CN106871797B - Non-contact sample thickness measuring method and measuring device based on Michelson interference principle - Google Patents
Non-contact sample thickness measuring method and measuring device based on Michelson interference principle Download PDFInfo
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- G01—MEASURING; TESTING
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- 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
- G01B11/0616—Measuring arrangements characterised by the use of optical techniques for measuring length, width or thickness for measuring thickness ; e.g. of sheet material of coating
- G01B11/0675—Measuring arrangements characterised by the use of optical techniques for measuring length, width or thickness for measuring thickness ; e.g. of sheet material of coating using interferometry
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Abstract
The invention discloses a non-contact sample thickness measuring method and a measuring device based on the Michelson interference principle, wherein the optical path of a laser beam is changed by adjusting the angle between an M1 reflector and a sample plane, so that interference fringes move, and the thickness of a sample to be measured is calculated according to a formula provided by the invention; because the physical quantity required to be controlled by the measuring method is only the angle between the M1 reflector and the sample plane, the measuring error is extremely small, the measuring process is simplified, and the measuring precision of the sample thickness is improved; the measuring device for realizing the measuring method has simple measuring principle and does not need expensive instruments with high precision, so that the optical path component can be integrated into an integrated device and the measuring device can be designed into a miniaturized portable device.
Description
Technical Field
The invention belongs to the technical field of optical measurement, and particularly relates to a non-contact type sample thickness measuring method and device based on the Michelson interference principle.
Background
For the measurement of the thickness of the sample, contact measurement (for example, measurement by using a vernier caliper, a micrometer screw, or the like) or non-contact measurement (for example, a measurement method based on the michelson interference principle) may be used; however, in some special cases, a high-precision non-contact measuring device has irreplaceability, for example, in the manufacturing process of a glass instrument, the glass in a molten state is required to be measured for properties such as thickness, refractive index and the like; in this case, the contact measurement method may not only affect the shape and structure of the material, but also has a very limited accuracy.
Therefore, there is a need for industrial production that provides high-precision non-contact measurement methods and instruments. The traditional Michelson interference measurement method can only measure film samples with the thickness of hundreds of micrometers, and is difficult to apply to industrial production. At present, the industry has used a two-dimensional laser scanning non-contact measurement technology to measure the thickness of a thick sample (see shanoza, yochun optical non-contact profile measurement technology research progress optical technology 2008.12, volume 34, supplement 216-217), which uses the shielding of the sample from the laser to generate and record the light intensity difference on the receiving screen, so as to determine the profile of the object to be measured, thereby obtaining the thickness of the sample. The key of the method for influencing the measurement precision lies in the stability and accuracy of laser imaging; therefore, when the optical system is designed, the image plane illumination distribution is uniform, the stray light is less, the imaging geometric distortion is small, and the like, so that the design is complex, and the manufacturing cost of the instrument is very high.
Disclosure of Invention
In view of the above-mentioned deficiencies in the prior art, the present invention aims to provide a non-contact measurement method based on the michelson interference principle, which is convenient for measurement and has small error, and can realize non-contact measurement of the thickness of a sample.
Another object of the present invention is to provide a device for implementing the above mentioned non-contact type sample thickness measuring method based on michelson interference principle.
Aiming at the first invention purpose, the non-contact sample thickness measuring method based on the Michelson interference principle provided by the invention measures the sample thickness by utilizing an optical path component which is mainly composed of an M1 reflector, an M2 reflector, a laser source, a receiving device, a beam splitter and a compensation plate, wherein the laser source, the beam splitter, the compensation plate and the M2 reflector are sequentially arranged along the same direction, and the beam splitter and the compensation plate are parallel to each other and form an included angle of 45 degrees with the mirror surface of the M1 reflector; the object stage for placing the sample is positioned between the M1 reflecting mirror and the light splitting plate; the sample thickness was measured by a method comprising the following steps:
s1, placing a sample to be detected on an objective table;
s2, opening the laser source, adjusting the objective table or the optical path component until the receiving device receives the interference fringes, and recording the relative rotation angle alpha between the sample plane and the mirror surface of the M1 reflector 1 ；
S3, continuously adjusting the objective table or the light path component to move L interference fringes received by the receiving device, and recording the relative rotation included angle alpha between the sample plane and the mirror surface of the M1 reflector 2 ；
S4，The included angle alpha between the sample plane recorded in the step S2 and the step S3 and the M1 reflecting mirror 1 、α 2 And substituting the moving number L of the interference fringes into the following formula to calculate the thickness of the sample to be measured:
wherein x is the thickness of the sample to be measured, and λ is the wavelength of the laser source.
