CN114719774A - Superstructure dispersion confocal-based complex curved surface morphology measurement method and system - Google Patents
Superstructure dispersion confocal-based complex curved surface morphology measurement method and system Download PDFInfo
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- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
- G01N21/84—Systems specially adapted for particular applications
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Abstract
The invention discloses a superstructure dispersion confocal complex curved surface morphology measurement method and a superstructure dispersion confocal complex curved surface morphology measurement system. The method combines a plane superstructure with a dispersion confocal technology, provides a miniature dispersion confocal probe capable of replacing a traditional dispersion confocal lens group, has the characteristics of strong designability, small and exquisite structure, lightness and thinness, capability of realizing axial and radial dispersion simultaneously and the like, and can finish super-resolution measurement of the surface morphology of a complex curved surface or even a special-shaped structure.
Description
Technical Field
The invention relates to the technical field of ultra-precision manufacturing and measurement, in particular to a superstructure dispersion confocal complex curved surface morphology measurement method and system.
Background
With the rapid development of the precision manufacturing technology, the requirement on the shape precision of products in the high-end manufacturing fields of aerospace, ships, automobiles and the like is higher and higher, and the ultra-precision complex curved surface shape measurement technology is developed accordingly. The dispersion confocal technology utilizes the optical dispersion principle to establish the mapping relation between the optical wavelength and the distance to realize the distance measurement, and the method has the advantages of unique confocal axial response characteristic, high measurement precision and insensitivity to the inclination of a measured sample.
Chinese patent application CN109373927A discloses a color confocal three-dimensional topography measuring method and system, which uses a polychromatic light source and a dispersion mirror group to obtain axial dispersion, and uses a color camera to perform one-time imaging to obtain the measured distance, thereby realizing three-dimensional measurement of the topography of the measured surface. Chinese patent application CN111366102A discloses a refractive color confocal measuring head structure for measuring the surface morphology of an inner hole, which realizes the measurement of the morphology of the inner wall of a hole piece by arranging a rotating right-angle prism driven by a micro motor on the object side of a dispersion objective lens. However, the existing shape measurement method based on the dispersive confocal principle adopts a dispersive lens group with a complex structure, a large volume and a complex assembly process, the measurement accuracy has strong dependence on the assembly precision, the measurement on a complex curved surface is difficult to stably and flexibly carry out, and higher requirements are provided for the working environment.
The complexity of the conventional dispersive confocal lens structure severely limits the practical application value of the technology, and therefore, a light-weight and small-sized dispersive element needs to be provided to replace the conventional dispersive confocal lens group. The plane superstructure is an artificially designed sub-wavelength periodic structure, and can realize the regulation and control of the amplitude, the phase and the polarization of light by introducing a phase mutation method on an interface. According to the difference of the arrangement structure and the size parameters, the super-lens is widely applied to aspects of super-lenses, holographic imaging, stealth clothes and the like in recent years. The plane superstructure is combined with the dispersion confocal technology, the traditional dispersion confocal lens group can be replaced, the device has the remarkable advantages of small size, thinness, easiness in integration and the like, and the device can be used for measuring the appearance of the inner surface of a small hole.
Disclosure of Invention
Aiming at the defects of the prior art, the invention provides a complex curved surface morphology measurement method and system based on superstructure dispersion confocal.
The technical scheme of the invention is as follows:
a superstructure dispersion confocal-based complex curved surface morphology measurement system comprises a wide-spectrum laser light source, a transmission optical fiber, a coupler, an optical fiber collimator, a miniature dispersion confocal probe, a spectrometer, a microprocessor, a precise three-dimensional motion table and a wide-range translation table.
