Lightweight femtosecond pulse waveguide forming process

Abstract

The invention discloses a light-weight femtosecond pulse waveguide forming process, which utilizes the ultrashort pulse characteristic of femtosecond laser to generate local refractive index change in a transparent dielectric material so as to form a high-quality waveguide structure. According to the technology, the pulse energy, the repetition frequency and the scanning speed of femtosecond laser are accurately controlled, and flexible design and efficient machining of a waveguide path are achieved. Femtosecond laser can freely scan in a three-dimensional space, flexible design and machining of a complex waveguide structure are achieved, the application range of the waveguide is expanded, tiny defects on the surface of the waveguide can be effectively reduced by accurately controlling laser parameters, the transmission loss and geometric accuracy of the waveguide are improved, the femtosecond laser machining speed is high, the process is simple, and the cost is low. The invention provides a waveguide forming process which is efficient, flexible and high in precision, the problems existing in the prior art are solved, and the preparation quality and the application potential of the waveguide are remarkably improved.

Description

Technical Field

[0001] The invention belongs to the technical field of waveguide forming, and in particular relates to a lightweight femtosecond pulse waveguide forming process. Background Art

[0002] In the current field of optical communication and optical interconnection, the preparation of waveguide structures is one of the key technologies to achieve efficient optical transmission. Traditional waveguide preparation methods mainly include ion exchange, sol-gel method, ultraviolet exposure and electron beam etching. Although these methods can meet the needs of waveguide preparation to a certain extent, they have obvious limitations in flexibility, precision and efficiency.

[0003] Ion exchange method: By immersing the glass material in molten salt, ions diffuse on the surface of the material, thereby changing the local refractive index. This method is simple to operate, but it is difficult to achieve complex three-dimensional waveguide structures, and the refractive index change is limited, which affects the transmission performance of the waveguide.

[0004] Sol-gel method: A thin film with different refractive indices is formed on the substrate through chemical reaction, and then a waveguide is formed through photolithography and etching processes. This method can produce a more complex waveguide structure, but the process is complex, the cycle is long, and the cost is high.

[0005] UV exposure method: UV light is used to produce a change in the refractive index in the photosensitive material to form a waveguide. This method is suitable for specific types of photosensitive materials, but it is highly selective for the material and the refractive index change is limited, which limits its application range.

[0006] Electron beam etching: The waveguide structure is etched on the surface of the material by an electron beam. This method can achieve high-precision waveguide preparation, but the equipment is expensive, the operation is complicated, and it is not suitable for large-scale production.

[0007] Although the above methods have their own advantages in waveguide preparation, they also have some common technical problems, especially in the preparation of high-quality and high-precision three-dimensional waveguide structures. These problems mainly include:

[0008] Lack of flexibility: Traditional methods make it difficult to achieve flexible design and processing of complex three-dimensional waveguide structures, limiting the application scope of waveguides.

[0009] Low precision: Traditional methods easily introduce tiny defects during the preparation process, which increases the transmission loss of the waveguide and affects its optical performance.

[0010] Inefficiency: Traditional methods have complex processes, long cycles, and high costs, which are not conducive to large-scale production and rapid iteration. Summary of the invention

[0011] The purpose of the present invention is to provide a lightweight femtosecond pulse waveguide forming process, which realizes flexible design and efficient processing of waveguide paths by precisely controlling the pulse energy, repetition frequency and scanning speed of the femtosecond laser, so as to solve the problems raised in the above-mentioned background technology.

[0012] The purpose of the present invention is to provide a lightweight femtosecond pulse waveguide forming process, which realizes flexible design and efficient processing of waveguide paths by precisely controlling the pulse energy, repetition frequency and scanning speed of the femtosecond laser, so as to solve the problems raised in the above-mentioned background technology.

[0013] To achieve the above object, the present invention adopts the following technical solution: a lightweight femtosecond pulse waveguide forming process, comprising the following steps:

[0014] S1: providing a transparent medium material, wherein the material has good light transmittance and can withstand the action of femtosecond laser;

[0015] S2: determining the path of the waveguide forming area on the material provided in step S1, and calculating the position sequence of the laser focus points based on the shape and size of the required waveguide;

[0016] S3: According to the position sequence determined in step S2, the working parameters of the femtosecond laser are adjusted, and the pulse energy is set to ensure that a local refractive index change is generated inside the material without destroying the material structure;

[0017] S4: Using the parameters set in step S3, start the femtosecond laser, so that the laser scans point by point inside the material along the path of the waveguide forming area planned in step S2 to form an initial waveguide profile;

[0018] S5: Performing quality inspection on the initial waveguide profile formed in step S4 to evaluate the transmission loss and geometric accuracy of the waveguide;

[0019] S6: If the quality inspection result of step S5 does not meet the preset standard, fine-tune the working parameters of the femtosecond laser in step S3 according to the inspection result to optimize the pulse energy or repetition frequency of the femtosecond laser;

[0020] S7: re-execute step S4 according to the parameters adjusted in step S6 until the transmission loss and geometric accuracy of the waveguide meet the requirements;

[0021] S8: After the waveguide is formed, the material is surface treated to remove tiny defects that may be caused by the laser action and improve the overall performance of the waveguide;

[0022] S9: Perform a final inspection on the waveguide processed in step S8 to confirm that all indicators of the waveguide meet the design requirements and complete the waveguide forming process.

[0023] Preferably, step S1 includes the following sub-processes:

[0024] S11: Select the type of transparent medium material and ensure that the refractive index n of the material meets the requirements, wherein the refractive index n should be greater than 1.4 and less than 1.6;

[0025] S12: Measure the initial absorption coefficient α of the material selected in step S11 o , and calculate the absorption enhancement factor F = exp(α o L), where L is the laser penetration depth;

[0026] S13: Based on the absorption enhancement factor F in step S12, adjust the output power P of the laser to minimize the thermal effect generated inside the material. The calculation formula is P adj =P initial / F, where P initial is the initial output power of the laser;

[0027] S14: Using the laser output power P adjusted in step S13 adj , pre-process the selected transparent medium material.

