Optical experiment device based on interference principle

Abstract

The invention 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 shooting mechanism, a sample placing mechanism and a light source mechanism are sequentially arranged on the base and are positioned on the same horizontal line; the sample placing mechanism and the camera shooting mechanism are electrically connected with the computer, and the computer is used for storing and identifying optical interference videos shot by the camera shooting mechanism and controlling the sample placing mechanism 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 invention relates to the technical field of optical detection, and in particular to an optical experimental device based on the interference principle. Background Art

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

[0003] When using light 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 parameters to be measured with the spacing of interference fringes through geometric formulas, and obtain the parameters to be measured through calculation. This type of optical experiment usually uses an ordinary reading microscope to measure the distance between multiple dark fringes, and then uses the formula to calculate the required parameters. This requires the measurer to count the number of interference fringes for a long time and record the actual distance between multiple interference fringes at the same time. In order to make the contrast between light and dark fringes clearer, the experimental environment needs to be dim. The experimenter takes a long time to read and count a large number of readings in the microscope in this environment, which requires a high degree of patience and meticulousness from the experimenter. Not only that, this test method is not only very easy to cause eye fatigue and reading errors in the experimenter, but also the difference in the same spacing read by different light environments or different experimenters is also large.

[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 radius of curvature of plano-convex lenses, and the refractive index of liquids. Summary of the invention

[0005] In order to achieve the above object, the present invention adopts the following technical solution: An optical experimental device based on the interference principle, comprising: A computer and a base, wherein the base is arranged on one side of the computer; a camera mechanism, a sample placement mechanism and a light source mechanism are arranged on the base in sequence, 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 respectively. The computer is used to store and identify the optical interference video footage taken by the camera mechanism and control the rise / fall of the sample placement mechanism.

[0006] Furthermore, it also includes a shooting box, and the base, the camera mechanism, the sample placement mechanism and the light source mechanism are all arranged in the shooting box, so that the camera mechanism can achieve a better shooting effect.

[0007] Furthermore, the camera mechanism includes a camera adjustment component and a camera; The camera is arranged on the camera adjustment component, and the camera adjustment component is arranged at one end of the base away from the light source mechanism; the camera adjustment component is used to drive the camera to move away from / close to the sample placement mechanism; The camera is connected to the computer, and the computer is used to store and identify the optical interference video footage shot by the camera.

[0008] Furthermore, the camera adjustment assembly includes a camera platform, a fixing seat, a first slider and a first screw rod; The fixing seat is arranged at one 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 a 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.

[0009] Furthermore, a crosshair is arranged in the center of the lens of the camera.

[0010] Further, the sample placement mechanism includes an XY axis adjustment component, a sample lifting platform and a sample holder; The XY axis adjustment component is arranged on the base, the sample lifting platform is arranged on the XY axis adjustment component, and the sample holder is fixed on the top of the sample lifting platform; the sample holder is used to place optical components, and the XY axis adjustment component 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.

[0011] Further, the XY axis adjustment assembly includes a Y-axis base, a Y-axis slide, an X-axis base and an X-axis slide; The Y-direction base is fixedly mounted on the base; a second screw rod is arranged on the Y-direction 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 Y-direction base and is connected to a second knob; the Y-direction slide plate is arranged on the second screw rod and is provided with a second internal thread matched with the second screw rod; the top of the Y-direction slide plate is fixedly connected to the bottom of the X-direction base; The X-axis base is provided with a third screw rod perpendicular to the second screw rod, and one end of the third screw rod passes through the X-axis base and is connected to a third knob; the X-axis slide is arranged on the third screw rod and is provided with a third internal thread matching the third screw rod; the sample lifting platform is arranged on the top of the X-axis slide.

[0012] Furthermore, 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.

[0013] Further, 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 taken by the camera; The image recognition module is connected to the control module and the timer respectively.

[0014] Furthermore, the image recognition module, the control module, and the timer cooperate with each other to automatically record the time when the central crosshairs of the lens overlap with the interference dark fringes, and the distance between the multiple dark fringes is obtained by multiplying the time difference of the crosshairs passing through the multiple dark fringes by the uniform descending 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 film, the wavelength of the light wave, the radius of curvature of the plano-convex lens, and the refractive index parameter value of the liquid using a formula; 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 plano-convex lens type optical component or the thickness or length of the wedge-shaped optical component. Beneficial Effects

[0015] The present invention does not adopt the method of reading the distance between the dark stripes, but uses time measurement instead of distance measurement to obtain the spacing between the dark stripes; uses the image recognition module to identify the time when the central crosshairs of the camera coincide with the interference dark stripes, and multiplies the time difference of the crosshairs 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 tiny 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

[0016] Figure 1 It is a structural schematic diagram of the optical experimental device of the present invention; Figure 2 It is a structural schematic diagram of the shooting box of the present invention; Figure 3 It is a process diagram of photographing the curvature radius of a plano-convex lens by the optical experimental device of the present invention; Figure 4 It is a process diagram of measuring the thickness of the air film in the wedge-shaped optical component by the optical experimental device of the present invention; Among them, 1. Base; 2. XY axis adjustment component; 3. Camera adjustment component; 4. Camera; 5. Sample lifting platform; 6. Light source mechanism. DETAILED DESCRIPTION Example 1

[0017] refer to Figure 1-Figure 2 , an optical experimental device based on the interference principle, comprising: A computer and a base 1, wherein the base 1 is arranged on one side of the computer; a camera mechanism, a sample placement mechanism and a light source mechanism 6 are arranged on the base 1 in sequence, and the camera mechanism, the sample placement mechanism and the light source mechanism 6 are located on the same horizontal line; The sample placement mechanism and the camera mechanism are electrically connected to a computer respectively. The computer is used to store and identify the optical interference video footage taken by the camera mechanism and to control the rise / fall of the sample placement mechanism.

