An intelligent method and system for detecting and adjusting a fundamental light wave

Abstract

The present application belongs to the field of photoelectric precision manufacturing technology, and discloses an intelligent method for detecting and adjusting basic light waves. The whole system structure contains a detection or control unit. The relative positions of various components are obtained by the initial position and the moving distance of the components. The component position is moved by a servo motor. The light intensity or interference fringe information is received by a CCD to judge the light wave condition, and the light wave collimation state is automatically detected. The required diverging spherical wave, converging spherical wave or plane wave is obtained by adjusting the internal optical device position through a computer, and no human intervention is required. The wave surface curvature radius can be reproduced and adjusted to provide the required spherical wave or plane wave. These are all conducive to providing accurate illumination light sources for various optical systems. The analysis of the CCD interference fringes in the system, combined with the detection and control of the positions of various components, is completely analyzed and calculated by a computer program before being controlled, so as to realize the adjustment without human intervention, thereby realizing the intelligence of the instrument.

Description

Technical Field

[0001] This invention belongs to the field of optoelectronic precision manufacturing technology, and in particular relates to an intelligent method and system for detecting and regulating basic light waves. Background Technology

[0002] In optoelectronic precision manufacturing, measurement, and imaging fields, plane waves and spherical waves are the basic forms of illumination light waves. The generation, detection, and modulation of these basic light waves are crucial to the operational accuracy of the working system. Especially in imaging systems and precision measurement, measuring the radius of curvature of spherical waves is of great significance for wavefront analysis, optical system calibration, and beam quality control. Currently, commonly used methods for measuring the radius of curvature of beams include the knife-edge method and interferometry.

[0003] The knife-edge method is a scanning measurement technique based on light intensity distribution. It calculates wavefront curvature by blocking the light beam with a knife edge and recording the intensity attenuation curve. The advantages of this method are simple equipment and low cost, but its measurement accuracy is low and it heavily relies on the stability and repeatability of the mechanical scanning. The knife-edge method requires extremely high axial positioning accuracy during measurement; even small mechanical vibrations or displacement errors can lead to significant measurement deviations. Furthermore, the knife-edge method requires the light beam to have an ideal Gaussian distribution or uniform intensity, while actual spherical waves may exhibit asymmetric or distorted characteristics due to aberrations or scattering effects of the optical system, further reducing the applicability and reliability of this method.

[0004] Interferometry (such as the Mach-Zehnder interferometer) extracts wavefront curvature information by analyzing the interference fringes between the measured spherical or plane wave and a standard plane wave. Measuring the radius of curvature of a spherical wave using interferometry requires a standard plane wave as a reference wavefront. However, obtaining an ideal plane wave necessitates a precisely calibrated collimating optical system to provide the plane wave as a reference, significantly increasing the complexity of the measurement system. High-precision optical components and complex calibration devices are required, resulting in high cost and cumbersome operation. In particular, when measuring spherical waves with large radii of curvature, an additional auxiliary beam expander system is needed to match the dynamic range of the interferometer. These limitations pose numerous challenges to traditional interferometry in practical engineering applications.

[0005] Lens focusing is a simple and commonly used laboratory method for generating or detecting spherical or plane waves. It utilizes the converging effect of a lens on light waves emitted from a point source and the parallel propagation of plane waves to determine the radius of the spherical wave and thus whether a plane wave has formed. Specifically, a lens with a known focal length and an observation screen are placed behind the point source, with the lens positioned at one focal length of the point source. Behind the lens, a parallel plane wave should be observed. However, due to errors in lens focal length measurement, the wave behind the lens may not be perfectly collimated. To improve the accuracy of the plane wave measurement, the observation screen is moved back and forth along the axis. The size of the light spot on the screen changes with distance. If the spot diameter increases as the screen moves away from the lens, it is a diverging spherical wave; otherwise, it is a converging spherical wave. If the spot size does not change with the distance from the screen, the wave behind the lens can be considered a plane wave, and the radius of curvature of the spherical wave is equal to the focal length of the lens. This method is extremely simple to use, requiring no standard plane wave interference and almost no additional instruments. However, it suffers from poor accuracy in generating plane waves, wastes significant human resources, and hinders the automation and intelligentization of light source generation and detection systems.

[0006] Based on existing technologies, their common shortcomings are mainly reflected in the following three aspects: First, existing technologies often require the use of standard plane waves as a reference to detect plane waves or measure the radius of curvature of spherical wave beams, which increases the experimental cost to a certain extent. Second, existing technologies lack automated and integrated operation processes, and manual operation is complex and inefficient. It is difficult to meet the detection requirements of high-frequency experiments due to the need for readjustment according to different experimental environments, which seriously restricts the development of large-scale precision experiments.

[0007] Therefore, overcoming the above problems and improving the accuracy, reliability, automation, and intelligence of experiments has become a key issue that urgently needs to be addressed in the field of laboratory optical analysis.

[0008] Based on the above analysis, the problems and shortcomings of the existing technology are as follows:

[0009] (1) Existing technologies for detecting plane waves or measuring the radius of curvature of spherical wave beams often require the use of a standard plane wave as a reference, which increases the experimental cost to some extent.

[0010] (2) Existing technologies lack automated and integrated operation processes. Manual operation is complex and inefficient. It requires readjustment according to different experimental environments, which makes it difficult to meet the detection needs of high-frequency experiments and seriously restricts the development of large-scale precision experiments. Summary of the Invention

[0011] In view of the problems existing in the prior art, the present invention provides an intelligent method for detecting and regulating basic light waves.

[0012] This invention is implemented as follows: an intelligent method for detecting and modulating fundamental light waves includes:

[0013] S101, Optical path initialization: Place the laser, attenuator, microscope objective pinhole assembly, thin convex lens, aperture stop, Fresnel double prism, and CCD sequentially on the optical slide rail. Adjust all components to be coaxial and at the same height. Connect the servo motors of the three-dimensional optical base of the thin convex lens, Fresnel double prism, and CCD to the computer. Connect the CCD to the computer and turn on the power to the computer and laser.