[0028] Preferably, step S2 includes the following sub-processes:

[0029] S21: Determine the boundary conditions of the waveguide forming area and define the starting point P of the waveguide s and the end point P e , and the centerline path C of the waveguide;

[0030] S22: Based on the path C defined in step S21, calculate the waveguide width W and height H, and determine the shape of the waveguide cross section;

[0031] S23: Using the shape of the waveguide cross section determined in step S22 and the waveguide centerline path C, calculate the laser focus position sequence S = {S1, S2, ..., S n}, where S i For each position point, it is evenly distributed along the path C with a spacing of d. The calculation formula is: Where N is the total number of focus points;

[0032] S24: Optimize the position sequence S obtained in step S23, and check whether the distances between adjacent focal points are uniform. If non-uniformity is found, adjust the number of focal points N or recalculate the spacing d.

[0033] Preferably, step S3 includes the following sub-processes:

[0034] S31: Calculate the total number of pulses M required for waveguide forming according to the position sequence of the laser focus points determined in step S2, where M is equal to the number of focus points in the position sequence;

[0035] S32: Based on the total number of pulses M calculated in step S31, estimate the energy range of a single pulse to ensure that the total energy does not exceed the damage threshold of the material. The calculation formula is: Where E th is the damage threshold energy of the material;

[0036] S33: Considering the energy accumulation effect in the waveguide shaping process, adjust the energy E of a single pulse so that the energy E of a single pulse is within E min and E max The calculation formula is Where E min To ensure the minimum energy required for the refractive index change;

[0037] S34: Apply the single pulse energy E determined in step S33 to the femtosecond laser, set the pulse energy parameters of the laser, and perform preliminary tests to verify whether the pulse energy can effectively produce a local refractive index change without damaging the material.

[0038] Preferably, step S4 includes the following sub-processes:

[0039] S41: Initializing the working parameters of the femtosecond laser according to the pulse energy E and the total number of pulses M set in step S3;

[0040] S42: Based on the position sequence of the laser focal points determined in step S2, set the scanning path of the laser so that the laser scans point by point along the path, scanning one focal point each time, and calculate the total length L of the scanning path total ,in S i is the position of the i-th focal point, S i+1 is the position of the i+1th focal point;

[0041] S43: Determine the laser scanning speed v to ensure that the laser action time at each focus point is sufficient to produce the required refractive index change. The calculation formula is: where t total is the total scan time;

[0042] S44: Start the femtosecond laser, scan point by point according to the scanning speed v set in step S43 and the path set in step S42 to form an initial waveguide profile, and monitor the laser power and position deviation in real time during the scanning process.

[0043] Preferably, step S5 includes the following sub-processes:

[0044] S51: Use a high-precision optical microscope to perform geometric accuracy detection on the initial waveguide formed in step S4, record the deviation between the actual path of the waveguide and the designed path, the deviation in the x direction Δx and the deviation in the y direction Δy, and calculate the geometric accuracy error

[0045] S52: Based on the geometric accuracy error ε detected in step S51 geom , evaluate whether the geometric accuracy of the waveguide meets the design requirements. If the error exceeds the preset threshold ε max , then it is necessary to adjust the laser scanning parameters and re-form the waveguide;

[0046] S53: Use an optical spectrum analyzer to measure the transmission loss of the waveguide by inputting the optical power P in And the output optical power P out , calculate the transmission loss

[0047] S54: The transmission loss L measured in step S53 is trans The transmission loss threshold L required by the design max For comparison, if the transmission loss exceeds the transmission loss threshold L max , it is necessary to optimize the laser pulse energy or scanning speed and re-form the waveguide.

[0048] Preferably, step S6 includes the following sub-processes:

[0049] S61: According to the geometric accuracy error ε detected in step S5 geom and transmission loss L trans , to determine whether the waveguide quality meets the preset standard. If the geometric accuracy error exceeds the threshold ε max Or the transmission loss exceeds the threshold L max , then proceed to the next step;

[0050] S62: Analyze the problems of the detection results in step S5 and determine the parameters that need to be optimized. If the main problem is that the geometric accuracy error is too large, adjust the laser scanning speed v and calculate the new scanning speed

[0051] S63: If the main problem is that the transmission loss is too high, adjust the laser pulse energy E and calculate the new pulse energy

[0052] S64: applying the parameters adjusted in step S62 or step S63 to the femtosecond laser, and re-performing steps S4 to S5 until the waveguide quality detection result reaches a preset standard.

[0053] Preferably, step S7 includes the following sub-processes:

[0054] S71: Reinitialize the pulse energy E of the femtosecond laser according to the laser operating parameters adjusted in step S6 new and scanning speed v new ;

[0055] S72: using the parameters set in step S71, re-execute the laser scanning process in step S4, so that the laser scans point by point inside the material along the path planned in step S2 to form a new waveguide profile;

[0056] S73: After completing the scan in step S72, perform the quality inspection in step S5 again to evaluate the transmission loss L of the new waveguide. trans and geometric accuracy error ε geom ;

[0057] S74: Compare the transmission loss L measured in step S73 trans and geometric accuracy error ε geom Compared with the preset standard value L max and ε max If it still does not meet the requirements, return to step S6 to continue adjusting the parameters until the waveguide quality meets the requirements.