The light emitted by the wide-spectrum laser light source is transmitted through the transmission optical fiber and the coupler, the light is collimated into parallel light by the optical fiber collimator fixed at the end part of the transmission optical fiber, the parallel light reaches the micro dispersion confocal probe to generate spectral dispersion, the light focused on the surface of the measured object is reflected back to the spectrometer through the transmission optical fiber primary path, and the microprocessor decodes the spectral-distance mapping relation to obtain a measured value. The micro dispersion confocal probe is fixed on the precise three-dimensional motion platform and used for scanning the tested complex curved surface sample arranged on the wide-range translation platform.
Furthermore, the micro dispersion confocal probe consists of an ultrathin plane super-structure lens, a band-pass filter and a micro fixed lens barrel, wherein the ultrathin plane super-structure lens has certain collection and amplification effects on evanescent waves, so that far-field super-diffraction limit measurement can be realized. The band-pass filter is used for filtering light rays in a non-working waveband in the light source, and interference of light rays outside the working waveband on a measurement process is avoided. The aperture of the micro dispersion confocal probe is less than 1mm, and the micro dispersion confocal probe can be inserted into a porous structure with a large depth-diameter ratio and even a special-shaped structure to measure the internal appearance.
Furthermore, the ultra-thin planar super-structure lens can change incident planar light into axial dispersion light with different wavelengths converged at different focal length positions along the optical axis direction, the aperture of the ultra-thin planar super-structure lens is 50-200 μm, the dispersion range delta f of the ultra-thin planar super-structure lens is determined by the aperture of the ultra-thin planar super-structure lens and the manipulation degree of the nano-structure units on phase dispersion, the customized design is carried out according to the linear dispersion rule within the limit, and the corresponding numerical aperture is designed to be 0.02-0.8.
Furthermore, the ultra-thin planar super-structure lens can realize customized regulation and control of the wavefront of light by designing the geometric shape and the periodic arrangement mode of the nano-structure units, focuses light rays with different wavelengths along the optical axis direction and generates linear dispersion.
The nano-structure unit on the ultra-thin plane ultra-structure lens in the micro dispersion confocal probe can be designed into a cylindrical structure, a square structure and various shapes and structures formed by combining the cylindrical structure and the square structure. Each type of nanostructure unit structure needs to have more than two dimensional regulation degrees of freedom to meet the design requirement for generating linear dispersion, the spacing between units is 0.1-2 μm, and the unit height is 0.2-4 μm.
Furthermore, the nanostructure units on the ultrathin planar super-structured lens are made of metal materials or dielectric materials with high refractive index and low loss in working wave bands.
Furthermore, the micro dispersion confocal probe can change the original axial direction of confocal light into radial propagation by adding a right-angle prism or changing the inclination angle of the ultrathin plane super-structured lens and the structure and arrangement of the nano units thereof, thereby realizing radial dispersion confocal and obtaining a lateral measurement value.
Further, the microprocessor is used for performing data analysis and decoding on the spectrum signal obtained by the spectrometer, and calculating to obtain a distance measurement value.
A superstructure dispersion confocal-based complex curved surface morphology measurement method comprises the following steps:
s1: the spectrum which is uniformly distributed in the working frequency interval is generated by the wide-spectrum laser light source, so that the influence of the light source characteristics on the measurement precision of the sensor is reduced;
s2: light emitted by the wide-spectrum laser light source enters the micro dispersion confocal probe through the transmission optical fiber, the coupler and the optical fiber collimator to generate axial spectral dispersion; the light is collimated into parallel light by the optical fiber collimator, and then the ultrathin plane super-structured lens in the micro dispersion confocal probe forms continuously distributed focusing light spots with different wavelengths on an optical axis by using the parallel light, namely axial position dispersion;
s3: when the complex curved surface to be measured is positioned in the spectral dispersion measurement range, light spots focused on the complex curved surface to be measured and with specific wavelength lambda are reflected and enter a spectrometer, light with other wavelengths cannot be focused and only can form diffuse spots on the surface, and the reflected light intensity is extremely weak due to the large size and the energy dispersion of the defocused light spots;
s4: extracting a return light spectrum signal obtained by a spectrometer through a microprocessor, carrying out data analysis and decoding on the spectrum signal, and establishing a mapping relation between a spectrum peak and a distance so as to obtain a distance measurement result;
s5: a precise three-dimensional motion table drives a micro dispersion confocal probe fixed on the precise three-dimensional motion table to scan local three-dimensional topography characteristics of a complex curved surface;
s6: the method comprises the steps of arranging a tested complex curved surface sample on a large-range translation table, and setting a scanning path of the large-range translation table according to a scanning interval of a precise three-dimensional motion table so as to realize global scanning of large-area complex curved surface appearance.
