Optical experiment device based on interference principle

Abstract

The utility model relates to an optical experiment device based on an interference principle, and belongs to the technical field of optical detection. Comprising a computer and a base, and the base is arranged on one side of the computer; a camera bracket, a sample placing bracket and a light source mechanism are sequentially arranged on the base, and are positioned on the same horizontal line; a camera is arranged on the camera bracket; the sample placing support and the camera are electrically connected with the computer, and the computer is used for storing and recognizing optical interference videos shot by the camera and controlling the sample placing support to ascend / descend. The device not only can be used for automatically measuring small diameters, thicknesses or curvature radiuses of plano-convex lenses in industrial production and reducing reading errors, but also can be applied to teaching of experimental principles of light interference, and is wide in application range.

Description

Technical Field

[0001] The utility model relates to the technical field of optical detection, in particular to an optical experimental device based on the interference principle. Background Art

[0002] The interference of light gives rise to numerous classic optical phenomena, such as "Newton's rings" and "wedge interference fringes." By splitting a parallel beam into two, various interference patterns are produced when these two beams overlap. These interference fringes can be used to measure the thickness of optical films, the wavelength of light waves, the radius of curvature of plano-convex lenses, the refractive index of liquids, the machining quality of lenses, and the surface topography of optical components.

[0003] When using optical interference to measure parameters such as the thickness of optical films, the wavelength of light waves, the radius of curvature of plano-convex lenses, and the refractive index of liquids, the principle is to link the desired parameter to the spacing of interference fringes using a geometric formula, and then calculate the desired parameter. Such optical experiments typically use a standard reading microscope to measure the distance between multiple dark fringes, and then use a formula to calculate the desired parameter. This requires the measurer to spend a long time counting the number of interference fringes and simultaneously recording the actual distances between the fringes. To achieve a clearer contrast between the light and dark fringes, the experimental environment must be relatively dim. The experimenter must perform numerous readings and counting under the microscope for an extended period of time in such an environment, requiring a high level of patience and meticulousness. Furthermore, this testing method is not only highly susceptible to eye fatigue and erroneous readings, but also results in significant discrepancies in the readings of the same spacing under different lighting conditions or by different experimenters.

[0004] Therefore, it is particularly important to provide an optical experimental instrument that can more accurately and automatically obtain the number of interference fringes and the distance between interference fringes, and then use formulas to calculate parameters such as the thickness of optical films, the wavelength of light waves, the curvature radius of plano-convex lenses, and the refractive index of liquids. Utility Model Content

[0005] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0006] An optical experimental device based on the interference principle, comprising:

[0007] A computer and a base, wherein the base is arranged on one side of the computer; a camera bracket, a sample placement bracket and a light source mechanism are sequentially arranged on the base, and the camera bracket, the sample placement bracket and the light source mechanism are located on the same horizontal line; a camera is arranged on the camera bracket;

[0008] The sample placement bracket and the camera are electrically connected to the computer respectively. The computer is used to store and identify the optical interference video captured by the camera and control the rise / descent of the sample placement bracket.

[0009] Furthermore, it also includes a shooting box, in which the base, the camera bracket, the camera, the sample placement bracket and the light source mechanism are all arranged.

[0010] Furthermore, the camera bracket includes a camera platform, a fixing seat, a first slider and a first screw rod;

[0011] The fixing seat is arranged at an end of the base away from the light source mechanism; the first screw rod is rotatably arranged on the fixing seat and arranged along the length direction of the base; one end of the first screw rod passes through the fixing seat and is connected to the first knob;

[0012] The first slider is arranged on the first screw rod and is provided with a first internal thread matched with the first screw rod; the top of the first slider is fixedly connected to the bottom of the camera platform;

[0013] The camera is arranged on the imaging platform.

[0014] Furthermore, a crosshair is provided in the center of the lens of the camera.

[0015] Furthermore, the sample placement bracket includes a multi-axis adjustment component and a sample bracket;

[0016] The multi-axis adjustment assembly is arranged on the base, and the sample holder is arranged on the top of the multi-axis adjustment assembly; the sample holder is used to place optical components, and the multi-axis adjustment assembly is used to adjust the relative positions of the optical components;

[0017] The multi-axis adjustment component is connected to the computer.

[0018] Furthermore, the multi-axis adjustment assembly includes a sample lifting platform, a Y-axis base, a Y-axis slide, an X-axis base and an X-axis slide;

[0019] The Y-axis base is fixedly mounted on the base; a second screw rod is provided on the Y-axis base, and the second screw rod is arranged along the width direction of the base; one end of the second screw rod passes through the fixing base and is connected to a second knob; the Y-axis slide is provided on the second screw rod and is provided with a second internal thread that cooperates with the second screw rod; the top of the Y-axis slide is fixedly connected to the bottom of the X-axis base;

[0020] The X-axis base is provided with a third screw rod perpendicular to the second screw rod, one end of the third screw rod passes through the fixing seat and is connected to a third knob; the X-axis slide is provided on the third screw rod and is provided with a third internal thread that matches the third screw rod; the sample lifting platform is provided on the top of the X-axis slide;

[0021] The sample lifting platform is connected to the computer.