[0058] Preferably, step S8 includes the following sub-processes:

[0059] S81: Use a high-resolution optical microscope to perform a detailed inspection on the surface of the material after waveguide forming, identify and mark the tiny defect areas caused by the laser action, and record them as a defect point set D;

[0060] S82: Calculate the area A of each defect point based on the defect point set D identified in step S81 i and depth d i , and record these parameters;

[0061] S83: Calculate the processing parameters according to the defect point parameters recorded in step S82. For chemical polishing, calculate the polishing liquid concentration C and the processing time t. The formula is C = k1·max(A i ) and t = k2·max(d i ), where k1 and k2 are empirical constants;

[0062] S84: Apply the processing parameters determined in step S83 to process the material surface to remove defective spots, and then re-inspect the surface using an optical microscope.

[0063] Preferably, step S9 includes the following sub-processes:

[0064] S91: Use an optical microscope to perform a final inspection on the waveguide surface processed in step S8, and record the surface roughness parameter R, which is calculated by the formula: where h j is the height of each measuring point, h avg is the average height of all measurement points, N s is the number of measurement points;

[0065] S92: Based on the roughness parameter R measured in step S91, evaluate whether the roughness of the waveguide surface meets the design requirements. If the roughness parameter exceeds a preset threshold R thresh , then it is necessary to re-perform the surface treatment in step S8;

[0066] S93: Use an optical spectrum analyzer to measure the final transmission loss of the waveguide by inputting the optical power P input And the output optical power P output , calculate the final transmission loss and compare it with the data in step S5 to ensure that the transmission loss has not been deteriorated due to the surface treatment;

[0067] S94: Based on the test results from step S91 to step S93, it is confirmed that all indicators of the waveguide meet the design requirements, and the waveguide forming process is completed.

[0068] Technical effects and advantages of the present invention: Compared with the prior art, the lightweight femtosecond pulse waveguide forming process proposed by the present invention has the following advantages:

[0069] The present invention utilizes the ultrashort pulse characteristics of femtosecond lasers to produce local refractive index changes inside transparent dielectric materials, thereby forming a high-quality waveguide structure. The process achieves flexible design and efficient processing of waveguide paths by precisely controlling the pulse energy, repetition frequency and scanning speed of the femtosecond laser. Femtosecond lasers can scan freely in three-dimensional space, enabling flexible design and processing of complex waveguide structures, expanding the application range of waveguides, and by precisely controlling laser parameters, can effectively reduce tiny defects on the waveguide surface, improve the transmission loss and geometric accuracy of the waveguide. Femtosecond laser processing speed is fast, the process is simple, suitable for large-scale production and rapid iteration, and reduces the preparation cost. The present invention provides an efficient, flexible and high-precision waveguide forming process, which solves the problems existing in the prior art and significantly improves the preparation quality and application potential of waveguides. BRIEF DESCRIPTION OF THE DRAWINGS

[0070] Figure 1 The present invention is a flowchart of a lightweight femtosecond pulse waveguide forming process. DETAILED DESCRIPTION

[0071] The following will be combined with the accompanying drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. The specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0072] The present invention provides a lightweight femtosecond pulse waveguide forming process, which aims to utilize the ultrashort pulse characteristics of femtosecond lasers to produce local refractive index changes inside transparent dielectric materials, thereby forming a high-quality waveguide structure. The process achieves flexible design and efficient processing of waveguide paths by precisely controlling the pulse energy, repetition frequency and scanning speed of femtosecond lasers. The details are as follows:

[0073] like Figure 1 As shown, in this embodiment, a lightweight femtosecond pulse waveguide forming process includes the following steps:

[0074] S1: providing a transparent medium material, wherein the material has good light transmittance and can withstand the action of femtosecond laser; further comprising the following sub-processes:

[0075] S11 selects the type of transparent medium material to ensure that the refractive index n of the material meets the specific application requirements. In order to ensure that the material has good light transmittance and can withstand the effect of femtosecond laser, materials with a refractive index between 1.4 and 1.6 can be selected. Commonly used materials include quartz glass, silicon-based materials, etc. Selecting a material with a refractive index between 1.4 and 1.6 can ensure that the material has good light transmittance and can withstand the effect of femtosecond laser, avoiding damage to the material during processing.

[0076] S12 Measurement step S11 Initial absorption coefficient α of the selected material o , and calculate the absorption enhancement factor F = exp(α o L), where L is the laser penetration depth; specifically, after selecting the material, use a high-precision spectrometer to measure the initial absorption coefficient of the material. The absorption coefficient reflects the material's ability to absorb light. Next, calculate the absorption enhancement factor of the material under the action of a femtosecond laser. The absorption enhancement factor refers to the increase in the absorption coefficient of the material due to the nonlinear absorption effect under the action of a femtosecond laser. The laser penetration depth refers to the effective depth of the laser inside the material.

[0077] By measuring the initial absorption coefficient and calculating the absorption enhancement factor, the response characteristics of the material to femtosecond laser can be accurately evaluated, providing a scientific basis for subsequent laser parameter adjustments and ensuring that the material will not be damaged due to excessive absorption during the processing.

[0078] S13 adjusts the output power P of the laser based on the absorption enhancement factor F in step S12 to minimize the thermal effect generated inside the material. The calculation formula is P adj =P initial / F, where P initial is the initial output power of the laser;

[0079] Specifically, based on the absorption enhancement factor calculated in step S12, the output power of the femtosecond laser is adjusted. The purpose is to minimize the thermal effect generated inside the material and avoid irreversible damage to the material due to overheating. By adjusting the output power of the laser, it is ensured that the material can stably withstand the action of the laser during the processing. By adjusting the output power of the laser, the thermal effect inside the material can be effectively reduced, and damage to the material due to overheating can be avoided, thereby improving the quality and stability of waveguide forming.

[0080] S14 uses the laser output power P adjusted in step S13 adj , the selected transparent medium material is pre-treated to verify the response characteristics of the material to femtosecond laser and ensure that the material can stably withstand the laser action without irreversible damage.