In the above non-contact type sample thickness measuring method based on the michelson interference principle, in order to make the measured sample thickness more accurate, it is better to repeat the steps S1 to S4 several times to obtain multiple groups of numerical values of the thickness of the sample to be measured, calculate the average value of the multiple groups of numerical values of the thickness of the sample to be measured, and use the average value as the thickness of the sample to be measured.
Aiming at the second purpose, the device for realizing the non-contact sample thickness measuring method based on the michelson interference principle comprises a rotatable objective table and a light path component, wherein the light path component mainly comprises an M1 reflector, an M2 reflector, a laser source, a receiving device, a beam splitter and a compensation plate, the laser source, the beam splitter, the compensation plate and the M2 reflector are sequentially arranged along the same direction, and the beam splitter and the compensation plate are parallel to each other and form an included angle of 45 degrees with the mirror surface of the M1 reflector; the rotatable object stage is positioned between the M1 reflector and the light splitting plate; the beam splitter divides laser emitted by the laser source into two beams, wherein one beam of laser is incident to the M1 reflector through a sample on the rotatable objective table, and the other beam of laser is incident to the M2 reflector through the compensation plate; the reflected light reflected by the M1 reflector is received by the receiving device through the sample on the rotatable objective table and the spectroscopic plate, and the reflected light reflected by the M2 reflector is reflected to the receiving device through the spectroscopic plate and the compensation plate; and adjusting the rotation angle of the rotatable object stage to enable the two beams of reflected light to form interference fringes on the receiving device. The device realizes the relative rotation of the sample plane and the mirror surface of the M1 reflector by adjusting the objective table, and further realizes the measurement of the thickness of the sample.
In the above non-contact sample thickness measuring apparatus based on the michelson interference principle, the receiving Device is a receiving screen or a CCD (Charge-coupled Device) element; the CCD element is a plane lattice charge coupled element or a linear charge coupled element; the planar lattice charge-coupled device can be a CCD camera, a digital camera, a mobile phone camera and the like; such as a CCD element in a scanner or the like.
The device for implementing the non-contact sample thickness measurement method based on the michelson interference principle, which is directed to the second invention object, may also be designed to implement the relative rotation between the sample plane and the M1 mirror surface by adjusting the optical path component, that is, the device includes a fixed stage for placing the sample to be measured and an optical path component enclosed in a housing; the light path component mainly comprises an M1 reflector, an M2 reflector, a laser source, a receiving device, a light splitting plate, a compensation plate and a micro-electromechanical gyroscope which are arranged on a base in the shell; the laser source, the light splitting plate, the compensation plate and the M2 reflector are sequentially arranged along the same direction, and the light splitting plate and the compensation plate are mutually parallel and form an included angle of 45 degrees with the mirror surface of the M1 reflector; the base and the micro-electromechanical gyroscope are arranged on the central shaft, so that the linkage of base rotation and angle measurement is realized; the beam splitter divides laser emitted by the laser source into two beams, wherein one beam of laser is incident to the M1 reflector through the sample, and the other beam of laser is incident to the M2 reflector through the compensation plate; the reflected light reflected by the M1 reflector is received by the receiving device through the sample and the light splitting plate, and the reflected light reflected by the M2 reflector is reflected to the receiving device through the light splitting plate through the compensation plate; adjusting the rotation angle of a base in the shell to enable the receiving device to receive the interference fringes; the shell is provided with an opening with the thickness larger than that of the sample, and the fixed object stage can enable the sample placed on the fixed object stage to enter the shell along the opening and is positioned between the M1 reflecting mirror and the light splitting plate.