Furthermore, the measurement type also comprises the thickness of the ultrathin transparent material, compensation modeling analysis is carried out on data acquired by the spectrometer according to the basic principle of geometric optics by utilizing the refractive index parameter of the ultrathin transparent material, and the thickness of the ultrathin transparent material is obtained after calculation by the microprocessor.
Furthermore, the measurement type also comprises the bottom surface and side wall appearance of the hole-shaped and special-shaped structure with large depth-diameter ratio; the aperture of the micro dispersion confocal probe is only in the sub-millimeter level, so that the micro dispersion confocal probe can penetrate into a micro hole-shaped structure with a large depth-diameter ratio, and the bottom surface and the side wall of the hole can be scanned by using two measurement modes of axial dispersion and radial dispersion of the micro dispersion confocal probe respectively to obtain the three-dimensional appearance inside the hole; and axial and radial dispersion can be simultaneously realized in one miniature probe through the beam splitter prism, and the shape in the hole can be obtained through single scanning.
Furthermore, the transverse resolution of the micro-dispersion confocal probe can break through the characteristic of the traditional optical diffraction limit, and the method can be used for detecting the micro-defects on the surface of an ultra-smooth material.
The beneficial effects of the invention are as follows:
1) the miniature dispersive confocal probe can replace a traditional dispersive confocal lens group, is high in designability, convenient to optimize, simple and thin in structure and easy to integrate.
2) The micro dispersion confocal probe can be conveniently designed into an axial dispersion mode and a radial dispersion mode, and can realize super-resolution measurement of the surface morphology of complex and even special-shaped structures such as a porous structure with small aperture and high depth-diameter ratio by utilizing the characteristic of small size.
3) Through adjusting the coarse positioning measuring point of the wide-range translation stage, the precise measurement can be carried out on the local three-dimensional appearance of the complex curved surface by matching with the precise three-dimensional motion stage, and the global scanning of the complex curved surface can be realized by moving the wide-range translation stage.
Drawings
FIG. 1 is a schematic diagram of the system of the present invention.
FIG. 2 is a schematic diagram of chromatic dispersion confocal structure of the micro-chromatic dispersion confocal probe of the present invention.
FIG. 3 is a schematic diagram of the dispersion curve of the micro-dispersive confocal probe of the present invention.
FIG. 4 is a schematic diagram of the shape of the nanostructure element of the ultrathin planar super-structured lens of the present invention.
Fig. 5 is a schematic diagram of two radial dispersion schemes of a microdispersion confocal probe of the invention.
FIG. 6 is a schematic view of the measurement of the internal morphology of the high depth-to-diameter ratio hole-like structure of the micro-dispersion confocal probe of the invention.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more clear, the following detailed description is made with reference to the accompanying drawings and examples. It should be understood, however, that the examples specifically described herein are for the purpose of illustration only and are not intended to limit the scope of the present invention in any way.
The invention discloses a superstructure dispersion confocal-based complex curved surface morphology measurement system, which comprises a wide-spectrum laser light source 1, a transmission optical fiber and coupler 2, an optical fiber collimator 3, a micro dispersion confocal probe 6, a spectrometer 4, a microprocessor 5, a precise three-dimensional motion platform 7 and a wide-range translation platform 8, as shown in figure 1.