[0081] Specifically, the selected transparent medium material is pretreated using the laser output power adjusted in step S13. The purpose of the pretreatment is to verify the response characteristics of the material to the femtosecond laser and to ensure that the material can stably withstand the laser action without irreversible damage during the actual processing process. During the pretreatment process, the response characteristics of the material can be evaluated by observing the changes on the surface of the material and measuring the physical properties of the material.

[0082] Through pretreatment, the response characteristics of the material to femtosecond laser can be discovered in advance, ensuring that the material can stably withstand the laser action during the actual processing, avoiding processing failures caused by mismatched material properties, and improving the success rate and quality of waveguide forming.

[0083] By selecting appropriate transparent dielectric materials, measuring and calculating the absorption characteristics of the materials, adjusting the output power of the laser, and performing pretreatment, it is possible to ensure that the materials can stably withstand processing under the action of femtosecond lasers and avoid damage, thereby improving the quality and reliability of waveguide forming.

[0084] S2: determining a waveguide forming area on the material provided in step S1, and calculating a position sequence of laser focus points based on the shape and size of the required waveguide; further comprising the following sub-processes:

[0085] S21 determines the boundary conditions of the waveguide forming area and defines the starting point P of the waveguide s and the end point P e , and the centerline path C of the waveguide; the purpose of this step is to clarify the starting and ending points of the waveguide, as well as the approximate direction of the waveguide in the material, to provide a basis for subsequent detailed design. By clarifying the starting point, end point, and centerline path of the waveguide, it can be ensured that the design of the waveguide meets the actual application requirements and avoid path deviation or discontinuity problems in the subsequent processing process.

[0086] S22 calculates the waveguide width W and height H based on the path C defined in step S21, and determines the shape of the waveguide cross section. Common waveguide cross-sectional shapes include rectangle and ellipse. The width and height of the waveguide should be reasonably selected according to the actual application requirements and material properties to ensure that the waveguide has good transmission performance. By calculating the width and height of the waveguide and determining the cross-sectional shape, it can be ensured that the geometric dimensions of the waveguide after molding meet the design requirements, thereby improving the transmission efficiency and optical performance of the waveguide.

[0087] S23 uses the shape of the waveguide cross section determined in step S22 and the waveguide centerline path C to calculate the laser focus position sequence S = {S1, S2, ..., S n}, where each position point S i Evenly distributed along path C, with a spacing of d, the calculation formula is Where N is the total number of focus points; the purpose of this step is to ensure that the laser can evenly cover the entire waveguide path when scanning point by point inside the material to form a continuous waveguide structure. By calculating the position sequence of the laser focus points, it is possible to ensure that the laser scanning path inside the material is evenly distributed, avoiding the problem of discontinuity of the waveguide structure or increased transmission loss caused by uneven spacing between focus points.

[0088] S24 optimizes the position sequence S obtained in step S23, checks whether the distances between adjacent focus points are uniform, and if non-uniformity is found, adjusts the number of focus points N or recalculates the spacing d to ensure that the distances between all focus points meet the design requirements. By optimizing the position sequence, it is possible to ensure that the distances between all focus points are evenly distributed, avoid waveguide structural defects caused by non-uniform spacing between focus points, and improve the geometric accuracy and transmission performance of the waveguide.

[0089] By determining the boundary conditions of the waveguide forming area, calculating the width and height of the waveguide, calculating the position sequence of the laser focus points, and optimizing the position sequence, it is possible to ensure that the geometric dimensions and transmission performance of the waveguide after forming meet the design requirements, thereby improving the forming quality and reliability of the waveguide.

[0090] S3: According to the position sequence determined in step S2, the working parameters of the femtosecond laser are adjusted to set a suitable pulse energy to ensure that a local refractive index change is generated inside the material without destroying the material structure; further comprising the following sub-processes:

[0091] S31 calculates the total number of pulses M required for waveguide forming according to the position sequence of the laser focus points determined in step S2, where M is equal to the number of focus points in the position sequence; the purpose of this step is to determine the total number of pulses required in the entire waveguide forming process, providing a basis for subsequent parameter adjustments. By calculating the total number of pulses, it can be ensured that the number of laser pulses matches the number of designed focus points during the waveguide forming process, avoiding incomplete waveguide structure or material damage caused by insufficient or excessive pulses.

[0092] S32 estimates the energy range of a single pulse based on the total number of pulses M calculated in step S31 to ensure that the total energy does not exceed the damage threshold of the material. The calculation formula is Where E th The damage threshold energy of the material; the purpose of this step is to ensure that the energy of each pulse is within a reasonable range to avoid material damage due to excessive total energy. By estimating the energy range of a single pulse, it can be ensured that during the waveguide forming process, the energy of each pulse will not exceed the damage threshold of the material, avoiding irreversible damage to the material due to excessive energy, and improving the reliability of waveguide forming.

[0093] S33 considers the energy accumulation effect in the waveguide shaping process and adjusts the energy E of a single pulse so that it is within E min and E max The calculation formula is Where E min To ensure the minimum energy required for the refractive index change; the purpose of this step is to minimize the energy accumulation effect and avoid local overheating of the material while ensuring the refractive index change. By adjusting the energy of a single pulse, it can be ensured that during the waveguide forming process, the energy of each pulse can produce the required local refractive index change without causing local overheating of the material due to the energy accumulation effect, thereby improving the quality and stability of the waveguide forming.

[0094] S34 applies the single pulse energy E determined in step S33 to the femtosecond laser, sets the pulse energy parameters of the laser, and performs preliminary tests to verify whether the pulse energy can effectively produce local refractive index changes without damaging the material. The preliminary test can be performed by observing changes on the surface of the material and measuring the physical properties of the material. The purpose of this step is to ensure that the pulse energy of the laser is set correctly and can effectively achieve waveguide forming.

[0095] By setting the pulse energy parameters of the laser and performing preliminary tests, it is possible to verify whether the pulse energy setting is appropriate, ensuring that local refractive index changes can be effectively produced during the actual processing without damaging the material, thereby improving the success rate and quality of waveguide forming.