In the above non-contact sample thickness measuring device based on michelson interference principle, the receiving device is a CCD element; the CCD element is the same as the CCD element, and is a plane lattice charge coupled element or a linear charge coupled element; the planar lattice charge coupled device is a CCD video camera, a digital camera, a mobile phone camera and the like; such as a CCD element in a scanner or the like.
According to the non-contact sample thickness measuring device based on the Michelson interference principle, the base is installed in the shell through the central shaft, the shell, the base and the central shaft can be fixedly connected for convenience of operation, and the base and the central shaft can rotate through rotating the shell; certainly, the shell, the base and the central shaft can also be not fixedly connected, but a rotating handle is arranged at one end of the central shaft, which is positioned outside the shell, and the base is rotated by rotating the rotating handle; furthermore, the rotation of the central shaft can also be realized by a stepping motor.
According to the non-contact sample thickness measuring device based on the Michelson interference principle, the micro-electromechanical gyroscope and the receiving device are respectively and electrically connected with the single chip microcomputer, and the single chip microcomputer is used for recording and processing the rotation angle of the base and the image data.
According to the non-contact sample thickness measuring device based on the Michelson interference principle, the single chip microcomputer can be located in the shell, mounted on the base in the shell, or located outside the shell; the single chip microcomputer is electrically connected with a display device positioned outside the shell, and the single chip microcomputer and the display device can be integrated in the same controller, such as a computer, a mobile phone and the like. Such as LCD displays, LED displays, etc.
Compared with the prior art, the invention has the following beneficial effects:
1. the invention relates to a non-contact sample thickness measuring method based on the Michelson interference principle, which is characterized in that the optical path of a laser beam is changed by adjusting the angle between an M1 reflector and a sample plane, so that interference fringes move, and the thickness of a sample to be measured is calculated according to a formula provided by the invention; because the physical quantity required to be controlled by the measuring method is only the angle between the M1 reflector and the sample plane, the measuring error is extremely small, and the measuring process is simplified while the measuring precision of the sample thickness is improved.
2. The non-contact sample thickness measuring method based on the Michelson interference principle is expected to achieve the measuring accuracy of 1 mu m, and can meet most production and measurement requirements.
3. According to the non-contact sample thickness measuring method based on the Michelson interference principle, the angle adjusting range between the M1 reflector and the sample plane can be from a place close to the laser source to the position between the M1 reflectors, and a large angle adjusting range is provided, so that a thick sample can be measured, and the thickness of the sample can reach the centimeter magnitude.
4. The non-contact sample thickness measuring device based on the Michelson interference principle only needs to know the number of interference fringe movement in the rotation period of the M1 reflector relative to the sample plane, has low requirements on laser source imaging, and avoids the need of meeting the requirements of uniform image surface illumination distribution, less stray light and imaging geometric distortion pins, thereby reducing the requirements on equipment (such as a CCD element) precision and greatly reducing the measurement cost.
5. The non-contact sample thickness measuring device based on the Michelson interference principle has the advantages that the measuring principle is simple, high-precision expensive instruments are not needed, and therefore, the light path assembly formed by the M1 reflector, the M2 reflector, the laser source, the receiving device, the light splitting plate and the compensating plate can be integrated into an integrated device, the space is saved, the size of the measuring device is reduced, and the device can be even designed into a miniaturized portable device.
Drawings
Fig. 1 is a schematic diagram of a first non-contact sample thickness measuring device based on the michelson interference principle according to the present invention.
FIG. 2 is a schematic diagram of the laser interference path through a sample.
Fig. 3 is a schematic diagram of a second non-contact sample thickness measuring device based on the michelson interference principle according to the present invention.
