CN116183175A - Device and method for measuring refractive index of flat optical element - Google Patents

Device and method for measuring refractive index of flat optical element Download PDF

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CN116183175A
CN116183175A CN202310013113.4A CN202310013113A CN116183175A CN 116183175 A CN116183175 A CN 116183175A CN 202310013113 A CN202310013113 A CN 202310013113A CN 116183175 A CN116183175 A CN 116183175A
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refractive index
optical element
interference
light
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CN116183175B (en
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王军
孙文卿
胡亦有
沈艺岚
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Suzhou University of Science and Technology
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    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01M—TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR
    • G01M11/00—Testing of optical apparatus; Testing structures by optical methods not otherwise provided for
    • G01M11/02—Testing optical properties
    • G01M11/0228—Testing optical properties by measuring refractive power
    • 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
    • G01N21/41—Refractivity; Phase-affecting properties, e.g. optical path length
    • G01N21/45—Refractivity; Phase-affecting properties, e.g. optical path length using interferometric methods; using Schlieren methods
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    • Y02A—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
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Abstract

The invention discloses a device and a method for measuring refractive index of a flat optical element. The laser is vertically incident on the plate glass with powder particles coated on the upper surface, scattered light in all directions formed on the upper surface and reflected light on the lower surface of the plate glass form equal-inclination interference, and the refractive index can be measured by analyzing interference fringes. The device takes the laser as a light source, can directly enter the tested element to form an obvious interference pattern, does not need complex and precise light path adjustment, and is simple to operate; according to the method, the refractive index of the flat optical element can be measured by analyzing the radiuses of the annular interference fringes of different orders and combining the distance parameters of the light path, so that the defect that most refractive index measuring methods need to process the optical element into a triangular prism is overcome.