[0096] By calculating the total number of pulses required for waveguide forming, estimating the energy range of a single pulse, adjusting the energy of a single pulse, and setting the pulse energy parameters of the laser, it can be ensured that during the waveguide forming process, the pulse energy of the laser can both produce the required local refractive index change within the material and not exceed the damage threshold of the material.

[0097] S4: Using the parameters set in step S3, start the femtosecond laser, so that the laser scans point by point inside the material along the path planned in step S2 to form an initial waveguide profile; further including the following sub-processes:

[0098] S41 initializes the working parameters of the femtosecond laser according to the pulse energy E and the total number of pulses M set in step S3 to ensure that the output pulse energy of the laser is stable; the purpose of this step is to ensure that the laser can continuously output stable pulse energy during operation and provide reliable energy support for subsequent waveguide forming. By initializing the working parameters of the femtosecond laser, it can be ensured that the laser outputs stable pulse energy during the waveguide forming process, avoiding uneven waveguide structure or material damage caused by energy fluctuations, and improving the stability and reliability of waveguide forming.

[0099] S42 sets the scanning path of the laser based on the position sequence of the laser focal points determined in step S2, so that the laser scans point by point along the path, scanning one focal point each time. Calculate the total length L of the scanning path total ,in S i is the position of the i-th focal point; S i+1 is the position of the i+1th focusing point; by setting the scanning path of the laser, it can be ensured that the laser scans point by point inside the material according to the predetermined path to form a continuous and precise waveguide profile, avoiding the problem of discontinuity of the waveguide structure or increased transmission loss due to path deviation.

[0100] S43 determines the laser scanning speed v to ensure that the laser action time at each focus point is sufficient to produce the required refractive index change. The calculation formula is: where t total is the total scanning time, which can be set according to material properties and experimental experience. By determining the appropriate laser scanning speed, it can be ensured that the laser action time at each focal point is sufficient to avoid insufficient refractive index change due to too fast scanning speed or overheating of the material due to too slow scanning speed, thereby improving the quality and stability of waveguide forming.

[0101] S44 starts the femtosecond laser, scans point by point according to the scanning speed v set in step S43 and the path set in step S42, forms the initial waveguide profile, and monitors the laser power and position deviation in real time during the scanning process to ensure scanning accuracy and stability. By real-time monitoring of laser power and position deviation, any deviation in the scanning process can be discovered and corrected in time, ensuring the accuracy and stability of the scanning process, thereby improving the quality and reliability of waveguide forming.

[0102] By initializing the working parameters of the femtosecond laser, setting the scanning path of the laser, determining the laser scanning speed, and starting the femtosecond laser for scanning, it can be ensured that during the waveguide forming process, the laser can stably output pulse energy, accurately scan point by point along the predetermined path, and form a high-quality initial waveguide profile.

[0103] S5: Performing quality inspection on the initial waveguide profile formed in step S4 to evaluate the transmission loss and geometric accuracy of the waveguide; further comprising the following sub-processes:

[0104] S51 uses a high-precision optical microscope to perform geometric accuracy detection on the initial waveguide formed in step S4, records the deviations Δx and Δy between the actual path of the waveguide and the designed path, and calculates the geometric accuracy error By using a high-precision optical microscope for geometric accuracy detection, the deviation between the actual path of the waveguide and the designed path can be accurately recorded, the geometric accuracy error can be calculated, and the geometric accuracy of the waveguide can be ensured to meet the design requirements, thus avoiding increased transmission loss or signal distortion caused by path deviation.

[0105] S52 is based on the geometric accuracy error ε detected in step S51 geom , evaluate whether the geometric accuracy of the waveguide meets the design requirements. If the error exceeds the preset threshold ε max , it is necessary to adjust the laser scanning parameters and re-form the waveguide; by evaluating the geometric accuracy error, the geometric deviation in the waveguide forming process can be discovered in time, and necessary adjustment measures can be taken to ensure that the geometric accuracy of the waveguide meets the design requirements and improve the transmission performance and reliability of the waveguide.

[0106] S53 uses an optical spectrum analyzer to measure the transmission loss of the waveguide by inputting the optical power P in And the output optical power P out , calculate the transmission loss By using an optical spectrum analyzer to measure transmission loss, the transmission performance of the waveguide can be accurately evaluated to ensure that the transmission loss of the optical signal in the waveguide meets the design requirements, thus avoiding signal attenuation or communication quality problems caused by excessive transmission loss.

[0107] S54 converts the transmission loss L measured in step S53 into transThe transmission loss threshold L required by the design max By comparison, if the transmission loss exceeds the threshold, it is necessary to optimize the laser pulse energy or scanning speed and re-form the waveguide. By evaluating the transmission loss, the transmission loss problem in the waveguide forming process can be discovered in time, and necessary optimization measures can be taken to ensure that the transmission loss of the waveguide meets the design requirements and improve the transmission performance and reliability of the waveguide.

[0108] By using a high-precision optical microscope to detect and evaluate geometric accuracy, and using a spectrum analyzer to measure and evaluate transmission loss, it can be ensured that during the waveguide molding process, the geometric accuracy and transmission loss of the waveguide meet the design requirements, avoiding performance problems caused by geometric deviation or excessive transmission loss.

[0109] S6: If the quality inspection result of step S5 does not meet the preset standard, fine-tune the working parameters of the femtosecond laser in step S3 according to the inspection result to optimize the pulse energy or repetition frequency of the femtosecond laser; further comprising the following sub-processes:

[0110] S61 is based on the geometric accuracy error ε detected in step S5. geom and transmission loss L trans , to determine whether the waveguide quality meets the preset standard. If the geometric accuracy error exceeds the threshold ε max Or the transmission loss exceeds the threshold L max , then proceed to the next step; by judging the geometric accuracy error and transmission loss of the waveguide, quality problems in the waveguide forming process can be discovered in time, providing a basis for subsequent parameter optimization and ensuring that the performance of the waveguide meets the design requirements.