Fig. 4 is a schematic diagram of a third non-contact sample thickness measuring device based on the michelson interference principle according to the present invention.
The objects identified by the reference numerals in the figures are: the device comprises a 1-M1 reflector, a 2-M2 reflector, a 3-rotatable object stage, a 3' -fixed object stage, a 4-sample, a 5-laser source, a 6-receiving device, a 7-beam splitter, an 8-compensation plate, a 9-central shaft, a 10-micro-electromechanical gyroscope, an 11-single chip microcomputer, a 12-display device and a 13-shell.
Detailed Description
The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings, and it is to be understood that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the disclosure of the present invention, those skilled in the art can implement the present invention in other embodiments without creative efforts, and the implementation of these embodiments is within the protection scope of the present invention.
Example 1
The embodiment provides a non-contact sample thickness measuring device based on the michelson interference principle, the structure of which is shown in fig. 1, the measuring device comprises a rotatable object stage 3 and a light path component which is mainly composed of an M1 reflector 1, an M2 reflector 2, a laser source 5, a receiving device 6, a beam splitter plate 7 and a compensation plate 8, wherein the laser source 5, the beam splitter plate 7, the compensation plate 8 and the M2 reflector 2 are sequentially arranged along the same direction, the beam splitter plate 7 and the compensation plate 8 are parallel to each other and form an included angle of 45 degrees with the mirror surface of the M1 reflector; the rotatable object stage 3 is positioned between the M1 reflector 1 and the light splitting plate 7; the receiving device 6 is a receiving screen.
When the non-contact sample thickness measuring device based on the Michelson interference principle is used, the beam splitter 7 divides laser emitted by the laser source 5 into two beams, wherein one beam of laser is incident to the M1 reflector 1 through the sample 4 positioned on the rotatable objective table 3, and the other beam of laser is incident to the M2 reflector 2 through the compensation plate 8; the reflected light reflected by the M1 reflector 1 is received by the receiving screen through the sample 4 on the rotatable objective table 3 and the light splitting plate 7, and the reflected light reflected by the M2 reflector 2 is reflected to the receiving screen through the compensating plate 8 and then through the light splitting plate 7; the rotation angle of the rotatable stage 3 is adjusted so that the two beams of reflected light form interference fringes on the receiving screen.
The laser interference light path passing through the sample 4 is shown in fig. 2, where α is an incident angle, β is a refraction angle, γ is a deflection angle of a refracted light ray relative to an incident light ray after the sample 4 is placed, x is a thickness of the sample 4 to be measured, h is a light path of a straight light ray propagating before the sample 4 is placed, Δ is a light path difference of a light ray propagating before and after the sample 4 is placed, and α is an included angle between a sample plane and an M1 mirror surface as can be seen from a geometric relationship in the figure:
α＝β+γ
the three equations in (1) are combined to obtain
Since the refractive index of sample 4 is
Obtained by combining (2) and (3)
When the rotatable object stage 3 is adjusted to enable interference fringes to appear on the receiving screen twice, and when the interference fringes appear each time, the included angles between the plane of the sample 4 and the mirror surface of the M1 reflector are respectively alpha 1 And alpha 2 When the interference fringe appears twice, the optical path difference delta 1 And Δ 2 Respectively as follows:
the process of the optical path difference change can be embodied as the change of the number of interference fringes on the receiving screen, and simultaneously, according to the Michelson interferometer principle, the condition for obtaining the interference bright fringes is that the optical path difference of two laser beams separated by the split beam reaching the receiving screen is changed into integral multiple of the laser wavelength, so that the optical path difference is changed into integral multiple of the laser wavelength
2|Δ 1 -Δ 2 |＝Lλ (6)
The equation (5) and the formula (6) are combined to obtain
From the above analysis, it can be seen that the included angles between the plane of the sample 4 and the mirror surface of the M1 mirror are respectively α when only two interference fringes appear 1 And alpha 2 Then substituting the formula to obtain the thickness of the sample 4, wherein L is the moving number of the interference fringes; n is the refractive index of sample 4 and can be obtained by methods already disclosed in the art (e.g., tekkaido, chentong, opto-electronic based glass refractive index measurement application optics 2010 (5): 777-780).
