulting in a large design size, this invention proposes a novel and more efficient reverse design method for thermally adiabatic InP waveguide integrated platforms. This method is versatile and efficient, applicable to the design of thermally adiabatic InP waveguide integrated platforms with complex geometries, boundaries, materials, and various types. It enables the reverse design of thermally adiabatic InP waveguide integrated platforms, allowing for the design of ultra-small thermally adiabatic InP waveguide integrated platforms with optimal waveguide shapes. This effectively improves the design capabilities of complex thermally adiabatic InP waveguide integrated platforms and promotes the development of photonic integrated chips towards higher integration levels.

[0034] 2. The reverse design method developed in this invention allows for a device structure with a total length of only 250 μm to achieve 90% power transmission efficiency, while the proposed invention, "An InP-based thermally insulating waveguide system suitable for optical and millimeter-wave communication," requires 750 μm to achieve the same 90% power transmission efficiency. Therefore, compared to previous designs, the design method proposed in this invention can reduce the device size by a factor of three, achieving a compact design of the waveguide integration platform. Attached Figure Description

[0035] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used together with the embodiments of the invention to explain the invention and do not constitute a limitation thereof.

[0036] Figure 1 This is a schematic diagram of the InP-based grating waveguide structure.

[0037] Figure 2 This is a schematic diagram of the InP-based ridge waveguide structure.

[0038] Figure 3 This is a schematic diagram illustrating the "slowly changing" width of the six outer gratings in this invention.

[0039] Figure 4 This is a schematic diagram of the “rapidly decreasing width” of the six outer gratings of the present invention.

[0040] Figure 5 This diagram illustrates where the width of the six outermost gratings is reduced to 0 in this invention.

[0041] Figure 6 This is a schematic diagram showing the specific layout of the silicon core of the present invention.

[0042] Figure 7 A schematic diagram comparing the transmission efficiency of the present invention and existing technologies.

[0043] The reference numerals in the attached figures are: 1-silicon dioxide lower cladding, 2-silicon core, 3-air cladding, 4-InP lower cladding, 5-InP middle cladding, 6-InP upper cladding, and 7-silicon dioxide upper cladding. Detailed Implementation

[0044] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. Of course, the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0045] Example 1

[0046] like Figure 1 and Figure 2 As shown, an adiabatic InP waveguide integrated platform includes an InP-based grating waveguide structure and an InP-based ridge waveguide structure, with the InP-based grating waveguide structure serving as the input end and the InP-based ridge waveguide structure serving as the output end.

[0047] Both the InP-based grating waveguide structure and the InP-based ridge waveguide structure include a cladding and a silicon core 2. The cladding and silicon core 2, from bottom to top, are: silicon dioxide lower cladding 1, air cladding 3, InP lower cladding 4, InP middle cladding 5, InP upper cladding 6, and silicon dioxide upper cladding 7.

[0048] The silicon dioxide lower cladding 1 is connected to the silicon core 2, the silicon core 2 is connected to the air cladding 3, the air cladding 3 is connected to the InP lower cladding 4, the InP lower cladding 4 is connected to the InP middle cladding 5, the InP middle cladding 5 is connected to the InP upper cladding 6, and the InP upper cladding 6 is connected to the silicon dioxide upper cladding 7.

[0049] The thickness of the silicon dioxide undercoat 1 is h1 = 1 μm, and the refractive index n SiO2 =1.445; Refractive index n of silicon core 2 Si =3.455, silicon plate thickness h2 = 0.08 μm, silicon ridge thickness h3 = 0.42 μm; air cladding 3 refractive index n Air=1, Thickness h3 = 0.42 μm; InP underlayer 4 refractive index n InP(4) =3.1825, thickness h4 = 0.15 μm; InP cladding 5 refractive index n InP(5) =3.4195, thickness h5=0.396μm; InP cladding 6 refractive index n InP(6) =3.1787, thickness h6 = 1.5 μm; the thickness of the silicon dioxide cladding layer 7 is h1 = 0.5 μm, refractive index n SiO2 =1.445.