[0014] S102, Microscope objective pinhole assembly adjustment: Computer-controlled servo motors control the thin convex lens and Fresnel biprism to lower their height so as not to affect the light spot illuminating the CCD, and to bring them as close as possible to the CCD base as possible to the microscope objective pinhole assembly; Computer-controlled servo motors make minute movements of the microscope objective pinhole assembly in the overall up, down, left, and right directions, so that the CCD receives the laser spot, calculates its variance to the minimum, and ensures that it is coaxial with the laser beam to generate a good point light source for the next adjustment;

[0015] S103, Basic light wave generation: The computer program controls the raising of the collimating lens, Fresnel double prism, and CCD to a coaxial height, and controls the three to move backward by a calculated distance to generate basic spherical waves or plane waves, and records the relative position information.

[0016] S104, Basic Light Wave Detection: The computer program receives the CCD signal, acquires and analyzes the interference fringes, calculates the fringe width, and determines whether the light wave is the required plane wave or a converging and diverging spherical wave. If there is an error, the front and back positions of the lens are slightly adjusted until the required light wave is acquired. If the CCD does not receive the interference fringes, the position parameter settings of the Fresnel double prism and the CCD are changed until interference fringes appear.

[0017] S105, Use of illumination light waves: After the basic light wave is detected and qualified, the computer program controls the servo motor to lower the height of the Fresnel double prism and CCD so as not to affect the propagation of the beam, and provide the required spherical wave or plane wave to the subsequent information processing system.

[0018] Furthermore, the coaxial assembly of the microscope objective adjustment pinholes specifically includes:

[0019] The formula for calculating the image mean μ is shown in (1).

[0020]

[0021] W and H are the width and height of the image, respectively. N = W × H is the total number of pixels, and I(x,y) is the light intensity distribution received on the CCD. If the optical paths are coaxial, the light spot energy is concentrated, the mean is high, and the variance is low. If the mean is too low, the variance is large, and the image is not in a coaxial state.

[0022] Calculate the image variance (σ)2 The formula for (2) is shown in (2).

[0023]

[0024] Furthermore, the generation of the basic light wave specifically includes:

[0025] Imaging formula of a thin convex lens

[0026]

[0027] Calculate the distance d2 from the point source image to the convex lens; in equation (3), f represents the focal length of the convex lens; d2 is a very important parameter for the spherical wave behind the lens; based on the position of the lens and the specific value of d2, the propagation of the spherical wave behind the lens can be determined, and the position of the center of the spherical wave can be obtained.

[0028] Furthermore, the detection of the basic light wave specifically includes:

[0029] A Fresnel biprism is formed by connecting the bases of two right-angled prisms with very small apex angles (around 0.5°). When the Fresnel biprism is raised, the diverging spherical waves generated by a point light source are converged by a lens into plane waves or other diverging or converging spherical waves with different radii of curvature. These are then split and refracted by the Fresnel biprism into upper and lower wavefronts that refract in opposite directions, splitting the light emitted from light source S0 into two coherent beams. Interference occurs in their overlapping region. The image point S of the lens is then imaged again by the biprism into two virtual light sources S1 and S2, each forming spherical waves that interfere. The spacing Δx between two adjacent interference fringes in the corresponding interference pattern is...

[0030]

[0031] In the formula, a is the distance between the point image S and the biprism, d is the distance between the two light source images S1 and S2 formed by the biprism, and b is the distance between the biprism and the CCD. These quantities determine the interference area, the spacing of the interference fringes, the clarity of the interference fringes, etc.

[0032] Let the refractive index of the Fresnel biprism be n, the apex angle be θ, and the incident angle be i. If the parameters are chosen to satisfy the condition that both θ and i are very small, then the deflection angle α ≈ θ(n-1). From this approximation, we can obtain...

[0033] d=2aθ(n-1) (5)

[0034] Substituting formula (5) into formula (4), we can easily obtain the formula for the fringe spacing Δx.

[0035]

[0036] When d1 < f, the point light source generates a partially collimated diverging spherical wave after passing through the thin convex lens, forming a virtual image in the opposite direction of the light source propagation. At this time, it can be approximately regarded as a point light source starting from the virtual image points S1 and S2 of the lens directly irradiating on the Fresnel biprism; if c represents the distance from the lens to the biprism, at this time the distances from the two light source images S1 and S2 formed by the biprism to the biprism are a = c + d2, and equation (6) can be written as

[0037]

[0038] After arrangement, it can be obtained that

[0039]

[0040] to calculate the distances from the virtual images S1 and S2 of the lens to the lens;

[0041] The positions of the lens, biprism, and CCD can be obtained by a computer program, and b is a known quantity; the value of c can be determined by the initial measurement value c0 and the moving distance Δc of the lens, that is, c = c0 + Δc; the fringe spacing Δx is also obtained from the interference pattern processed by the computer for the CCD. For a definite biprism, 2θ(n - 1) is a definite parameter; it can be seen that using equation (8) can calculate d2 and obtain the parameters of the light wave after the lens;

[0042] When d1 > f and d2 < c, at this time the light source generates a converging spherical wave after passing through the lens. The converging spherical wave will converge at a distance d2 behind the lens (between the lens and the biprism), but after being deflected by the biprism, two virtual light sources are formed. Then the distance from the virtual light sources of the biprism to the biprism is a = c - d2, and the fringe spacing formula becomes

[0043]

[0044] After arrangement, it is obtained that

[0045]

[0046] When d1 > f and d2 > (b + c), at this time the light source generates a converging spherical wave after passing through the lens. The converging spherical wave will converge behind the CCD, and after being deflected by the biprism, two virtual light sources are formed. Then the distance from the virtual light sources of the biprism to the biprism is a = d2 - c, and the fringe spacing formula becomes

[0047]

