An optical experimental device based on the principle of interference

Abstract

This invention relates to an optical experimental device based on the principle of interference, belonging to the field of optical detection technology. It includes a computer and a base, with the base positioned to one side of the computer. A camera mechanism, a sample placement mechanism, and a light source mechanism are sequentially arranged on the base, all on the same horizontal line. The sample placement mechanism and the camera mechanism are electrically connected to the computer, which stores and identifies the optical interference video recordings captured by the camera mechanism and controls the raising / lowering of the sample placement mechanism. This invention can not only be used for the automatic measurement of minute diameters, thicknesses, or the radius of curvature of plano-convex lenses in industrial production, reducing reading errors, but also for teaching the principles of light interference experiments, making it widely applicable.

Description

Technical Field

[0001] This invention relates to the field of optical detection technology, and more specifically to an optical experimental device based on the principle of interference. Background Technology

[0002] Based on the interference of light, many classic optical phenomena such as "Newton's rings" and "wedge interference fringes" are produced. By splitting a parallel beam of light into two beams, when these two parallel beams are superimposed and overlapped again, various interference patterns will be produced. These interference fringes can be used to detect the thickness of optical thin films, the wavelength of light waves, the radius of curvature of plano-convex lenses, the refractive index of liquids, the processing quality of lenses, and the surface morphology of optical components.

[0003] When using light interference to measure parameters such as the thickness of optical thin films, the wavelength of light waves, the radius of curvature of plano-convex lenses, and the refractive index of liquids, the principle is to relate the parameter to be measured to the spacing of interference fringes through geometric formulas, and then calculate the parameter. Such optical experiments typically use a standard reading microscope to measure the distance between multiple dark fringes, and then use formulas to calculate the desired parameter. This requires the observer to count the number of interference fringes for an extended period while simultaneously recording the actual distances between them. To make the contrast between bright and dark fringes clearer, a relatively dim experimental environment is required. The observer must then perform extensive readings and counting under the microscope for a long time in this environment, demanding a high level of patience and meticulousness. Furthermore, this testing method is not only prone to causing eye fatigue and reading errors, but also results in significant differences in the readings of the same spacing under different lighting conditions or by different observers.

[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 them, and then use formulas to calculate parameters such as the thickness of the optical thin film, the wavelength of the light wave, the radius of curvature of the plano-convex lens, and the refractive index of the liquid. Summary of the Invention

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

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

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

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

[0009] Furthermore, it also includes a shooting box, in which the base, the camera mechanism, the sample placement mechanism, and the light source mechanism are all disposed, so that the camera mechanism can achieve better shooting results.

[0010] Furthermore, the camera mechanism includes a camera adjustment assembly and a camera;

[0011] The camera is mounted on the camera adjustment assembly, which is located at the end of the base away from the light source mechanism; the camera adjustment assembly is used to drive the camera to move away from / near the sample placement mechanism.

[0012] The camera is connected to the computer, which is used to store and identify the optical interference video captured by the camera.

[0013] Furthermore, the camera adjustment assembly includes a camera platform, a fixed base, a first slider, and a first lead screw;

[0014] The fixed base is located at the end of the base away from the light source mechanism; the first lead screw is rotatably mounted on the fixed base and is arranged along the length direction of the base; one end of the first lead screw passes through the fixed base and is connected to a first knob;

[0015] The first slider is mounted on the first lead screw and has a first internal thread that mates with the first lead screw; the top of the first slider is fixedly connected to the bottom of the camera platform.

[0016] The camera is mounted on the camera platform.

[0017] Furthermore, a crosshair is provided in the center of the camera lens.

[0018] Furthermore, the sample placement mechanism includes an XY axis adjustment assembly, a sample lifting platform, and a sample holder;

[0019] The XY-axis adjustment assembly is mounted on the base, the sample lifting platform is mounted on the XY-axis adjustment assembly, and the sample holder is fixed to the top of the sample lifting platform. The sample holder is used to place optical components, and the XY-axis adjustment assembly and the sample lifting platform cooperate with each other to adjust the relative position of the optical components.