[0018] Preferably, a shooting box is also included, and the base 1, the camera mechanism, the sample placement mechanism and the light source mechanism 6 are all arranged in the shooting box, so that the camera mechanism can achieve a better shooting effect.

[0019] Preferably, the camera mechanism includes a camera adjustment component 3 and a camera 4; The camera 4 is arranged on the camera adjustment component 3, and the camera adjustment component 3 is arranged at an end of the base 1 away from the light source mechanism 6; the camera adjustment component 3 is used to drive the camera 4 to move away from / close to the sample placement mechanism; The camera 4 is connected to a computer, and the computer is used to store and identify the optical interference video footage taken by the camera 4 .

[0020] Preferably, the camera adjustment assembly 3 includes a camera platform, a fixing seat, a first slider and a first screw rod; 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; 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 4 is arranged on the camera platform.

[0021] Preferably, a crosshair is arranged in the center of the lens of the camera 4.

[0022] Preferably, the sample placement mechanism includes an XY axis adjustment component 2, a sample lifting platform 5 and a sample holder; The XY axis adjustment component 2 is arranged on the base, the sample lifting platform 5 is arranged on the XY axis adjustment component 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 component 2 and the sample lifting platform 5 cooperate with each other to adjust the relative position of the optical components; The sample lifting platform 5 is connected to the computer.

[0023] Preferably, the XY axis adjustment assembly 2 comprises a Y-axis base, a Y-axis slide, an X-axis base and an X-axis slide; The Y-direction base is fixedly mounted on the base 1; a second screw rod is arranged on the Y-direction base, and the second screw rod is arranged along the width direction of the base 1; one end of the second screw rod passes through the Y-direction base and is connected to a second knob; the Y-direction slide plate is arranged on the second screw rod and is provided with a second internal thread matched with the second screw rod; the top of the Y-direction slide plate is fixedly connected to the bottom of the X-direction base; A third screw rod perpendicular to the second screw rod is arranged on the X-axis base, and one end of the third screw rod passes through the X-axis base and is connected to a third knob; the X-axis slide is arranged on the third screw rod and is provided with a third internal thread matching the third screw rod; the sample lifting platform is arranged on the top of the X-axis slide.

[0024] Preferably, the sample lifting platform 5 includes an automatic adjustment module and a manual adjustment module; The automatic adjustment module is connected to a computer, and the computer is used to control the sample lifting platform 5 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.

[0025] Preferably, 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 uniform rise / fall of the sample lifting platform and adjust the lifting speed of the sample lifting platform 5; The image recognition module is connected to the camera, and the image recognition module is used to store and recognize the optical interference video footage taken by the camera; The image recognition module is connected with the control module and the timer respectively.

[0026] Preferably, the image recognition module, the control module, and the timer cooperate with each other to automatically record the time when the central crosshairs of the lens overlap with the interference dark fringes, and the distance between the multiple dark fringes is obtained by multiplying the time difference of the crosshairs passing through the multiple dark fringes by the speed at which the sample lifting platform descends at a uniform speed; using the distance between the dark fringes, the image recognition module will automatically calculate the thickness of the optical film, the wavelength of the light wave, the radius of curvature of the plano-convex lens, and the refractive index parameter value of the liquid using a formula; 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 plano-convex lens type optical component or the thickness or length of the wedge-point type optical component. Example 2

[0027] refer to Figure 3 This embodiment is an optical experimental device of Application Example 1, and is used for a method for measuring the curvature radius of a plano-convex lens. The measuring method includes: S1. Fix a flat glass on one side of the curved surface of a plano-convex lens, place the plano-convex lens with the flat glass fixed 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; In this embodiment, the curved surface of the plano-convex lens is arranged in close contact with the flat glass.

[0028] S2. Adjust the height of the lifting platform under the sample holder, and fine-tune the position of the plano-convex lens device so that one of the cross wires is perpendicular to the moving direction of the sample lifting platform, and one passes through the center of the interference ring; at this time, the cross wire just coincides with the dark pattern of the 40th ring below the interference fringe, and this is used as the reference position, such as Figure 3 As shown in A; S3. Enable the instrument, start the timer, and at the same time, the sample lift table starts to slowly descend at a certain speed. At this time, the crosshairs in the field of view do not move, and the interference ring moves downward. When the crosshairs are tangent to each level of dark ring, the timer will automatically record the time until the crosshairs coincide with the 40th ring of dark ring above the interference fringes. Figure 3 As shown in C, the timing ends; 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 overlap of the crosshairs and the interference fringes in the interference pattern, and automatically calculate the curvature radius R of the optical component such as the plano-convex lens.

