CN113251897B - Gauge block measuring device and method based on white light interference - Google Patents

Gauge block measuring device and method based on white light interference Download PDF

Info

Publication number
CN113251897B
CN113251897B CN202110535055.2A CN202110535055A CN113251897B CN 113251897 B CN113251897 B CN 113251897B CN 202110535055 A CN202110535055 A CN 202110535055A CN 113251897 B CN113251897 B CN 113251897B
Authority
CN
China
Prior art keywords
interference
transparent plate
interference spectrum
block
light
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.)
Active
Application number
CN202110535055.2A
Other languages
Chinese (zh)
Other versions
CN113251897A (en
Inventor
王毅
姜云飞
马振鹤
彭思龙
汪雪林
顾庆毅
赵效楠
王一洁
郭晓锋
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Suzhou Zhongke Xingzhi Intelligent Technology Co ltd
Northeastern University Qinhuangdao Branch
Original Assignee
Suzhou Zhongke Xingzhi Intelligent Technology Co ltd
Northeastern University Qinhuangdao Branch
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Suzhou Zhongke Xingzhi Intelligent Technology Co ltd, Northeastern University Qinhuangdao Branch filed Critical Suzhou Zhongke Xingzhi Intelligent Technology Co ltd
Priority to CN202110535055.2A priority Critical patent/CN113251897B/en
Publication of CN113251897A publication Critical patent/CN113251897A/en
Application granted granted Critical
Publication of CN113251897B publication Critical patent/CN113251897B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

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
    • G01B5/00—Measuring arrangements characterised by the use of mechanical techniques
    • G01B5/02—Measuring arrangements characterised by the use of mechanical techniques for measuring length, width or thickness
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
    • G01B9/00—Measuring instruments characterised by the use of optical techniques
    • G01B9/02—Interferometers
    • G01B9/02055—Reduction or prevention of errors; Testing; Calibration
    • G01B9/0207—Error reduction by correction of the measurement signal based on independently determined error sources, e.g. using a reference interferometer
    • G01B9/02071—Error reduction by correction of the measurement signal based on independently determined error sources, e.g. using a reference interferometer by measuring path difference independently from interferometer
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
    • G01B9/00—Measuring instruments characterised by the use of optical techniques
    • G01B9/02—Interferometers
    • G01B9/02055—Reduction or prevention of errors; Testing; Calibration
    • G01B9/02075—Reduction or prevention of errors; Testing; Calibration of particular errors
    • G01B9/02076—Caused by motion
    • G01B9/02077—Caused by motion of the object
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
    • G01B9/00—Measuring instruments characterised by the use of optical techniques
    • G01B9/02—Interferometers
    • G01B9/02083—Interferometers characterised by particular signal processing and presentation
    • G01B9/02084—Processing in the Fourier or frequency domain when not imaged in the frequency domain
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
    • G01B9/00—Measuring instruments characterised by the use of optical techniques
    • G01B9/02—Interferometers
    • G01B9/0209—Low-coherence interferometers

Abstract

The invention discloses a measuring block measuring device and method based on white light interference, which relate to the technical field of measurement and comprise a low-coherence light source, a light splitting element, a measuring block, a spectrometer, a first transparent plate and a second transparent plate, wherein light emitted by the low-coherence light source enters the light splitting element, and light output from one end of the light splitting element is converged on the left surface of the measuring block through a first lens component; light output from the other end of the light splitting element is converged on the right surface of the gauge block through a second lens component; light reflected from the gauge block and the first transparent plate enters the spectrometer through the light splitting element to form a first interference spectrum; the light reflected by the gauge block and the second transparent plate returns to the light splitting element and enters the spectrometer to form a second interference spectrum; the spectrometer records the superposed signals of the two interference spectrums and then transmits the superposed signals to the data processing module for processing. The method combines the frequency and the phase of Fourier transform, realizes high-precision measurement of the gauge block based on white light interference, does not need contact, and is convenient to operate.