The light emitted by the wide-spectrum laser light source 1 is transmitted through the transmission optical fiber and the coupler 2, the light is collimated into parallel light by the optical fiber collimator 3 fixed at the end part of the transmission optical fiber, the parallel light reaches the micro dispersion confocal probe 6 to generate spectral dispersion, the light focused on the surface of a measured object is reflected back to the spectrometer 4 through the transmission optical fiber primary path, and the microprocessor 5 decodes the spectral-distance mapping relation to obtain a measured value. The micro dispersion confocal probe 6 is fixed on a precise three-dimensional motion platform 7 and is used for scanning a tested complex curved surface sample arranged on a wide-range translation platform 8.
The micro dispersion confocal probe 6 consists of an ultrathin plane super-structure lens 9, a band-pass filter and a micro fixed lens barrel, wherein the ultrathin plane super-structure lens 9 has certain collection and amplification effects on evanescent waves, so that far-field super-diffraction limit measurement can be realized. The band-pass filter is used for filtering light rays in a non-working waveband in the light source, and interference of light rays outside the working waveband on a measurement process is avoided. FIG. 3 is a schematic diagram of the dispersion curve of the micro-dispersive confocal probe of the present invention.
The ultra-thin plane super-structure lens 9 can change incident plane light into axial dispersion light with different wavelengths converged at different focal length positions along the optical axis direction, the aperture of the ultra-thin plane super-structure lens is 50-200 mu m, the dispersion range delta f of the ultra-thin plane super-structure lens is determined by the aperture of the ultra-thin plane super-structure lens and the manipulation degree of a nano-structure unit on phase dispersion, the customized design is carried out according to the linear dispersion rule within the limit, and the corresponding numerical aperture is designed to be 0.02-0.8.
The ultra-thin planar super-structure lens 9 can realize customized regulation and control of light wave front by designing the geometric shape and the periodic arrangement mode of the nano-structure units, focuses light rays with different wavelengths along the optical axis direction and generates linear dispersion, and has the advantage of consistent measurement sensitivity at different positions in a measuring range compared with the traditional nonlinear dispersion confocal lens.
The nano-structure unit on the ultra-thin plane ultra-structure lens 9 in the micro dispersion confocal probe 6 can be designed into a cylindrical structure, a square structure and various shape structures combined by the cylindrical structure and the square structure. Each type of nanostructure unit structure needs to have more than two dimensional regulation degrees of freedom to meet the design requirement for generating linear dispersion, the spacing between units is 0.1-2 μm, and the unit height is 0.2-4 μm.
The material of the nanostructure unit on the ultrathin plane metamaterial lens can be selected from metal materials represented by gold or dielectric materials represented by Si and Ge with high refractive index and low loss in working wave bands.
The micro dispersion confocal probe 6 can change the original axial direction of confocal light into radial propagation by adding a right-angle prism or changing the inclination angle of the ultrathin plane super-structured lens 9 and the structure and arrangement of nano units thereof, thereby realizing radial dispersion confocal and obtaining a lateral measurement value.
Fig. 5 is a schematic diagram of two radial dispersion schemes of a microdispersion confocal probe of the invention.
The aperture of the micro dispersion confocal probe 6 is less than 1mm, and the micro dispersion confocal probe can be inserted into a porous structure with a large depth-diameter ratio and even a special-shaped structure to measure the internal appearance.
And the microprocessor 5 is used for carrying out data analysis and decoding on the spectrum signal obtained by the spectrometer 4 and calculating to obtain a distance measurement value.
The precise three-dimensional motion platform 7 can drive the micro dispersion confocal probe fixed on the precise three-dimensional motion platform to scan local three-dimensional topography characteristics. Meanwhile, the tested complex curved surface sample is arranged on a wide-range translation stage 8, so that the universal scanning of large-area complex curved surface morphology is realized by matching with a precise three-dimensional motion stage 7.
