CN110823110A - Method, system and equipment for determining electric parameters of reflecting material medium - Google Patents
Method, system and equipment for determining electric parameters of reflecting material medium Download PDFInfo
- Publication number
- CN110823110A CN110823110A CN201911107451.4A CN201911107451A CN110823110A CN 110823110 A CN110823110 A CN 110823110A CN 201911107451 A CN201911107451 A CN 201911107451A CN 110823110 A CN110823110 A CN 110823110A
- Authority
- CN
- China
- Prior art keywords
- reflection
- polarization direction
- data information
- time
- measured
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 238000000034 method Methods 0.000 title claims abstract description 49
- 239000000463 material Substances 0.000 title claims abstract description 44
- 230000010287 polarization Effects 0.000 claims abstract description 132
- 238000001328 terahertz time-domain spectroscopy Methods 0.000 claims abstract description 28
- 239000000126 substance Substances 0.000 claims abstract description 25
- 238000004364 calculation method Methods 0.000 claims abstract description 14
- 230000005855 radiation Effects 0.000 claims description 90
- 230000005684 electric field Effects 0.000 claims description 71
- 238000012545 processing Methods 0.000 claims description 21
- 238000004590 computer program Methods 0.000 claims description 6
- 230000003287 optical effect Effects 0.000 abstract description 11
- 239000000523 sample Substances 0.000 description 31
- 238000010586 diagram Methods 0.000 description 9
- 238000004891 communication Methods 0.000 description 4
- 230000008569 process Effects 0.000 description 4
- 239000002184 metal Substances 0.000 description 3
- 229910052751 metal Inorganic materials 0.000 description 3
- 230000004048 modification Effects 0.000 description 3
- 238000012986 modification Methods 0.000 description 3
- 238000004458 analytical method Methods 0.000 description 2
- PCHJSUWPFVWCPO-UHFFFAOYSA-N gold Chemical compound [Au] PCHJSUWPFVWCPO-UHFFFAOYSA-N 0.000 description 2
- 229910052737 gold Inorganic materials 0.000 description 2
- 239000010931 gold Substances 0.000 description 2
- 238000002310 reflectometry Methods 0.000 description 2
- 239000004576 sand Substances 0.000 description 2
- 229910052709 silver Inorganic materials 0.000 description 2
- 239000004332 silver Substances 0.000 description 2
- 238000004611 spectroscopical analysis Methods 0.000 description 2
- 238000003325 tomography Methods 0.000 description 2
- NAWXUBYGYWOOIX-SFHVURJKSA-N (2s)-2-[[4-[2-(2,4-diaminoquinazolin-6-yl)ethyl]benzoyl]amino]-4-methylidenepentanedioic acid Chemical compound C1=CC2=NC(N)=NC(N)=C2C=C1CCC1=CC=C(C(=O)N[C@@H](CC(=C)C(O)=O)C(O)=O)C=C1 NAWXUBYGYWOOIX-SFHVURJKSA-N 0.000 description 1
- 238000003491 array Methods 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 238000000576 coating method Methods 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000001514 detection method Methods 0.000 description 1
- 235000019800 disodium phosphate Nutrition 0.000 description 1
- 239000003814 drug Substances 0.000 description 1
- 229940079593 drug Drugs 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 239000002657 fibrous material Substances 0.000 description 1
- 230000006870 function Effects 0.000 description 1
- 239000006115 industrial coating Substances 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 239000007769 metal material Substances 0.000 description 1
- 238000009659 non-destructive testing Methods 0.000 description 1
- 239000003973 paint Substances 0.000 description 1
- 230000002093 peripheral effect Effects 0.000 description 1
- 230000035699 permeability Effects 0.000 description 1
- 238000001228 spectrum Methods 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
- 238000012360 testing method Methods 0.000 description 1
Images
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
- G01B11/00—Measuring arrangements characterised by the use of optical techniques
- G01B11/02—Measuring arrangements characterised by the use of optical techniques for measuring length, width or thickness
- G01B11/06—Measuring arrangements characterised by the use of optical techniques for measuring length, width or thickness for measuring thickness ; e.g. of sheet material
-
- 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
- G01N21/17—Systems in which incident light is modified in accordance with the properties of the material investigated
- G01N21/25—Colour; Spectral properties, i.e. comparison of effect of material on the light at two or more different wavelengths or wavelength bands
- G01N21/31—Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry
- G01N21/35—Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry using infrared light
- G01N21/3581—Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry using infrared light using far infrared light; using Terahertz radiation
- G01N21/3586—Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry using infrared light using far infrared light; using Terahertz radiation by Terahertz time domain spectroscopy [THz-TDS]
Landscapes
- Physics & Mathematics (AREA)
- Spectroscopy & Molecular Physics (AREA)
- General Physics & Mathematics (AREA)
- Health & Medical Sciences (AREA)
- Toxicology (AREA)
- Chemical & Material Sciences (AREA)
- Analytical Chemistry (AREA)
- Biochemistry (AREA)
- General Health & Medical Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Immunology (AREA)
- Pathology (AREA)
- Investigating Or Analysing Materials By Optical Means (AREA)
Abstract
The invention provides a method, a system and equipment for determining an electrical parameter of a reflective material medium, wherein the method for determining the electrical parameter of the reflective material medium comprises the following steps: acquiring reference reflection data information and actual reflection data information by using a terahertz time-domain spectroscopy system; the reference reflection data information is reflection data information obtained by using a reflector as a reflecting surface; the actual reflection data information is reflection data information obtained by taking the surface of the object to be measured as a reflecting surface; and calculating the dielectric electrical parameters of the reflecting substance of the object to be measured according to a preset parameter calculation mode. The method can obtain the actual thickness of the sample to be measured instead of the optical path thickness information on the premise that the refractive index information of the sample to be measured cannot be obtained in a priori (which is usually unavoidable in practical engineering application). Meanwhile, the reflection coefficient under different incident polarization conditions can be rapidly measured and calculated, and the reflection parameter in practical application is rapidly corrected, so that the obtained electric parameter of the reflective material medium is more accurate and reliable.
Description
Technical Field
The invention belongs to the technical field of optics, relates to a determination method and a determination system, and particularly relates to a determination method, a determination system and determination equipment for an electrical parameter of a reflecting material medium.