[0022] Furthermore, the sample lifting platform includes an automatic adjustment module and a manual adjustment module;

[0023] The automatic adjustment module is connected to the computer, and the computer is used to control the sample lifting platform to rise / fall at a uniform speed; the manual adjustment module includes a fourth knob, and the fourth knob is used to fine-tune the height of the sample lifting platform.

[0024] Furthermore, the computer includes a control module, an image recognition module and a timer;

[0025] The control module is connected to the automatic adjustment module, and is used to control the sample lifting platform to rise / fall at a uniform speed and adjust the lifting speed of the sample lifting platform;

[0026] The image recognition module is connected to the camera, and the image recognition module is used to store and recognize the optical interference video captured by the camera;

[0027] The image recognition module is connected to the control module and the timer respectively.

[0028] Beneficial effects:

[0029] The utility model does not adopt the method of reading the distance between dark stripes, but uses time measurement instead of distance measurement to obtain the spacing between dark stripes; uses the image recognition module to identify the time when the central cross hairs of the camera coincide with the interference dark stripes, and multiplies the time difference of the cross hairs passing through multiple dark stripes by the uniform descent speed of the sample lifting platform to obtain the distance between the multiple dark stripes; this can not only be used for automatic measurement of small diameters, thicknesses or curvature radii of plano-convex lenses in industrial production and reduce reading errors, but can also be applied to the teaching of the principles of light interference experiments, and has a wide range of uses. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a structural schematic diagram of the optical experimental device of the present utility model;

[0031] Figure 2 This is a structural diagram of the shooting box of the utility model;

[0032] Among them, 1. Base; 2. Multi-axis adjustment component; 3. Camera bracket; 4. Camera; 5. Sample lifting platform; 6. Light source mechanism. DETAILED DESCRIPTION

[0033] Example 1

[0034] refer to Figure 1-Figure 2 , an optical experimental device based on the interference principle, comprising:

[0035] A computer and a base 1, wherein the base 1 is arranged on one side of the computer; a camera bracket 3, a sample placement bracket and a light source mechanism 6 are sequentially arranged on the base 1, and the camera bracket 3, the sample placement bracket and the light source mechanism 6 are located on the same horizontal line; a camera 6 is arranged on the camera bracket;

[0036] The sample placement bracket and the camera 4 are electrically connected to a computer respectively. The computer is used to store and identify the optical interference video captured by the camera 4 and to control the rise / descent of the sample placement bracket.

[0037] Example 2

[0038] In order to enable the computer to better recognize the captured optical interference video, this embodiment is further configured on the basis of the first embodiment.

[0039] It also includes a shooting box, in which the base 1, the camera bracket 3, the camera 4, the sample placement bracket and the light source mechanism 6 are all arranged.

[0040] Example 3

[0041] In order to better adjust the initial position of the camera, this embodiment is further configured on the basis of the second embodiment.

[0042] The camera bracket 3 includes a camera platform, a fixing seat, a first slider and a first screw rod;

[0043] The fixing seat is arranged at one end of the base 1 away from the light source mechanism; the first screw rod is rotatably arranged on the fixing seat and arranged along the length direction of the base 1; one end of the first screw rod passes through the fixing seat and is connected to the first knob;

[0044] The first slider is arranged on the first screw rod and is provided with a first internal thread matched with the first screw rod; the top of the first slider is fixedly connected to the bottom of the camera platform;

[0045] The camera 4 is arranged on the camera platform.

[0046] Preferably, a crosshair is provided in the center of the lens of the camera 4.

[0047] Preferably, the sample placement bracket includes a multi-axis adjustment component 2 and a sample bracket;

[0048] The multi-axis adjustment component 2 is arranged on the base 1, and the sample holder is arranged on the top of the multi-axis adjustment component 2; the sample holder is used to place optical components, and the multi-axis adjustment component 2 is used to adjust the relative position of the optical components;

[0049] The multi-axis adjustment component 2 is connected to the computer.

[0050] Preferably, the multi-axis adjustment assembly 2 includes a sample lifting platform 5, a Y-direction base, a Y-direction slide, an X-direction base and an X-direction slide;

[0051] The Y-axis base is fixedly mounted on the base 1; a second screw rod is provided on the Y-axis base and is arranged along the width direction of the base 1; one end of the second screw rod passes through the fixed base and is connected to the second knob; the Y-axis slide is provided on the second screw rod and is provided with a second internal thread that cooperates with the second screw rod; the top of the Y-axis slide is fixedly connected to the bottom of the X-axis base;

[0052] A third screw rod is provided on the X-axis base and is perpendicular to the second screw rod. One end of the third screw rod passes through the fixed seat and is connected to a third knob. The X-axis slide is provided on the third screw rod and is provided with a third internal thread that matches the third screw rod. The sample lifting platform is provided on the top of the X-axis slide.