Description

Device and method for measuring refractive index of flat optical element
Technical Field
The invention belongs to the field of optical detection, and particularly relates to a device and a method for measuring refractive index of a flat optical element.
Background
The refractive index of the optical material is one of the key performance parameters, and the method for measuring the refractive index mainly comprises an angle measurement method and an interferometry method. Common goniometry methods include minimum deflection angle method, brewster angle method, limit angle method, differential total reflection method (critical angle method), etc. The goniometry method generally requires that an optical material be made into a specific shape, such as a prism, and the refractive index of the material is calculated by measuring the deflection angle after the light is refracted, and the measurement accuracy is affected by the processing accuracy of the prism. The interferometry is generally based on Michelson interferometers, fabry-Perot interferometers and other precise optical instruments, refractive index measurement is achieved by analyzing interference fringe patterns, and the method is complex in light path and high in adjustment difficulty.
Disclosure of Invention
Compared with the prior art of refractive index measurement, the invention provides a refractive index measurement method based on powder scattering, which can be used for measuring a flat optical element, a measured optical material is not required to be processed into a triangular prism, interference fringes can be generated by utilizing a simple light path, a precise and complex interferometer light path system is not required, and refractive index measurement is realized by analyzing a single interference pattern. The invention provides a device and a method for measuring the refractive index of a flat optical element, comprising the following steps:
the technical proposal for realizing the aim of the invention is that
According to the refractive index measuring device designed according to the invention, as shown in fig. 1, the specific use flow of the measuring device is that 3 incident light is emitted by a 2 laser fixed on a 1 support rod, the 3 incident light is vertically incident on a 6-plate optical element arranged on a 5 base through a 4-beam splitter, 7 powder particles are coated on the upper surface of the 6-plate optical element, the powder with smaller particle size has better scattering effect, scattered powder for lady cosmetics can be used, the scattered light in all directions formed on the upper surface forms equal-inclination interference with the reflected light on the lower surface of the flat glass, the interference pattern is collected by an 8-camera after being reflected by the 4-beam splitter, and the refractive index can be measured by analyzing interference fringes.
Analysis of the process of IsoTilt interference is shown in FIG. 2, laser beams are vertically incident on 7 powder particles to scatter to form reflected light in different directions, one pair of interference light rays is taken to analyze interference optical path difference, and the included angle between 9 scattered light rays and normal is
Figure 749690DEST_PATH_IMAGE002
The method comprises the steps of carrying out a first treatment on the surface of the At the same time, 3 incident light will be refracted into the plate glass, reflected by the back surface and refracted out of the front surface, wherein 10 of the refracted light rays have an included angle of +.>
Figure 923182DEST_PATH_IMAGE003
The two beams of light rays have the same propagation direction, and equal-inclination interference can occur to form circular interference fringes. The optical path difference between them is +.>
Figure 933864DEST_PATH_IMAGE005
WhereinnThe refractive index of the 6-plate optical element. When the optical path difference is
Figure 432978DEST_PATH_IMAGE007
When interference counteracts, dark rings appear, corresponding to adjacent level dark rings +.>
Figure 529110DEST_PATH_IMAGE009
The change of the angle can be recorded as +.>
Figure 240714DEST_PATH_IMAGE011
Then
Figure 637061DEST_PATH_IMAGE013
，（1）
According to the law of refraction
Figure 775918DEST_PATH_IMAGE015
And in actual measurement, < >>
Figure 359346DEST_PATH_IMAGE016
Can be regarded as a small angle, then
Figure 140220DEST_PATH_IMAGE018
Thus, formula (1) can be written +.>
Figure 125494DEST_PATH_IMAGE020
，（2）
The analysis process of the interference propagation light path is as shown in fig. 3, and for visual sense, the section of reflection light path from the 6-plate optical element to the 8-camera is reflected by the 4-beam splitter and unfolded into a horizontal light path. In the light pathIn (3), distance between 6-plate optical element and 11 imaging plane of 8 cameraDFar greater than the radius of the interference fringe dark ring on the screenRThus, it is
Figure 435252DEST_PATH_IMAGE022
Formula (2) can be converted into:
Figure 505976DEST_PATH_IMAGE024
，（3）
wherein, the liquid crystal display device comprises a liquid crystal display device,
Figure 841274DEST_PATH_IMAGE026
is the difference of adjacent interference dark fringes. The refractive index can be calculated using the above equation.
The beneficial effects of the invention are as follows: the method can realize the measurement of the refractive index by using a simple light path and equipment, does not need an expensive and precise optical system, has simple light path adjustment, and can realize the measurement of the refractive index of the flat optical element by simple processing of an interference pattern.
Drawings
