System and method for measuring thickness and tilt angle of transparent materials

Abstract

The present invention provides a system and method for measuring the thickness and tilt angle of a transparent material. The measured tilt angle is used to correct the thickness measurement data in real time to obtain the actual thickness, eliminate the influence of the tilt angle error, and solve the problem that the thickness measurement is greatly affected by the tilt angle error, the system is unreliable, and the practicality is reduced in the prior art. The system includes a thickness measurement unit and a tilt angle measurement unit; the thickness measurement unit transmits the dispersed light waves reflected from the upper and lower surfaces of the measured transparent material to a data processing module, and the tilt angle measurement unit transmits the angle measurement light waves reflected from the surface of the measured transparent material to the data processing module. The data processing module solves the spectrum of the dispersed light waves and obtains the distance that the focusing point of the angle measurement light waves on the photoelectric detector deviates from the center of the photoelectric detector. Through signal processing and data solving, the tilt angle of the measured transparent material is obtained, and the thickness measurement data is corrected by the tilt angle to obtain the actual thickness of the measured transparent material.

Description

Technical Field

[0001] The invention belongs to the field of precision measurement of photoelectric sensor systems, and in particular relates to a system and method for realizing thickness and tilt angle measurement of transparent materials. Background Art

[0002] The basic working principle of the transparent material thickness measurement system using the spectral confocal method is as follows: Figure 1 As shown, the light source emits a wide spectrum of polychromatic white light, which is transmitted to the dispersive objective lens through the optical fiber and coupler. Axial dispersion is generated by the dispersive objective lens, and each spectrum forms a corresponding monochromatic focal point. The direction of the outgoing light axis within a certain range forms an accurate correspondence between the focal position and the wavelength. When the transparent material is placed within the measurement range, both the upper and lower surfaces will reflect back light of a specific wavelength; other light waves cannot be focused on the surface and form diffuse spots, and the light energy reflected back to the measurement system is extremely weak. The light beams reflected from the upper and lower surfaces of the transparent material to be measured are again transmitted to the spectroscopic system through the dispersive objective lens, coupler, and optical fiber. After passing through the spectroscopic system, they are received by the CCD photodetector. The thickness of the transparent material can be calculated based on the spatial positions of the two peaks of the spectrum curve corresponding to the upper and lower surfaces. The thickness H of the transparent material can be expressed as:

[0003]

[0004] like Figure 2 As shown in the figure, the light waves focused on the upper and lower surfaces after passing through the dispersive objective are λ1 and λ2 respectively, h0 is the axial dispersion distance of λ1 and λ2 in the air, n is the refractive index of the transparent material, and θ1 is the incident angle of λ2 incident on the upper surface of the transparent material. The spectral confocal method uses a wide-spectrum light source to produce axial chromatic aberration in the dispersive objective through the principle of optical dispersion, establishes the corresponding relationship between the dispersion distance and the wavelength, and uses a spectrophotometer to detect the peak wavelength of the spectrum focused on the surface of the object and reflected back to obtain accurate axial position or micro-displacement data. The system can break through the diffraction limit of ordinary optical microscopes and achieve ultra-high measurement resolution of the order of nm. It is not easily affected by interference factors such as stray light and vibration, and has a wide range of adaptability to the environment and materials.

[0005] In actual application, due to human operation or installation errors, when placing transparent materials, there may be situations where the surface of the material is not completely perpendicular to the optical axis of the dispersion objective lens, such as Figure 3 As shown, when the transparent material surface is inclined at an angle of θ, there is a deviation between the measured thickness H' and the actual thickness H, thereby affecting the measurement accuracy of the system.

[0006] H=H′cosθ

[0007] Ideally, the measurement accuracy is highest when the optical axis of the dispersion objective lens is completely perpendicular to the surface of the transparent material being measured. Due to environmental vibration or operation and assembly errors, it is difficult to ensure that the surface of the transparent material is completely horizontal. Therefore, in order to achieve accurate measurement, an additional tilt angle measurement system is required. The surface tilt angle θ obtained by actual measurement is used to complete the data compensation of the thickness measurement according to the value of θ. However, the additional introduction of the tilt angle measurement system will lead to a complex structure and a large volume of the overall system, which is inconsistent with the demand for miniaturization and lightweight optical measuring instruments. In addition, it will increase the system cost, make installation and debugging difficult, and make the operation complicated. Especially for mass-produced transparent materials, if the surface tilt angle of the material is measured before measuring the thickness of each material, it will add a lot of extra workload, which is time-consuming and not worth the cost. Summary of the invention