A superstructure dispersion confocal-based complex curved surface morphology measurement method comprises the following steps:
s1: the spectrum which is uniformly distributed in the working frequency interval is generated by the wide-spectrum laser light source 1, so that the influence of the light source characteristics on the measurement precision of the sensor is reduced;
s2: light emitted by the wide-spectrum laser light source 1 enters the micro-dispersion confocal probe 6 through the transmission optical fiber, the coupler 2 and the optical fiber collimator 3 to generate axial spectral dispersion. The light is collimated into parallel light by the optical fiber collimator 3, and then the ultrathin plane super-structure lens 9 in the micro-dispersion confocal probe 6 forms continuously distributed focusing light spots with different wavelengths on an optical axis by using the parallel light, namely, axial position dispersion;
s3: when the complex curved surface to be measured is positioned in the spectral dispersion measurement range, light spots focused on the complex curved surface to be measured and with specific wavelength lambda are reflected and enter the spectrometer 4, light with other wavelengths cannot be focused and only can form diffuse spots on the surface, and the reflected light intensity is extremely weak due to the large size and the energy dispersion of the defocused light spots;
s4: extracting a return light spectrum signal obtained by a spectrometer through a microprocessor 5, carrying out data analysis and decoding on the spectrum signal, and establishing a mapping relation between a spectrum peak and a distance so as to obtain a distance measurement result;
s5: the precise three-dimensional motion table 7 drives the micro dispersion confocal probe 6 fixed on the precise three-dimensional motion table to scan the local three-dimensional topography characteristics of the complex curved surface;
s6: and arranging the tested complex curved surface sample on the wide-range translation stage 8, and setting a scanning path of the wide-range translation stage 8 according to a scanning interval of the precise three-dimensional motion stage 7 so as to realize global scanning of the large-area complex curved surface morphology.
As a preferred embodiment, the measurement type further includes the thickness of the ultrathin transparent material, compensation modeling analysis is performed on data acquired by the spectrometer according to the basic principle of geometric optics by using the refractive index parameter of the ultrathin transparent material, and the thickness of the ultrathin transparent material is obtained through calculation by the microprocessor.
As a preferred embodiment, the measurement types also comprise the bottom surface and side wall appearances of the hole-shaped and special-shaped structures with large depth-diameter ratio. As shown in fig. 6, the aperture of the micro-dispersion confocal probe is only in the sub-millimeter order, and the micro-dispersion confocal probe can penetrate into a micro-hole structure with a large depth-diameter ratio, and the bottom surface and the side wall of the hole can be scanned to obtain the three-dimensional topography of the inside of the hole by using two measurement modes, namely, the axial dispersion (fig. 6a) and the radial dispersion (fig. 6b) of the micro-dispersion confocal probe. In addition, the axial and radial dispersion can be realized in one miniature probe by means of the beam splitter prism, and the shape in the hole can be obtained by single scanning.
As a preferred implementation mode, the transverse resolution of the micro-dispersion confocal probe can break through the traditional optical diffraction limit, and the micro-dispersion confocal probe can be used for detecting micro defects on the surface of an ultra-smooth material.
The design method for the ultra-thin planar super-structured lens 9 is further explained below.
After parallel light with the wavelength of lambda is incident into the ultrathin plane super-structured lens, focusing is carried out at a focus f, and an abrupt phase generated at the center of the lens is assumed
r is the distance between each nanostructure unit on the ultra-thin plane super-structure lens and the lens central point, and the sudden change phase of the lens along the radius direction is as follows:
the plane wave thus incident can exit in the form of a convergent spherical wave and be focused at the focal length f. Based on this principle, in the case where linear dispersion is satisfied (i.e., Δ f ═ k Δ λ, k denotes axial dispersion ratio), it is derived that the condition of abrupt phase at a distance r from the center of the lens when generating axial linear dispersion for a complex-color plane light is:
and designing a nano-structure unit meeting the requirement of wide-spectrum abrupt phase response in the formula by using an FDTD algorithm, and determining an optimal nano-structure unit arrangement mode from a nano-structure unit database by using a genetic algorithm or a particle swarm algorithm, so that the ultra-thin planar super-structure lens generates linear dispersion on the premise of ensuring high transmission. As shown in fig. 2, after collimated broad-spectrum parallel light passes through the ultrathin planar super-structured lens, Δ f dispersion is generated along the axial direction, the corresponding wavelength range is Δ λ, and under the condition that the wavelength range of incident light is fixed, the larger the axial dispersion ratio k is, the larger the generated axial position dispersion Δ f is, and the larger the measurement range is. Further, the nanostructure elements shown in fig. 4 demonstrate several possible geometries for ultra-thin planar super-structured lenses that may be used in the present invention.