Description

Gauge block measuring device and method based on white light interference
Technical Field
The invention relates to the technical field of measuring of a gauge block, in particular to a device and a method for measuring the gauge block based on white light interference.
Background
The gauge block is an international universal real object transfer standard of the most important length value, is one of the most widely applied measuring instruments in the fields of measuring technology and engineering measurement, transfers the length unit to each link of industrial production, and plays an important role in a product quality assurance system. The measuring block is used as a measuring instrument, and it is necessary that the indication value is accurate, so the verification work of the measuring block is an indispensable step for ensuring the normal use of the measuring block, and the optical interference technology is the most important high-precision measuring method of the measuring block at present. Although the optical interference technique theoretically has the advantage of high resolution, the optical interference technique measures the optical path difference relative to a reference surface, so that the optical interference technique is susceptible to external interference, including the flow of air, temperature change and the influence of vibration of a sample relative to an interference system, and has strict requirements on the measurement environment. Since only the decimal part of the interference fringe can be measured from the interference fringe pattern, but the integer part of the interference fringe cannot be obtained, the measurable range is increased by using a decimal recurrence method at present, and the same measuring block needs to be measured by adopting a plurality of wavelengths, so that the system is complex. Meanwhile, since the measurement length is related to the wavelength of the light source, the light source is required to have high stability. On the other hand, when single-ended measurement is used, although the structure is relatively simple, the single-ended measurement is influenced by the auxiliary flat crystal grinding; in the case of double-end measurement, although there is no auxiliary flat crystal lapping effect, multiple distances need to be measured, which increases the system error.
Chinese patent CN110595351B discloses a method for measuring the quantity value of a white light interferometer with an etalon, a block to be measured is arranged on a steel flat crystal, the measurement precision is influenced by the steel flat crystal and the grinding performance of the block, and meanwhile, the contact measurement is easy to cause the surface of the block to be polluted and damaged; moreover, the sample light and the reference light are not in a common optical path mode, and thus are susceptible to external interference, including air flow, temperature change and steel flat crystal vibration. Chinese patent CN201306998Y discloses a second-class gauge block contact type laser interferometer, wherein a measuring head is in contact with the upper surface of a gauge block during measurement, and the lower surface of the gauge block is in contact with a workbench for measurement; a rib-type workbench which needs special processing; the gauge block deformation may cause the gauge block to be in unreliable contact with the main rib in the middle of the workbench, and measurement errors are caused.
Disclosure of Invention
In order to solve the technical problems, the invention provides a measuring block measuring device and method based on white light interference.
In order to realize the purpose of the invention, the technical scheme adopted by the invention is as follows:
a gauge block measuring device based on white light interference comprises a low-coherence light source, a light splitting element, a spectrometer, a first lens assembly, a first transparent plate, a gauge block, a second transparent plate, a second lens assembly and a data processing module; the low-coherence light source is connected with the light splitting element through an optical fiber; the light splitting element, the spectrometer and the data processing module are sequentially arranged; the gauge block is arranged between the first transparent plate and the second transparent plate;
the first transparent plate, the first lens assembly and the light splitting element are sequentially arranged in the direction from the left surface close to the gauge block to the left surface far away from the gauge block;
a second transparent plate, a second lens assembly and a light splitting element are sequentially arranged from the direction close to the right surface of the gauge block to the direction far away from the right surface of the gauge block;
the light reflected from the left surface of the gauge block and the light reflected from the right surface of the first transparent plate return to the light splitting element and enter a spectrometer to form a first interference spectrum;
the light reflected by the right surface of the gauge block and the light reflected by the left surface of the second transparent plate return to the light splitting element and enter the spectrometer to form a second interference spectrum;
and the spectrometer records the superposed interference signal of the first interference spectrum and the second interference spectrum, and then transmits the superposed interference signal to the data processing module for processing.
Further, the first lens assembly includes at least one first lens, and the second lens assembly includes at least one second lens.
Further, the device also comprises a translation platform, wherein the translation platform is arranged below the first transparent plate or below the second transparent plate.
Further, the light splitting element is selected to be a 2*2 coupler.
A measuring method of a gauge block measuring device based on white light interference is characterized by comprising the following steps:
step S1: placing a standard gauge block between a first transparent plate and a second transparent plate of a measuring device, setting the length of the standard gauge block to be L1,
the light reflected from the left surface of the standard gauge block and the light reflected from the right surface of the first transparent plate return to the light splitting element and enter the spectrometer to form an interference spectrum I11;
the light reflected from the right surface of the standard gauge block and the light reflected from the left surface of the second transparent plate return to the light splitting element and enter the spectrometer to form an interference spectrum I12;
calculating the distance from the right surface of the first transparent plate to the left surface of the standard gauge block according to the I11, and recording as a11;
calculating the distance from the left surface of the second transparent plate to the right surface of the standard gauge block according to I12, and marking as a12;
l0= a11+ a12+ L1, where L0 represents the distance between the right surface of the first transparent plate and the left surface of the second transparent plate;
step S2: replacing the standard measuring block with the measuring block, arranging the measuring block between the first transparent plate and the second transparent plate, setting the length of the measuring block to be L2,