[0050] The silicon core 2 of the InP-based grating waveguide structure has seven grating structures, including: two outer gratings, two sub-outer gratings inside the two outer gratings, two inner gratings inside the two sub-outer gratings, and a central core grating inside the two inner gratings. The width W of the seven gratings is... I =0.2μm, and the gap between gratings G =0.45μm.

[0051] Silicon core 2 of the InP-based ridge waveguide structure has only one ridge waveguide with a width W. O =1.5μm.

[0052] A reverse design method for an adiabatic InP waveguide integrated platform, comprising the following steps:

[0053] Step 1: Determine the variation trend of the silicon core in the beam propagation direction;

[0054] Because the waveguide structures at the input and output ends of this invention are completely different—the silicon core 2 at the input end contains seven grating structures, while the silicon core 2 at the output end is a conventional ridge waveguide structure, i.e., it has only one grating structure—this invention requires determining the variation trend of silicon core 2 in the beam propagation direction.

[0055] Step one uses a comparison method to determine the variation trend of the silicon core in the beam propagation direction, comparing two cases:

[0056] "Slowly changing situation": The six grating structures on the outer side of the input silicon core 2 only change from width W to the output end. L Reduce to 0, such as Figure 3 As shown;

[0057] "Rapidly Changing Situation": The six grating structures on the outer side of the input silicon chip 2 only extend to half the width of the output end from W. L Reduce to 0, such as Figure 4 As shown.

[0058] Calculate the mode-field diameter and effective refractive index n of the TE0 mode in both cases. eff As shown in Tables 1 and 2.

[0059] Table 1. Mode field diameter and effective mode refractive index of fundamental mode TE0 ("slow variation")

[0060]

[0061] Table 2. Mode field diameter and effective mode refractive index of fundamental mode TE0 (“Rapid Changes”)

[0062]

[0063] As can be seen from Tables 1 and 2, when the width of the central core grating exceeds 625 nm, the mode field diameter is basically the same in both cases. This result indicates that the portion of the six outer gratings near the output end has virtually no impact on the entire adiabatic InP waveguide integrated platform. Therefore, by comparing the two methods, the second variation method selected in this invention, where the width of the six outer gratings of the input silicon core 2 can be quickly reduced from W... L Reduce to 0.

[0064] Step 2: Improve the variation trend of silicon core 2 in the beam propagation direction;

[0065] Using the information obtained in Step 1, in Step 2, determine the width of each of the six outer grating structures from W... L The conditions required to reduce to 0, such as Figure 5 As shown:

[0066] (1) Simulations were performed on silicon core 2 at the input terminal with different numbers of grating structures, where the grating thickness W = 0.2 μm and the grating gap G = 0.45 μm, as shown in Case 1 of Table 3. In this case, the mode field diameter is smaller when the number of gratings is seven than when the number of gratings is five or seven, indicating that the InP-based grating waveguide structure has a good energy-gathering effect when the number of gratings is seven.

[0067] (2) Simulations were performed on an InP-based grating waveguide structure with a grating thickness W = 0.325 μm and a grating gap G = 0.325 μm. The mode field diameters for three cases with three, five, and seven gratings were obtained, as shown in Case 2 of Table 3. In this case, the mode field diameter is the smallest when the number of gratings is five, indicating that at this grating thickness, the width of the two outer gratings is reduced to 0 at this point.

[0068] (3) Simulations were performed on an InP-based grating waveguide structure with a grating thickness W = 0.45 μm and a grating gap G = 0.2 μm. The mode field diameters were obtained for three cases with one, three, and five gratings, as shown in Case 3 of Table 3. In this case, the mode field diameter was the smallest when the number of gratings was three, indicating that at this grating thickness, the width of the two outermost gratings decreased to 0 at this point.

[0069] (4) When the width of the central core grating increases to 1 μm, the width of the two inner gratings decreases to 0 at this point.