The above-mentioned embodiments are merely illustrative of the technical concepts and features of the present invention, and are intended to enable those skilled in the art to understand the contents of the present invention and implement the present invention, and not to limit the scope of the present invention. All equivalent changes and modifications made according to the spirit of the present invention should be covered within the protection scope of the present invention.
Claims (10)
1. A superstructure dispersion confocal-based complex curved surface morphology measurement system is characterized by comprising a wide-spectrum laser light source, a transmission optical fiber, a coupler, an optical fiber collimator, a miniature dispersion confocal probe, a spectrometer, a microprocessor, a precise three-dimensional motion platform and a wide-range translation platform;
the light emitted by the wide-spectrum laser light source is transmitted through the transmission optical fiber and the coupler, the light is collimated into parallel light by the optical fiber collimator fixed at the end part of the transmission optical fiber, the parallel light reaches the micro-dispersion confocal probe to generate spectral dispersion, the light focused on the surface of the measured object is reflected back to the spectrometer through the original path of the transmission optical fiber, and the microprocessor decodes the spectral-distance mapping relation to obtain a measured value; the micro dispersion confocal probe is fixed on the precise three-dimensional motion platform and used for scanning the tested complex curved surface sample arranged on the wide-range translation platform.
2. The system for measuring the complex curved surface morphology based on the superstructure dispersion confocal of claim 1, wherein the micro dispersion confocal probe is composed of an ultrathin plane super-structure lens, a band-pass filter and a micro fixed lens barrel, wherein the ultrathin plane super-structure lens can realize far-field super-diffraction limit measurement due to certain collection and amplification effects on evanescent waves; the band-pass filter is used for filtering light rays in a non-working waveband in the light source, and interference of light rays outside the working waveband on a measurement process is avoided; the aperture of the micro dispersion confocal probe is less than 1mm, and the micro dispersion confocal probe can be inserted into a porous structure with a large depth-diameter ratio and even a special-shaped structure to measure the internal appearance.
3. The confocal complicated curved surface morphology measurement system based on superstructure dispersion as claimed in claim 2, wherein the ultra-thin planar super-structure lens can change incident plane light into axial dispersion light with different wavelengths converging at different focal length positions along the optical axis direction, the aperture of the ultra-thin planar super-structure lens is 50-200 μm, the dispersion range Δ f is determined by the aperture of the ultra-thin planar super-structure lens and the manipulation degree of the nano-structure units on the phase dispersion, the custom design is carried out within the limit according to the linear dispersion criterion, and the corresponding numerical aperture is designed to be 0.02-0.8.
4. The system for measuring the complex curved surface morphology based on the superstructure dispersion confocal of claim 3, wherein the ultra-thin planar superstructure lens can realize the customized regulation and control of the light wavefront by designing the geometric shape and the periodic arrangement mode of the nanostructure units, focuses the light with different wavelengths along the optical axis direction and generates linear dispersion, and has the advantage of consistent measurement sensitivity at different positions in the measuring range compared with the traditional nonlinear dispersion confocal lens;
the nano-structure unit on the ultra-thin plane ultra-structure lens in the micro dispersion confocal probe can be designed into a cylindrical structure, a square structure and various shape structures formed by combining the cylindrical structure and the square structure; each type of nanostructure unit structure needs to have more than two dimensional regulation degrees of freedom to meet the design requirement for generating linear dispersion, the spacing between units is 0.1-2 μm, and the unit height is 0.2-4 μm.