[0048] It should be noted that when d1 > f and c < d2 < b + c, the two light beams behind the biprism cannot be superimposed, and no interference fringes are generated; at this time, the CCD should be moved to reduce b so that the CCD is in the interference region;

[0049] When d1 = f, it is equivalent to d2 being at infinity, and the fundamental light wave generated by the lens is a plane wave. When the plane wave is incident, the double prism splits the wavefront into two plane waves with an included angle of 2δ. The interference fringes are determined by the included angle 2θ(n-1) (twice the deflection angle) between the two plane waves. The expression for the fringe spacing Δx at this time is:

[0050]

[0051] Furthermore, the use of the basic light wave specifically includes: lowering the height of the Fresnel biprism and CCD to allow the light beam to enter the optical information processing system and provide illumination for the system; if it is necessary to change the wavefront curvature radius of the basic light wave during processing, the Fresnel biprism and CCD can be raised, the positions of the lens, Fresnel biprism, and CCD can be adjusted according to preset parameters, the light wave parameters can be detected, and if the conditions are met, the height of the Fresnel biprism and CCD can be lowered to provide a new illumination source for the system.

[0052] Another object of the present invention is to provide an intelligent system for detecting and modulating fundamental light waves, comprising:

[0053] The system includes components such as a laser, attenuator, microscope objective pinhole assembly, collimating lens (thin convex lens), aperture stop, Fresnel biprism, and CCD. The laser emits laser light, the attenuator attenuates the laser light to prevent excessive laser light from damaging subsequent optical components, the microscope objective pinhole assembly focuses and filters the laser light to generate a high-quality point light source, the collimating lens adjusts the radius of curvature of the spherical wave, the aperture stop controls the size of the light spot, the Fresnel biprism causes the beam to self-interfere, and the CCD collects data and inputs it into the computer.

[0054] The microscope objective pinhole assembly is mounted on a electrically adjustable two-dimensional platform. The collimating lens, Fresnel biprism, and CCD are mounted on an electrically adjustable platform that can be moved along a guide rail by a servo motor. The servo motors moving the platform along the guide rail are connected to control the up, down, left, right, forward, and backward movements of each component. In the device, the slide, three-dimensional slide, support rod, optical bench, and guide rail are used for coaxial fine-tuning of each optical component to ensure optical path collimation and system stability. After the entire device is adjusted for height and coaxiality, the laser emitted from the laser first passes through an attenuator to reduce its intensity, then passes through the microscope objective for focusing and pinhole filtering to eliminate stray light, and then passes through a thin convex lens for collimation. Next, the collimated laser beam passes through an aperture stop to control the beam diameter and enters the Fresnel biprism, where it is split into two coherent beams to produce interference. The interference pattern is received and recorded by the CCD.

[0055] In this optical experimental system, a servo motor is connected to the microscope objective pinhole assembly, convex lens, Fresnel double prism, and CCD base. The servo motor is linked to a computer to control these devices, forming a complete automatic feedback adjustment system. The CCD acquires interference fringe images modulated by the optical system in real time and transmits the data to the computer. The computer analyzes the beam spot or interference fringe width using image processing algorithms, compares it with preset fringe width parameters, and generates an error signal. The computer sends commands to the servo motor to precisely adjust the lifting, lowering, forward, backward, left, and right positions of the components. The encoder built into the servo motor provides real-time feedback of the actual position information, forming a closed-loop control to ensure precise control of the beam wavefront.

[0056] Another object of the present invention is to provide a computer device including a memory and a processor, the memory storing a computer program that, when executed by the processor, causes the processor to perform the steps of the intelligent method for detecting and modulating a basic light wave.

[0057] Another object of the present invention is to provide a computer-readable storage medium storing a computer program that, when executed by a processor, causes the processor to perform the steps of the intelligent method for detecting and modulating a basic light wave.

[0058] Another objective of this invention is to provide an information data processing terminal for implementing the intelligent system for detecting and adjusting basic light waves.

[0059] Based on the above technical solutions and the technical problems solved, please analyze the advantages and positive effects of the technical solution to be protected by this invention from the following aspects:

[0060] First, addressing the technical problems existing in the prior art and the difficulty in solving them, this paper closely analyzes, in conjunction with the technical solution to be protected by this invention and the results and data obtained during the research and development process, how the technical solution of this invention solves the technical problems, and the inventive technical effects brought about by solving these problems. The specific description is as follows:

[0061] 1. Traditional techniques require interference between the light wave to be tested and a standard plane wave to generate interference fringes for detecting plane or spherical waves. The proposed design eliminates the need for a standard plane wave interference reference. Instead, it utilizes a Fresnel double prism to generate self-interference, obtaining interference fringes to detect both plane and spherical waves. Unlike experiments where the collimation of spherical waves is determined by observing the spot size, this design eliminates the need to move the CCD, relying instead on the received interference fringes for judgment, saving time and space and improving detection accuracy. Furthermore, it allows for online detection or, as needed, online adjustment of the spherical wave's radius of curvature during experiments, instantly obtaining the required spherical or plane wave source.

[0062] 2. The system design is simple in structure, and the cost of adding some optical components is low. Compared with the traditional methods of obtaining illumination sources in photoelectric detection systems, this system only adds a Fresnel double prism and components for interferometric detection, analysis, and component position control, achieving self-interference. This improves the automation and accuracy of the illumination system detection without significantly increasing experimental costs.

[0063] 3. The entire system structure includes detection or control units. The relative positions of each component are obtained based on the initial position and the component's movement distance. Servo motors move the components, and a CCD receives light intensity or interference fringe information to determine the light wave's condition, automatically detecting the collimation state. The computer adjusts the positions of internal optical components, obtaining the desired diverging spherical wave, converging spherical wave, or plane wave without human intervention. It can reproduce and adjust the wavefront curvature radius to provide the required spherical or plane wave. All of these features facilitate providing accurate illumination sources for various optical systems.

[0064] 4. The analysis of CCD interference fringes within the system, combined with the detection and control of the positions of various components, is entirely analyzed and calculated by a computer program before control, achieving adjustment without human intervention and realizing the intelligence of the instrument.