the light reflected from the left surface of the block to be measured and the light reflected from the right surface of the first transparent plate return to the light splitting element and enter the spectrometer to form an interference spectrum I21;
the light reflected by the right surface of the block to be measured and the light reflected by the left surface of the second transparent plate return to the light splitting element and enter the spectrometer to form an interference spectrum I22;
calculating the distance from the right surface of the first transparent plate to the left surface of the block to be measured according to the I21, and recording as a21;
calculating the distance from the left surface of the second transparent plate to the right surface of the block to be measured according to the I22, and marking as a22;
then L0= a21+ a22+ L2;
and step S3: obtaining the length difference delta between the standard measuring block and the measuring block to be measured: Δ = L1-L2= a21+ a22-a11-a12.
Further, the calculating step of a 11:
step 1: when a standard gauge block is used for measurement, signals collected by a spectrometer are separated through a filter to obtain an interference spectrum I11 and an interference spectrum I12;
step 2: fourier transformation is carried out on the interference spectrum I11 to obtain a magnitude spectrum of the interference spectrum, and the abscissa ordinal number of a maximum value point of the magnitude spectrum is set as M11;
and step 3: dividing the interference spectrum I11 into two parts equally, and setting the central wave numbers of the two interference spectra to be K respectively C1 And K C2 And Fourier transform is respectively carried out on the two interference spectrums to obtain the phase theta of the two interference spectrums 111 And theta 112 Calculating
Figure BDA0003069484330000031
And 4, step 4: obtaining an optical path difference P11:
Figure BDA0003069484330000032
round () represents a round operation;
and 5: correcting P11, comparing the sizes of P11 and 2 pi (M11 + 1)/delta k, determining whether round () has an error for the wave number width corresponding to the spectrometer; when P11 is greater than 2 π (M11 + 1)/Δ K, P11 minus 2 π/(K) c1 -K c2 ) To obtain a11; when P11 is less than 2 π (M11 + 1)/Δ k, the values of P11 and a11 are equal.
Further, the calculation steps of a12 are as follows:
step 1: when a standard gauge block is used for measurement, signals collected by a spectrometer are separated through a filter to obtain an interference spectrum I11 and an interference spectrum I12;
step 2: fourier transformation is carried out on the interference spectrum I12 to obtain a magnitude spectrum of the interference spectrum, and the abscissa ordinal number of a maximum value point of the magnitude spectrum is set as M12;
and 3, step 3: the interference spectrum I12 is divided into two parts to obtain the phase of the two interference spectraθ 121 And theta 122 Calculating
Figure BDA0003069484330000041
And 4, step 4: obtaining an optical path difference P12:
Figure BDA0003069484330000042
and 5: correcting P12, comparing the sizes of P12 and 2 pi (M12 + 1)/delta k, and judging whether the round () function has errors; when P12 is greater than 2 π (M12 + 1)/Δ K, P12 minus 2 π/(K) c1 -K c2 ) To obtain a12; when P12 is less than 2 π (M12 + 1)/Δ k, the values of P12 and a12 are equal.
Further, the calculation steps of a21 are as follows:
step 1: when the measurement block to be measured is adopted for measurement, signals collected by the spectrograph are separated through a filter to obtain an interference spectrum I21 and an interference spectrum I22;
step 2: fourier transformation is carried out on the interference spectrum I21 to obtain the magnitude spectrum of the interference spectrum, and the abscissa ordinal number of the maximum value point of the magnitude spectrum is set as M21;
and step 3: the interference spectrum I21 is divided into two parts equally, and Fourier transformation is respectively carried out on the two parts of interference spectrum to obtain the phase theta of the two parts of interference spectrum 211 And theta 212 Calculating
Figure BDA0003069484330000043
And 4, step 4: obtaining an optical path difference P21:
Figure BDA0003069484330000044
and 5: correcting P21, comparing the sizes of P21 and 2 pi (M21 + 1)/delta k, and judging whether the round () function has errors or not; when P21 is greater than 2 π (M21 + 1)/Δ K, P21 minus 2 π/(K) c1 -K c2 ) To obtain a21; when P21 is less than 2 π (M21 + 1)/Δ k, the values of P21 and a21 are equal.
Further, the calculation step of a22 is as follows:
step 1: when the measurement block to be measured is adopted for measurement, signals collected by the spectrograph are separated through a filter to obtain an interference spectrum I21 and an interference spectrum I22;
step 2: fourier transformation is carried out on the interference spectrum I22 to obtain a magnitude spectrum of the interference spectrum, and the abscissa ordinal number of a maximum value point of the magnitude spectrum is set as M22;
and step 3: the interference spectrum I22 is divided into two parts equally, and Fourier transformation is respectively carried out on the two parts of interference spectrum to obtain the phase theta of the two parts of interference spectrum 221 And theta 222 Calculating
Figure BDA0003069484330000051
And 4, step 4: obtaining an optical path difference P22:
Figure BDA0003069484330000052
and 5: correcting P22, comparing P22 with 2 pi (M22 + 1)/Δ K, judging whether round () has error, when P22 is greater than 2 pi (M22 + 1)/Δ K, subtracting 2 pi/(K) from P22 c1 -K c2 ) To obtain a22; when P22 is less than 2 π (M22 + 1)/Δ k, the values of P22 and a22 are equal.
Compared with the prior art, the invention has the technical effects that:
(1) The method combines the frequency and the phase of Fourier transform, realizes the high-precision measurement of a larger distance based on white light interference, does not need to use the existing decimal repetition method based on multiple wavelength measurement, and is convenient and quick to operate;
(2) The sample light and the reference light in the invention adopt a common light path mode, thus effectively eliminating the error of the system;
(3) The invention adopts a double-end measurement structure, so that the placing position of the sample has no strict requirement, the vibration error of the sample relative to a detection system is eliminated, and the stability and the anti-interference capability of the system are improved;
(4) According to the invention, an indirect measuring block measuring method with high sensitivity, high stability, strong anti-interference capability and simple operation is adopted, the measuring result is not influenced by the stability of a light source, and the stability of the system is further improved;
(5) The invention adopts non-contact measurement and is not influenced by auxiliary flat crystal grinding.
Drawings
FIG. 1 is a schematic view of the structure of an apparatus of example 1;
FIG. 2 is a schematic diagram of the spectrometer of example 1 collecting signals;
FIG. 3 is a diagram showing the magnitude spectrum of the signal acquired by the spectrometer of example 1 after Fourier transform;
FIG. 4 is a diagram of the interference spectrum I11 obtained by filtering in example 1 after shaping;
FIG. 5 is a diagram showing the magnitude spectrum of the interference spectrum I11 after Fourier transform in example 1;
FIG. 6 is a schematic view of the structure of an apparatus according to embodiment 2;