5. The system of claim 4, wherein the nanostructure units on the ultra-thin planar super-structured lens are made of metal or dielectric material with high refractive index and low loss in working band.
6. The system for measuring the complex curved surface morphology based on the superstructure dispersion confocal of any one of claims 2 to 5, wherein the miniature dispersion confocal probe can change the confocal light from the original axial direction to the radial direction by adding a right-angle prism or changing the inclination angle of the ultrathin planar super-structured lens and the structure and arrangement of the nanometer units thereof, so as to realize the radial dispersion confocal and obtain the lateral measurement value.
7. A superstructure dispersion confocal-based complex curved surface morphology measurement method is characterized by comprising the following steps:
s1: the spectrum which is uniformly distributed in the working frequency interval is generated by the wide-spectrum laser light source, so that the influence of the light source characteristics on the measurement precision of the sensor is reduced;
s2: light emitted by the wide-spectrum laser light source enters the micro dispersion confocal probe through the transmission optical fiber, the coupler and the optical fiber collimator to generate axial spectral dispersion; the light is collimated into parallel light by the optical fiber collimator, and then the ultrathin plane super-structured lens in the micro dispersion confocal probe forms continuously distributed focusing light spots with different wavelengths on an optical axis by using the parallel light, namely axial position dispersion;
s3: when the complex curved surface to be measured is positioned in the spectral dispersion measurement range, light spots focused on the complex curved surface to be measured and with specific wavelength lambda are reflected and enter a spectrometer, light with other wavelengths cannot be focused and only can form diffuse spots on the surface, and the reflected light intensity is extremely weak due to the large size and the energy dispersion of the defocused light spots;
s4: extracting a return light spectrum signal obtained by a spectrometer through a microprocessor, carrying out data analysis and decoding on the spectrum signal, and establishing a mapping relation between a spectrum peak and a distance so as to obtain a distance measurement result;
s5: a precise three-dimensional motion platform drives a miniature dispersion confocal probe fixed on the precise three-dimensional motion platform to scan the local three-dimensional topography characteristic of the complex curved surface;
s6: the method comprises the steps of arranging a tested complex curved surface sample on a large-range translation table, and setting a scanning path of the large-range translation table according to a scanning interval of a precise three-dimensional motion table so as to realize global scanning of large-area complex curved surface appearance.
8. The superstructure dispersion confocal-based complex curved surface morphology measurement method according to claim 7, wherein the measurement type further comprises the thickness of the ultrathin transparent material, the data acquired by the spectrometer is subjected to compensation modeling analysis according to the basic principle of geometric optics by using the refractive index parameter of the ultrathin transparent material, and the thickness of the ultrathin transparent material is obtained after calculation by the microprocessor.
9. The method for measuring the topography of the complex curved surface based on the superstructure dispersion confocal method according to claim 7, wherein the measurement types further comprise the topography of the bottom surface and the side wall of the hole-shaped and special-shaped structure with large depth-diameter ratio; the aperture of the micro dispersion confocal probe is only in the sub-millimeter level, so that the micro dispersion confocal probe can penetrate into a micro hole-shaped structure with a large depth-diameter ratio, and the bottom surface and the side wall of the hole can be scanned by using two measurement modes of axial dispersion and radial dispersion of the micro dispersion confocal probe respectively to obtain the three-dimensional appearance inside the hole; and axial and radial dispersion can be simultaneously realized in one miniature probe through the beam splitter prism, and the shape in the hole can be obtained through single scanning.
10. The method for measuring the shape and appearance of the complex curved surface based on the confocal chromatic dispersion of the superstructure according to claim 7, characterized in that the transverse resolution of the micro-chromatic dispersion confocal probe can break through the limit of the traditional optical diffraction, and can be used for detecting the micro-defects on the surface of the ultra-smooth material.