[0020] The sample lifting platform is connected to the computer.

[0021] Furthermore, the XY axis adjustment assembly includes a Y-axis base, a Y-axis sliding plate, an X-axis base, and an X-axis sliding plate;

[0022] The Y-axis base is fixedly installed on the base; a second lead screw is provided on the Y-axis base, and the second lead screw is arranged along the width direction of the base; one end of the second lead screw passes through the Y-axis base and is connected to a second knob; the Y-axis slide plate is arranged on the second lead screw and is provided with a second internal thread that cooperates with the second lead screw; the top of the Y-axis slide plate is fixedly connected to the bottom of the X-axis base.

[0023] The X-axis base is provided with a third lead screw perpendicular to the second lead screw, one end of the third lead screw passes through the X-axis base and is connected to a third knob; the X-axis slide plate is provided on the third lead screw and is provided with a third internal thread that cooperates with the third lead screw; the sample lifting platform is provided on the top of the X-axis slide plate.

[0024] Furthermore, the sample lifting platform includes an automatic adjustment module and a manual adjustment module;

[0025] The automatic adjustment module is connected to the computer, which controls the sample lifting platform to rise / fall at a constant speed; the manual adjustment module includes a fourth knob, which is used to fine-tune the height of the sample lifting platform.

[0026] Furthermore, the computer includes a control module, an image recognition module, and a timer;

[0027] 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.

[0028] 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;

[0029] The image recognition module is connected to the control module and the timer, respectively.

[0030] Furthermore, the image recognition module, the control module, and the timer work together to automatically record the time when the central crosshair of the lens coincides with the interference dark fringes. The distance between the dark fringes is obtained by multiplying the time difference of the crosshair passing through multiple dark fringes by the uniform descent speed of the sample lifting platform. Using the distance between the dark fringes, the image recognition module will automatically calculate the thickness of the optical thin film, the wavelength of the light wave, the radius of curvature of the plano-convex lens, and the refractive index parameter of the liquid using formulas.

[0031] The image recognition module, the control module, and the timer work together to identify the displacement of the lifting platform at the point where the crosshairs and interference fringes in the interference pattern coincide, and automatically calculate the radius of curvature of plano-convex lens-type optical components or the thickness or length of wedge-type optical components. Beneficial effects

[0032] This invention does not use the method of reading the distance between dark fringes, but uses time measurement instead of distance measurement to obtain the spacing between dark fringes; it uses an image recognition module to identify the time when the central crosshair of the camera coincides with the interference dark fringes, and uses the time difference of the crosshair passing through multiple dark fringes multiplied by the speed of the sample lifting platform descending at a uniform speed to obtain the distance between multiple dark fringes; this can not only be used for the automatic measurement of small diameters, thicknesses or the radius of curvature of plano-convex lenses in industrial production and reduce reading errors, but also be applied to the teaching of the principles of light interference experiments, with wide applications. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of the optical experimental apparatus of the present invention;

[0034] Figure 2 This is a schematic diagram of the shooting box of the present invention;

[0035] Figure 3 This is a process diagram of the optical experimental apparatus of the present invention capturing the radius of curvature of a plano-convex lens;

[0036] Figure 4 This is a process diagram of the optical experimental apparatus of the present invention for measuring the thickness of an air film in a wedge-shaped optical component;

[0037] The components include: 1. Base; 2. XY axis adjustment assembly; 3. Camera adjustment assembly; 4. Camera; 5. Sample lifting platform; and 6. Light source mechanism. Detailed Implementation Example 1

[0038] refer to Figures 1-2 An optical experimental device based on the principle of interference, comprising:

[0039] The computer and the base 1 are arranged on one side of the computer. The base 1 is provided with a camera mechanism, a sample placement mechanism and a light source mechanism 6 in sequence, and the camera mechanism, the sample placement mechanism and the light source mechanism 6 are located on the same horizontal line.

[0040] The sample placement mechanism and the camera mechanism are electrically connected to the computer. The computer is used to store and identify the optical interference video captured by the camera mechanism and to control the rise / fall of the sample placement mechanism.