[0065] 5. High precision, stable and reliable. By controlling the position of the moving lens or biprism and CCD through computer control, it can be ensured that the CCD is within the area where interference fringes appear, i.e., within the interference domain.

[0066] Secondly, as supplementary evidence of the inventive step of the claims of this invention, it is also reflected in the following important aspects:

[0067] (1) The expected benefits and commercial value of the technical solution of this invention after transformation are as follows:

[0068] Traditional interferometry requires a precise collimation system to provide a standard plane wave. This invention adds only a single Fresnel double prism, replacing the standard reference wave with self-interference, thus saving hardware costs; an automated system (servo motor + CCD + computer closed-loop control) replaces manual adjustment; the original text points out that the lens focusing method requires "moving the observation screen back and forth to observe the changes in the light spot" (background technology), which is time-consuming and has low accuracy; this invention greatly improves the adjustment speed by analyzing interference fringes in real time (S104).

[0069] (2) The technical solution of the present invention overcomes technical bias:

[0070] Firstly, at the level of detection principle, traditional technologies generally believe that high-precision optical wave detection must rely on a standard reference wavefront or a mechanical scanning device. This invention, through an innovative design of Fresnel double-prism beam splitting self-interference, achieves a static detection method that requires no reference wavefront and does not rely on mechanically moving parts. This design completely eliminates the dependence of traditional interferometers on standard plane waves, while overcoming the inherent stability defects of mechanical scanning techniques such as the knife-edge method.

[0071] Secondly, regarding measurement methods, existing technologies typically require direct measurement of optical path geometric parameters to obtain the radius of curvature. This invention creatively establishes an indirect measurement model based on interference fringe analysis, which can accurately derive the wavefront curvature using the optical properties of a double prism and system position parameters, breaking through the dependence of traditional methods on direct ranging. This innovation effectively solves the technical challenge of accurately measuring geometric parameters in minute spaces.

[0072] Finally, in terms of system implementation, this invention breaks with the traditional understanding that "high-precision detection must employ complex optical systems." By combining a simple optical element, the Fresnel biprism, with an intelligent control system, a detection platform with a concise structure but superior performance is constructed. This design provides a new technical approach for simplifying optical detection equipment. Attached Figure Description

[0073] Figure 1 This is a flowchart of an intelligent method for detecting and adjusting basic light waves provided in an embodiment of the present invention.

[0074] Figure 2 This is a diagram of the basic optical wave experimental element for detection and adjustment provided in an embodiment of the present invention.

[0075] Figure 3 This is a diagram of a device for detecting and adjusting basic light waves provided in an embodiment of the present invention.

[0076] Figure 4 This is a schematic diagram illustrating the principle of generating and detecting plane waves and spherical waves provided in an embodiment of the present invention.

[0077] Figure 5 These are the intensity maps and variances recorded by the CCD for fine-tuning the pinhole combination position of the microscope objective provided in the embodiments of the present invention; (a) intensity map when completely coaxial; (b) intensity map when the microscope objective and pinhole are deviated downwards; (c) intensity map when the microscope objective and pinhole are deviated upwards; (d) intensity map when the microscope objective and pinhole are deviated to the left; (e) intensity map when the microscope objective and pinhole are deviated to the right.

[0078] Figure 6 These are the interferograms and normalized spectrum diagrams for d1 < f and d1 = f provided in the embodiments of the present invention.

[0079] Figure 7These are the interferograms and normalized spectrum diagrams provided in the embodiments of the present invention when d1 > f and d2 > b + c.

[0080] Figure 8 This is a diagram showing the correspondence between Δx and d1 provided in an embodiment of the present invention.

[0081] Figure 9 This is an experimental optical path diagram of a digital holographic imaging system for generating and detecting basic light waves in a reference optical path, provided in an embodiment of the present invention.

[0082] Figure 10 These are holographic reconstruction images of a resolution plate under different reference lights provided in the embodiments of the present invention; (a) holographic reconstruction image with spherical wave as reference light; (b) holographic reconstruction image with plane wave as reference light.

[0083] Figure 2 In the middle: 1. Laser; 2. Attenuator; 3. Microscope objective; 4. Pinhole; 5. Thin convex lens; 6. Aperture stop; 7. Fresnel double prism; 8. CCD; 9. Slide; 10. Support rod; 11. Three-dimensional slide; 12. Optical bench; 13. Guide rail. Detailed Implementation

[0084] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0085] like Figure 1 As shown, an intelligent method for detecting and modulating fundamental light waves provided by an embodiment of the present invention includes the following steps:

[0086] S101, Optical path initialization: Place the laser, attenuator, microscope objective pinhole assembly, thin convex lens, aperture stop, Fresnel double prism, and CCD sequentially on the optical slide rail. Adjust all components to be coaxial and at the same height. Connect the servo motors of the three-dimensional optical base of the thin convex lens, Fresnel double prism, and CCD to the computer. Connect the CCD to the computer and turn on the power to the computer and laser.

[0087] S102, Microscope objective pinhole assembly adjustment: Computer-controlled servo motors control the thin convex lens and Fresnel biprism to lower their height so as not to affect the light spot illuminating the CCD, and to bring them as close as possible to the CCD base as possible to the microscope objective pinhole assembly; Computer-controlled servo motors make minute movements of the microscope objective pinhole assembly in the overall up, down, left, and right directions, so that the CCD receives the laser spot, calculates its variance to the minimum, and ensures that it is coaxial with the laser beam to generate a good point light source for the next adjustment;

[0088] S103, Basic light wave generation: The computer program controls the raising of the collimating lens, Fresnel double prism, and CCD to a coaxial height, and controls each of the three to move backward by a calculated distance to generate basic spherical waves or plane waves, and records the relative position information.