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Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101872064A (en) * | 2009-04-24 | 2010-10-27 | 陈亮嘉 | Linear multi-wavelength confocal microscope module and confocal microscopic method and system thereof |
| CN102506754A (en) * | 2011-11-09 | 2012-06-20 | 西安工业大学 | Confocal measurement device for simultaneously measuring surface appearance and color of object and using method thereof |
| CN102605335A (en) * | 2012-04-01 | 2012-07-25 | 湖南大学 | Method for preparing microcrystalline silicon film by two-step method of ion beam and magnetron sputtering and device for coating composite film by ion beam and magnetron sputtering |
| CN103105231A (en) * | 2013-01-21 | 2013-05-15 | 北京理工大学 | Method and device for confocal Raman spectrum detection with high spatial discrimination |
| CN103926197A (en) * | 2013-09-06 | 2014-07-16 | 北京理工大学 | High spatial resolution biaxial differential confocal spectrum microscopic imaging method and apparatus |
| CN104375383A (en) * | 2013-08-13 | 2015-02-25 | 上海微电子装备有限公司 | Focusing and leveling device and method for photo-etching equipment |
| CN106556353A (en) * | 2015-09-24 | 2017-04-05 | 上海思信科学仪器有限公司 | The confocal displacement transducers of 2D |
| CN108107498A (en) * | 2017-12-15 | 2018-06-01 | 中国科学院光电技术研究所 | A kind of non-linear phase gradient based on rotation crystal orientation surpasses surface |
| CN108827172A (en) * | 2018-10-11 | 2018-11-16 | 中国人民解放军国防科技大学 | Non-contact laser thickness measuring device and method based on solid zoom lens |
-
2022
- 2022-04-01 CN CN202210347541.6A patent/CN114719774B/en active Active
Patent Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101872064A (en) * | 2009-04-24 | 2010-10-27 | 陈亮嘉 | Linear multi-wavelength confocal microscope module and confocal microscopic method and system thereof |
| CN102506754A (en) * | 2011-11-09 | 2012-06-20 | 西安工业大学 | Confocal measurement device for simultaneously measuring surface appearance and color of object and using method thereof |
| CN102605335A (en) * | 2012-04-01 | 2012-07-25 | 湖南大学 | Method for preparing microcrystalline silicon film by two-step method of ion beam and magnetron sputtering and device for coating composite film by ion beam and magnetron sputtering |
| CN103105231A (en) * | 2013-01-21 | 2013-05-15 | 北京理工大学 | Method and device for confocal Raman spectrum detection with high spatial discrimination |
| CN104375383A (en) * | 2013-08-13 | 2015-02-25 | 上海微电子装备有限公司 | Focusing and leveling device and method for photo-etching equipment |
| CN103926197A (en) * | 2013-09-06 | 2014-07-16 | 北京理工大学 | High spatial resolution biaxial differential confocal spectrum microscopic imaging method and apparatus |
| CN106556353A (en) * | 2015-09-24 | 2017-04-05 | 上海思信科学仪器有限公司 | The confocal displacement transducers of 2D |
| CN108107498A (en) * | 2017-12-15 | 2018-06-01 | 中国科学院光电技术研究所 | A kind of non-linear phase gradient based on rotation crystal orientation surpasses surface |
| CN108827172A (en) * | 2018-10-11 | 2018-11-16 | 中国人民解放军国防科技大学 | Non-contact laser thickness measuring device and method based on solid zoom lens |
Non-Patent Citations (3)
| Title |
|---|
| QINGYU: "A novel chromatic confocal one-shot 3D measurement system based on DMD", 《MEASUREMENT》 * |
| 李怀新: "基于全介质超表面的分辨共焦集成透镜研究", 《硕士论文库》 * |
| 牛春晖: "光谱共焦透镜组设计及性能优化", 《北京信息科技大学学报》 * |
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