Background
The terahertz time-domain spectrum signal is a great important application of terahertz frequency band 'gap'. Due to its broad spectrum and its permeability to non-polar and non-metallic substances, it is widely used for substance analysis and non-destructive testing. Because terahertz radiation cannot transmit metal and polar media, a reflective measurement mode of a terahertz time-domain spectroscopy system is required to be used in a large number of engineering applications. At present, a more common method describes different dielectric property levels inside a sample by analyzing time domain positions of each reflection peak of a reflection signal based on each reflection peak of a terahertz time-domain reflection signal and corresponding to a principle of interface reflection between different dielectric layers inside a nonpolar medium. The terahertz time-domain spectroscopy system can further form tomography by utilizing a point-by-point scanning mode, is an important application of the existing terahertz time-domain spectroscopy system in the industrial field, and is used for surface or internal nondestructive detection in a series of fields such as vehicle paint thickness, fiber materials, drug coatings, industrial coating and the like.
However, the reference surface of the reflection-type time domain signal and the reflection surface of the actual sample have position deviation, and in actual operation, the position difference between the actual test object and the reference reflection surface cannot be obtained; meanwhile, because the delay of the reflective time domain signal corresponds to the optical path information of the thickness, for some application occasions needing to measure the thickness instead of internal tomography, the refractive index of the medium needs to be known a priori, and then the actual thickness information can be calculated according to the optical path propagation model, and for the condition of uneven surface, a large amount of errors are generated in the measured thickness information due to the deviation of the incident angle. Generally, when the incident angle is adjusted to 90 ° vertical incidence, the related variables can be greatly reduced, however, the complete 90 ° incident angle not only theoretically needs to separate incidence from reflection through a beam splitter, which reduces the utilization rate of signals, but also in practical engineering, additional optical path devices further increase errors of the optical path model of the reflected signals and the practical situation, and thus are not reliable.
Therefore, how to provide a method, a system and a device for determining an electrical parameter of a reflective material medium to solve the problems that the prior art cannot accurately determine refractive index information of a sample, and the current reflective terahertz time-domain spectroscopy system has application limitations and the like, has become a technical problem to be solved urgently by those skilled in the art.
Disclosure of Invention
In view of the above drawbacks of the prior art, an object of the present invention is to provide a method, a system, and an apparatus for determining an electrical parameter of a reflective material medium, which are used to solve the problems that the prior art cannot accurately determine refractive index information of a sample, and a current reflective terahertz time-domain spectroscopy system has application limitations.
In order to achieve the above and other related objects, the present invention provides a method for determining an electrical parameter of a reflective material medium, which is applied to an object to be measured; the method for determining the dielectric electrical parameter of the reflective substance comprises the following steps: acquiring reference reflection data information and actual reflection data information by using a terahertz time-domain spectroscopy system; the reference reflection data information is reflection data information obtained by using a reflector as a reflecting surface; the actual reflection data information is reflection data information obtained by taking the surface of the object to be measured as a reflecting surface; and calculating the dielectric electrical parameters of the reflecting substance of the object to be measured according to a preset parameter calculation mode.
In an embodiment of the invention, the method for determining the dielectric parameter of the reflective material further includes: and after the electrical parameters of the reflecting material medium are obtained, calculating the actual thickness of the object to be measured by combining the reflection peak delay quantity and the light velocity constant of the upper and lower surfaces of the reflection time domain signal of the object to be measured.
In an embodiment of the present invention, the thz time-domain spectroscopy system includes a radiation photoconductive antenna and a receiving photoconductive antenna.
In an embodiment of the present invention, the reference reflection data information includes: reflecting the time domain signal at the S-polarized reference radiation electric field intensity and the P-polarized reference radiation electric field intensity; the step of acquiring the reference reflection data information by using the terahertz time-domain spectroscopy system includes measuring a time-domain pulse peak value of the reflection time-domain signal in the S polarization direction and a time-domain pulse peak value of the reflection time-domain signal in the P polarization direction by using a reflector as a reflecting surface, so as to calculate a reference radiation electric field strength of the reflection time-domain signal in the S polarization direction and a reference radiation electric field strength of the reflection time-domain signal in the P polarization direction.
In an embodiment of the present invention, the actual reflection data information includes: the actual radiation electric field intensity of the reflection time domain signal in the S polarization direction and the actual radiation electric field intensity in the P polarization direction, the reflection coefficient of the sample to be detected in the S polarization direction and the reflection coefficient of the sample to be detected in the P polarization direction.
In an embodiment of the present invention, the step of acquiring actual reflected data information by using the terahertz time-domain spectroscopy system further includes rotating the radiation photoconductive antenna and the reception photoconductive antenna in the same direction to an arbitrary angle with the surface of the object to be measured as a reflection surface, and measuring a time-domain pulse peak value of the reflected time-domain signal in the S polarization direction and a time-domain pulse peak value of the reflected time-domain signal in the P polarization direction to determine an actual radiation electric field strength of the reflected time-domain signal in the S polarization direction and an actual radiation electric field strength of the reflected time-domain signal in the P polarization direction.
In an embodiment of the invention, the electrical parameters of the reflective material medium of the object to be measured include a refractive index, an incident angle and a refraction angle of the object to be measured.
In an embodiment of the present invention, a reflection coefficient of the sample to be tested in the S polarization direction is equal to an actual radiation electric field strength of the reflected time domain signal in the S polarization direction/a reference radiation electric field strength of the reflected time domain signal in the S polarization direction; the reflection coefficient of the sample to be measured in the P polarization direction is equal to the actual radiation electric field strength of the reflection time domain signal in the P polarization direction/the reference radiation electric field strength of the reflection time domain signal in the P polarization direction; and (3) the refractive index of the object to be measured is equal to the sine value of the incident angle/the sine value of the refraction angle.
The invention also provides a system for determining the dielectric parameters of the reflecting material, which is applied to an object to be measured; the system for determining the dielectric parameter of the reflecting substance comprises: the acquisition module is used for acquiring reference reflection data information and actual reflection data information by utilizing a terahertz time-domain spectroscopy system; the reference reflection data information is reflection data information obtained by using a reflector as a reflecting surface; the actual reflection data information is reflection data information obtained by taking the surface of the object to be measured as a reflecting surface; and the processing module is used for calculating the dielectric electrical parameters of the reflecting substance of the object to be detected according to a preset parameter calculation mode.
A final aspect of the invention provides an apparatus comprising: a processor and a memory; the memory is used for storing a computer program, and the processor is used for executing the computer program stored by the memory so as to cause the device to execute the method for determining the dielectric parameter of the reflecting substance.