The non-contact type sample thickness measuring device based on the michelson interference principle is used for measuring glass with standard thicknesses of 3.85mm, 4.81mm, 7.85mm, 9.86mm and 11.90mm (the standard thicknesses are measured by an electronic vernier caliper), wherein the refractive index of the glass to be measured in the embodiment is n =1.623, the wavelength of a laser source is 654.3mm, and the measuring process is as follows:
s1, placing glass to be detected on a rotatable object stage 3;
s2, turning on the laser source 5, adjusting the rotatable object stage 3 to the receiving screen to receive the interference fringes, and recording the relative rotation angle alpha between the glass plane to be measured and the mirror surface of the M1 reflector 1 1 ；
S3, continuously adjusting the rotatable object stage 3 to move L interference fringes received by the receiving screen, and recording the relative rotation included angle alpha between the plane of the glass to be measured and the mirror surface of the M1 reflector 1 2 ；
S4, recording the relative rotation angle alpha between the glass plane to be measured and the M1 reflector 1 recorded in the steps S2 and S3 1 、α 2 And the moving number L of interference fringeThe thickness of the glass to be measured is calculated by the following formula:
wherein x is the thickness of the sample to be detected, and lambda is the wavelength of the laser source;
and S5, repeating the steps from S1 to S4 to obtain 3 groups of numerical values of the thickness of the glass to be detected, calculating an average value of the 3 groups of numerical values of the thickness of the glass to be detected, and taking the average value as the average thickness of the glass to be detected.
The alpha values obtained by measuring glass having standard thicknesses of 3.85mm, 4.81mm, 7.85mm, 9.86mm and 11.90mm by the above-mentioned procedure 1 、α 2 Calculated thickness x, relative error from standard thickness (by mathematical software)
Calculated according to the error transfer formula) and the average of the three sets of measurements are shown in table 1.
TABLE 1 measured data of standard thickness glass measured by measuring device
As can be seen from the above measurement data, the measurement apparatus and the measurement method provided in this embodiment achieve non-contact measurement of the thickness of glass (which may be replaced by other transparent objects), and the maximum relative deviation between the measured value and the standard value is less than 2.5%, and decreases as the thickness of the sample to be measured increases. The absolute precision of the measurement reaches 0.1mm magnitude, and the requirement of daily production and life can be met.
Example 2
The embodiment provides a non-contact sample thickness measuring device based on the michelson interference principle, the structure of which is shown in fig. 3, the measuring device comprises a fixed stage 3' for placing a sample 4 to be measured and an optical path component enclosed in a shell 13; the light path component mainly comprises an M1 reflector 1, an M2 reflector 2, a laser source 5, a receiving device 6, a light splitting plate 7, a compensation plate 8, a micro-electromechanical gyroscope 10 and a single chip microcomputer 11 which are arranged on a base in a shell 13; the laser source 5, the light splitting plate 7, the compensation plate 8 and the M2 reflector 2 are sequentially arranged along the same direction, and the light splitting plate 7 and the compensation plate 8 are parallel to each other and form an included angle of 45 degrees with the mirror surface of the M1 reflector; the base is arranged in the shell 13 through a central shaft 9, and the micro-electromechanical gyroscope 10 is arranged on the central shaft 9 so as to realize linkage of base rotation and angle measurement; one end of the central shaft 9, which is positioned outside the shell 13, is provided with a rotating handle; the micro-electromechanical gyroscope 10 and the receiving device 6 are respectively and electrically connected with the singlechip 11; the single chip microcomputer 11 is electrically connected with an LED display positioned outside the shell 13; an opening which is larger than the thickness of the sample is designed on the shell 13, and the fixed object stage 3' can enable the sample placed on the fixed object stage to enter the shell 13 along the opening and is positioned between the M1 reflector 1 and the light splitting plate 7; the receiving device 6 here is a CCD camera.