[0089] S104, Basic Light Wave Detection: The computer program receives the CCD signal, obtains and analyzes the interference fringes, calculates the fringe width, and determines whether the light wave is the required plane wave or a converging and diverging spherical wave; if there is an error, the front and back positions of the lens are slightly adjusted until the required light wave is obtained; if the CCD does not receive the interference fringes, the position parameter settings of the Fresnel double prism and the CCD are changed until interference fringes appear.

[0090] S105, Use of illumination light waves: After the basic light wave is detected and qualified, the computer program controls the servo motor to lower the height of the Fresnel double prism and CCD so as not to affect the propagation of the beam, and provide the required spherical wave or plane wave to the subsequent information processing system.

[0091] The coaxial combination of the microscope objective adjustment pinhole provided in this embodiment of the invention specifically includes:

[0092] The formula for calculating the image mean μ is shown in (1).

[0093]

[0094] W and H are the width and height of the image, respectively. N = W × H is the total number of pixels, and I(x,y) is the light intensity distribution received on the CCD. If the optical path is coaxial, the light spot energy is concentrated, the mean is high, and the variance is low. If the mean is too low and the variance is large, it indicates that the optical path is not in a coaxial state.

[0095] The formula for calculating the image variance (σ²) is shown in (2).

[0096]

[0097] During the optical path adjustment process, the light spot needs to be centered as much as possible by adjusting the position of the microscope objective pinhole (up, down, left, and right). Simultaneously, the CCD image is observed and its statistical characteristics are analyzed. The adjustment objective is to minimize the image variance σ. 2 The goal is to minimize the concentration of light spot energy while maintaining a high mean μ (ensuring sufficient light intensity). The criterion for the optimal coaxial state is that the variance reaches a minimum and the mean remains at a high level; if the mean decreases while the variance increases, it indicates that the optical path has deviated, leading to energy loss. Based on real-time monitoring of statistical changes, the position of the microscope objective pinhole combination is adjusted by a computer and servo motors to gradually approach the optimal coaxial state.

[0098] The generation of the basic light wave provided in this embodiment of the invention specifically includes:

[0099] Figure 4 This is a schematic diagram illustrating the interference principle of a diverging spherical wave after passing through a lens and a Fresnel double prism. The laser beam emitted by the laser is focused into a point source by a microscope objective, passes through a pinhole, and becomes an ideal diverging spherical wave. After being collimated by a collimating lens, it is focused into a diverging or converging spherical wave or plane wave. If d1 is the distance from the laser beam convergence point (i.e., the pinhole position) to the lens, the imaging formula of a thin convex lens can be used.

[0100]

[0101] Calculate the distance d2 from the point source image to the convex lens. In equation (3), f represents the focal length of the convex lens. d2 is a very important parameter for the spherical wave behind the lens. Based on the position of the lens and the specific value of d2, the propagation of the spherical wave behind the lens can be determined, the position of the center of the spherical wave can be obtained, and the wave function of the spherical wave can be written. Because the range of variation of the parameter d2 is very large, especially when d1 is close to f, d2 is close to infinity and may not be measurable, especially in the already adjusted optical path. Of course, d2 can also be obtained by measuring d1 and using equation (3), but the pinhole is inside the spatial filter, making it difficult to obtain an accurate position, resulting in poor measurement accuracy and a large error in the value of d2. Directly measuring d1 or d2 will not only consume manpower and resources, but also bring a large error to the generated spherical wave. This design uses Fresnel double prism interference to determine d2, which is not only easy to automate, but also ensures its accuracy.

[0102] The detection of basic light waves provided in this embodiment of the invention specifically includes:

[0103] A Fresnel biprism is formed by connecting the bases of two right-angled prisms with very small apex angles (around 0.5°). When the Fresnel biprism is raised, the diverging spherical waves generated by a point light source are converged by a lens into plane waves or other diverging or converging spherical waves with different radii of curvature. These are then split and refracted by the Fresnel biprism into upper and lower wavefronts that refract in opposite directions, splitting the light emitted from light source S0 into two coherent beams. Interference occurs in their overlapping region. The image point S of the lens is then imaged again by the biprism into two virtual light sources S1 and S2, each forming spherical waves that interfere. The spacing Δx between two adjacent interference fringes in the corresponding interference pattern is...

[0104]

[0105] In the formula, a is the distance between the point image S and the biprism, d is the distance between the two light source images S1 and S2 formed by the biprism, and b is the distance between the biprism and the CCD. These quantities determine the interference area, the spacing of the interference fringes, the clarity of the interference fringes, etc.

[0106] Let the refractive index of the Fresnel biprism be \(n\), the apex angle be \(\theta\), and the angle of incidence be \(i\). Select parameter configurations such that both \(\theta\) and \(i\) are very small. Then the deviation angle \(\alpha\approx\theta(n - 1)\). From the approximate relationship, we have

[0107] \(d = 2a\theta(n - 1)\ (5)\)

[0108] Substitute equation (5) into equation (4), and it is easy to obtain the formula for the fringe spacing \(\Delta x\)

[0109]

[0110] When \(d_1\lt f\), the point source generates a partially collimated divergent spherical wave through the thin convex lens, forming a virtual image in the opposite direction of the light source propagation. At this time, it can be approximately regarded as a point source starting from the virtual image points \(S_1\) and \(S_2\) of the lens directly irradiating on the Fresnel biprism; if \(c\) represents the distance from the lens to the biprism, at this time the distances from the two light source images \(S_1\) and \(S_2\) formed by the biprism to the biprism are \(a = c + d_2\), and equation (6) can be written as

[0111]

[0112] After arrangement, we can get

[0113]

[0114] to calculate the distances from the virtual images \(S_1\) and \(S_2\) of the lens to the lens;

[0115] The positions of the lens, biprism, and CCD can be obtained by a computer program, and \(b\) is a known quantity; the value of \(c\) can be determined by the initial measurement value \(c_0\) and the moving distance \(\Delta c\) of the lens, that is, \(c = c_0+\Delta c\); the fringe spacing \(\Delta x\) is also obtained by the computer processing the interference pattern acquired by the CCD. For a definite biprism, \(2\theta(n - 1)\) is a definite parameter; it can be seen that using equation (8) can calculate \(d_2\) and obtain the parameters of the light wave after the lens;