[0053] The sample lifting platform 5 is connected to the computer.

[0054] Preferably, the sample lifting platform 5 includes an automatic adjustment module and a manual adjustment module;

[0055] The automatic adjustment module is connected to a computer, which is used to control the sample lifting platform 5 to rise / fall at a uniform speed; the manual adjustment module includes a fourth knob, which is used to fine-tune the height of the sample lifting platform 5.

[0056] Preferably, the computer includes a control module, an image recognition module and a timer;

[0057] The control module is connected to the automatic adjustment module and is used to control the sample lifting platform 5 to rise / fall at a uniform speed and adjust the lifting speed of the sample lifting platform 5;

[0058] The image recognition module is connected to the camera, and is used to store and recognize the optical interference video captured by the camera;

[0059] The image recognition module is connected with the control module and the timer respectively.

[0060] Working Principle: The image recognition module, control module, and timer work together to automatically record the time when the central crosshairs of the lens coincide with the interference dark fringes. The distance between the multiple dark fringes is calculated by multiplying the time difference between the crosshairs passing through the multiple dark fringes by the uniform descent speed of the sample lifting platform. Based on the distance between the dark fringes, the image recognition module will automatically calculate the values ​​of parameters such as the thickness of the optical film, the wavelength of the light wave, the curvature radius of the plano-convex lens, and the refractive index of the liquid using a formula.

[0061] The image recognition module, the control module and the timer cooperate with each other to identify the displacement of the lifting platform at the overlap of the crosshairs and the interference fringes in the interference pattern, and automatically calculate the curvature radius of the optical component such as the plano-convex lens or the thickness or length of the optical component such as the wedge tip.

[0062] Example 4

[0063] This embodiment is an optical experimental device using Example 1, and is used for measuring the curvature radius of a plano-convex lens. The measuring method includes:

[0064] S1. Fix a flat glass on the curved side of a plano-convex lens. Place the plano-convex lens with the flat glass fixed on it on the sample holder. Turn on the light source and computer. Adjust the focal length of the camera and the position of the sample lift so that the crosshairs in the camera and the interference fringes formed by the plano-convex lens are clearly visible in the field of view.

[0065] In this embodiment, the curved surface of the plano-convex lens is placed in close contact with the flat glass.

[0066] S2. Adjust the height of the lift platform below the sample holder and fine-tune the position of the plano-convex lens assembly so that one crosshair is perpendicular to the direction of movement of the sample lift platform and one crosshair passes through the center of the interference ring. At this point, the crosshairs coincide with the dark fringe 40 rings below the interference fringe, and this serves as the reference position.

[0067] S3. The instrument is activated and the timer starts counting. Simultaneously, the sample lift begins to descend slowly and uniformly at a certain speed. At this time, the crosshairs in the field of view remain stationary, and the interference ring moves downward. The timer automatically records the time when the crosshairs are tangent to each dark ring. This is until the crosshairs coincide with the dark ring 40 rings above the interference fringe, at which point the timing ends.

[0068] S4. The image recognition module, control module and timer in the computer cooperate with each other to identify the displacement of the lifting platform at the intersection of the crosshairs and the interference fringes in the interference pattern, and automatically calculate the curvature radius R of the plano-convex lens optical component.

[0069] In this embodiment, the distance between each ring of dark patterns is the time difference between each ring of dark patterns multiplied by the uniform descent speed of the lifting platform. According to optical knowledge, a thin air film with a thin center and thick edges is formed between the plano-convex lens and the flat glass. When parallel monochromatic light is incident vertically, the coherent light formed interferes, forming a series of concentric ring-shaped stripes centered on the contact point, which are alternating light and dark, sparse in the center and dense at the edges. During measurement, as long as the diameters of multiple dark rings are measured, a straight line can be obtained by the least squares method and Excel linear fitting. The slope of this straight line is the curvature radius R of the plano-convex lens.

[0070] Example 5

[0071] This embodiment is an optical experimental device according to embodiment 1, and is used to measure the thickness of an air film in a wedge-shaped optical component. The measurement method includes:

[0072] S1. Place a wedge-shaped optical component on the sample holder, turn on the light source and computer, and adjust the camera focus and the position of the sample lift so that the interference fringes formed by the crosshairs in the camera and the wedge-shaped optical component are clearly visible in the field of view.