[0008] The purpose of the present invention is to solve the problem that when measuring the thickness of a transparent material by the existing spectral confocal method, the random tilt angle of the transparent material surface affects the measurement accuracy, the error is large, and the performance and practicality of the measurement system are reduced. A system and method for measuring the thickness and tilt angle of a transparent material are provided. The system and method can also measure the tilt angle of the transparent material surface at the same time, and use the measured tilt angle to correct the thickness measurement data to obtain the actual thickness of the transparent material.

[0009] In order to achieve the above object, the present invention adopts the following technical solutions:

[0010] The system for measuring the thickness and tilt angle of a transparent material of the present invention comprises a thickness measuring unit and a tilt angle measuring unit; the thickness measuring unit comprises a first light source, a coupler, a dispersive objective lens, a spectroscopic system, a photodetector and a data processing module; the complex light waves emitted by the first light source are transmitted to the surface of the transparent material to be measured via the coupler and the dispersive objective lens, under the action of the dispersive objective lens, the λ1 light waves and the λ2 light waves in the complex light waves are respectively focused on the upper surface and the lower surface of the transparent material to be measured, the upper surface and the lower surface of the transparent material to be measured respectively reflect the λ1 light waves and the λ2 light waves back to the dispersive objective lens, and are received by the photodetector after passing through the coupler and the spectroscopic system, and the photodetector transmits the signals of the received λ1 light waves and λ2 light waves to the data processing module; the tilt angle measuring unit comprises a first spectroscopic prism, a second spectroscopic prism, a second light source and a self-collimating optical system; the first spectroscopic prism is arranged above the transparent material to be measured, and is used to reflect the λ1 light waves and the λ2 light waves, and the second spectroscopic prism ... The prism is arranged between the light splitting system and the photoelectric detector, and is used for transmitting the λ1 light wave and the λ2 light wave; the λ3 light wave emitted by the second light source is transmitted by the second light splitting prism and collimated by the self-collimating optical system, and then becomes a parallel light beam to be emitted, and the parallel light beam is transmitted by the first light splitting prism to the upper surface of the transparent material to be measured, and then reflected back to the first light splitting prism and the self-collimating optical system by the upper surface of the transparent material to be measured, and then focused on the end face of the photoelectric detector after being focused by the self-collimating optical system and reflected by the second light splitting prism, and then received by the photoelectric detector; the photoelectric detector transmits the received λ1 light wave, λ2 light wave and λ3 light wave signals to the data processing module, and the data processing module solves the spectrum of the λ1 light wave and the λ2 light wave, and obtains the distance of the focus point of the λ3 light wave on the photoelectric detector from the center of the photoelectric detector, and obtains the inclination angle of the transparent material to be measured through signal processing and data solving, and corrects the measured thickness through the inclination angle to obtain the actual thickness H of the transparent material to be measured. S The data processing module includes a computer program, which implements the following algorithm when executed:

[0011]

[0012]

[0013]

[0014] Wherein, h0 is the axial dispersion distance of λ1 light wave and λ2 light wave in air; n is the refractive index of the transparent material to be measured, θ1 is the incident angle of λ2 light wave incident on the upper surface of the transparent material to be measured; H C is the measured thickness of the transparent material being measured; y' is the distance that the focusing point of the λ3 light wave on the photodetector deviates from the center of the photodetector; f' is the focal length of the autocollimation optical system, and θ is the surface inclination angle of the transparent material being measured.

[0015] Furthermore, in order to avoid the light wave spectrum of one of the dispersed light waves λ1 and λ2 being the same as the light wave spectrum of the angle measuring light wave λ3, so that the data processing module cannot judge the dispersed light waves λ1, λ2 and the angle measuring light wave λ3; the system of the present invention is also provided with an electric control device; the electric control device is connected to the data processing module and the second light source, and when the data processing module only receives two spectral signals, the data processing module drives the electric control device to cut off the power of the second light source, so that the data processing module first determines the dispersed light waves λ1 and λ2; then the second light source is powered on through the electric control device, so that the data processing module determines the angle measuring light wave λ3; in other cases, when the system is working, the data processing module controls the second light source to be powered on through the electric control device.