As described above, the method, system and apparatus for determining the electrical parameter of the reflective material medium according to the present invention have the following advantages:
by the method, the system and the equipment for determining the electrical parameters of the reflective substance medium, the actual thickness of the sample to be measured can be obtained instead of the optical path thickness information on the premise that the refractive index information of the sample to be measured cannot be obtained in advance (which is usually unavoidable in practical engineering application). For the occasion of using the reflective terahertz time-domain spectroscopy system to measure the thickness of the sample, the application convenience of the system can be improved. Meanwhile, the reflection coefficients under different incident polarization conditions can be quickly measured and calculated by simply changing polarization direction components of incident and received terahertz radiation relative to the incident and reflecting surfaces of the sample, so that the reflection parameters in actual application are quickly corrected by combining the complete calculation process provided by the scheme, and the obtained electrical parameters of the reflective substance medium are more accurate and reliable.
Drawings
FIG. 1 is a flow chart illustrating a method for determining an electrical parameter of a reflective material medium according to an embodiment of the present invention.
Fig. 2 is a schematic diagram of the schematic structure of the terahertz time-domain spectroscopy system of the present invention.
Fig. 3 is a schematic diagram of a reflective terahertz optical path according to the present invention.
Fig. 4 shows a signal pulse diagram of a reference reflected time domain signal with a planar mirror according to the present invention.
Fig. 5 is a schematic signal pulse diagram of a reflection time domain signal in which a sample to be measured is a plane according to the present invention.
Fig. 6 is a schematic diagram illustrating a terahertz wave propagation path inside an object to be measured according to the present invention.
FIG. 7 is a schematic structural diagram of a system for determining an electrical parameter of a reflective material medium according to an embodiment of the present invention.
Description of the element reference numerals
Detailed Description
The embodiments of the present invention are described below with reference to specific embodiments, and other advantages and effects of the present invention will be easily understood by those skilled in the art from the disclosure of the present specification. The invention is capable of other and different embodiments and of being practiced or of being carried out in various ways, and its several details are capable of modification in various respects, all without departing from the spirit and scope of the present invention. It is to be noted that the features in the following embodiments and examples may be combined with each other without conflict.
It should be noted that the drawings provided in the following embodiments are only for illustrating the basic idea of the present invention, and the components related to the present invention are only shown in the drawings rather than drawn according to the number, shape and size of the components in actual implementation, and the type, quantity and proportion of the components in actual implementation may be changed freely, and the layout of the components may be more complicated.
The invention provides a method, a system and equipment for determining dielectric parameters of a reflecting substance. Furthermore, after the refractive index information is obtained, the method can be combined with a conventional reflected signal analysis method to analyze the actual thickness of the measured object instead of the optical path thickness information, so that the application limitation of the current reflective terahertz time-domain spectroscopy system can be greatly reduced.
Example one
The embodiment provides a method for determining an electrical parameter of a reflective material medium, which is applied to an object to be measured; the method for determining the dielectric electrical parameter of the reflective substance comprises the following steps:
acquiring reference reflection data information and actual reflection data information by using a terahertz time-domain spectroscopy system; the reference reflection data information is reflection data information obtained by using a reflector as a reflecting surface; the actual reflection data information is reflection data information obtained by taking the surface of the object to be measured as a reflecting surface;
and calculating the dielectric electrical parameters of the reflecting substance of the object to be measured according to a preset parameter calculation mode.
The method for determining the electrical parameter of the reflective material medium provided in the present embodiment will be described in detail with reference to the drawings. The method for determining the electrical parameter of the reflective material medium can be used for correcting the incident angle of the object to be measured, determining the refractive index information of the object to be measured, and further analyzing the actual thickness of the object to be measured after obtaining the refractive index information.
Referring to fig. 1, a flow chart of a method for determining an electrical parameter of a reflective material medium according to an embodiment is shown. As shown in fig. 1, the method for determining the dielectric parameter of the reflective material specifically includes the following steps:
and S11, acquiring reference reflection data information and actual reflection data information by using the terahertz time-domain spectroscopy system.
Please refer to fig. 2, which is a schematic structural diagram of a terahertz time-domain spectroscopy system. As shown in fig. 2, the thz time-domain spectroscopy system 2 includes a radiation photoconductive antenna 21 and a receiving photoconductive antenna 22. A reflective terahertz light path is established between the radiation photoconductive antenna 21 and the receiving photoconductive antenna 22. As shown in fig. 2, the radiation photoconductive antenna 21 and the receiving photoconductive antenna 22 are adjusted to be incident on the reflecting surface of the mirror in the horizontal position and the surface of the object to be measured in the horizontal position with S polarization, and the incident angle can be arbitrarily selected, and hereinafter, the initial state of the radiation probe in an embodiment rotated by 45 ° is described. Here, the AA direction is represented as a terahertz radiation propagation direction, and the BB direction is represented as an electric field polarization direction of the terahertz radiation.
The incident beam can be defined as S-polarization and P-polarization according to the propagation direction of the incident wave, the polarization direction of the incident wave, and the correlation between the incident and reflection planes, the polarization direction of the S-polarization is perpendicular to the incident and reflection planes, and the polarization direction of the P-polarization is within the incident and reflection planes. Please refer to fig. 3, which is a schematic diagram of a reflective terahertz optical path. As shown in fig. 3, 31 is a terahertz incident wave; 32 is a terahertz reflected wave; the polarization direction of the terahertz wave S when polarized incident is as indicated by the point (∙) in fig. 3, which is perpendicular to the paper surface; the polarization direction at the time of S-polarization reflection of the terahertz wave is indicated as being out of the vertical paper surface with a cross (x) in fig. 3; 34 is the polarization direction of the terahertz wave when P polarization is incident; 35 is the polarization direction of the terahertz wave P during polarization reflection; 36 is a reflecting surface; and 37 is the normal of the reflecting surface.
In this embodiment, the reference reflection data information is reflection data information obtained by using a mirror as a reflection surface, and specifically, a mirror located at a horizontal position is used as a reflection surface. Specifically, the reference reflection data information includes: the intensity of the reference radiation electric field of the reflected time domain signal in S polarization and the intensity of the reference radiation electric field in P polarization, etc.
In S11, the step of acquiring the reference reflection data information by using the terahertz time-domain spectroscopy system includes measuring a time-domain pulse peak value of the reflection time-domain signal in the S polarization direction and a time-domain pulse peak value of the reflection time-domain signal in the P polarization direction by using a mirror located at a horizontal position as a reflection surface, and calculating a reference radiation electric field strength of the reflection time-domain signal in the S polarization direction and a reference radiation electric field strength of the reflection time-domain signal in the P polarization direction. In the present embodiment, the reflector is a metal reflector (e.g., gold, silver, or aluminum-plated reflector) having a high reflectivity.