[0111] S62 analyzes the specific problems of the test results in step S5 and determines the parameters that need to be optimized. If the main problem is that the geometric accuracy error is too large, adjust the laser scanning speed v and calculate the new scanning speed The purpose of this step is to determine the parameters that need to be optimized based on the specific test results so that targeted adjustments can be made. By analyzing the test results, the main problems in the waveguide forming process can be accurately identified, providing a clear direction for subsequent parameter optimization and improving the accuracy and reliability of waveguide forming.

[0112] S63 If ​​the main problem is that the transmission loss is too high, adjust the laser pulse energy E and calculate the new pulse energy By adjusting the laser pulse energy, the transmission loss can be effectively reduced, the transmission performance of the waveguide can be improved, and the transmission loss of the optical signal in the waveguide can be ensured to be within an acceptable range.

[0113] S64 applies the parameters adjusted in step S62 or step S63 to the femtosecond laser, and re-executes steps S4 to S5 until the waveguide quality test result reaches the preset standard. By re-executing the waveguide shaping and quality test, it can be ensured that the geometric accuracy and transmission loss of the waveguide reach the preset standard after multiple adjustments, avoiding waveguide quality problems caused by improper parameter settings, and improving the reliability and success rate of waveguide shaping.

[0114] S7: re-execute step S4 according to the parameters adjusted in step S6 until the transmission loss and geometric accuracy of the waveguide meet the requirements; further comprising the following sub-processes:

[0115] S71 reinitializes the pulse energy E of the femtosecond laser according to the laser operating parameters adjusted in step S6. new and scanning speed v new ; By reinitializing the working parameters of the femtosecond laser, it can be ensured that the laser can operate stably under the new parameter settings, avoiding waveguide quality problems caused by improper parameter settings, and improving the accuracy and reliability of waveguide forming.

[0116] S72 uses the parameters set in step S71 to re-execute the laser scanning process in step S4, so that the laser scans point by point inside the material along the path planned in step S2 to form a new waveguide profile; by re-executing the laser scanning process, it can be ensured that the new parameter settings are effectively applied in the actual waveguide forming process, forming a high-quality waveguide profile and improving the transmission performance and geometric accuracy of the waveguide.

[0117] S73 After completing the scanning in step S72, the quality inspection in step S5 is performed again to evaluate the transmission loss L of the new waveguide. trans and geometric accuracy error ε geom ; By performing quality inspection again, it is possible to verify whether the new parameter settings have effectively solved the previous quality problems, ensure that the geometric accuracy and transmission loss of the waveguide meet the preset standards after multiple adjustments, and improve the reliability and success rate of waveguide forming.

[0118] S74 compares the transmission loss L measured in step S73 trans and geometric accuracy error ε geom Compared with the preset standard value L max and ε max If it still does not meet the requirements, return to step S6 to continue adjusting the parameters until the waveguide quality meets the requirements. By comparing the test results with the preset standards, quality problems in the waveguide molding process can be discovered in time, and necessary adjustment measures can be taken to ensure that the geometric accuracy and transmission loss of the waveguide ultimately meet the design requirements, thereby improving the transmission performance and reliability of the waveguide.

[0119] By reinitializing the working parameters of the femtosecond laser, re-executing the laser scanning process, performing quality inspection again, and comparing the inspection results with the preset standards, it can be ensured that during the waveguide forming process, the geometric accuracy and transmission loss of the waveguide finally meet the design requirements after multiple adjustments.

[0120] S8: After the waveguide is formed, the material is surface treated to remove tiny defects that may be caused by the laser action and improve the overall performance of the waveguide; further including the following sub-processes:

[0121] S81 uses a high-resolution optical microscope to conduct a detailed inspection of the surface of the material after waveguide molding, identifies and marks the tiny defect areas caused by the laser action, and records them as the defect point set D; by using a high-resolution optical microscope for detailed inspection, the tiny defects on the material surface can be accurately identified, ensuring that these defects can be removed in a targeted manner in subsequent processing, thereby improving the overall performance of the waveguide.

[0122] S82 Calculate the area A of each defect point based on the defect point set D identified in step S81 i and depth d i , and record these parameters; by calculating the area and depth of each defect point, the nature of the defect can be understood in detail, providing accurate data support for subsequent surface treatment and ensuring the effectiveness and pertinence of the treatment method.

[0123] S83 selects an appropriate surface treatment method, such as chemical polishing or mechanical grinding, and calculates the treatment parameters based on the defect point parameters recorded in step S82. For chemical polishing, the polishing liquid concentration C and the treatment time t are calculated, and the formula is C = k1·max(A i ) and t = k2 max (d i ), where k1 and k2 are empirical constants, and max represents the maximum value; by selecting a suitable surface treatment method and calculating the treatment parameters, the effectiveness and accuracy of the surface treatment process can be ensured, new defects or material damage caused by improper treatment can be avoided, and the overall performance of the waveguide can be improved.

[0124] S84 applies the processing parameters determined in step S83 to process the surface of the material to remove the defect points, and then re-inspects the surface using an optical microscope to ensure that all defect points have been effectively removed. By performing surface treatment and re-inspecting the surface, it can be ensured that all defect points are effectively removed, improve the surface quality and overall performance of the waveguide, avoid increased transmission loss or signal distortion caused by surface defects, and ensure the reliability and transmission performance of the waveguide.