the reference numbers are as follows: 1. a light source; 2. a light-splitting element; 3. a spectrometer; 4. a first lens assembly; 5. a first transparent plate; 6. measuring blocks; 7. a translation stage; 8. a second lens assembly; 9. a second transparent plate; 10. and a data processing module.
Detailed Description
In order to make the purpose and technical solutions of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below with reference to the embodiments.
Example 1
The measuring block measuring device based on white light interference comprises a low-coherence light source 1, a light splitting element 2, a measuring block 6, a spectrometer 3, a first transparent plate 5, a second transparent plate 9, a first lens assembly 4 and a second lens assembly 8, wherein the light splitting element 2 shown in fig. 1 is a 2*2 coupler, the first lens assembly 4 is provided with two first lenses, the second lens assembly 8 is provided with two second lenses, light emitted by the low-coherence light source 1 enters the coupler through an optical fiber, light output from one end of the coupler passes through one first lens far away from the first transparent plate 5 in the first lens assembly 4 to become parallel light beams, and the parallel light beams are converged on the left surface of the measuring block 6 through one first lens close to the first transparent plate 5; the light output from the other end of the coupler is changed into parallel light beams through a second lens far away from the second transparent plate 9, and the parallel light beams are converged on the right surface of the gauge block 6 through a second lens close to the second transparent plate 9;
the gauge block 6 is arranged between the first transparent plate 5 and the second transparent plate 9; the light reflected from the left surface of the gauge block 6 and the light reflected from the right surface of the first transparent plate return to the coupler and enter the spectrometer 3, forming a first interference spectrum; the light reflected from the right surface of the gauge block 6 and the light reflected from the left surface of the second transparent plate return to the coupler and enter the spectrometer 3 to form a second interference spectrum; the spectrometer 3 records the superimposed interference signal of the first interference spectrum and the second interference spectrum, and then transmits the superimposed interference signal to the data processing module 10 for processing. The thick solid line connections in fig. 1 indicate optical fiber connections, and the spacing between the gauge block 6 and the first and second transparent plates 5 and 9 is adjusted so that after fourier transform (FFT) of the signal collected by the spectrometer 3, the signals corresponding to the first and second interference spectra are separated in the FFT magnitude spectrum, as shown in fig. 3.
The coupler is a waveguide structure 2*2 coupler, and the low coherent light source 1 can be an SLD low coherent light source 1. The first transparent plate 5 is disposed at a position near the left surface of the gauge block 6, and the second transparent plate 9 is disposed at a position near the right surface of the gauge block 6. The measuring device further comprises a translation stage 7, the first lens assembly 4 and the first transparent plate 5 are arranged on the translation stage 7, or the second lens assembly 8 and the second transparent plate 9 are arranged on the translation stage 7, the translation stage 7 can move along the direction of the detection light, and the distance between the first transparent plate 5 and the second transparent plate 9 can be changed by moving the translation stage 7 so as to adapt to measuring blocks with different thicknesses.
The measuring principle of the measuring block measuring device based on white light interference is as follows:
moving the translation stage 7 according to the thickness of the gauge block 6, changing the distance between the first transparent plate 5 and the second transparent plate 9, placing a standard gauge block between the first transparent plate 5 and the second transparent plate 9 of the measuring device, setting the length of the standard gauge block to be L1, and as shown in FIG. 1, returning light reflected from the left surface of the standard gauge block and light reflected from the right surface of the first transparent plate 5 to the coupler through the optical fiber and entering the spectrometer 3 to form an interference spectrum I11; the light reflected from the right surface of the standard gauge block and the light reflected from the left surface of the second transparent plate 9 return to the coupler and enter the spectrometer 3 to form an interference spectrum I12; calculating the distance from the right surface of the first transparent plate 5 to the left surface of the standard gauge block according to the I11, and recording as a11; calculating the distance from the left surface of the second transparent plate 9 to the right surface of the standard gauge block according to the I12, and recording as a12; l0= a11+ a12+ L1, L0 representing the distance between the right surface of the first transparent board 5 and the left surface of the second transparent board 9;
then the standard measuring block is replaced by the measuring block, the measuring block is arranged between the first transparent plate 5 and the second transparent plate 9, the length of the measuring block is set to be L2,
the light reflected from the left surface of the block to be measured and the light reflected from the right surface of the first transparent plate 5 return to the coupler and enter the spectrometer 3 to form an interference spectrum I21; the light reflected from the right surface of the block to be measured and the light reflected from the left surface of the second transparent plate 9 return to the coupler and enter the spectrometer 3 to form an interference spectrum I22; calculating the distance from the right surface of the first transparent plate 5 to the left surface of the block to be measured according to the I21, and recording as a21; calculating the distance from the left surface of the second transparent plate 9 to the right surface of the block to be measured according to the I22, and recording as a22; since the positions of the first transparent board 5 and the second transparent board 9 are unchanged at the time of two measurements, the distance L0= a21+ a22+ L2 between the right surface of the first transparent board 5 and the left surface of the second transparent board 9;
and further obtaining the length difference delta between the standard measuring block and the measuring block to be measured:
Δ = (L1-L2) = (a 21+ a 22) - (a 11+ a 12) (formula 1)
As can be seen from formula 1, Δ is not affected by the positions of the standard gauge block and the gauge block, i.e., Δ is not affected when the positions of the standard gauge block and the gauge block are different; further, assuming that the standard mass is vibrating with respect to the system at the time of measurement, assuming that a11 becomes (a 11+ d 1), a12 becomes (a 12-d 1), and (a 11+ d 1) + (a 12-d 1) = (a 21+ a 22), it can be seen that the value of (a 11+ a 12) is not affected by the vibration of the mass, and similarly, the value of (a 21+ a 22) is not affected by the vibration of the mass 6, and thus the system has high stability.