[0016] Furthermore, the first light source and the coupler are connected via a first optical fiber, and the coupler and the light splitting system are connected via a second optical fiber.

[0017] Furthermore, the axis of the dispersive objective lens is perpendicular to the axis of the autocollimating optical system; the first beam splitter prism is arranged above the transparent material to be measured, with its center at the intersection of the axes of the dispersive objective lens and the autocollimating optical system, and the incident end faces of the first beam splitter prism are perpendicular to the axis of the incident light beam; the first beam splitter prism reflects the λ1 light wave and the λ2 light wave, and transmits the λ3 light wave.

[0018] Furthermore, the axis of the spectroscopic system is perpendicular to the axis of the λ3 light beam emitted by the second light source; the second spectroscopic prism is arranged between the spectroscopic system and the photodetector, with its center at the intersection of the axes of the spectroscopic system and the λ3 light beam emitted by the second light source, and the incident end faces of the second spectroscopic prism are perpendicular to the axes of the incident light beams; the second spectroscopic prism transmits the λ1 light wave and the λ2 light wave, transmits the incident λ3 light wave emitted by the second light source, and reflects the λ3 light wave reflected back from the upper surface of the transparent material.

[0019] Furthermore, the second light source is located at the object focus of the self-collimating optical system, and the photodetector is located at the image focus of the self-collimating optical system; the self-collimating optical system collimates the λ3 light wave emitted by the second light source transmitted through the second beam splitter prism, and the emergent light beam is a parallel light beam; the self-collimating optical system focuses the λ3 light wave reflected back from the upper surface of the transparent material transmitted through the first beam splitter prism, and the emergent light beam is a converging light beam.

[0020] Furthermore, the inclined plane between the first beam splitter prism and the second beam splitter prism is a beam splitter plane, which transmits and reflects the light beam at the same time; and the photodetector is a CCD or a CMOS.

[0021] At the same time, the present invention also provides a method for measuring the thickness of a transparent material, comprising the following steps:

[0022] Step 1: Place the transparent material to be measured on the measuring platform;

[0023] Step 2: Arrange a first light source, a coupler, a dispersive objective lens, a light splitting system, a photodetector, a data processing module, a second light source, a self-collimating optical system, a first light splitting prism and a second light splitting prism above the transparent material to be measured;

[0024] Step 3: The complex light waves emitted by the first light source are transmitted to the surface of the transparent material to be measured through a coupler and a dispersive objective lens. Under the action of the dispersive objective lens, the λ1 light waves and the λ2 light waves in the complex light waves are respectively focused on the upper surface and the lower surface of the transparent material to be measured. The upper surface and the lower surface of the transparent material to be measured respectively reflect the λ1 light waves and the λ2 light waves back to the dispersive objective lens, and are received by the photodetector after passing through the coupler and the spectroscopic system.

[0025] Step 4: The λ3 light wave emitted by the second light source is transmitted by the second beam splitter prism and collimated by the self-collimating optical system to become a parallel light beam. The parallel light beam is transmitted by the first beam splitter prism to the upper surface of the transparent material to be measured, and is reflected back to the first beam splitter prism and the self-collimating optical system through the upper surface of the transparent material to be measured. After being focused by the self-collimating optical system and reflected by the second beam splitter prism, it is focused on the end face of the photodetector and received by the photodetector.

[0026] Step 5: The photoelectric detector transmits the received λ1 light wave, λ2 light wave and λ3 light wave signals to the data processing module. The data processing module calculates the spectrum of the λ1 light wave and the λ2 light wave, and obtains the distance of the focus point of the λ3 light wave on the photoelectric detector from the center of the photoelectric detector. Through signal processing and data calculation, the tilt angle of the measured transparent material is obtained, and the thickness H is measured by the tilt angle. C Make corrections to obtain the actual thickness H of the transparent material being measured S ;

[0027]

[0028]

[0029]

[0030] Wherein, h0 is the axial dispersion distance of λ1 light wave and λ2 light wave in air; n is the refractive index of the transparent material to be measured, θ1 is the incident angle of λ2 light wave incident on the upper surface of the transparent material to be measured; H C is the measured thickness of the transparent material being measured; y' is the distance that the focusing point of the λ3 light wave on the photodetector deviates from the center of the photodetector; f' is the focal length of the autocollimation optical system, and θ is the surface inclination angle of the transparent material being measured.