[0070] Table 3 Simulation results of the modulus diameter in three cases

[0071]

[0072] Step 3: Tilt the outer end of the grating of silicon core 2 towards the central core grating, as follows: Figure 6 As shown; at this time, the distance between the tip and the adjacent grating is 0.1μm, which is the minimum spacing, thereby realizing the design of the compact thermally adiabatic InP waveguide integrated platform of the present invention.

[0073] Step 4: Determine the width division of silicon core 2;

[0074] In step four, the input end is defined as Region 1, the output end as Region 3, and the intermediate transmission region to be designed is defined as Region 2. Region 2 is divided into nine segments along the beam propagation direction, and the width of the grating in each segment of Region 2 is determined, such as... Figure 6 As shown.

[0075] The width of the first segment of the central core grating increased from 0.2 μm to 0.2625 μm; the width of the second segment increased from 0.2625 μm to 0.325 μm; the width of the third segment increased from 0.325 μm to 0.4 μm; the width of the fourth segment increased from 0.4 μm to 0.45 μm; the width of the fifth segment increased from 0.45 μm to 0.525 μm; the width of the sixth segment increased from 0.525 μm to 0.75 μm; the width of the seventh segment increased from 0.75 μm to 1 μm; and the width of the eighth segment increased from 1 μm to 1.5 μm.

[0076] The width of the first to fourth segments of the two inner gratings changes in the same way as the width of the central core grating; the width of the fifth segment decreases from 0.45μm to 0.2375μm; the width of the sixth segment decreases from 0.2375μm to 0.1μm; and the width of the seventh segment decreases from 0.1μm to 0.

[0077] The width changes of the first and second segments of the two secondary outer gratings are consistent with the width changes of the middle core grating; the width of the third segment decreases from 0.325μm to 0.1625μm; and the width of the fourth segment decreases from 0.1625μm to 0.

[0078] The width of the first segment of the two outer gratings is reduced from 0.2 μm to 0.1 μm; the width of the second segment is reduced from 0.1 μm to 0.

[0079] The width of the gap can be calculated by those skilled in the art.

[0080] Step 5: Determine the length of each silicon core segment 2;

[0081] In step five, the SLA algorithm was used to calculate the lengths of the following segments: L1 = 916 μm; L2 = 455 μm; L3 = 213 μm; L4 = 161 μm; L5 = 45 μm; L6 = 285 μm; L7 = 105 μm; and L8 = 29 μm.

[0082] Step 6: Assemble all the segments into an adiabatic InP waveguide integrated platform.

[0083] Example 2

[0084] Based on Example 1, the following can be calculated: Figure 6 The power transmission efficiency of the thermally adiabatic InP waveguide integrated platform shown is as follows: Figure 7 As shown.

[0085] Figure 7 The power transmission efficiency of the thermally adiabatic InP waveguide integrated platform designed in this embodiment is given, and the invention "An InP-based thermally adiabatic waveguide system suitable for optical communication and millimeter-wave communication" is compared with this invention. Figure 7 As can be seen, for the same power transmission, the device length designed by the algorithm of this invention is much shorter than that of previously designed devices. For example, when the power transmission efficiency is 90%, the length required by the method of this invention is 250 μm, while the length required for "An InP-based thermally adiabatic waveguide system suitable for optical communication and millimeter-wave communication" is 750 μm. Therefore, when 90% power transmission efficiency is required, the length required for "An InP-based thermally adiabatic waveguide system suitable for optical communication and millimeter-wave communication" is more than three times the length required by the method of this invention. This demonstrates that the thermally adiabatic InP waveguide integrated platform designed by the method proposed in this invention has the advantage of small size, enabling the design of a compact thermally adiabatic InP waveguide integrated platform and helping photonic chips develop towards higher integration levels.