[0116] When \(d_1\gt f\) and \(d_2\lt c\), at this time the light source generates a converging spherical wave through the lens. The converging spherical wave will converge at a distance \(d_2\) behind the lens (between the lens and the biprism), but after being deflected by the biprism, two virtual light sources are formed. Then the distance from the virtual light sources of the biprism to the biprism is \(a = c - d_2\), and the fringe spacing formula becomes

[0117]

[0118] After arrangement, we get

[0119]

[0120] When d1 > f and d2 > (b + c), at this time, the light source generates a converging spherical wave through the lens. The converging spherical wave will converge behind the CCD. After being deflected by the biprism, two virtual light sources are formed. Then, the distance from the virtual light source of the biprism to the biprism is a = d2 - c, and the fringe spacing formula becomes

[0121]

[0122] It should be noted that when d1 > f and c < d2 < b + c, the two light beams behind the biprism cannot be superimposed, so no interference fringes are generated. At this time, the CCD should be moved to reduce b so that the CCD is in the interference region.

[0123] When d1 = f, it is equivalent to d2 being at infinity, and the basic light wave generated by the lens is a plane wave. When the plane wave is incident, the biprism divides the wavefront into two plane waves with an included angle of 2δ. The interference fringes are determined by the included angle 2θ(n - 1) (twice the deviation angle) of the two plane waves. At this time, the expression of the fringe spacing Δx is

[0124]

[0125] The fringe width at this time is the critical state of the diverging spherical wave and the converging spherical wave. The interference fringes greater than and less than this width respectively correspond to the light wave behind the lens being a diverging spherical wave and a converging spherical wave, which can be used to judge whether the light wave is a diverging spherical wave or a converging spherical wave.

[0126] The change of the fringe spacing Δx has an inverse relationship with d1. Because as d1 increases, the spherical wave behind the lens gradually changes from a diverging spherical wave to a converging spherical wave when propagating to the right. After passing through the biprism, the converging included angle becomes larger, making the interference fringes denser and the fringe width smaller. That is, as d1 increases, the fringe spacing Δx decreases. If the observed fringe spacing conforms to the calculation result of formula (13), it means that the light wave in front of the biprism is a plane wave and the pinhole is at the focal point of the lens. When d1 < f, a diverging spherical wave is generated, and when d1 > f, the wave behind the lens is a converging spherical wave. By measuring the fringe spacing of the system, according to the above formula, we can not only effectively distinguish light waves with different wavefront characteristics such as plane waves and spherical waves at the numerical level, but also calculate the parameter d2 of the spherical wave according to formulas (8), (10), and (12), write its complex amplitude, so as to achieve the purpose of detection. We can also calculate d1 by combining formula (3) to obtain the position information of the pinhole.

[0127] The specific use of the basic light wave provided in this embodiment of the invention includes: lowering the Fresnel biprism and CCD to allow the light beam to enter the optical information processing system and provide illumination for the system. If it is necessary to change the wavefront curvature radius of the basic light wave during processing, the Fresnel biprism and CCD can be raised, and the positions of the lens, Fresnel biprism, and CCD can be adjusted according to the set parameters. The light wave parameters are detected, and if the conditions are met, the height of the Fresnel biprism and CCD is lowered to provide a new illumination source for the system.

[0128] To verify the effectiveness of the proposed method and system, specific experiments were conducted. The wavelength of the green laser used in the experiment was 532.2 nm. Figure 5 To obtain the spot statistics by fine-tuning the microscope objective pinhole assembly when the lens and prism are lowered and the CCD is close to the pinhole assembly of the microscope objectives, it is obvious that... Figure 5 (a) It has lower variance and higher average intensity, therefore it is chosen Figure 5 (a) The parameters of the fixed microscope objective pinhole assembly are used. The lens and biprism are raised and their movement is controlled to a certain distance.

[0129] The actual distance c from the lens to the biprism is 0.22m, the distance b from the biprism to the CCD is 0.20m, the focal length of the thin lens used is 0.13m, and the parameter θ(n-1) of the Fresnel biprism is 0.070. The distance d1 from the light source to the convex lens is set to 0.08m.

[0130] The acquired stripe image was subjected to a two-dimensional Fourier transform and centered using a MATLAB program to obtain its spectral distribution. Then, the DC component at the center of the spectrum was eliminated, and the frequency domain feature position of the stripes was determined by searching for the maximum peak point in the spectrum. Next, the distance between the peak point and the center of the spectrum was calculated, and the stripe spacing in pixels was directly calculated based on the ratio of the image size to the distance. Finally, the pixel units were converted to SI distance units using the pixel physical size parameters calibrated by the system (1 pixel = 4.65μm * 4.65μm), and the stripe spacing was measured at this point.

[0131] When d1 < f and d1 = f, the actual measured grayscale image and normalized spectrum of the interferogram are as follows: Figure 6 As shown. When d1 > f and d2 > b + c, the actual measured grayscale image and normalized spectrum of the interferogram are as follows. Figure 7 As shown.

[0132] To investigate the relationship between d1 and interference fringes, the fringe widths corresponding to multiple sets of different d1 values ​​were measured. The distance from the light source to the convex lens ranged from 0.06 m to 0.17 m, and a set of interference images was captured every 0.01 m. The curves showing the relationship between the fringe spacing Δx and d1 and the theoretical relationship are as follows: Figure 8As shown in the figure, experimental data indicate that as the distance d1 from the light source to the convex lens increases from 0.06m to 0.17m, the fringe spacing exhibits a significant decreasing trend. This trend is consistent with theoretical predictions. Within the range of d1 = 0.06m to 0.14m, the experimental data shows a high degree of agreement with the theoretical data, indicating that the measurement system has higher reliability within this range. However, within the range of d1 = 0.15m to 0.17m, there is a slight deviation between the experimental data and the theoretical value. Possible error factors include the fact that as the distance d1 from the light source to the convex lens increases, the ray deflection angle α and its tangent no longer satisfy the approximate relationship condition in the formula.