FIG. 1 is a schematic view of a refractive index measuring device and an optical path structure according to the present invention;
FIG. 2 is a schematic diagram of an optical path difference analysis for generating an equal-tilt interference in the present invention;
FIG. 3 is a schematic diagram of the geometry of the expanded reflection path of the present invention;
Detailed Description
In order to better understand the technical solutions of the present invention, the following description will clearly and completely describe the technical solutions of the examples of the present invention with reference to the accompanying drawings in the examples of the present invention, and it is apparent that the described embodiments are only some embodiments of the present invention, but not all embodiments. All other embodiments of the invention, which are obvious to those skilled in the art to which the invention pertains without inventive faculty, are intended to be within the scope of the invention.
Embodiment 1 provides an apparatus and a method for measuring refractive index of a plate optical element, including the following steps:
step 1: according to the refractive index measuring device designed according to the invention, as shown in fig. 1, the specific use flow of the measuring device is that 3 incident light is emitted by a 2 laser fixed on a 1 support rod, the 3 incident light is vertically incident on a 6-plate optical element arranged on a 5 base through a 4-beam splitter, 7 powder particles are coated on the upper surface of the 6-plate optical element, the powder with smaller particle size has better scattering effect, scattered powder for lady cosmetics can be used, the scattered light in all directions formed on the upper surface forms equal-inclination interference with the reflected light on the lower surface of the flat glass, the interference pattern is collected by an 8-camera after being reflected by the 4-beam splitter, and the refractive index can be measured by analyzing interference fringes.
Step 2: analysis of the process of IsoTilt interference is shown in FIG. 2, laser beams are vertically incident on 7 powder particles to scatter to form reflected light in different directions, one pair of interference light rays is taken to analyze interference optical path difference, and the included angle between 9 scattered light rays and normal is
Figure DEST_PATH_IMAGE027
The method comprises the steps of carrying out a first treatment on the surface of the At the same time, 3 incident light will be refracted into the plate glass, reflected by the back surface and refracted out of the front surface, wherein 10 of the refracted light rays have an included angle of +.>
Figure 681054DEST_PATH_IMAGE028
The two beams of light rays have the same propagation direction, and equal-inclination interference can occur to form circular interference fringes. The optical path difference between them is +.>
Figure 692872DEST_PATH_IMAGE030
WhereinnThe refractive index of the 6-plate optical element. When the optical path difference is
Figure DEST_PATH_IMAGE032
When interference counteracts, dark rings appear, corresponding to adjacent level dark rings +.>
Figure 985313DEST_PATH_IMAGE009
The change of the angle can be recorded as +.>
Figure DEST_PATH_IMAGE034
Then
Figure 373569DEST_PATH_IMAGE013
，（1）/>
Step 3: according to the law of refraction
Figure 67856DEST_PATH_IMAGE015
And in actual measurement, < >>
Figure 250576DEST_PATH_IMAGE016
Can be regarded as a small angle, then +.>
Figure DEST_PATH_IMAGE036
Such that formula (1) can be written as
Figure 295892DEST_PATH_IMAGE020
，（2）
Step 4: the analysis process of the interference propagation light path is as shown in fig. 3, and for visual sense, the section of reflection light path from the 6-plate optical element to the 8-camera is reflected by the 4-beam splitter and unfolded into a horizontal light path. In the light path, the distance between the 6-plate optical element and the 11 imaging plane of the 8-cameraDFar greater than the radius of the interference fringe dark ring on the screenRThus, it is
Figure 972992DEST_PATH_IMAGE022
Formula (2) can be converted into:
Figure 521785DEST_PATH_IMAGE024
，（3）
wherein, the liquid crystal display device comprises a liquid crystal display device,
Figure 609827DEST_PATH_IMAGE026
is the difference of adjacent interference dark fringes. The refractive index can be calculated using the above equation.
The embodiment of the invention can show that the device and the method for measuring the refractive index have simple optical path structure, the measured optical material is not required to be processed into a triangular prism, interference fringes can be generated by utilizing a simple optical path, a precise and complex interferometer optical path system is not required, the refractive index is measured by analyzing a single interference pattern, the measuring efficiency can be improved, and the device and the method have great application potential in the field of optical detection.
It will be evident to those skilled in the art that the invention is not limited to the details of the foregoing illustrative embodiments, and that the present invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. Any reference sign in a claim should not be construed as limiting the claim concerned.
Furthermore, it should be understood that although the present disclosure describes embodiments, not every embodiment is provided with a separate embodiment, and that this description is provided for clarity only, and that the disclosure is not limited to the embodiments described in detail below, and that the embodiments described in the examples may be combined as appropriate to form other embodiments that will be apparent to those skilled in the art.