[0125] S9: Perform a final inspection on the waveguide processed in step S8 to confirm that all indicators of the waveguide meet the design requirements and complete the waveguide forming process. Further including the following sub-processes:

[0126] S91 uses a high-precision optical microscope to perform a final inspection on the waveguide surface processed in step S8, and records the surface roughness parameter R, which is calculated by the formula: where h j is the height of each measuring point, h avg is the average height of all measurement points, N s is the number of measurement points; by using a high-precision optical microscope for final inspection, the roughness parameters of the waveguide surface can be accurately recorded to ensure that the waveguide surface is smooth after surface treatment and avoid increased transmission loss or signal distortion caused by surface roughness.

[0127] S92 evaluates whether the roughness of the waveguide surface meets the design requirements based on the roughness parameter R measured in step S91. If the roughness parameter exceeds the preset threshold R thresh , it is necessary to re-execute the surface treatment in step S8; by evaluating the roughness of the waveguide surface, problems in the surface treatment can be discovered in time, and necessary adjustment measures can be taken to ensure that the roughness of the waveguide surface meets the design requirements and improve the transmission performance and reliability of the waveguide.

[0128] S93 uses an optical spectrum analyzer to measure the final transmission loss of the waveguide by inputting the optical power P input And the output optical power P output , calculate the final transmission loss Among them, log 10 It represents the logarithm with base 10, also known as the common logarithm. The transmission loss is compared with the data in step S5 to ensure that the transmission loss has not deteriorated due to the surface treatment; by measuring the final transmission loss and comparing it with the previous test results, it can be ensured that the surface treatment process has not introduced new transmission loss, ensuring that the transmission performance of the waveguide meets the design requirements and avoiding performance degradation caused by surface treatment.

[0129] S94 integrates the test results from step S91 to step S93, confirms that all indicators of the waveguide meet the design requirements, including surface roughness, transmission loss and geometric accuracy, and completes the waveguide molding process. By comprehensively evaluating various indicators of the waveguide, it can be ensured that the performance of the waveguide in multiple aspects meets the design requirements, avoids overall performance problems caused by non-compliance with performance in one aspect, and improves the reliability and transmission performance of the waveguide.

[0130] By finally checking the waveguide surface roughness, evaluating the surface roughness, measuring the final transmission loss, and comprehensively evaluating the waveguide indicators, it can be ensured that during the waveguide forming process, the various performance indicators of the waveguide meet the design requirements and avoid performance problems caused by surface treatment or other factors. These measures effectively improve the quality and reliability of waveguide forming and ensure that the transmission performance and geometric accuracy of the waveguide meet the design requirements.

[0131] Finally, it should be noted that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A lightweight femtosecond pulse waveguide forming process, characterized in that: The following steps are involved: S1: providing a transparent medium material, wherein the material has good light transmittance and can withstand the action of femtosecond laser; S2: determining the path of the waveguide forming area on the material provided in step S1, and calculating the position sequence of the laser focus points based on the shape and size of the required waveguide; S3: According to the position sequence determined in step S2, adjusting the working parameters of the femtosecond laser, setting the pulse energy to ensure that a local refractive index change is generated inside the material without destroying the material structure; S4: Using the working parameters set in step S3, start the femtosecond laser, so that the laser scans point by point inside the material along the path of the waveguide forming area planned in step S2 to form an initial waveguide profile; S5: Performing quality inspection on the initial waveguide profile formed in step S4 to evaluate the transmission loss and geometric accuracy of the waveguide; S6: If the quality inspection result of step S5 does not meet the preset standard, fine-tune the working parameters of the femtosecond laser in step S3 according to the inspection result to optimize the pulse energy or repetition frequency of the femtosecond laser; S7: re-execute step S4 according to the parameters adjusted in step S6 until the transmission loss and geometric accuracy of the waveguide meet the requirements; S8: After the waveguide forming area is formed, the material is surface treated to remove tiny defects that may be caused by the laser action, thereby improving the overall performance of the waveguide; S9: Perform a final inspection on the waveguide forming area processed in step S8 to confirm that all indicators of the waveguide forming area meet the design requirements and complete the waveguide forming process.

2. A lightweight femtosecond pulse waveguide forming process according to claim 1, characterized in that: Step S1 includes the following sub-processes: S11: Select the type of transparent medium material and ensure that the refractive index n of the material meets the requirements, wherein the refractive index n should be greater than 1.4 and less than 1.6; S12: Measure the initial absorption coefficient α of the material selected in step S11 o , and calculate the absorption enhancement factor F = exp(α o L), where L is the laser penetration depth; S13: Based on the absorption enhancement factor F in step S12, adjust the output power P of the laser to minimize the thermal effect generated inside the material. The calculation formula is P adj =P initial / F, where P initial is the initial output power of the laser; S14: Using the laser output power P adjusted in step S13 adj , pre-process the selected transparent medium material.

3. A lightweight femtosecond pulse waveguide forming process according to claim 2, characterized in that: Step S2 includes the following sub-processes: S21: Determine the boundary conditions of the waveguide forming area and define the starting point P of the waveguide s and the end point P e , and the centerline path C of the waveguide; S22: Based on the path C defined in step S21, calculate the waveguide width W and height H, and determine the shape of the waveguide cross section; S23: Using the shape of the waveguide cross section determined in step S22 and the waveguide centerline path C, calculate the laser focus position sequence S = {S1, S2, ..., S n }, where S i For each position point, it is evenly distributed along the path C with a spacing of d. The calculation formula is: Where N is the total number of focus points; S24: Optimize the position sequence S obtained in step S23, and check whether the distances between adjacent focal points are uniform. If non-uniformity is found, adjust the number of focal points N or recalculate the spacing d.