[0041] Preferably, it also includes a shooting box, in which the base 1, camera mechanism, sample placement mechanism and light source mechanism 6 are all arranged, so that the camera mechanism can achieve better shooting results.

[0042] Preferably, the camera mechanism includes a camera adjustment assembly 3 and a camera 4;

[0043] The camera 4 is mounted on the camera adjustment assembly 3, which is located at the end of the base 1 away from the light source mechanism 6. The camera adjustment assembly 3 is used to drive the camera 4 to move away from / closer to the sample placement mechanism.

[0044] Camera 4 is connected to a computer, which is used to store and identify the optical interference video captured by camera 4.

[0045] Preferably, the camera adjustment assembly 3 includes a camera platform, a fixed base, a first slider, and a first lead screw;

[0046] The fixed base is located at the end of the base 1 away from the light source mechanism; the first lead screw is rotatably mounted on the fixed base and is arranged along the length of the base 1; one end of the first lead screw passes through the fixed base and is connected to a first knob;

[0047] The first slider is mounted on the first lead screw and has a first internal thread that mates with the first lead screw; the top of the first slider is fixedly connected to the bottom of the camera platform.

[0048] Camera 4 is mounted on the camera platform.

[0049] Preferably, a crosshair is provided in the center of the lens of camera 4.

[0050] Preferably, the sample placement mechanism includes an XY axis adjustment assembly 2, a sample lifting platform 5, and a sample holder;

[0051] The XY axis adjustment assembly 2 is mounted on the base, the sample lifting platform 5 is mounted on the XY axis adjustment assembly 2, and the sample holder is fixed on the top of the sample lifting platform 5. The sample holder is used to place optical components, and the XY axis adjustment assembly 2 and the sample lifting platform 5 cooperate with each other to adjust the relative position of the optical components.

[0052] The sample lifting platform 5 is connected to the computer.

[0053] Preferably, the XY axis adjustment assembly 2 includes a Y-axis base, a Y-axis sliding plate, an X-axis base, and an X-axis sliding plate;

[0054] The Y-axis base is fixedly installed on the base 1; a second lead screw is provided on the Y-axis base, and the second lead screw is arranged along the width direction of the base 1; one end of the second lead screw passes through the Y-axis base and is connected to a second knob; the Y-axis slide plate is set on the second lead screw and is provided with a second internal thread that mates with the second lead screw; the top of the Y-axis slide plate is fixedly connected to the bottom of the X-axis base.

[0055] A third lead screw perpendicular to the second lead screw is provided on the X-axis base. One end of the third lead screw passes through the X-axis base and is connected to a third knob. The X-axis slide plate is provided on the third lead screw and has a third internal thread that mates with the third lead screw. The sample lifting platform is located on top of the X-axis slide plate.

[0056] Preferably, the sample lifting platform 5 includes an automatic adjustment module and a manual adjustment module;

[0057] The automatic adjustment module is connected to a computer, which controls the sample lifting platform 5 to rise / fall at a constant speed; the manual adjustment module includes a fourth knob, which is used to fine-tune the height of the sample lifting platform.

[0058] Preferably, the computer includes a control module, an image recognition module, and a timer;

[0059] 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 5.

[0060] The image recognition module is connected to the camera and is used to store and recognize the optical interference video captured by the camera.

[0061] The image recognition module is connected to the control module and the timer, respectively.

[0062] Preferably, the image recognition module, control module, and timer work together to automatically record the time when the central crosshair of the lens coincides with the interference dark fringes. The distance between the dark fringes is obtained by multiplying the time difference of the crosshair passing through multiple dark fringes by the uniform descent speed of the sample lifting platform. Using the distance between the dark fringes, the image recognition module will automatically calculate the thickness of the optical thin film, the wavelength of the light wave, the radius of curvature of the plano-convex lens, and the refractive index parameter of the liquid using formulas.