Because the first transparent plate 5 and the second transparent plate 9 which are used as reference surfaces are very close to the measuring block to be measured or the standard measuring block, and the reference light and the sample light form a common light path mode, the external disturbance such as the flow of air, the change of temperature and the like can be eliminated, and the stability of the system is further improved.
According to the measuring method of the gauge block shown in fig. 2-3, when the standard gauge block is placed between the two plates, the signals collected by the spectrometer are fourier transformed as shown in fig. 2, and the amplitude spectrum of the interference spectrum is obtained, the amplitude spectrum is shown in fig. 3, the first peak in fig. 3 is the signal corresponding to the interference spectrum I11 on the right surface of the first transparent plate 5 and the left surface of the standard gauge block, and the second peak is the signal corresponding to the interference spectrum I12 on the left surface of the second transparent plate 9 and the right surface of the standard gauge block. The interference spectrum is filtered using a filter, the two interference signals are separated, and their corresponding optical paths are calculated.
According to the demodulation method for the optical path corresponding to a11 shown in fig. 4-5, the signal collected by the spectrometer 3 is separated by a filter to obtain an interference spectrum I11, as shown in fig. 4; the magnitude spectrum is obtained through fourier transform, and as shown in fig. 5, the abscissa ordinal number of the maximum point of the magnitude spectrum is set to be M11. Dividing the interference spectrum into two parts equally, and setting the central wave number of the two parts of spectrum as K C1 And K C2。 Fourier transform is respectively carried out on the two interference spectrums to obtain the phase theta of the two interference spectrums 111 And theta 112 Calculating
Figure BDA0003069484330000081
The winding interval of A is 2 pi/(K) c1 -K c2 ) The frequency resolution of FFT is 2 pi/Δ K, Δ K is the wave number width corresponding to spectrometer 3, Δ K is equal to 2 (K) c1 -K c2 ) And therefore the frequency resolution is exactly half the a wrap interval. Therefore, when M is increased by 2, winding is generated once, the winding number of A is determined by M, and the optical path difference P11 is obtained:
Figure BDA0003069484330000082
round () represents a round-rounding operation.
Correcting P11, comparing the magnitudes of P11 and 2 pi (M11 + 1)/Δ k, wherein Δ k is the wave number width corresponding to the spectrometer, and judging whether a round () function has an error; when P11 is greater than 2 π (M11 + 1)/Δ K, P11 minus 2 π/(K) c1 -K c2 ) To obtain a11; when P11 is less than 2 π (M11 + 1)/Δ k, the values of P11 and a11 are equal.
Similarly, the calculation steps of a12 are as follows:
step 1: when a standard gauge block is used for measurement, signals collected by a spectrometer are separated through a filter to obtain an interference spectrum I11 and an interference spectrum I12;
step 2: fourier transformation is carried out on the interference spectrum I12 to obtain a magnitude spectrum of the interference spectrum, and the abscissa ordinal number of a maximum value point of the magnitude spectrum is set as M12;
and step 3: the interference spectrum I12 is divided into two parts equally, and Fourier transform is respectively carried out on the two parts of interference spectrum to obtain the phase theta of the two parts of interference spectrum 121 And theta 122 Calculating
Figure BDA0003069484330000091
And 4, step 4: obtaining an optical path difference P12:
Figure BDA0003069484330000092
and 5: correcting P12, comparing the sizes of P12 and 2 pi (M12 + 1)/delta k, and judging whether the round () function has errors; when P12 is greater than 2 π (M12 + 1)/Δ K, P12 minus 2 π/(K) c1 -K c2 ) To obtain a12; when P12 is less than 2 π (M12 + 1)/Δ k, the values of P12 and a12 are equal.
The calculation steps of a21 are as follows:
step 1: when the measurement is carried out by adopting the measuring block to be measured, signals collected by the spectrograph are separated by the filter to obtain an interference spectrum I21 and an interference spectrum I22;
step 2: fourier transform is carried out on the interference spectrum 121 to obtain the magnitude spectrum of the interference spectrum, and the abscissa ordinal number of the maximum value point of the magnitude spectrum is set as M21;
and 3, step 3: the interference spectrum I21 is divided into two parts equally, and Fourier transformation is respectively carried out on the two parts of interference spectrum to obtain the phase theta of the two parts of interference spectrum 211 And theta 212 Calculating
Figure BDA0003069484330000093
And 4, step 4: obtaining an optical path difference P21:
Figure BDA0003069484330000094
and 5: correcting P21, comparing the sizes of P21 and 2 pi (M21 + 1)/delta k, and judging whether the round () function has errors; when P21 is greater than 2 π (M21 + 1)/Δ K, P21 minus 2 π/(K) c1 -K c2 ) To obtain a21; when P21 is less than 2 π (M21 + 1)/Δ k, the values of P21 and a21 are equal.
Further, the calculation steps of a22 are as follows:
step 1: when the measurement block to be measured is adopted for measurement, signals collected by the spectrograph are separated through a filter to obtain an interference spectrum I21 and an interference spectrum I22;
and 2, step: fourier transformation is carried out on the interference spectrum I22 to obtain a magnitude spectrum of the interference spectrum, and the abscissa ordinal number of a maximum value point of the magnitude spectrum is set as M22;
and step 3: the interference spectrum I22 is divided into two parts equally, and Fourier transform is respectively carried out on the two parts of interference spectrum to obtain the phase theta of the two parts of interference spectrum 221 And theta 222 Calculating
Figure BDA0003069484330000101
And 4, step 4: obtaining an optical path difference P22:
Figure BDA0003069484330000102
and 5: correcting P22, comparing P22 with 2 pi (M22 + 1)/Δ K, judging whether round () has error, when P22 is greater than 2 pi (M22 + 1)/Δ K, P22 subtracting 2 pi/(K22 + 1)/Δ K c1 -K c2 ) To obtain a22; when P22 is less than 2 π (M22 + 1)/Δ k, the values of P22 and a22 are equal.
By the above calculation method, the intervals a12, a21 and a22 can be calculated from the interference spectrum I12, the interference spectrum I21 and the interference spectrum I22, respectively, and the measured intervals a11, a12, a21 and a22 are substituted into the above formula 1, so that the length difference Δ between the standard measuring block and the measuring block can be obtained.
Example 2
According to a white light interference-based gauge block measuring device shown in fig. 6, different from embodiment 1, the first lens assembly comprises a first lens, the second lens assembly comprises a second lens, the rest of the arrangements are the same, and the applied method principle is the same as that in embodiment 1.
The above description is only an embodiment of the present invention, and the present invention is described in detail and specifically, but not to be construed as limiting the scope of the present invention. It should be noted that various changes and modifications can be made by those skilled in the art without departing from the spirit of the invention, and these changes and modifications are all within the scope of the invention.