Specifically, the time domain pulse peak value of the reflected time domain signal in the S polarization direction at this time is obtained, that is, the absolute value (denoted as E) between the maximum value and the minimum value of the reflected time domain signal in the S polarization direction is calculateds,ref41 in fig. 4) to calculate the reference radiation electric field intensity E of the reflected time domain signal in the S polarization directionth,s。
Specifically, the reference radiation electric field intensity E of the reflected time domain signal in the S polarization direction is calculated according to the formula (1)th,s:
rs,ref＝Es,ref/Eth,sRotating the transmitting and receiving antenna by 90 degrees clockwise according to the formula (1), switching the terahertz radiation wave in the S polarization state and the P polarization state, and acquiring a time domain pulse peak value (marked as E) of the reflected time domain signal in the P polarization direction at the timep,ref) Calculating the absolute value between the maximum value and the minimum value of the reflection time domain signal in the P polarization direction to calculate the reference radiation electric field intensity E of the reflection time domain signal in the P polarization directionth,p。
Specifically, the reference radiation electric field intensity E of the reflection time domain signal in the P polarization direction is calculated according to the formula (2)th,p：
rp,ref＝Ep,ref/Eth,pFormula (2) 1
In this embodiment, the actual reflection data information is reflection data information obtained by using the surface of the object to be measured as a reflection surface, and specifically, is the surface of the object to be measured located at a horizontal position. The actual reflection data information includes: the actual radiation electric field intensity of the reflection time domain signal in the S polarization direction and the actual radiation electric field intensity in the P polarization direction, the reflection coefficient of the sample to be detected in the S polarization direction and/or the reflection coefficient of the sample to be detected in the P polarization direction, and the like.
Replacing the reflector with the object to be measured, S11 ZhongliThe step of acquiring actual reflection data information by using the terahertz time-domain spectroscopy system comprises the step of acquiring a time-domain pulse peak value of a reflection time-domain signal in a P polarization direction by using the surface of an object to be detected positioned at a horizontal position so as to acquire the actual radiation electric field intensity E of the reflection time-domain signal in the P polarization directionp,samI.e. 51 as shown in fig. 5.
Rotating the receiving and transmitting antenna by 90 degrees anticlockwise, switching the terahertz radiation wave in a P polarization state and an S polarization state, and acquiring a time domain pulse peak value of the reflected time domain signal in the S polarization direction at the moment so as to acquire the actual radiation electric field intensity E of the reflected time domain signal in the S polarization directions,samAnd the reflection peak delay Δ t of the upper and lower surfaces of the reflected time domain signal of the object to be measured (i.e. 51 shown in fig. 5).
And S12, calculating the electric parameters of the reflecting material medium of the object to be measured according to a preset parameter calculation mode. In this embodiment, the electrical parameters of the reflective material medium of the object to be measured include the refractive index n and the incident angle θ of the object to be measurediAnd angle of refraction thetat。
The S12 specifically includes the following steps:
according to the actual radiation electric field intensity E of the reflection time domain signal in the P polarization directionp,samActual radiation electric field intensity E of reflected time domain signal in S polarization directions,samReflecting the time domain signal in the P polarization directionth,pAnd reflecting the time domain signal in the S polarization directionth,sCalculating the reflection coefficient r of P polarizationp,samAnd reflection coefficient r of S polarizations,sam。
Specifically, r is calculated according to formula (3) and formula (4)p,samAnd rs,samTo calculate the incident angle thetaiAnd angle of refraction thetat。
rs,sam＝Es,sam/Eth,s＝(cosθi-ncosθt)/(cosθi+ncosθt) Formula (3)
rp,sam＝Ep,sam/Eth,p＝(ncosθi-cosθt)/(ncosθi+cosθt) Formula (4)
The refractive index n of the object to be measured is calculated according to equation (5).
n＝sinθt/sinθiFormula (5)
And S13, after the electrical parameters of the reflecting material medium are obtained, calculating the actual thickness d of the object to be measured by combining the reflection peak delay delta t and the light velocity constant c of the upper and lower surfaces of the reflected time domain signal of the object to be measured. In the present embodiment, the actual thickness d of the object to be measured is calculated according to the formula (6).
d＝cΔt/(2ncosθt) Formula (6) please refer to fig. 6, which shows the terahertz wave propagation path inside the object to be measured. As shown in fig. 6, the actual thickness d of the object to be measured is marked 61: the refracted wave mark 62 when the terahertz wave is incident into the sample, the propagation path 66 of the second reflected pulse in the reflected signal of the object to be measured, and the included angle between the incident wave 63 and the normal 64 is the incident angle thetaiThe angle between the refracted wave 62 and the normal 64 is the refraction angle thetatThe refractive index in the medium is n.
In another embodiment, the radiation probe is rotated by an arbitrary angle θ (between 0 and 90 °), and the method for determining the dielectric electrical parameter of the reflective substance comprises the following steps:
obtaining the intensity of the terahertz electric field emitted by the radiation probe as E0To calculate the reference radiation electric field intensity E of the reflected time domain signal in the S polarization directionth,sAnd reflecting the time domain signal in the reference radiation electric field intensity E of the P polarization directionth,p。
Wherein E isth,s＝E0cosθ，Eth,p＝E0sinθ；
Then according to Es,ref/Eth,s＝-1，Ep,ref/Eth,p1, am, Es,ref/Ep,ref＝-ctgθ；
The reflector at horizontal position is used as a reflecting surface to obtain the reference radiation electric field intensity E of the reflected time domain signalref(e.g., 41 as shown in FIG. 4) by
|Eref|＝[(Es,ref)2+(Ep,ref)2]1/2Formula (7)
Calculation of Es,refAnd Ep,ref。
Acquiring the actual radiation electric field intensity E of the reflected time domain signal on the surface of the object to be measured positioned at the horizontal positionsam(e.g., 51 as shown in FIG. 5)
Obtaining the actual radiation electric field intensity E of the reflection time domain signal in the P polarization direction according to the formulas (8), (9) and (10)p,samAnd the actual radiation electric field intensity E of the reflected time domain signal in the S polarization directions,sam。
|Esam|＝[(Es,sam)2+(Ep,sam)2]1/2Formula (8)
Es,sam＝Esamcos theta equation (9)
Ep,sam＝Esamsin theta formula (10)
According to the actual radiation electric field intensity E of the reflection time domain signal in the P polarization directionp,samActual radiation electric field intensity E of reflected time domain signal in S polarization directions,samReflecting the time domain signal in the P polarization directionth,pAnd reflecting the time domain signal in the S polarization directionth,sCalculating the reflection coefficient r of P polarizationp,samAnd reflection coefficient r of S polarizations,sam。
I.e. r is calculated according to formula (3) and formula (4)p,samAnd rs,samTo calculate the incident angle thetaiAnd angle of refraction thetat。
rs,sam＝Es,sam/Eth,s＝(cosθi-ncosθt)/(cosθi+ncosθt) Formula (3)
rp,sam＝Ep,sam/Eth,p＝(ncosθi-cosθt)/(ncosθi+cosθt) Formula (4)
The refractive index n of the object to be measured is calculated according to equation (5).