[0063] The image recognition module, control module, and timer work together to identify the displacement of the lifting platform at the point where the crosshairs and interference fringes in the interference pattern coincide, and automatically calculate the radius of curvature of plano-convex lens-type optical components or the thickness or length of wedge-type optical components. Example 2

[0064] refer to Figure 3 This embodiment applies the optical experimental apparatus of Embodiment 1 to a method for measuring the radius of curvature of a plano-convex lens. The measurement method includes:

[0065] S1. Fix a flat glass to one side of the curved surface of a plano-convex lens. Place the plano-convex lens with the fixed flat glass on the sample holder. Turn on the light source mechanism and the computer. Adjust the focal length of the camera and the position of the sample lifting platform 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.

[0066] In this embodiment, the curved side of the plano-convex lens is closely attached to the flat glass.

[0067] S2. Adjust the height of the lifting platform below the sample holder, and fine-tune the position of the plano-convex lens device so that one of the crosshairs is perpendicular to the direction of movement of the sample lifting platform, and the other passes through the center of the interference rings; at this time, the crosshairs just coincide with the 40 dark rings below the interference fringes, and use this as a reference position, such as... Figure 3 As shown in A;

[0068] S3. Activate the instrument; the timer starts timing. Simultaneously, the sample lifting platform begins to descend slowly and uniformly at a certain speed. At this time, the crosshair in the field of view remains stationary, while the interference rings move downwards. When the crosshair is tangent to each dark ring, the timer will automatically record the time once, until the crosshair exactly coincides with the 40th dark ring above the interference fringes. Figure 3 As shown in C, the timer has ended;

[0069] S4. The image recognition module, control module, and timer in the computer work together to identify the displacement of the lifting platform at the point where the crosshairs and interference fringes in the interference pattern coincide, and automatically calculate the radius of curvature R of plano-convex lens-type optical components.

[0070] In this embodiment, the distance between each dark ring is the time difference between each dark ring multiplied by the speed at which the lifting platform descends at a constant speed. As we know from optical knowledge, a thin air film, thin in the middle and thick at the two sides, is formed between the plano-convex lens and the flat glass. When parallel monochromatic light is incident perpendicularly, due to the interference of the coherent light formed, a series of concentric ring-shaped fringes with alternating bright and dark colors, sparse in the center and dense at the edges, are formed around the contact point. When measuring, as long as the diameter of multiple dark rings is measured, a straight line can be obtained by linear fitting using the least squares method through Excel. The slope of this straight line is the radius of curvature R of the plano-convex lens. Example 3

[0071] refer to Figure 4 This embodiment uses the optical experimental apparatus of Embodiment 1 to measure the thickness of the air film in wedge-shaped optical components. The measurement method includes:

[0072] S1. Place a wedge-shaped optical component on the sample holder, turn on the light source mechanism and computer, and adjust the focal length of the camera and the position of the sample lifting platform 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 below the sample holder, and fine-tune the position of the optical components so that one of the crosshairs is perpendicular to the direction of movement of the lifting platform, and the other coincides with the first-level dark fringe. Use this as a reference position. Figure 4 As shown in A;

[0074] S3. Activate the instrument; the timer starts timing. Simultaneously, the sample lifting platform begins to descend slowly and uniformly at a certain speed. At this time, the crosshairs in the field of view remain stationary, and the parallel interference fringes move downwards. When the crosshairs are tangent to each dark ring, the timer will automatically record the time until the crosshairs coincide with the last dark interference fringe. Figure 4 As shown in C, the timer has ended;

[0075] S4. The image recognition module, control module, and timer in the computer work together to identify the time when the crosshairs and interference fringes in the interference pattern coincide. The distance between the multiple dark fringes is obtained by multiplying the time difference of the crosshairs passing through multiple dark fringes by the speed at which the sample lifting platform descends at a constant speed. Using the distance between the dark fringes, the image recognition module will automatically calculate the thickness of the optical thin film using a formula.

[0076] In this embodiment, the number of times is the total number of dark stripes; as we know from optical knowledge, the total number of dark stripes multiplied by half the wavelength of light is the thickness of the air film.