[0031] In addition, the present invention also provides a method for measuring the tilt angle of a transparent material, comprising the following steps:

[0032] Step 1: Place the transparent material to be measured on the measuring platform;

[0033] Step 2: Arrange a second light source, a second beam splitter prism, a self-collimating optical system, a first beam splitter prism, a photoelectric detector and a data processing module above the transparent material to be tested;

[0034] Step 3: The λ3 light wave emitted by the second light source is transmitted by the second beam splitter prism and collimated by the self-collimating optical system, and then becomes a parallel light beam, which is transmitted to the upper surface of the transparent material to be measured by the first beam splitter prism, and then reflected back to the first beam splitter prism and the self-collimating optical system by the upper surface of the transparent material to be measured, and then focused by the self-collimating optical system and reflected by the second beam splitter prism, and then focused on the end face of the photodetector and received by the photodetector;

[0035] Step 4: The photoelectric detector transmits the received λ3 light wave signal to the data processing module, and the data processing module obtains the distance that the focus point of the λ3 light wave on the photoelectric detector deviates from the center of the photoelectric detector, and obtains the tilt angle of the measured transparent material through signal processing and data solution;

[0036]

[0037] Wherein, y' is the distance that the focusing point of the λ3 light wave on the photodetector deviates from the center of the photodetector; f' is the focal length of the autocollimation optical system, and θ is the surface inclination angle of the transparent material being measured.

[0038] Compared with the prior art, the system and method of the present invention have the following beneficial effects:

[0039] 1. The device and method of the present invention add a function for measuring the surface tilt angle of the measured transparent material, and can obtain the surface tilt angle while solving the thickness data using the dispersed wavelength, and perform real-time correction on the thickness data affected by the surface tilt angle, thereby eliminating the influence of the tilt angle error and solving the problem in the prior art that the measured transparent material has a surface tilt, resulting in large system measurement errors, unreliability, and reduced practicality.

[0040] 2. In the device and method of the present invention, the measurement of the tilt angle of the surface of the measured transparent material is based on the principle of optical autocollimation. This method has high angle measurement accuracy and can effectively ensure the accuracy and precision of the thickness measurement data of the corrected system. At the same time, the device of the present invention uses two dichroic prisms to integrate the transparent material thickness measurement unit based on the spectral confocal method and the surface tilt angle measurement unit based on the optical autocollimation method, and shares a photoelectric detector, so that the device has a compact structure and reduces costs. After installation and debugging are completed, the calibration work before each measurement can be omitted, the measurement speed is fast, time is saved, and it is particularly suitable for continuous measurement of batch products.

[0041] 3. When the optical autocollimation method is used in the device of the present invention to measure the surface inclination angle, a determined single spectrum is used, and a control part is added. The problem that the angle measurement light wave spectrum is the same as the dispersion light wave spectrum is solved by using an electronic control device, so that the system obtains the dispersion light wave and the angle measurement light wave without being affected by each other; in addition, the device of the present invention can replace other range dispersion objective lenses according to the thickness range of the transparent material to be measured, and the rest of the device can remain unchanged, which is easy to operate and has wide applicability.

[0042] 4. Compared with the traditional method of adding an additional angle measurement system, the device of the present invention has fewer error influencing factors and higher measurement accuracy; at the same time, it has the characteristics of simple principle, convenient operation and strong engineering ability. The device of the present invention can also be expanded to the measurement of thickness and thickness distribution of multi-surface / multi-layer transparent materials and tilt angles, and has a wide range of applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 It is the basic principle diagram of the existing spectral confocal method transparent material thickness measurement system;

[0044] Figure 2 A schematic diagram of measuring the thickness of transparent materials using the existing spectral confocal method;

[0045] Figure 3 Schematic diagram of thickness measurement error when the transparent material surface has an inclination angle θ;

[0046] Figure 4 It is a schematic structural diagram of the first beam splitter prism in the measurement system of the present invention;

[0047] Figure 5 A schematic diagram of the structure of a second beam splitter prism in the measurement system of the present invention;

[0048] Figure 6 This is a schematic diagram of a system for measuring the thickness and tilt angle of a transparent material according to the present invention.