4. A lightweight femtosecond pulse waveguide forming process according to claim 3, characterized in that: Step S3 includes the following sub-processes: S31: Calculate the total number of pulses M required for waveguide forming according to the position sequence of the laser focus points determined in step S2, where M is equal to the number of focus points in the position sequence; S32: Based on the total number of pulses M calculated in step S31, estimate the energy range of a single pulse to ensure that the total energy does not exceed the damage threshold of the material. The calculation formula is: Where E th is the damage threshold energy of the material; S33: Considering the energy accumulation effect in the waveguide shaping process, adjust the energy E of a single pulse so that the energy E of a single pulse is within E min and E max The calculation formula is Where E min To ensure the minimum energy required for the refractive index change; S34: Apply the single pulse energy E determined in step S33 to the femtosecond laser, set the pulse energy parameters of the laser, and perform preliminary tests to verify whether the pulse energy can effectively produce a local refractive index change without damaging the material.

5. A lightweight femtosecond pulse waveguide forming process according to claim 4, characterized in that: Step S4 includes the following sub-processes: S41: Initializing the working parameters of the femtosecond laser according to the pulse energy E and the total number of pulses M set in step S3; S42: Based on the position sequence of the laser focal points determined in step S2, set the scanning path of the laser so that the laser scans point by point along the path, scanning one focal point each time, and calculate the total length L of the scanning path total ,in S i is the position of the i-th focal point; S43: Determine the laser scanning speed v to ensure that the laser action time at each focus point is sufficient to produce the required refractive index change. The calculation formula is: where t total is the total scan time; S44: Start the femtosecond laser, scan point by point according to the scanning speed v set in step S43 and the path set in step S42 to form an initial waveguide profile, and monitor the laser power and position deviation in real time during the scanning process.

6. A lightweight femtosecond pulse waveguide forming process according to claim 5, characterized in that: Step S5 includes the following sub-processes: S51: Use a high-precision optical microscope to perform geometric accuracy detection on the initial waveguide formed in step S4, record the deviation between the actual path of the waveguide and the designed path, the deviation in the x direction Δx and the deviation in the y direction Δy, and calculate the geometric accuracy error S52: Based on the geometric accuracy error ε detected in step S51 geom , evaluate whether the geometric accuracy of the waveguide meets the design requirements. If the error exceeds the preset threshold ε max , then it is necessary to adjust the laser scanning parameters and re-form the waveguide; S53: Use an optical spectrum analyzer to measure the transmission loss of the waveguide by inputting the optical power P in And the output optical power P out , calculate the transmission loss S54: The transmission loss L measured in step S53 is trans The transmission loss threshold L required by the design max For comparison, if the transmission loss exceeds the transmission loss threshold L max , it is necessary to optimize the laser pulse energy or scanning speed and re-form the waveguide.

7. A lightweight femtosecond pulse waveguide forming process according to claim 6, characterized in that: Step S6 includes the following sub-processes: S61: According to the geometric accuracy error ε detected in step S5 geom and transmission loss L trans , to determine whether the waveguide quality meets the preset standard. If the geometric accuracy error exceeds the threshold ε max Or the transmission loss exceeds the threshold L max , then proceed to the next step; S62: Analyze the problems of the detection results in step S5 and determine the parameters that need to be optimized. If the main problem is that the geometric accuracy error is too large, adjust the laser scanning speed v and calculate the new scanning speed S63: If the main problem is that the transmission loss is too high, adjust the laser pulse energy E and calculate the new pulse energy S64: applying the parameters adjusted in step S62 or step S63 to the femtosecond laser, and re-performing steps S4 to S5 until the waveguide quality detection result reaches a preset standard.

8. A lightweight femtosecond pulse waveguide forming process according to claim 7, characterized in that: Step S7 includes the following sub-processes: S71: Reinitialize the pulse energy E of the femtosecond laser according to the laser operating parameters adjusted in step S6 new and scanning speed v new ; S72: using the parameters set in step S71, re-execute the laser scanning process in step S4, so that the laser scans point by point inside the material along the path planned in step S2 to form a new waveguide profile; S73: After completing the scan in step S72, perform the quality inspection in step S5 again to evaluate the transmission loss L of the new waveguide. trans and geometric accuracy error ε geom ; S74: Compare the transmission loss L measured in step S73 trans and geometric accuracy error ε geom Compared with the preset standard value L max and ε max If it still does not meet the requirements, return to step S6 to continue adjusting the parameters until the waveguide quality meets the requirements.

9. A lightweight femtosecond pulse waveguide forming process according to claim 8, characterized in that: Step S8 includes the following sub-processes: S81: Use a high-resolution optical microscope to perform a detailed inspection on the surface of the material after waveguide forming, identify and mark the tiny defect areas caused by the laser action, and record them as a defect point set D; S82: Calculate the area A of each defect point based on the defect point set D identified in step S81 i and depth d i , and record these parameters; S83: Calculate the processing parameters according to the defect point parameters recorded in step S82. For chemical polishing, calculate the polishing liquid concentration C and the processing time t. The formula is C = k1·max(Ai) and t = k2·max(di), where k1 and k2 are empirical constants. S84: Apply the processing parameters determined in step S83 to process the material surface to remove defective spots, and then re-inspect the surface using an optical microscope.

10. A lightweight femtosecond pulse waveguide forming process according to claim 9, characterized in that: Step S9 includes the following sub-processes: S91: Use an optical microscope to perform a final inspection on the waveguide surface processed in step S8, and record the surface roughness parameter R, which is calculated by the formula: where h j is the height of each measuring point, h avg is the average height of all measurement points, N s is the number of measurement points; S92: Based on the roughness parameter R measured in step S91, evaluate whether the roughness of the waveguide surface meets the design requirements. If the roughness parameter exceeds a preset threshold R thresh , then it is necessary to re-perform the surface treatment in step S8; S93: Use an optical spectrum analyzer to measure the final transmission loss of the waveguide by inputting the optical power P input And the output optical power P output , calculate the final transmission loss and compare it with the data in step S5 to ensure that the transmission loss has not been deteriorated due to the surface treatment; S94: Based on the test results from step S91 to step S93, it is confirmed that all indicators of the waveguide meet the design requirements, and the waveguide forming process is completed.

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