n＝sinθt/sinθiFormula (5)
Obtaining the dielectric parameters (refractive index n and incident angle theta of the object to be measured)iAnd angle of refraction thetat) And then, calculating the actual thickness d of the object to be measured by combining the reflection peak delay delta t of the upper surface and the reflection peak delay delta t of the lower surface of the reflection time domain signal of the object to be measured and the light velocity constant c.
By the method for determining the electrical parameters of the reflective substance medium, the actual thickness of the sample to be measured can be obtained instead of the optical path thickness information on the premise that the refractive index information of the sample to be measured cannot be obtained a priori (which is usually unavoidable in practical engineering application). For the occasion of using the reflective terahertz time-domain spectroscopy system to measure the thickness of the sample, the application convenience of the system can be improved. Meanwhile, the reflection coefficients under different incident polarization conditions can be quickly measured and calculated by simply changing polarization direction components of incident and received terahertz radiation relative to the incident and reflecting surfaces of the sample, so that the reflection parameters in actual application are quickly corrected by combining the complete calculation process provided by the scheme, and the obtained electrical parameters of the reflective substance medium are more accurate and reliable.
Example two
The embodiment provides a system for determining the dielectric parameters of a reflecting substance, which is applied to an object to be measured; the system for determining the dielectric parameter of the reflecting substance comprises:
the acquisition module is used for acquiring reference reflection data information and actual reflection data information by utilizing a terahertz time-domain spectroscopy system; the reference reflection data information is reflection data information obtained by using a reflector as a reflecting surface; the actual reflection data information is reflection data information obtained by taking the surface of the object to be measured as a reflecting surface;
and the processing module is used for calculating the dielectric electrical parameters of the reflecting substance of the object to be detected according to a preset parameter calculation mode.
The system for determining the dielectric parameter of the reflecting material according to the present embodiment will be described in detail with reference to the drawings. The system for determining the electrical parameters of the reflecting material medium is used for correcting the incident angle of the object to be measured, determining the refractive index information of the object to be measured, and further analyzing the actual thickness of the object to be measured after obtaining the refractive index information.
Fig. 7 is a schematic structural diagram of a determination system of an electrical parameter of a reflective material medium in an embodiment. As shown in fig. 7, the determination system 7 of the dielectric parameter of the reflecting material comprises an acquisition module 71 and a processing module 72.
The obtaining module 71 obtains reference reflection data information and actual reflection data information by using a terahertz time-domain spectroscopy system.
In this embodiment, the reference reflection data information is reflection data information obtained by using a mirror as a reflection surface, and specifically, a mirror located at a horizontal position is used as a reflection surface. Specifically, the reference reflection data information includes: the intensity of the reference radiation electric field of the reflected time domain signal in S polarization and the intensity of the reference radiation electric field in P polarization, etc.
The obtaining module 71 obtains the reference reflection data information by using the terahertz time-domain spectroscopy system, and needs to measure a time-domain pulse peak value of the reflection time-domain signal in the S polarization direction and a time-domain pulse peak value of the reflection time-domain signal in the P polarization direction by using a mirror located at a horizontal position as a reflection surface, so as to calculate a reference radiation electric field strength of the reflection time-domain signal in the S polarization direction and a reference radiation electric field strength of the reflection time-domain signal in the P polarization direction. In the present embodiment, the reflector is a metal reflector (e.g., gold, silver, or aluminum-plated reflector) having a high reflectivity.
Specifically, the obtaining module 71 obtains the time-domain pulse peak value of the reflected time-domain signal in the S-polarization direction at this time, that is, calculates the absolute value (marked as E) between the maximum value and the minimum value of the reflected time-domain signal in the S-polarization directions,ref41 in fig. 4) to calculate the reference radiation electric field intensity E of the reflected time domain signal in the S polarization directionth,s。
Specifically, the reference radiation electric field intensity E of the reflected time domain signal in the S polarization direction is calculated according to the following formulath,s:
rs,ref＝Es,ref/Eth,s＝-1
The receiving and transmitting antenna is rotated clockwise for 90 degrees, the terahertz radiation wave is switched between the S polarization state and the P polarization state, and the acquisition module 71 acquires the time domain pulse peak value (marked as E) of the reflected time domain signal in the P polarization direction at the timep,ref) Calculating the absolute value between the maximum value and the minimum value of the reflection time domain signal in the P polarization direction to calculate the reference radiation electric field intensity E of the reflection time domain signal in the P polarization directionth,p。
Specifically, the reference radiation electric field intensity E of the reflected time domain signal in the P polarization direction is calculated according to the following formulath,p：
rp,ref＝Ep,ref/Eth,p＝1
In this embodiment, the actual reflection data information is reflection data information obtained by using the surface of the object to be measured as a reflection surface, and specifically, is the surface of the object to be measured located at a horizontal position. The actual reflection data information includes: the actual radiation electric field intensity of the reflection time domain signal in the S polarization direction and the actual radiation electric field intensity in the P polarization direction, the reflection coefficient of the sample to be detected in the S polarization direction and/or the reflection coefficient of the sample to be detected in the P polarization direction, and the like.
The reflector is replaced by the object to be measured, and at this time, the acquiring module 71 acquires the time domain pulse peak value of the reflected time domain signal in the P polarization direction with the surface of the object to be measured in the horizontal position, so as to acquire the actual radiation electric field intensity E of the reflected time domain signal in the P polarization directionp,samI.e. 51 as shown in fig. 5.