[0086] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An adiabatic InP waveguide integration platform, characterized by, It includes InP-based grating waveguide structure and InP-based ridge waveguide structure, with InP-based grating waveguide structure as the input end and InP-based ridge waveguide structure as the output end; Both the InP-based grating waveguide structure and the InP-based ridge waveguide structure include a cladding and a silicon core (2). The cladding and silicon core (2) are arranged from bottom to top as follows: silicon dioxide lower cladding (1), air cladding (3), InP lower cladding (4), InP middle cladding (5), InP upper cladding (6), and silicon dioxide upper cladding (7). The silicon dioxide lower cladding (1) is connected to the silicon core (2), the silicon core (2) is connected to the air cladding (3), the air cladding (3) is connected to the InP lower cladding (4), the InP lower cladding (4) is connected to the InP middle cladding (5), the InP middle cladding (5) is connected to the InP upper cladding (6), and the InP upper cladding (6) is connected to the silicon dioxide upper cladding (7). The silicon core (2) of the InP-based grating waveguide structure has seven grating structures, including: two outer gratings, two sub-outer gratings inside the two outer gratings, two inner gratings inside the two sub-outer gratings, and a central core grating inside the two inner gratings; wherein the width W of the seven gratings is... I = 0.2 μm, gap G between gratings = 0.45 μm; The silicon core (2) of the InP-based grating waveguide structure is divided into eight segments along the beam propagation direction; the width of the two outer gratings decreases from 0.2 μm to 0.1 μm in the first segment and from 0.1 μm to 0 in the second segment; the width of the two secondary outer gratings decreases from 0.325 μm to 0.1625 μm in the third segment and from 0.1625 μm to 0 in the fourth segment. The ends of both the outer and second outermost gratings are inclined toward the central core grating, and the distance between the tips and the adjacent gratings is 0.1 μm; The thickness of the silica undercoat (1) is h1 = 1 μm, and the refractive index is n SiO2 = 1.445; Silicon core (2) refractive index n Si =3.455, silicon plate thickness h2= 0.08 μm, silicon ridge thickness h3= 0.42 μm; air cladding (3) refractive index n Air = 1. Thickness is 0.42 μm; InP underlayer (4) refractive index n InP(4) = 3.1825, thickness h4 = 0.15 μm; InP cladding (5) refractive index n InP(5) = 3.4195, thickness h5 = 0.396 μm; InP cladding (6) refractive index n InP(6) = 3.1787, thickness h6 = 1.5 μm; the thickness of the silicon dioxide cladding layer (7) is 0.5 μm, and the refractive index n SiO2 = 1.445; The silicon core (2) of the InP-based ridge waveguide structure has only one ridge waveguide with a width W O = 1.5 μm.

2. A reverse design method of a thermally insulated InP waveguide integration platform according to claim 1, characterized in that, The method includes the following steps: Step 1: Determine the variation trend of silicon core (2) in the beam propagation direction; Step 2: Improve the variation trend of silicon core (2) in the beam propagation direction; Step 3: Tilt the outer end of the grating of the silicon core (2) towards the central core grating; Step 4: Determine the width division of the silicon core (2); Step 5: Determine the length of each silicon core segment (2); Step 6: Assemble all the segments into an adiabatic InP waveguide integrated platform; In step one, a comparative method is used to determine the variation trend of the silicon core (2) in the beam propagation direction. Two cases are compared: the six grating structures on the outer side of the silicon core (2) at the input end only change from width W to the output end. L The six grating structures on the outer side of the input silicon core (2) are reduced to 0 and extend only half the width from the output end from W. L Reduce to 0; In step two, the six outer gratings are determined to have a width from W L the condition required to reduce to 0 In step four, the input end is defined as Region 1, the output end is defined as Region 3, and the intermediate transmission area to be designed is defined as Region 2; Region 2 is divided into nine segments along the beam propagation direction, and the width of each grating segment in Region 2 is determined respectively. In step five, the SLA algorithm was used to calculate the lengths of the following segments: L1 = 916 μm for the first segment, L2 = 455 μm for the second segment, L3 = 213 μm for the third segment, L4 = 161 μm for the fourth segment, L5 = 45 μm for the fifth segment, L6 = 285 μm for the sixth segment, L7 = 105 μm for the seventh segment, and L8 = 29 μm for the eighth segment.

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