[0133] By precisely monitoring the fringe spacing, the position of the thin convex lens can be finely controlled, enabling the optical path to generate plane waves or spherical waves that meet experimental requirements. This provides an important reference light wave for applications such as optical measurement and surface topography inspection. Especially in measurement scenarios requiring specific spherical waves, the measurement distance parameters can be optimized based on the experimental results.

[0134] To address the problems existing in current plane wave and spherical wave generation and detection technologies, this invention provides a high-precision, intelligent self-detection and adjustment method for fundamental light waves that does not require a standard reference plane wave. Compared to commonly used basic devices, this method only adds a Fresnel biprism and a CCD interferometric fringe detector to achieve the generation and detection of both spherical and plane waves. The designed system uses a combination of microscope objectives with pinholes and a thin convex lens to establish the experimental optical path for generating spherical and collimated plane waves. Utilizing the beam-splitting effect of the Fresnel biprism, and by establishing a quantitative mapping relationship between the image light source dynamic positioning model and the fringe spacing, quantitative and accurate discrimination and detection of plane and spherical waves are achieved. Precise adjustment of the positions of the microscope objective pinhole combination and the thin convex lens base, etc., is achieved using MATLAB software and servo motors, realizing the automation and intelligence of standard fundamental light wave detection and adjustment.

[0135] According to such Figure 2 The system shown includes a laser 1, an attenuator 2, a combination of a microscope objective 3 and a pinhole 4, a collimating lens (thin convex lens 5), an aperture stop, a Fresnel double prism 7, and a CCD 8. The laser 1 emits laser light, the attenuator 2 attenuates the laser to prevent excessive laser intensity from damaging subsequent optical components, the combination of the microscope objective 3 and the pinhole 4 focuses and filters the laser to generate a high-quality point light source, the collimating lens adjusts the radius of curvature of the spherical wave, the aperture stop controls the spot size, the Fresnel double prism 7 causes self-interference of the beam, and the CCD 8 collects data and inputs it into a computer.

[0136] The microscope objective 3 and pinhole 4 are mounted on a electrically adjustable two-dimensional platform. The collimating lens, Fresnel biprism 7, and CCD 8 are mounted on an electrically adjustable platform that can be moved by a servo motor on a guide rail 13. The servo motors on the guide rail 13 are connected to control the up, down, left, right, forward, and backward movements of each component. In the device, the slide 9, three-dimensional slide 11, support rod 10, optical bench 12, and guide rail 13 are used for coaxial fine-tuning of each optical component to ensure optical path collimation and system stability. After the entire device is adjusted for height and coaxiality, the laser emitted from the laser 1 first passes through the attenuator 2 to reduce its intensity, then is focused by the microscope objective 3 and filtered by the pinhole 4 to eliminate stray light, and then collimated by the thin convex lens 5. Next, the collimated laser beam passes through the aperture stop 6 to control the beam diameter and enters the Fresnel biprism 7, where it is split into two coherent beams to produce interference. The interference pattern is received and recorded by the CCD 8.

[0137] like Figure 3 As shown in the optical experimental system, a servo motor is connected to the microscope objective 3 pinhole 4 assembly, a convex lens, a Fresnel biprism 7, and a CCD 8 base. The servo motor is connected to a computer to control these devices, forming a complete automatic feedback adjustment system. The CCD 8 acquires the interference fringe image modulated by the optical system in real time and transmits the data to the computer. The computer analyzes the beam spot or interference fringe width using image processing algorithms, compares it with preset fringe width parameters, and generates an error signal. The computer sends commands to the servo motor to precisely adjust the lifting, lowering, forward, backward, left, and right positions of the components. The encoder built into the servo motor provides real-time feedback of the actual position information, forming a closed-loop control to ensure precise control of the beam wavefront.

[0138] Another object of the present invention is to provide a computer device including a memory and a processor, the memory storing a computer program that, when executed by the processor, causes the processor to perform the steps of the intelligent method for detecting and modulating a basic light wave.

[0139] Another object of the present invention is to provide a computer-readable storage medium storing a computer program that, when executed by a processor, causes the processor to perform the steps of the intelligent method for detecting and modulating a basic light wave.

[0140] Another objective of this invention is to provide an information data processing terminal for implementing the intelligent system for detecting and adjusting basic light waves.

[0141] The intelligent method and system for detecting and modulating fundamental light waves provided by this invention have broad application prospects in the fields of optoelectronic precision measurement and optical imaging, mainly covering the following specific application directions:

[0142] A structured light illumination super-resolution microscopy imaging system. This invention provides a high-precision, intelligent illumination source for structured light illumination microscopy. By dynamically adjusting the position of a thin convex lens, it can generate plane wave arrays in different directions in real time, meeting the multi-angle illumination mode requirements of structured light illumination microscopy. The system employs closed-loop feedback control to ensure the phase stability of the illumination wavefront, providing a reliable light source for super-resolution imaging. In particular, this invention enables rapid switching of illumination light waves, significantly improving the imaging speed of structured light illumination microscopy, making it suitable for applications with high temporal resolution requirements, such as dynamic observation of live cells. Simultaneously, the system has an automatic calibration function, effectively eliminating the optical path offset problem caused by mechanical vibration or temperature changes in traditional methods.

[0143] This invention relates to a combined Fourier correlation recognition system. In the field of optical correlation recognition, this invention provides precisely controllable illumination waves. By adjusting the radius of curvature of the spherical wave, the input wavefront of the combined transform correlator can be optimized, improving the signal-to-noise ratio of the correlation peak and the recognition accuracy. The system's intelligent adjustment function can adapt to the needs of different recognition scenarios. The real-time monitoring and automatic adjustment capabilities of this invention ensure stable recognition performance during long-term operation, making it particularly suitable for applications requiring continuous and stable operation, such as security monitoring and target tracking. Furthermore, the system can automatically select the optimal illumination parameters according to different recognition objects, significantly improving the intelligence level of the recognition system.