Claims (2)

1. An apparatus and method for measuring refractive index of a planar optical element, comprising the steps of:
step 1: according to the refractive index measuring device, a 2 laser fixed on a 1 support rod emits 3 incident light, the 3 incident light vertically enters a 6-plate optical element arranged on a 5 base through a 4 beam splitter, 7 powder particles are coated on the upper surface of the 6-plate optical element, scattered light in all directions formed on the upper surface and reflected light on the lower surface of plate glass form equal-inclination interference, an 8-camera collects an interference pattern, and interference fringes are analyzed to obtain a refractive index measured value;
step 2: the optical path difference between the 9 scattered light on the upper surface of the 6-plate optical element and the 10 reflected light on the lower surface of the 6-plate optical element, which generates equal-tilt interference, is
Figure 217468DEST_PATH_IMAGE002
WhereinnIs the refractive index of the plate glass,dthickness of the sheet glass.
2. When the optical path difference is
Figure 245466DEST_PATH_IMAGE004
When interference cancellation occurs, dark rings corresponding to adjacent dark rings
Figure 958208DEST_PATH_IMAGE006
The amount of change in angle can be noted as
Figure 147880DEST_PATH_IMAGE008
There is
Figure 47703DEST_PATH_IMAGE010
，（1）
Step 3: in the actual measurement, the number of the measuring points,
Figure 613814DEST_PATH_IMAGE012
viewed as a small angle, according to the law of refraction
Figure 446641DEST_PATH_IMAGE014
There is
Figure 807215DEST_PATH_IMAGE016
Is combined with (1)
Figure 194334DEST_PATH_IMAGE018
，（2）
Step 3: by measuring interferometric ring halvesDiameter of the pipeRAnd the distance between the flat optical element and the imaging surface (interference fringe imaging position) of the 11 cameraDObtaining
Figure 846026DEST_PATH_IMAGE020
；
Step 4: according to the above steps, a formula for calculating the refractive index is obtained:
Figure 736622DEST_PATH_IMAGE022
，（3）
wherein the method comprises the steps of
Figure 533677DEST_PATH_IMAGE024
Is the difference of adjacent dark lines.
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Citations (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101464209A (en) * 2007-12-19 2009-06-24 鸿富锦精密工业（深圳）有限公司 Method and apparatus for measuring refractive index variable quantity of lens
KR20110031766A (en) * 2009-09-21 2011-03-29 부산대학교 산학협력단 Measurement of refractive index of wafer-type media by utilizing interference of transmitted and reflected beams
CN102128600A (en) * 2010-12-10 2011-07-20 西安科技大学 Method and device for measuring curvature radius of lens by use of laser
CN102213682A (en) * 2011-04-18 2011-10-12 中国计量学院 Method for measuring transmission of interference-insensitive terahertz wave
CN103808693A (en) * 2014-02-28 2014-05-21 陕西师范大学 Experimental device and experimental method for measuring refractive index of flat transparent medium
CN104316495A (en) * 2014-11-26 2015-01-28 中南大学 Method for measuring medium refractive index
CN106018345A (en) * 2016-05-24 2016-10-12 中国工程物理研究院激光聚变研究中心 System and method for measuring refractive index of optical plate glass based on short coherence
CN205749282U (en) * 2016-05-11 2016-11-30 黄河科技学院 A kind of experimental provision utilizing michelson interferometer optical path to measure air refraction
JP2018004409A (en) * 2016-06-30 2018-01-11 キヤノン株式会社 Refractive index measurement method, refractive index measurement device, and method of manufacturing optical element
CN108344712A (en) * 2018-04-12 2018-07-31 广东海洋大学 A kind of measuring device and its measurement method of Refractive Index of Material
CN114739954A (en) * 2022-03-30 2022-07-12 北京交通大学 System and method for simultaneously measuring thermal expansion coefficient and temperature refractive index coefficient of object

Patent Citations (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101464209A (en) * 2007-12-19 2009-06-24 鸿富锦精密工业（深圳）有限公司 Method and apparatus for measuring refractive index variable quantity of lens
KR20110031766A (en) * 2009-09-21 2011-03-29 부산대학교 산학협력단 Measurement of refractive index of wafer-type media by utilizing interference of transmitted and reflected beams
CN102128600A (en) * 2010-12-10 2011-07-20 西安科技大学 Method and device for measuring curvature radius of lens by use of laser
CN102213682A (en) * 2011-04-18 2011-10-12 中国计量学院 Method for measuring transmission of interference-insensitive terahertz wave
CN103808693A (en) * 2014-02-28 2014-05-21 陕西师范大学 Experimental device and experimental method for measuring refractive index of flat transparent medium
CN104316495A (en) * 2014-11-26 2015-01-28 中南大学 Method for measuring medium refractive index
CN205749282U (en) * 2016-05-11 2016-11-30 黄河科技学院 A kind of experimental provision utilizing michelson interferometer optical path to measure air refraction
CN106018345A (en) * 2016-05-24 2016-10-12 中国工程物理研究院激光聚变研究中心 System and method for measuring refractive index of optical plate glass based on short coherence
JP2018004409A (en) * 2016-06-30 2018-01-11 キヤノン株式会社 Refractive index measurement method, refractive index measurement device, and method of manufacturing optical element
CN108344712A (en) * 2018-04-12 2018-07-31 广东海洋大学 A kind of measuring device and its measurement method of Refractive Index of Material
CN114739954A (en) * 2022-03-30 2022-07-12 北京交通大学 System and method for simultaneously measuring thermal expansion coefficient and temperature refractive index coefficient of object

Non-Patent Citations (3)

* Cited by examiner, † Cited by third party
Title
KEJUAN XUE等: "Measurement of glass thickness and refractive index based on spectral interference tethnology", APPLIED OPTICS, vol. 60, no. 26 *
李季平等: "激光等密度等倾干涉条纹法测定透明介质的厚度和折射率", 物理实验, vol. 20, no. 3 *
邓晓颖, 刘钟燕: "用单色光等倾干涉测平板透明体厚度和折射率", 纺织高校基础科学学报, no. 03 *

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