The receiving and transmitting antenna is rotated counterclockwise by 90 degrees, the terahertz radiation wave is switched between the P polarization state and the S polarization state, the acquisition module 71 acquires the time domain pulse peak value of the reflected time domain signal in the S polarization direction at the moment so as to acquire the actual radiation electric field intensity E of the reflected time domain signal in the S polarization directions,samAnd the reflection peak delay Δ t of the upper and lower surfaces of the reflected time domain signal of the object to be measured (i.e., 52 shown in fig. 5).
And acquisition module 71 moduleThe coupled processing module 72 is configured to calculate the electrical parameter of the reflective material medium of the object to be measured according to a preset parameter calculation manner. In this embodiment, the electrical parameters of the reflective material medium of the object to be measured include the refractive index n and the incident angle θ of the object to be measurediAnd angle of refraction thetat。
The processing module 72 processes the actual radiation electric field intensity E in the P polarization direction according to the reflected time domain signalp,samActual radiation electric field intensity E of reflected time domain signal in S polarization directions,samReflecting the time domain signal in the P polarization directionth,pAnd reflecting the time domain signal in the S polarization directionth,sCalculating the reflection coefficient r of P polarizationp,samAnd reflection coefficient r of S polarizations,sam。
Specifically, the processing module 72 calculates r according to the following formulap,samAnd rs,samTo calculate the incident angle thetaiAnd angle of refraction thetat。
rs,sam＝Es,sam/Eth,s＝(cosθi-ncosθt)/(cosθi+ncosθt)
rp,sam＝Ep,sam/Eth,p＝(ncosθi-cosθt)/(ncosθi+cosθt)
The refractive index n of the object to be measured is calculated according to the following formula.
n＝sinθt/sinθi
The processing module 72 is further configured to calculate the actual thickness d of the object to be measured by combining the reflection peak delay Δ t and the light velocity constant c of the upper and lower surfaces of the reflection time domain signal of the object to be measured after obtaining the electrical parameter of the reflecting material medium. In the present embodiment, the actual thickness d of the object to be measured is calculated according to the following formula.
d＝cΔt/(2ncosθt)
For another embodiment, in which the radiation probe is rotated by an arbitrary angle θ (between 0 and 90 °), the system 7 for determining the electrical parameter of the reflective material medium comprises an acquisition module 71 and a processing module 72.
The obtaining module 71 obtains the intensity of the terahertz electric field emitted by the radiation probe as E0To calculate the reference radiation electric field intensity E of the reflected time domain signal in the S polarization directionth,sAnd reflecting the time domain signal in the reference radiation electric field intensity E of the P polarization directionth,p。
Wherein E isth,s＝E0cosθ，Eth,p＝E0sinθ；
Then according to Es,ref/Eth,s＝-1，Ep,ref/Eth,p1, am, Es,ref/Ep,ref＝-ctgθ；
The obtaining module 71 obtains the reference radiation electric field intensity E of the reflected time domain signal by using the mirror located at the horizontal position as the reflecting surfaceref(e.g., 41 as shown in FIG. 4), by | Eref|＝[(Es,ref)2+(Ep,ref)2]1/2Calculation of Es,refAnd Ep,ref。
With the surface of the object to be measured in a horizontal position, the obtaining module 71 obtains the actual radiation electric field intensity E of the reflected time domain signalsam(e.g., 51 as shown in FIG. 5)
Obtaining the actual radiation electric field intensity E of the reflection time domain signal in the P polarization direction according to the following formulap,samAnd the actual radiation electric field intensity E of the reflected time domain signal in the S polarization directions,sam。
|Esam|＝[(Es,sam)2+(Ep,sam)2]1/2
Es,sam＝Esamcosθ
Ep,sam＝Esamsinθ
The processing module 72 is configured to determine an actual radiation electric field intensity E in the P polarization direction according to the reflected time domain signalp,samActual radiation electric field intensity E of reflected time domain signal in S polarization directions,samReflecting the time domain signal in the P polarization directionth,pAnd reflecting the time domain signal in the S polarization directionth,sCalculating the reflection coefficient r of P polarizationp,samAnd reflection coefficient r of S polarizations,sam。
I.e. r is calculated according to the following formulap,samAnd rs,samTo calculate the incident angle thetaiAnd angle of refraction thetat。
rs,sam＝Es,sam/Eth,s＝(cosθi-ncosθt)/(cosθi+ncosθt)
rp,sam＝Ep,sam/Eth,p＝(ncosθi-cosθt)/(ncosθi+cosθt)
The refractive index n of the object to be measured is calculated according to the following formula.
n＝sinθt/sinθi
The processing module 72 obtains the dielectric parameters (refractive index n, incident angle theta of the object to be measured) of the reflecting materialiAnd angle of refraction thetat) And then, calculating the actual thickness d of the object to be measured by combining the reflection peak delay delta t of the upper surface and the reflection peak delay delta t of the lower surface of the reflection time domain signal of the object to be measured and the light velocity constant c.
It should be noted that the division of the modules of the above system is only a logical division, and the actual implementation may be wholly or partially integrated into one physical entity, or may be physically separated. And the modules can be realized in a form that all software is called by the processing element, or in a form that all the modules are realized in a form that all the modules are called by the processing element, or in a form that part of the modules are called by the hardware. For example: the x module can be a separately established processing element, and can also be integrated in a certain chip of the system. In addition, the x-module may be stored in the memory of the system in the form of program codes, and may be called by one of the processing elements of the system to execute the functions of the x-module. Other modules are implemented similarly. All or part of the modules can be integrated together or can be independently realized. The processing element described herein may be an integrated circuit having signal processing capabilities. In implementation, each step of the above method or each module above may be implemented by an integrated logic circuit of hardware in a processor element or an instruction in the form of software. These above modules may be one or more integrated circuits configured to implement the above methods, such as: one or more Application Specific Integrated Circuits (ASICs), one or more microprocessors (DSPs), one or more Field Programmable Gate Arrays (FPGAs), and the like. When a module is implemented in the form of a processing element scheduler code, the processing element may be a general-purpose processor, such as a Central Processing Unit (CPU) or other processor capable of calling program code. These modules may be integrated together and implemented in the form of a System-on-a-chip (SOC).
EXAMPLE III
This embodiment provides an apparatus, the apparatus comprising: a processor, memory, transceiver, communication interface, or/and system bus; the memory is used for storing a computer program, the communication interface is used for communicating with other devices, and the processor and the transceiver are used for operating the computer program to enable the devices to execute the steps of the determination method of the dielectric parameter of the reflecting material according to the embodiment.