[0049] Figure numerals: 1-first light source, 2-first optical fiber, 3-coupler, 4-dispersion objective lens, 5-spectrometric system, 6-photodetector, 7-second optical fiber, 8-first spectroscopic prism, 9-second spectroscopic prism, 10-second light source, 11-self-collimating optical system, 12-electric control device, 13-data processing module, 14-transparent material to be measured. DETAILED DESCRIPTION

[0050] The present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be understood by those skilled in the art that these embodiments are only used to explain the technical principles of the present invention and are not intended to limit the protection scope of the present invention.

[0051] The present invention provides a system and method for measuring the thickness and tilt angle of a transparent material. The system and method can measure the tilt angle of the transparent material surface while measuring the thickness of the transparent material. The measured tilt angle is used to correct the thickness measurement data affected by the surface tilt angle in real time to obtain the actual thickness of the transparent material, thereby eliminating the influence of the tilt angle error. The system solves the problem in the prior art that the measured transparent material has a tilted surface, resulting in a large error in the thickness measurement of the system, unreliability, and reduced system practicality.

[0052] like Figure 6 As shown, the system for measuring the thickness and tilt angle of a transparent material of the present invention includes a thickness measuring unit and a tilt angle measuring unit. The thickness measuring unit includes a first light source 1, a coupler 3, a dispersive objective lens 4, a spectroscopic system 5, a photodetector 6 and a data processing module 13. The first light source 1 and the coupler 3 are connected via a first optical fiber 2, and the coupler 3 and the spectroscopic system 5 are connected via a second optical fiber 7. The tilt angle measuring unit includes a first spectroscopic prism 8, a second spectroscopic prism 9, a second light source 10 and a self-collimating optical system 11.

[0053] The light waves emitted by the first light source 1 are transmitted to the dispersive objective lens 4 via the first optical fiber 2 and the coupler 3 in sequence, and then are transmitted to the surface of the transparent material 14 to be measured via reflection from the first dichroic prism 8; at this time, the light waves emitted by the first light source 1 are wide-spectrum polychromatic light. Under the action of the dispersive objective lens 4, the polychromatic light waves produce axial dispersion after passing through the dispersive objective lens 4, and each spectrum forms a corresponding monochromatic focal point in the axial direction of the light beam propagation, wherein the λ1 light wave and the λ2 light wave are respectively focused on the upper surface and the lower surface of the transparent material 14 to be measured, and are reflected back to the first dichroic prism 8 and the dispersive objective lens 4 via reflection from the upper surface and the lower surface, and the light of other wavelengths cannot be focused on the surface, and the reflected light energy is extremely weak, and after being reflected back to the dispersive objective lens 4, the λ1 light wave and the λ2 light wave are transmitted to the second dichroic prism 9 via the coupler 3, the second optical fiber 7, and the light splitting system 5, and reach the photodetector 6 via the transmission action of the second dichroic prism 9, and are received by the photodetector 6.

[0054] The λ3 light wave emitted by the second light source 10 is transmitted by the second beam splitter prism 9 and collimated by the self-collimating optical system 11 to become a parallel light beam. The parallel light beam is transmitted by the first beam splitter prism 8 to the upper surface of the transparent material 14 to be measured, and is reflected back to the first beam splitter prism 8 and the self-collimating optical system 11 by the reflection effect of the upper surface. After being focused by the self-collimating optical system 11 and reflected by the second beam splitter prism 9, it is focused on the end face of the photodetector 6 and received by the photodetector 6.

[0055] The photodetector 6 transmits the received λ1 light wave, λ2 light wave and λ3 light wave signals to the data processing module 13. The data processing module 13 calculates the spectra of the λ1 light wave and the λ2 light wave, and obtains the distance that the focusing point of the λ3 light wave on the photodetector 6 deviates from the center of the photodetector 6. Through signal processing and data calculation, the inclination angle of the measured transparent material 14 is obtained, and the calculated data is corrected by the inclination angle to obtain the actual thickness of the measured transparent material 14. The data processing module can specifically adopt a computer and other equipment.