[0144] This invention was introduced into a digital holographic imaging experiment to verify its effectiveness.

[0145] The optical path diagram of the digital holographic imaging experiment is as follows: Figure 9 As shown in the figure. In this experiment, a generation and detection system for the basic light wave was added to the reference optical path to perform holographic reconstruction of the resolution plate pattern. When the object light is a plane wave and the reference light wave is not a standard plane wave (i.e., a spherical wave), the system will exhibit the following during holographic reconstruction: Figure 10 (a) shows that the reconstructed holographic image has blurred edges and poor image quality. Using the basic light wave detection method proposed in this invention, the radius of curvature d2 of the spherical wave can be quickly calculated using MATLAB. Therefore, the distance d1 from the pinhole to the lens can be calculated according to the imaging formula of a convex lens. Comparing d1 with the focal length of the lens determines how the lens position should be adjusted. When the lens position is adjusted to d1 = f, the reference light is a plane wave, and the holographic reconstruction result is as follows... Figure 10 As shown in (b), the edges of the pattern are clear, and the reconstruction effect is greatly improved.

[0146] This experiment, by comparing the reconstruction results of spherical waves and plane waves in digital holographic experiments, fully verifies that the present invention can significantly improve the adjustment efficiency of experimental elements in digital holographic imaging, providing a more reliable basis for accurate phase measurement. Simultaneously, this experiment also demonstrates that the system can effectively measure the radius of curvature of spherical waves, thereby enabling precise adjustment of different fundamental light waves to meet various experimental requirements. The experimental results prove the technical advantages of the present invention and the feasibility of solving the problem of acquiring fundamental light waves.

Claims

1. An intelligent method for detecting and modulating fundamental light waves, characterized in that, Perform the following steps in sequence: Step 1: Initialize the optical path. Install the laser, attenuator, microscope objective pinhole assembly, thin convex lens, aperture stop, Fresnel double prism, and CCD sequentially on the same optical slide rail and complete the coaxial adjustment of the same height. The three-dimensional optical base of the thin convex lens, Fresnel double prism, and CCD is connected to the computer through a servo motor. Step 2: Adjustment of the microscope objective pinhole assembly. The computer drives the servo motor to lower the height of the thin convex lens and Fresnel double prism until they do not block the CCD receiving spot and are close to the microscope objective pinhole assembly. Then, the microscope objective pinhole assembly is controlled to make micro-displacement in the up, down and left and right directions. The CCD spot is collected in real time and the variance is calculated. When the variance reaches the minimum value, it is determined to be coaxial with the laser beam. Step 3: Basic light wave is generated. The computer-controlled servo motor raises the thin convex lens, Fresnel double prism, and CCD to the coaxial height and moves them backward according to the calculated distance to obtain spherical waves or plane waves and record the relative position information. Step 4: Basic light wave detection. The computer acquires the CCD interference fringes and calculates the fringe width. If there is an error between the light wave type or radius of curvature and the target value, the position of the thin convex lens is finely adjusted. If there are no interference fringes on the CCD, the Fresnel double prism and the position of the CCD are adjusted until fringes appear. Step 5: Use of illumination light waves. After the light wave parameters are qualified, the computer controls the servo motor to lower the height of the Fresnel double prism and CCD, so that the light beam enters the subsequent information processing system. Step 2, the spot evaluation, uses the mean μ and variance σ², calculated as the sum of all pixel gray values ​​divided by the total number of pixels, and the sum of the squares of the differences between all pixel gray values ​​and the mean divided by the total number of pixels, respectively. When μ is large and σ² is small, the optical path is determined to be coaxial. In step three, the position of the thin convex lens is determined by formula 1, where 1 / f equals 1 / d1 plus 1 / d2, where f is the focal length of the lens, d1 is the distance from the point source to the lens, d2 is the distance from the lens image point to the lens, and d2 is used to characterize the radius of curvature of the spherical wave behind the lens.

2. The method according to claim 1, characterized in that, In step four, the fringe spacing Δx satisfies the formula Δx equal to λ multiplied by b divided by d, where λ is the laser wavelength, b is the distance from the Fresnel double prism to the CCD, and d is the distance between the two virtual light sources formed by the double prism. The computer determines the light wave type based on Δx and makes closed-loop adjustments.

3. An intelligent system for detecting and modulating a fundamental light wave in accordance with the method of any one of claims 1 to 2, characterized in that, The system includes a laser, attenuator, microscope objective pinhole assembly, thin convex lens, aperture stop, Fresnel biprism, CCD, servo motor assembly, guide rail structure, and computer. The laser output is attenuated by the attenuator and then converged and filtered by the microscope objective pinhole assembly to form a point light source. The curvature radius is adjusted by the thin convex lens, and the spot diameter is controlled by the aperture stop before entering the Fresnel biprism to generate self-interference, which is then captured by the CCD. The computer analyzes the spot or interference fringes through the image processing module and outputs control commands to the servo motor, realizing three-dimensional pose closed-loop adjustment of the microscope objective pinhole assembly, thin convex lens, Fresnel biprism, and CCD.

4. The system according to claim 3, characterized in that, The servo motor has a built-in position encoder that forms a real-time position feedback channel with the computer, with a position resolution of no less than one micrometer.

5. The system according to claim 3, characterized in that, The computer has an image processing module for calculating the light spot mean, light spot variance, interference fringe width, and generating error signals. The error loop closing time is no more than fifty milliseconds.

6. The system according to claim 3, characterized in that, The aperture stop is mounted on an electric carriage, and the beam diameter can be adjusted under computer control to match different wavefront curvature radii.

7. A computer-readable storage medium having a computer program stored thereon, which, when loaded and executed, causes a processor to perform the steps of the method according to any one of claims 1 to 2.

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