When the non-contact sample thickness measuring device based on the Michelson interference principle is used, the beam splitter 7 divides laser emitted by the laser source 5 into two beams, wherein one beam of laser is incident to the M1 reflector 1 through the sample 4, and the other beam of laser is incident to the M2 reflector 2 through the compensation plate 8; the reflected light reflected by the M1 reflector 1 is received by the CCD camera through the sample 4 and the light splitting plate 7, and the reflected light reflected by the M2 reflector 2 is reflected to the CCD camera through the compensation plate 8 and the light splitting plate 7; the rotation angle of the base in the housing 13 is adjusted so that the CCD camera receives the interference fringes.
Before the non-contact sample thickness measuring device based on the Michelson interference principle is used for measuring a sample 4, a micro-electromechanical gyroscope 10 is initialized, and when the initialization angle of the micro-electromechanical gyroscope 10 is 0 degree, the mirror surface of an M1 reflector 1 is parallel to the upper end surface of a solid object stage 3', so that the rotation angle of the micro-electromechanical gyroscope 10 is ensured to be the included angle between the plane of the sample to be measured and the mirror surface of the M1 reflector 1; the measurement process after initialization of the micro-electromechanical gyroscope 10 is as follows:
s1, a sample 4 to be measured is placed on a fixed objective table 3', the sample enters a shell 13 along an opening on the shell 13, and the sample 4 entering the shell 13 is positioned between an M1 reflector 1 and a light splitting plate 7;
s2, turning on the laser source 5, rotating the handle, adjusting the optical assembly on the base until the CCD camera receives interference fringes (namely the interference fringes appear on the LED display), and recording the rotation angle alpha of the micro-electromechanical gyroscope 10 1 (namely the relative rotation angle between the plane of the sample 4 to be measured and the mirror surface of the M1 reflector 1);
s3, continuing to rotate the handle, adjusting the optical assembly on the base to move L interference fringes received by the CCD camera, and recording the rotation angle alpha of the micro-electromechanical gyroscope 2 (namely the relative rotation included angle between the plane of the sample 4 to be measured and the mirror surface of the M1 reflector 1);
s4, recording the rotation angle alpha of the micro-electromechanical gyroscope 10 recorded in the step S2 and the step S3 1 、α 2 And substituting the moving number L of the interference fringes into the following formula to calculate the thickness of the sample 4 to be measured:
wherein x is the thickness of the sample to be detected, and lambda is the wavelength of the laser source;
the step can be automatically calculated by the singlechip 11 according to the interference fringe information transmitted by the CCD camera, the rotation angle transmitted by the micro-motor gyroscope 10 and the formula (7);
and S5, repeating the steps S1 to S4 for a plurality of times to obtain a plurality of groups of values of the thickness of the sample to be detected, calculating an average value of the plurality of groups of values of the thickness of the sample to be detected 4, and taking the average value as the average thickness of the sample to be detected.
As the CCD camera is used as the interference fringe receiving device, the method can be used for distinguishing the interference non-integer fringe change, so that the measurement error is further reduced, the precision of the method is expected to reach 1 mu m, and the production requirement of higher precision requirement is met.
Example 3
The present embodiment provides a non-contact sample thickness measuring device based on the michelson interference principle, and the structure of the device is shown in fig. 4, the measuring device is basically the same as the device provided in embodiment 2, and the main difference is that the single chip microcomputer 11 in the present embodiment is disposed outside the housing 13.