The above-mentioned system bus may be a Peripheral Component Interconnect (PCI) bus, an Extended Industry Standard Architecture (EISA) bus, or the like. The system bus may be divided into an address bus, a data bus, a control bus, and the like. For ease of illustration, only one thick line is shown, but this does not mean that there is only one bus or one type of bus. The communication interface is used for realizing communication between the database access device and other equipment (such as a client, a read-write library and a read-only library). The Memory may include a Random Access Memory (RAM), and may further include a non-volatile Memory (non-volatile Memory), such as at least one disk Memory.
The Processor may be a general-purpose Processor, and includes a Central Processing Unit (CPU), a Network Processor (NP), and the like; the integrated Circuit may also be a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), a Field Programmable Gate Array (FPGA) or other Programmable logic device, discrete Gate or transistor logic device, or discrete hardware components.
The protection scope of the method for determining the dielectric parameter of the reflective material according to the present invention is not limited to the execution sequence of the steps illustrated in the embodiment, and all the solutions obtained by adding, subtracting, and replacing the steps according to the prior art according to the principles of the present invention are included in the protection scope of the present invention.
The present invention also provides a system for determining an electrical parameter of a reflective material medium, which can implement the method for determining an electrical parameter of a reflective material medium according to the present invention, but the implementation apparatus of the method for accessing a large amount of data according to the present invention includes, but is not limited to, the structure of the system for accessing a large amount of data as described in the present embodiment, and all structural modifications and substitutions of the prior art made according to the principles of the present invention are included in the scope of the present invention.
In summary, the method, the system and the device for determining the electrical parameter of the reflective material medium according to the present invention can obtain the actual thickness of the sample to be measured instead of the optical path thickness information on the premise that the refractive index information of the sample to be measured cannot be obtained a priori (which is usually unavoidable in practical engineering applications). For the occasion of using the reflective terahertz time-domain spectroscopy system to measure the thickness of the sample, the application convenience of the system can be improved. Meanwhile, the reflection coefficients under different incident polarization conditions can be quickly measured and calculated by simply changing polarization direction components of incident and received terahertz radiation relative to the incident and reflecting surfaces of the sample, so that the reflection parameters in actual application are quickly corrected by combining the complete calculation process provided by the scheme, and the obtained electrical parameters of the reflective substance medium are more accurate and reliable. The invention effectively overcomes various defects in the prior art and has high industrial utilization value.
The foregoing embodiments are merely illustrative of the principles and utilities of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or change the above-mentioned embodiments without departing from the spirit and scope of the present invention. Accordingly, it is intended that all equivalent modifications or changes which can be made by those skilled in the art without departing from the spirit and technical spirit of the present invention be covered by the claims of the present invention.
Claims (10)
1. A method for determining the electric parameters of a reflective substance medium is characterized in that the method is applied to an object to be measured; the method for determining the dielectric electrical parameter of the reflective substance comprises the following steps:
acquiring reference reflection data information and actual reflection data information by using a terahertz time-domain spectroscopy system; the reference reflection data information is reflection data information obtained by using a reflector as a reflecting surface; the actual reflection data information is reflection data information obtained by taking the surface of the object to be measured as a reflecting surface;
and calculating the dielectric electrical parameters of the reflecting substance of the object to be measured according to a preset parameter calculation mode.
2. The method of claim 1, further comprising:
and after the electrical parameters of the reflecting material medium are obtained, calculating the actual thickness of the object to be measured by combining the reflection peak delay quantity and the light velocity constant of the upper and lower surfaces of the reflection time domain signal of the object to be measured.
3. The method for determining the dielectric parameter of the reflecting material according to claim 1, wherein the terahertz time-domain spectroscopy system comprises a radiation photoconductive antenna and a receiving photoconductive antenna.
4. The method of claim 1, wherein said reference reflection data information comprises: reflecting the time domain signal at the S-polarized reference radiation electric field intensity and the P-polarized reference radiation electric field intensity;
the step of acquiring the reference reflection data information by using the terahertz time-domain spectroscopy system includes measuring a time-domain pulse peak value of the reflection time-domain signal in the S polarization direction and a time-domain pulse peak value of the reflection time-domain signal in the P polarization direction by using a reflector as a reflecting surface, so as to calculate a reference radiation electric field strength of the reflection time-domain signal in the S polarization direction and a reference radiation electric field strength of the reflection time-domain signal in the P polarization direction.
5. The method of claim 4, wherein said actual reflection data information comprises: the actual radiation electric field intensity of the reflection time domain signal in the S polarization direction and the actual radiation electric field intensity in the P polarization direction, the reflection coefficient of the sample to be detected in the S polarization direction and the reflection coefficient of the sample to be detected in the P polarization direction.
6. The method of claim 5, wherein the step of obtaining the actual reflection data information by using the terahertz time-domain spectroscopy system further includes rotating the radiation photoconductive antenna and the reception photoconductive antenna in the same direction to an arbitrary angle with the surface of the object to be measured as a reflection surface, and measuring a time-domain pulse peak value of the reflected time-domain signal in the S polarization direction and a time-domain pulse peak value of the reflected time-domain signal in the P polarization direction to determine the actual radiation electric field strength of the reflected time-domain signal in the S polarization direction and the actual radiation electric field strength of the reflected time-domain signal in the P polarization direction.
7. The method for determining an electrical parameter of a reflective material medium according to claim 6,
the electrical parameters of the reflecting material medium of the object to be detected comprise the refractive index, the incident angle and the refraction angle of the object to be detected.
8. The method for determining an electrical parameter of a reflective material medium according to claim 7,
the reflection coefficient of the sample to be tested in the S polarization direction is equal to the actual radiation electric field strength of the reflection time domain signal in the S polarization direction/the reference radiation electric field strength of the reflection time domain signal in the S polarization direction;
the reflection coefficient of the sample to be measured in the P polarization direction is equal to the actual radiation electric field strength of the reflection time domain signal in the P polarization direction/the reference radiation electric field strength of the reflection time domain signal in the P polarization direction;
and (3) the refractive index of the object to be measured is equal to the sine value of the incident angle/the sine value of the refraction angle.
9. A determination system of dielectric parameters of a reflecting substance is characterized by being applied to an object to be measured; the system for determining the dielectric parameter of the reflecting substance comprises:
the acquisition module is used for acquiring reference reflection data information and actual reflection data information by utilizing a terahertz time-domain spectroscopy system; the reference reflection data information is reflection data information obtained by using a reflector as a reflecting surface; the actual reflection data information is reflection data information obtained by taking the surface of the object to be measured as a reflecting surface;
and the processing module is used for calculating the dielectric electrical parameters of the reflecting substance of the object to be detected according to a preset parameter calculation mode.