[0029] In this embodiment, the distance between each ring of dark lines is the time difference between each ring of dark lines multiplied by the uniform descent speed of the lifting platform; from optical knowledge, it is known that a thin air film in the middle and thick on both sides will be formed between the plano-convex lens and the flat glass, and when parallel monochromatic light is incident vertically, due to the interference of the formed coherent light, a series of concentric ring-shaped stripes with alternating light and dark, sparse in the center and dense at the edges, centered on the contact point will be formed; when measuring, as long as the diameters of multiple dark rings are measured, a straight line can be obtained by the least squares method through Excel linear fitting, and the slope of this straight line is the curvature radius R of the plano-convex lens. Example 3

[0030] refer to Figure 4 This embodiment is an optical experimental device of application embodiment 1, and is used to measure the thickness of an air film in a wedge-shaped optical component. The measuring method includes: S1. Place a wedge-shaped optical component 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 wedge-shaped optical component are clearly visible in the field of view; 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 moving 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. Figure 4 As shown in A; S3. Enable the instrument, and the timer starts timing. At the same time, the sample lifting platform starts to slowly descend at a certain speed. At this time, the crosshairs in the field of view do not move, and the parallel interference fringes move downward. When the crosshairs are tangent to each level of dark ring, the timer will automatically record the time until the crosshairs coincide with the last level of interference dark fringes. Figure 4 As shown in C, the timing ends; S4. The image recognition module, control module and timer in the computer cooperate with each other to identify the time when the crosshairs and interference fringes in the interference pattern overlap, and the distance between the multiple dark fringes is obtained by multiplying the time difference when the crosshairs pass 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 film using a formula.

[0031] In this embodiment, the timing times are the total number of dark fringes. According to optical knowledge, the total number of dark fringes multiplied by half of the wavelength of light is the thickness of the air film.

[0032] 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 slight 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 mechanism, a sample placement mechanism and a light source mechanism are arranged on the base in sequence, 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 respectively. The computer is used to store and identify the optical interference video footage taken by the camera mechanism and control the rise / fall of the sample placement mechanism.

2. An 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 mechanism, the sample placement mechanism and the light source mechanism are all arranged, so that the camera mechanism can achieve a better shooting effect.

3. An optical experimental device based on the interference principle as claimed in claim 1, characterized in that: The camera mechanism includes a camera adjustment component and a camera; The camera is arranged on the camera adjustment component, and the camera adjustment component is arranged at one end of the base away from the light source mechanism; the camera adjustment component is used to drive the camera to move away from / close to the sample placement mechanism; The camera is connected to the computer, and the computer is used to store and identify the optical interference video footage shot by the camera.

4. An optical experimental device based on the interference principle as claimed in claim 3, characterized in that: The camera adjustment assembly includes a camera platform, a fixing seat, a first slider and a first screw rod; The fixing seat is arranged at one 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 a 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.

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

6. An optical experimental device based on the interference principle as claimed in claim 5, characterized in that: The sample placement mechanism includes an XY axis adjustment component, a sample lifting platform and a sample holder; The XY axis adjustment component is arranged on the base, the sample lifting platform is arranged on the XY axis adjustment component, and the sample holder is fixed on the top of the sample lifting platform; the sample holder is used to place optical components, and the XY axis adjustment component 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.

7. An optical experimental device based on the interference principle as claimed in claim 6, characterized in that: The XY axis adjustment assembly includes a Y-axis base, a Y-axis slide, an X-axis base and an X-axis slide; The Y-direction base is fixedly mounted on the base; a second screw rod is arranged on the Y-direction 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 Y-direction base and is connected to a second knob; the Y-direction slide plate is arranged on the second screw rod and is provided with a second internal thread matched with the second screw rod; the top of the Y-direction slide plate is fixedly connected to the bottom of the X-direction base; The X-axis base is provided with a third screw rod perpendicular to the second screw rod, and one end of the third screw rod passes through the X-axis base and is connected to a third knob; the X-axis slide is arranged on the third screw rod and is provided with a third internal thread matching the third screw rod; the sample lifting platform is arranged on the top of the X-axis slide.

8. An optical experimental device based on the interference principle as claimed in claim 7, 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.

9. An optical experimental device based on the interference principle as claimed in claim 8, 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.

10. An optical experimental device based on the interference principle as claimed in claim 9, characterized in that: The image recognition module, the control module and the timer cooperate with each other to automatically record the time when the central crosshairs of the lens overlap with the interference dark fringes, and the distance between the multiple dark fringes is obtained by multiplying the time difference of the crosshairs passing through the multiple dark fringes by the speed of the sample lifting platform descending at a uniform speed; using the distance between the dark fringes, the image recognition module will automatically calculate the thickness of the optical film, the wavelength of the light wave, the curvature radius of the plano-convex lens, and the refractive index parameter value of the liquid using a formula; 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 plano-convex lens type optical component or the thickness or length of the wedge-shaped optical component.

Images