[0056] The axis of the dispersion objective lens 4 is perpendicular to the axis of the self-collimation optical system 11; the first beam splitter prism 8 is arranged above the measured transparent material 14, and the center is at the intersection of the axes of the dispersion objective lens 4 and the self-collimation optical system 11, and the incident end faces of the first beam splitter prism 8 are perpendicular to the axes of the incident light beam; the first beam splitter prism 8 reflects the light waves emitted by the dispersion objective lens 4 and transmits the light waves emitted by the self-collimation optical system 11; the axis of the beam splitter system 5 is perpendicular to the axis of the light beam emitted by the second light source 10. The axis is vertical; the second beam splitter prism 9 is arranged between the beam splitter system 5 and the photodetector 6, and the center is located at the intersection of the axes of the light beams emitted by the beam splitter system 5 and the second light source 10. The incident end faces of the second beam splitter prism 9 are respectively perpendicular to the axes of the incident light beams; the second beam splitter prism 9 transmits the light waves emitted by the beam splitter system 5, transmits the incident light waves emitted by the second light source 10, and reflects the reflected light waves of the measured transparent material 14 returned by the self-collimating optical system 11; the second light The source 10 is at the object focus of the self-collimating optical system 11, and the photodetector 6 is at the image focus of the self-collimating optical system 11; the self-collimating optical system 11 collimates the light waves emitted by the second light source 10 transmitted through the second beam splitter prism 9, and the outgoing light beam is a parallel light beam; the self-collimating optical system 11 focuses the light waves reflected back from the upper surface of the transparent material 14 transmitted through the first beam splitter prism 8, and the outgoing light beam is a convergent light beam; the electric control device 12 is connected to the data processing module 13 and the second light source 10. When the data processing module 13 receives only two spectral signals, the data processing module 13 drives the electric control device 12 to power off the second light source 10, so that the data processing module 13 first determines the dispersion light waves emitted by the beam splitter 5, and then controls the second light source 10 to be powered on through the electric control device 12, so that the data processing module 13 determines the angle measurement light waves returned by the self-collimating optical system 11. In other cases, when the system is working, the data processing module 13 controls the second light source 10 to be powered on through the electric control device 12; Figure 4 and Figure 5 As shown, the inclined surface between the first beam splitter prism 8 and the second beam splitter prism 9 is a beam splitter surface, which transmits and reflects the light beam at the same time; the photodetector 6 is a CCD or CMOS.

[0057] When the transparent material 14 to be measured has a surface tilt angle θ, the focal point of the λ3 light wave emitted by the second light source 10 on the photodetector 6 deviates from the center of the photodetector 6 by a distance y', and the tilt angle θ is:

[0058]

[0059] Wherein, f' is the focal length of the self-collimating optical system 11; when y'=0 mm, θ=0°, at which time the λ3 light wave is focused at the center of the end face of the photodetector 6, which is called the zero position.

[0060] According to the measured inclination angle θ of the transparent material surface, combined with the axial dispersion distance corresponding to λ1 and λ2, the refractive index of the transparent material being measured, and the incident angle of λ2 incident on the upper surface of the transparent material being measured, the thickness of the transparent material being measured can be solved. The actual thickness H of the transparent material being measured S for:

[0061]

[0062]

[0063] Wherein, h0 is the axial dispersion distance of λ1 light wave and λ2 light wave in air; n is the refractive index of the transparent material to be measured, θ1 is the incident angle of λ2 light wave incident on the upper surface of the transparent material to be measured; H C is the measured thickness of the transparent material being measured, and θ is the surface inclination angle of the transparent material being measured.

[0064] In addition, the above system can replace other range dispersion objective lenses according to the thickness range of the transparent material to be measured, and the measuring device of the present invention can also be applied to the measurement of thickness and thickness distribution and tilt angle of multi-surface / multi-layer transparent materials. At this time, the number of surfaces or layers of the transparent material determines the number of reflected dispersion wavelengths.

Claims

1. A system for measuring the thickness and tilt angle of a transparent material, comprising a thickness measuring unit, wherein the thickness measuring unit comprises a first light source (1), a coupler (3), a dispersive objective lens (4), a spectroscopic system (5), a photodetector (6) and a data processing module (13); the first light source (1) and the coupler (3) are connected via a first optical fiber (2), and the coupler (3) and the spectroscopic system (5) are connected via a second optical fiber (7); characterized in that: It also includes an inclination angle measuring unit; the inclination angle measuring unit includes a first beam splitter prism (8), a second beam splitter prism (9), a second light source (10), a self-collimating optical system (11) and an electric control device (12); The first beam splitter prism (8), the self-collimating optical system (11), the second beam splitter prism (9), and the second light source (10) are arranged in order from bottom to top above the transparent material (14) to be measured; The dispersion objective lens (4) is located on the side of the first beam splitter prism (8) and its optical axis is perpendicular to the optical axis of the autocollimation optical system (11); the center of the first beam splitter prism (8) is located at the intersection of the axis of the dispersion objective lens (4) and the axis of the autocollimation optical system (11); The axis of the light splitting system (5) is perpendicular to the axis of the light beam of the second light source (10); the center of the second light splitting prism (9) is located at the intersection of the axis of the light splitting system (5) and the axis of the λ3 light beam emitted by the second light source (10); The electric control device (12) is connected to the data processing module (13) and the second light source (10) respectively, and the data processing module (13) controls the working state of the second light source (10) according to the received data; The second light source (10) is located at the object-side focus of the autocollimation optical system (11), and the photodetector (6) is located at the image-side focus of the autocollimation optical system (11).