Claims (7)
1. A non-contact sample thickness measuring method based on the Michelson interference principle is characterized in that a light path component mainly composed of an M1 reflector, an M2 reflector, a laser source, a receiving device, a beam splitter and a compensation plate is used for measuring the thickness of a sample, the laser source, the beam splitter, the compensation plate and the M2 reflector are sequentially arranged along the same direction, and the beam splitter and the compensation plate are parallel to each other and form an included angle of 45 degrees with the mirror surface of the M1 reflector; the object stage for placing the sample is positioned between the M1 reflecting mirror and the light splitting plate; the sample thickness was measured using a method comprising the following steps:
s1, placing a sample to be detected on an objective table;
s2, opening the laser source, adjusting the objective table or the optical path component until the interference fringe is received by the receiving device, and recording the relative rotation angle alpha 1 between the sample plane and the mirror surface of the M1 reflector;
s3, continuously adjusting the objective table or the light path component to move L interference fringes received by the receiving device, and recording a relative rotation included angle alpha 2 between the sample plane and the mirror surface of the M1 reflector;
s4, substituting the included angles alpha 1 and alpha 2 between the sample plane and the M1 reflector recorded in the steps S2 and S3 and the interference fringe movement number L into the following formula to calculate the thickness of the sample to be measured:
wherein x is the thickness of the sample to be measured, and λ is the wavelength of the laser source.
2. The method according to claim 1, wherein the steps S1 to S4 are repeated several times to obtain a plurality of sets of values of the thickness of the sample to be measured, and an average value of the plurality of sets of values of the thickness of the sample to be measured is calculated, and the average value is taken as the thickness of the sample to be measured.
3. A non-contact sample thickness measuring device based on the Michelson interference principle is characterized by comprising a fixed object stage (3') for placing a sample to be measured and an optical path component encapsulated in a shell (13); the light path component mainly comprises an M1 reflector (1), an M2 reflector (2), a laser source (5), a receiving device (6), a light splitting plate (7), a compensating plate (8) and a micro-electromechanical gyroscope (10), wherein the M1 reflector (1), the M2 reflector (2), the laser source, the receiving device, the light splitting plate (7), the compensating plate and the micro-electromechanical gyroscope are arranged on a base in a shell (13); the receiving device (6) is a CCD element; the micro-electromechanical gyroscope (10) and the receiving device (6) are respectively and electrically connected with the singlechip (11); the laser source (5), the light splitting plate (7), the compensation plate (8) and the M2 reflector (2) are sequentially arranged along the same direction, and the light splitting plate (7) and the compensation plate (8) are parallel to each other and form an included angle of 45 degrees with the mirror surface of the M1 reflector; the base and the micro-electromechanical gyroscope (10) are arranged on the central shaft (9) to realize linkage of base rotation and angle measurement; the beam splitting plate (7) divides laser emitted by the laser source (5) into two beams, wherein one beam of laser is incident to the M1 reflector (1) through the sample (4), and the other beam of laser is incident to the M2 reflector (2) through the compensation plate (8); the reflected light reflected by the M1 reflector (1) is received by the receiving device (6) through the sample (4) and the spectroscopic plate (7), and the reflected light reflected by the M2 reflector (2) is reflected to the receiving device (6) through the spectroscopic plate (7) through the compensation plate (8); adjusting the rotation angle of a base in the shell (13) to enable the receiving device (6) to receive the interference fringes; the shell (13) is provided with an opening with the thickness larger than that of the sample, and the fixed object stage (3') can enable the sample placed on the fixed object stage to enter the shell (13) along the opening and is positioned between the M1 reflecting mirror (1) and the light splitting plate (7).
4. The michelson interference principle-based non-contact sample thickness measuring device according to claim 3, wherein; the CCD element is a planar lattice charge coupled device or a linear charge coupled device.
5. The device according to claim 4, wherein the base is mounted in the housing (13) through a central shaft (9), and a rotary handle is mounted at one end of the central shaft outside the housing.
6. The non-contact sample thickness measuring device based on the michelson interference principle of claim 3 is characterized in that the single chip microcomputer (11) is mounted on an inner base of the shell (13); the single chip microcomputer (11) is electrically connected with a display device (12) located outside the shell (13).
7. The non-contact sample thickness measuring device based on the michelson interference principle according to claim 6, wherein the single chip microcomputer (11) is electrically connected with the display device (12), and both are located outside the housing (13).
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