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

Claims

1. An optical experimental method based on the principle of interference, characterized in that, include: A computer and a base, the base being disposed on one side of the computer; a camera mechanism, a sample placement mechanism and a light source mechanism are sequentially disposed on the base, and the camera mechanism, the sample placement mechanism and the light source mechanism are located on the same horizontal line; The sample placement mechanism and the camera mechanism are electrically connected to the computer. The computer is used to store and identify the optical interference video captured by the camera mechanism and to control the sample placement mechanism to rise / fall. The camera mechanism includes a camera adjustment component and a camera; The camera is mounted on the camera adjustment assembly, which is located at the end of the base away from the light source mechanism; the camera adjustment assembly is used to drive the camera to move away from / near the sample placement mechanism. The camera is connected to the computer, which is used to store and identify the optical interference video captured by the camera. A crosshair is provided in the center of the lens of the camera. The sample placement mechanism includes an XY axis adjustment assembly, a sample lifting platform, and a sample holder; The XY-axis adjustment assembly is mounted on the base, the sample lifting platform is mounted on the XY-axis adjustment assembly, and the sample holder is fixed to the top of the sample lifting platform. The sample holder is used to place optical components, and the XY-axis adjustment assembly and the sample lifting platform cooperate with each other to adjust the relative position of the optical components. The sample lifting platform is connected to the computer; The sample lifting platform includes an automatic adjustment module and a manual adjustment module; The automatic adjustment module is connected to the computer, which controls the sample lifting platform to rise / fall at a constant speed; the manual adjustment module includes a fourth knob, which is used to fine-tune the height of the sample lifting platform. 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; The image recognition module, the control module, and the timer work together to automatically record the time when the central crosshair of the lens coincides with the interference dark fringes. The distance between the dark fringes is obtained by multiplying the time difference of the crosshair passing through multiple dark fringes by the uniform descent speed of the sample lifting platform. Using the distance between the dark fringes, the image recognition module will automatically calculate the thickness of the optical thin film, the wavelength of the light wave, the radius of curvature of the plano-convex lens, and the refractive index parameter of the liquid using formulas. The image recognition module, the control module, and the timer work together to identify the displacement of the lifting platform at the point where the crosshairs and interference fringes in the interference pattern coincide, and automatically calculate the radius of curvature of plano-convex lens-type optical components or the thickness or length of wedge-type optical components.

2. The optical experimental method based on the principle of interference as described in claim 1, characterized in that, It also includes a shooting box, in which the base, the camera mechanism, the sample placement mechanism, and the light source mechanism are all disposed, so that the camera mechanism can achieve better shooting results.

3. The optical experimental method based on the principle of interference as described in claim 1, characterized in that, The camera adjustment assembly includes a camera platform, a fixed base, a first slider, and a first lead screw; The fixed base is located at the end of the base away from the light source mechanism; the first lead screw is rotatably mounted on the fixed base and is arranged along the length direction of the base; one end of the first lead screw passes through the fixed base and is connected to a first knob; The first slider is mounted on the first lead screw and has a first internal thread that mates with the first lead screw; the top of the first slider is fixedly connected to the bottom of the camera platform. The camera is mounted on the camera platform.

4. The optical experimental method based on the principle of interference as described in claim 1, characterized in that, The XY axis adjustment assembly includes a Y-axis base, a Y-axis sliding plate, an X-axis base, and an X-axis sliding plate; The Y-axis base is fixedly installed on the base; a second lead screw is provided on the Y-axis base, and the second lead screw is arranged along the width direction of the base; one end of the second lead screw passes through the Y-axis base and is connected to a second knob; the Y-axis slide plate is arranged on the second lead screw and is provided with a second internal thread that cooperates with the second lead screw; the top of the Y-axis slide plate is fixedly connected to the bottom of the X-axis base. The X-axis base is provided with a third lead screw perpendicular to the second lead screw, one end of the third lead screw passes through the X-axis base and is connected to a third knob; the X-axis slide plate is provided on the third lead screw and is provided with a third internal thread that cooperates with the third lead screw; the sample lifting platform is provided on the top of the X-axis slide plate.

Images