2. The system for measuring thickness and tilt angle of transparent materials according to claim 1, characterized in that: The second light source (10) is located at the object focus of the autocollimating optical system (11), and the photodetector (6) is located at the image focus of the autocollimating optical system (11); the autocollimating optical system (11) focuses the λ3 light wave reflected from the upper surface of the transparent material (14) to be measured and transmitted through the first beam splitter prism (8), and the outgoing light beam is a converging light beam.

3. The system for measuring thickness and tilt angle of transparent materials according to claim 2, characterized in that: The inclined surface between the first beam splitter prism (8) and the second beam splitter prism (9) is a beam splitter surface, which has a transmission and reflection effect on the light beam at the same time; the photoelectric detector (6) is a CCD or a CMOS.

4. A method for measuring the thickness of a transparent material, characterized in that: The following steps are involved: Step 1: Place the transparent material to be measured on the measuring platform; Step 2: Arrange a first light source, a coupler, a dispersive objective lens, a light splitting system, a photodetector, a data processing module, a second light source, a self-collimating optical system, a first light splitting prism and a second light splitting prism above the transparent material to be measured; Step 3: The complex light waves emitted by the first light source are transmitted to the surface of the transparent material to be measured through a coupler and a dispersive objective lens. Under the action of the dispersive objective lens, the λ1 light waves and the λ2 light waves in the complex light waves are respectively focused on the upper surface and the lower surface of the transparent material to be measured. The upper surface and the lower surface of the transparent material to be measured respectively reflect the λ1 light waves and the λ2 light waves back to the dispersive objective lens, and are received by the photodetector after passing through the coupler and the spectroscopic system. Step 4: The λ3 light wave emitted by the second light source is transmitted by the second beam splitter prism and collimated by the self-collimating optical system, and then becomes a parallel light beam, which is transmitted to the upper surface of the transparent material to be measured by the first beam splitter prism, and then reflected back to the first beam splitter prism and the self-collimating optical system by the upper surface of the transparent material to be measured, and then focused by the self-collimating optical system and reflected by the second beam splitter prism, and then focused on the end face of the photodetector and received by the photodetector; Step 5: The photoelectric detector transmits the received λ1 light wave, λ2 light wave and λ3 light wave signals to the data processing module. The data processing module calculates the spectrum of the λ1 light wave and the λ2 light wave, and obtains the distance of the focus point of the λ3 light wave on the photoelectric detector from the center of the photoelectric detector. Through signal processing and data calculation, the tilt angle of the measured transparent material is obtained, and the measured thickness is corrected by the tilt angle to obtain the actual thickness H of the measured transparent material. s : Wherein, h0 is the axial dispersion distance of λ1 light wave and λ2 light wave in air; n is the refractive index of the transparent material to be measured, θ1 is the incident angle of λ2 light wave incident on the upper surface of the transparent material to be measured; H C is the measured thickness of the transparent material; ， f is the distance from the focusing point of the λ3 light wave on the photodetector to the center of the photodetector; ， is the focal length of the autocollimating optical system, and θ is the inclination angle of the upper surface of the transparent material to be measured.

5. The method for measuring the thickness of a transparent material according to claim 4, characterized in that: In step five, when the data processing module receives only two spectral signals, the data processing module drives the electronic control device to cut off the power of the second light source, so that the data processing module first determines the dispersion λ1 light wave and the λ2 light wave; then the second light source is controlled to be powered on through the electronic control device, so that the data processing module determines the angle measurement light wave λ3; when the measurement system is working, the data processing module controls the second light source to be powered on through the electronic control device.

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