Claims (8)

1. A measuring block measuring method based on white light interference is characterized by comprising a low-coherence light source, a light splitting element, a spectrometer, a first lens assembly, a first transparent plate, a measuring block, a second transparent plate, a second lens assembly and a data processing module;
the method comprises the following steps:
step S1: the standard gauge block is arranged between a first transparent plate and a second transparent plate of the measuring device, the length of the standard gauge block is set to be L1,
the light reflected from the left surface of the standard gauge block and the light reflected from the right surface of the first transparent plate return to the light splitting element and enter the spectrometer to form an interference spectrum I11;
the light reflected from the right surface of the standard gauge block and the light reflected from the left surface of the second transparent plate return to the light splitting element and enter the spectrometer to form an interference spectrum I12;
calculating the distance from the right surface of the first transparent plate to the left surface of the standard gauge block according to the I11, and recording as a11;
calculating the distance from the left surface of the second transparent plate to the right surface of the standard gauge block according to I12, and marking as a12;
l0= a11+ a12+ L1, where L0 represents the distance between the right surface of the first transparent plate and the left surface of the second transparent plate;
step S2: replacing the standard measuring block with the measuring block, arranging the measuring block between the first transparent plate and the second transparent plate, setting the length of the measuring block to be L2,
the light reflected by the left surface of the block to be measured and the light reflected by the right surface of the first transparent plate return to the light splitting element and enter the spectrometer to form an interference spectrum I21;
the light reflected from the right surface of the block to be measured and the light reflected from the left surface of the second transparent plate return to the light splitting element and enter the spectrometer to form an interference spectrum I22;
calculating the distance from the right surface of the first transparent plate to the left surface of the block to be measured according to the I21, and recording as a21;
calculating the distance from the left surface of the second transparent plate to the right surface of the block to be measured according to the I22, and marking as a22;
then L0= a21+ a22+ L2;
and step S3: obtaining the length difference delta between the standard measuring block and the measuring block to be measured: Δ = L1-L2= a21+ a22-a11-a12;
a11 calculating step:
step 1: when a standard gauge block is used for measurement, signals collected by a spectrometer are separated through a filter to obtain an interference spectrum I11 and an interference spectrum I12;
step 2: fourier transformation is carried out on the interference spectrum I11 to obtain a magnitude spectrum of the interference spectrum, and the abscissa ordinal number of a maximum value point of the magnitude spectrum is set as M11;
and step 3: dividing the interference spectrum I11 into two parts equally, and setting the central wave numbers of the two interference spectra to be K respectively C1 And K C2 And Fourier transform is respectively carried out on the two interference spectrums to obtain the phase theta of the two interference spectrums 111 And theta 112 Calculating
Figure DEST_PATH_IMAGE001
；
And 4, step 4: obtaining an optical path difference P11:
Figure 76901DEST_PATH_IMAGE002
round () represents a round rounding operation;
and 5: correcting P11, comparing P11 with
Figure DEST_PATH_IMAGE003
The size of (a) is (b),
Figure DEST_PATH_IMAGE005
judging whether round () has errors or not for the wave number width corresponding to the spectrometer; when P11 is greater than
Figure 134987DEST_PATH_IMAGE006
When P11 is subtracted by 2 π/(K) c1 -K c2 ) To obtain a11; when P11 is less than
Figure DEST_PATH_IMAGE007
The values of P11 and a11 are equal.
2. A white-light interferometry-based gauge block measurement method according to claim 1, wherein the calculating step of a12 is as follows:
step 1: when a standard gauge block is used for measurement, signals collected by a spectrometer are separated through a filter to obtain an interference spectrum I11 and an interference spectrum I12;
step 2: fourier transformation is carried out on the interference spectrum I12 to obtain the magnitude spectrum of the interference spectrum, and the abscissa ordinal number of the maximum value point of the magnitude spectrum is set as M12;
and step 3: the interference spectrum I12 is divided into two parts equally, and Fourier transformation is respectively carried out on the two parts of interference spectrum to obtain the phase theta of the two parts of interference spectrum 121 And theta 122 Calculating
Figure 649144DEST_PATH_IMAGE008
；
And 4, step 4: obtaining an optical path difference P12:
Figure 122982DEST_PATH_IMAGE009
；
and 5: correcting P12, and comparing P12 with
Figure 406196DEST_PATH_IMAGE010
Judging whether the round () function has errors or not; when P12 is greater than
Figure DEST_PATH_IMAGE011