[0073] S2. Adjust the height of the lifting platform under the sample holder and fine-tune the position of the optical components so that one of the cross wires is perpendicular to the movement direction of the lifting platform and one of the cross wires coincides with the first-level dark pattern, and this is used as the reference position;

[0074] S3. The instrument is activated and the timer starts counting. At the same time, the sample lift begins to slowly descend at a constant speed. At this time, the crosshairs in the field of view remain stationary, while the parallel interference fringes move downward. When the crosshairs intersect with each dark ring, the timer automatically records the time until the crosshairs coincide with the last dark interference fringe, at which point the timing ends.

[0075] S4. The image recognition module, control module and timer in the computer cooperate with each other to identify the time when the crosshairs in the interference pattern overlap with the interference fringes. The time difference when the crosshairs pass through multiple dark fringes is multiplied by the uniform descent speed of the sample lifting platform to obtain the distance between the multiple dark fringes. Using the distance between the dark fringes, the image recognition module will automatically calculate the thickness of the optical film using a formula.

[0076] In this embodiment, the number of times counted is the total number of dark fringes. According to optical knowledge, the total number of dark fringes multiplied by half the wavelength of light is the thickness of the air film.

[0077] The above description is only a preferred embodiment of the present invention and does not limit the technical scope of the present invention. Therefore, any minor modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. An optical experimental device based on the interference principle, characterized in that: include: A computer and a base, wherein the base is arranged on one side of the computer; a camera bracket, a sample placement bracket and a light source mechanism are sequentially arranged on the base, and the camera bracket, the sample placement bracket and the light source mechanism are located on the same horizontal line; a camera is arranged on the camera bracket; The sample placement bracket and the camera are electrically connected to the computer respectively. The computer is used to store and identify the optical interference video captured by the camera and control the rise / descent of the sample placement bracket.

2. The optical experimental device based on the interference principle as claimed in claim 1, characterized in that: It also includes a shooting box, in which the base, the camera bracket, the camera, the sample placement bracket and the light source mechanism are all arranged.

3. The optical experimental device based on the interference principle as claimed in claim 2, characterized in that: The camera bracket includes a camera platform, a fixing seat, a first slider and a first screw rod; The fixing seat is arranged at an end of the base away from the light source mechanism; the first screw rod is rotatably arranged on the fixing seat and arranged along the length direction of the base; one end of the first screw rod passes through the fixing seat and is connected to the first knob; The first slider is arranged on the first screw rod and is provided with a first internal thread matched with the first screw rod; the top of the first slider is fixedly connected to the bottom of the camera platform; The camera is arranged on the imaging platform.

4. The optical experimental device based on the interference principle as claimed in claim 3, characterized in that: A crosshair is provided in the center of the lens of the camera.

5. The optical experimental device based on the interference principle as claimed in claim 4, characterized in that: The sample placement bracket includes a multi-axis adjustment component and a sample bracket; The multi-axis adjustment assembly is arranged on the base, and the sample holder is arranged on the top of the multi-axis adjustment assembly; the sample holder is used to place optical components, and the multi-axis adjustment assembly is used to adjust the relative positions of the optical components; The multi-axis adjustment component is connected to the computer.

6. The optical experimental device based on the interference principle as claimed in claim 5, characterized in that: The multi-axis adjustment assembly includes a sample lifting platform, a Y-axis base, a Y-axis slide, an X-axis base and an X-axis slide; The Y-axis base is fixedly mounted on the base; a second screw rod is provided on the Y-axis base, and the second screw rod is arranged along the width direction of the base; one end of the second screw rod passes through the fixing base and is connected to a second knob; the Y-axis slide is provided on the second screw rod and is provided with a second internal thread that cooperates with the second screw rod; the top of the Y-axis slide is fixedly connected to the bottom of the X-axis base; The X-axis base is provided with a third screw rod perpendicular to the second screw rod, one end of the third screw rod passes through the fixing seat and is connected to a third knob; the X-axis slide is provided on the third screw rod and is provided with a third internal thread that matches the third screw rod; the sample lifting platform is provided on the top of the X-axis slide; The sample lifting platform is connected to the computer.

7. The optical experimental device based on the interference principle as claimed in claim 6, characterized in that: The sample lifting platform includes an automatic adjustment module and a manual adjustment module; The automatic adjustment module is connected to the computer, and the computer is used to control the sample lifting platform to rise / fall at a uniform speed; the manual adjustment module includes a fourth knob, and the fourth knob is used to fine-tune the height of the sample lifting platform.

8. The optical experimental device based on the interference principle as claimed in claim 7, characterized in that: The computer includes a control module, an image recognition module and a timer; The control module is connected to the automatic adjustment module, and is used to control the sample lifting platform to rise / fall at a uniform speed and adjust the lifting speed of the sample lifting platform; The image recognition module is connected to the camera, and the image recognition module is used to store and recognize the optical interference video captured by the camera; The image recognition module is connected to the control module and the timer respectively.

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