10. An apparatus, comprising: a processor and a memory;
the memory is adapted to store a computer program, and the processor is adapted to execute the computer program stored by the memory to cause the apparatus to perform the method of determining an electrical parameter of a reflective material medium according to any of claims 1 to 8.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201911107451.4A CN110823110A (en) | 2019-11-13 | 2019-11-13 | Method, system and equipment for determining electric parameters of reflecting material medium |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201911107451.4A CN110823110A (en) | 2019-11-13 | 2019-11-13 | Method, system and equipment for determining electric parameters of reflecting material medium |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN110823110A true CN110823110A (en) | 2020-02-21 |
Family
ID=69554540
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201911107451.4A Pending CN110823110A (en) | 2019-11-13 | 2019-11-13 | Method, system and equipment for determining electric parameters of reflecting material medium |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN110823110A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111337430A (en) * | 2020-03-13 | 2020-06-26 | 华太极光光电技术有限公司 | Transmission type terahertz probe adjusting device and positioning method |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106841095A (en) * | 2017-01-04 | 2017-06-13 | 北京环境特性研究所 | A kind of method of use terahertz pulse measurement material parameter and material thickness |
| CN107764195A (en) * | 2017-10-09 | 2018-03-06 | 长春理工大学 | Coating high accuracy thickness detecting method based on Fresnel matrix THz ripple propagation models |
| CN109059786A (en) * | 2018-09-07 | 2018-12-21 | 西安航天化学动力厂 | The method of non-contact testing solid propellant rocket internal insulation thickness |
| CN109188105A (en) * | 2018-10-19 | 2019-01-11 | 北京环境特性研究所 | Suitable for Terahertz frequency range high reflection dielectric material parameter measuring apparatus and method |
| CN109211842A (en) * | 2018-10-19 | 2019-01-15 | 北京环境特性研究所 | A kind of Terahertz frequency range material reflection coefficient calibration measuring device and method |
| CN109883337A (en) * | 2019-01-25 | 2019-06-14 | 北京航天计量测试技术研究所 | Thermal barrier coating thickness measurement system and measurement method based on terahertz light spectral technology |
| CN110081826A (en) * | 2019-04-29 | 2019-08-02 | 中国矿业大学 | Heat-barrier coating ceramic layer thickness measure new method based on Terahertz Technology |
-
2019
- 2019-11-13 CN CN201911107451.4A patent/CN110823110A/en active Pending
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106841095A (en) * | 2017-01-04 | 2017-06-13 | 北京环境特性研究所 | A kind of method of use terahertz pulse measurement material parameter and material thickness |
| CN107764195A (en) * | 2017-10-09 | 2018-03-06 | 长春理工大学 | Coating high accuracy thickness detecting method based on Fresnel matrix THz ripple propagation models |
| CN109059786A (en) * | 2018-09-07 | 2018-12-21 | 西安航天化学动力厂 | The method of non-contact testing solid propellant rocket internal insulation thickness |
| CN109188105A (en) * | 2018-10-19 | 2019-01-11 | 北京环境特性研究所 | Suitable for Terahertz frequency range high reflection dielectric material parameter measuring apparatus and method |
| CN109211842A (en) * | 2018-10-19 | 2019-01-15 | 北京环境特性研究所 | A kind of Terahertz frequency range material reflection coefficient calibration measuring device and method |
| CN109883337A (en) * | 2019-01-25 | 2019-06-14 | 北京航天计量测试技术研究所 | Thermal barrier coating thickness measurement system and measurement method based on terahertz light spectral technology |
| CN110081826A (en) * | 2019-04-29 | 2019-08-02 | 中国矿业大学 | Heat-barrier coating ceramic layer thickness measure new method based on Terahertz Technology |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111337430A (en) * | 2020-03-13 | 2020-06-26 | 华太极光光电技术有限公司 | Transmission type terahertz probe adjusting device and positioning method |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US10365163B2 (en) | Optical critical dimension metrology | |
| CN111122460B (en) | Single-rotation compensator type spectroscopic ellipsometer parameter calibration method and device | |
| KR102433778B1 (en) | Ellipsometer and method of inspecting pattern asymmetry using the same | |
| JPS6134442A (en) | Ellipsometry measuring method for inspecting physical characteristic of sample surface or surface film layer of sample and device thereof | |
| US9897486B2 (en) | Method of calibrating and using a measuring apparatus that performs measurements using a spectrum of light | |
| US10663408B2 (en) | Optical phase measurement system and method | |
| CN106595501A (en) | Method of measuring thickness or uniformity of optical thin film | |
| CN105352915B (en) | A kind of dynamic measurement method of refractive index Two dimensional Distribution | |
| CN110376213B (en) | Optical detection system and method | |
| CN109781317A (en) | Optical glass stress detection system and detection method | |
| US10203202B2 (en) | Non-contact determination of coating thickness | |
| CN110823110A (en) | Method, system and equipment for determining electric parameters of reflecting material medium | |
| CN112903598B (en) | Differential spectrum calibration method for azimuth angle of polarization element in ellipsometry system | |
| CN114812889A (en) | Large-caliber optical element stress detection device and detection method thereof | |
| KR20170134567A (en) | Calibration method and apparatus for broadband non-chromatic aberration combined wave plate and corresponding measurement system | |
| CN114264632A (en) | In-situ calibration method for objective lens polarization effect in angle-resolved scatterometer | |
| WO2022055642A1 (en) | Calibration of azimuth angle for optical metrology stage using grating-coupled surface plasmon resonance | |
| CN113466140B (en) | Micro-lens polarization effect calibration method in low-light-spot ellipsometer | |
| CN117110205B (en) | Single-wavelength ellipsometry device with continuously variable angle and measurement method | |
| CN109115695B (en) | Method for extracting optical constants and Euler angles of anisotropic body materials | |
| CN108663665B (en) | Method and device for determining uncertainty of compact range | |
| CN110687052A (en) | Method and system for measuring optical band gap | |
| CN111912785B (en) | Optical constant measuring method and optical constant measuring equipment | |
| CN110426397B (en) | Optical detection system, device and method | |
| CN114324345A (en) | Material imaging method and device, terminal equipment and storage medium |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| WD01 | Invention patent application deemed withdrawn after publication | ||
| WD01 | Invention patent application deemed withdrawn after publication |
Application publication date: 20200221 |