When P12 is less than 2 pi/(K) c1 -K c2 ) To obtain a12; when P12 is less than
Figure 87713DEST_PATH_IMAGE012
The values of P12 and a12 are equal.
3. A white-light interferometry-based gauge block measurement method according to claim 1, wherein the calculating step of a21 is as follows:
step 1: when the measurement block to be measured is adopted for measurement, signals collected by the spectrograph are separated through a filter to obtain an interference spectrum I21 and an interference spectrum I22;
step 2: fourier transformation is carried out on the interference spectrum I21 to obtain the magnitude spectrum of the interference spectrum, and the abscissa ordinal number of the maximum value point of the magnitude spectrum is set as M21;
and step 3: the interference spectrum I21 is divided into two parts equally, and the two interference spectra are respectively subjected to Fourier transformThe phase theta of two-part interference spectrum is obtained by inner leaf transformation 211 And theta 212 Calculating
Figure DEST_PATH_IMAGE013
；
And 4, step 4: obtaining an optical path difference P21:
Figure 902216DEST_PATH_IMAGE014
；
and 5: correcting P21, and comparing P21 with
Figure DEST_PATH_IMAGE015
Judging whether the round () function has errors or not; when P21 is greater than
Figure 163434DEST_PATH_IMAGE016
When P21 minus 2 π/(K) c1 -K c2 ) To obtain a21; when P21 is less than
Figure 301154DEST_PATH_IMAGE017
The values of P21 and a21 are equal.
4. A white-light interferometry-based gauge block measurement method according to claim 1, wherein the calculating step of a22 is as follows:
step 1: when the measurement is carried out by adopting the measuring block to be measured, signals collected by the spectrograph are separated by the filter to obtain an interference spectrum I21 and an interference spectrum I22;
step 2: fourier transformation is carried out on the interference spectrum I22 to obtain a magnitude spectrum of the interference spectrum, and the abscissa ordinal number of a maximum value point of the magnitude spectrum is set as M22;
and step 3: the interference spectrum I22 is divided into two parts equally, and Fourier transform is respectively carried out on the two parts of interference spectrum to obtain the phase theta of the two parts of interference spectrum 221 And theta 222 Calculating
Figure 560097DEST_PATH_IMAGE018
；
And 4, step 4: obtaining an optical path difference P22:
Figure DEST_PATH_IMAGE019
；
and 5: correcting P22, and comparing P22 with
Figure 861896DEST_PATH_IMAGE020
Judging whether the round () has an error, when P22 is larger than
Figure DEST_PATH_IMAGE021
When P22 minus 2 π/(K) c1 -K c2 ) To obtain a22; when P22 is less than
Figure 457963DEST_PATH_IMAGE022
The values of P22 and a22 are equal.
5. A measuring device using the white light interference-based gauge block measuring method according to any one of claims 1 to 4,
the low-coherence light source is connected with the light splitting element through an optical fiber;
the light splitting element, the spectrometer and the data processing module are sequentially arranged;
the gauge block is arranged between the first transparent plate and the second transparent plate;
a first transparent plate, a first lens assembly and a light splitting element are sequentially arranged in the direction from the left surface close to the gauge block to the left surface far away from the gauge block;
a second transparent plate, a second lens assembly and a light splitting element are sequentially arranged from the direction close to the right surface of the gauge block to the direction far away from the right surface of the gauge block;
the light reflected by the left surface of the gauge block and the light reflected by the right surface of the first transparent plate return to the light splitting element and enter a spectrometer to form a first interference spectrum;
the light reflected by the right surface of the gauge block and the light reflected by the left surface of the second transparent plate return to the light splitting element and enter a spectrometer to form a second interference spectrum;
and the spectrometer records the superposed interference signals of the first interference spectrum and the second interference spectrum, and then transmits the superposed interference signals to the data processing module for processing.
6. The white-light interferometry-based measuring device of the method for measuring mass according to claim 5, wherein the first lens assembly comprises at least one first lens, and the second lens assembly comprises at least one second lens.
7. The measuring device of the white light interference-based measuring block measuring method according to claim 5, characterized by further comprising a translation stage, wherein the translation stage is arranged below the first transparent plate or the translation stage is arranged below the second transparent plate.
8. The measurement device of the white light interference-based measuring block measurement method according to claim 5, wherein the light splitting element is a 2*2 coupler.
CN202110535055.2A 2021-05-17 2021-05-17 Gauge block measuring device and method based on white light interference Active CN113251897B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202110535055.2A CN113251897B (en) 2021-05-17 2021-05-17 Gauge block measuring device and method based on white light interference

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202110535055.2A CN113251897B (en) 2021-05-17 2021-05-17 Gauge block measuring device and method based on white light interference

Publications (2)

Publication Number Publication Date
CN113251897A CN113251897A (en) 2021-08-13
CN113251897B true CN113251897B (en) 2022-11-11

Family

ID=77182199

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202110535055.2A Active CN113251897B (en) 2021-05-17 2021-05-17 Gauge block measuring device and method based on white light interference

Country Status (1)

Country Link
CN (1) CN113251897B (en)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114001657B (en) * 2021-09-26 2023-06-13 河北大学 Gauge block length calibration device and calibration method based on low-coherence light series interference

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103090808A (en) * 2013-01-22 2013-05-08 浙江大学 High-precision wide-range gap measuring method and system based on spectrum phase
CN103615996A (en) * 2013-11-14 2014-03-05 大连理工大学 Method for measuring thickness of coatings through ultrasonic signal spectrum filter technology in nondestructive mode

Family Cites Families (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7268887B2 (en) * 2004-12-23 2007-09-11 Corning Incorporated Overlapping common-path interferometers for two-sided measurement
US8537369B1 (en) * 2009-07-16 2013-09-17 Kla Tencor Method and apparatus for measuring the shape and thickness variation of a wafer by two single-shot phase-shifting interferometers
CN101701792B (en) * 2009-11-20 2012-11-21 广州市计量检测技术研究院 Gauge block automatic verification system and verification method
US20150176973A1 (en) * 2011-12-09 2015-06-25 Kla-Tencor Corporation A dual interferometer system with a short reference flat distance for wafer shape and thickness variation measurement
JP6725988B2 (en) * 2016-01-26 2020-07-22 大塚電子株式会社 Thickness measuring device and thickness measuring method
CN105716521B (en) * 2016-02-02 2018-08-17 东北大学 Increase the devices and methods therefor of frequency domain low-coherent light interferometry range
CN109781633A (en) * 2019-03-13 2019-05-21 山东大学 A kind of the white light Microscopic Interferometric Measuring System and method of available spectral information
CN110361099B (en) * 2019-07-17 2020-08-25 东北大学 Spectral domain low-coherence light interference optical path difference demodulation method

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103090808A (en) * 2013-01-22 2013-05-08 浙江大学 High-precision wide-range gap measuring method and system based on spectrum phase
CN103615996A (en) * 2013-11-14 2014-03-05 大连理工大学 Method for measuring thickness of coatings through ultrasonic signal spectrum filter technology in nondestructive mode

Also Published As

Publication number Publication date
CN113251897A (en) 2021-08-13

Similar Documents

Publication Publication Date Title
CN101718520B (en) System for quickly measuring surface quality
WO2017133128A1 (en) Method for correcting air refractive index in large-range absolute distance measurement
CN103954589B (en) The precision measurement apparatus of a kind of optical material specific refractory power and method
CN104296698A (en) Method for measuring evenness of optical surface with ultrahigh precision
CN103454249B (en) Based on optical glass homogeneity detection method and the device of white light interference
CN104215176A (en) High accuracy optical interval measurement device and method
CN102332956A (en) Dispersion compensation method for broadband light source
CN104748671A (en) Nonlinear error correcting method and device for angular displacement type single-frequency laser interferometer
CN113251897B (en) Gauge block measuring device and method based on white light interference
CN104634280A (en) Method for measuring absolute angle and rotating angle of universal horizontal turntable
JP3426552B2 (en) Shape measuring device
JPH06229922A (en) Very accurate air refractometer
US6462823B1 (en) Wavelength meter adapted for averaging multiple measurements
US5041988A (en) Method and device for measuring a surface contour
Ishii et al. New method for interferometric measurement of gauge blocks without wringing onto a platen
CN104006950A (en) Method for measuring birefringence dispersion values of polarization-maintaining fibers
TW201502492A (en) Method and apparatus for measuring refractive index and method for manufacturing optical element
CN113325574B (en) Double-light-source cavity length matching demodulation method of optical fiber Fabry-Perot sensor
CN105716521A (en) Device and method for enlarging measurement range of frequency domain low coherent light interference
JPH05272913A (en) Highly-accurate gage interferometer
CN103090801B (en) Device and method which are based on birefringence chromatic dispersion and are used for measuring picometer-order displacement
CN106839972B (en) A kind of interference signal processing method of full light fiber white light interference instrument
CN114001657B (en) Gauge block length calibration device and calibration method based on low-coherence light series interference
Liu et al. Theory and application of laser interferometer systems
CN116222390A (en) Gauge block measuring device and method

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
GR01 Patent grant
GR01 Patent grant