Light interference and diffraction experiment device

Abstract

The utility model discloses a light interference and diffraction experiment device, which comprises a laser transmitter and a first experiment part, the first experiment part comprises an interference instrument and a diffraction instrument; the interference device is of a thin sheet structure with uniform thickness, can be arranged on a propagation path of a laser beam, and divides the laser beam incident to the interference device into two emergent beams, so that the interference phenomenon of light is observed; the diffraction instrument can be arranged on the propagation path of the laser beam, one half of the laser beam entering the diffraction instrument is shielded, and the other half of the laser beam forms a spherical wave at the edge of the diffraction instrument, so that the diffraction phenomenon of light is observed. According to the utility model, the first experiment part can reproduce a Young's double-slit interference experiment and a Fraunhofer single-slit diffraction experiment only by using a flat sheet under the condition that double slits and single slits are not needed, and can intuitively show physical mechanisms such as wave splitting surfaces and wave surface limitation; and experiments of circular hole diffraction, cross diffraction, Poisson bright spots and the like can be demonstrated.

Description

Technical Field

[0001] The utility model relates to the technical field of physics teaching experiments, in particular to a light interference and diffraction experimental device. Background Art

[0002] Optics is the study of the generation, propagation, absorption, and interaction of light with matter. Wave optics is a crucial component of optics. The study of the interference and diffraction of light waves is a crucial avenue for exploring the nature and properties of light. Furthermore, the interference and diffraction of light are not merely physical phenomena; they also have numerous practical applications. One of the most common applications is the use of interferometers. Interferometers utilize the interference of light to measure wavelength, film thickness, and the refractive index of materials. They are widely used in optical instrumentation, scientific research, and engineering. With the continuous advancement of science and technology, the interference and diffraction of light will find even more applications in the future. For example, the recently emerging field of nano-optics is based on the interference and diffraction of light. By controlling and manipulating the structure and morphology of materials, it achieves precise control and manipulation of light. Advances in this field will contribute to applications such as higher-resolution optical microscopy, faster optical communications, and more efficient photovoltaic cells.

[0003] Therefore, in optics, interference and diffraction of light are very important concepts and phenomena. By understanding the basic principles of interference and diffraction of light, we can gain a deeper understanding of the wave nature of light and apply them to practical scientific research and engineering technology. The two most important experiments are Young's double-slit interference experiment and Fraunhofer's single-slit diffraction experiment. Young's double-slit experiment is a great experiment of epoch-making significance in the history of optical development and the entire history of physics, because many interference problems can be equivalent to Young's double-slit. Mastering Young's double-slit experiment is equivalent to opening a door to understanding the problem of light wave interference, and also laying the foundation for subsequent quantum physics research such as electron interference. At the same time, diffraction is also one of the important characteristics of wave optics; Fraunhofer single-slit diffraction experiment, circular aperture diffraction and Poisson spot are several basic experiments for studying diffraction phenomena, which are of great significance for a deep understanding of the principles of wave optics.

[0004] A lot of research has been done on Young's double-slit interference experiment and diffraction experiment. Researchers have proposed a series of demonstration experiment plans. Their basic idea is to combine the corresponding optical elements such as double slits, single slits, circular holes, light-shielding disks, small steel balls, etc. into a platform, and illuminate them separately with an external laser pen to demonstrate interference and diffraction patterns.

[0005] Although existing experimental schemes can reproduce Young's double-slit interference experiment and diffraction experiment, they have the following technical shortcomings:

[0006] (1) All Young's double-slit interference experiments and Fraunhofer's single-slit diffraction experiments need to be carried out under the conditions of double slits and single slits.

[0007] The requirements for making narrow slits are very high. The width must be less than a millimeter, and the gap must be uniform and the interface must be smooth. These requirements are difficult to achieve in daily life and require the use of professional equipment for processing or the purchase of corresponding finished devices. This makes it difficult for students to conduct further independent research on interference and diffraction phenomena outside the laboratory.

[0008] (2) It fails to fully reflect the essence of Young’s double-slit interference experiment, namely, the interference of partial wave surfaces.

[0009] To observe interference, three coherence conditions must be met simultaneously: identical frequency, consistent vibration direction, and constant phase difference. Ordinary light sources emit light at random frequencies, random vibration directions, and random phases. Only the same beam of light can be coherent with itself. Therefore, interference can only be observed when the same incident light beam is split into wavefronts and amplitudes. Although Young's double slit is essentially wavefront interference, because the wavefronts are invisible, learners find it difficult to clearly and accurately establish the physical image of wavefront splitting, making it difficult to understand how light achieves "self-coherence."

[0010] (3) It fails to fully reflect the essence of the Fraunhofer single-slit diffraction experiment, which is to restrict the wavefront.

[0011] Diffraction, in essence, occurs when light encounters an obstacle during propagation, causing the wavefront to be confined, resulting in deviation from a straight line of propagation and the expansion, diffusion, and uneven distribution of light intensity. The basic rule is: the more severely the light wavefront is confined, the more pronounced the diffraction pattern expands. The diffraction pattern on the receiving screen expands in the direction in which the light wavefront is confined on the diffraction screen. Conventional experiments all use a single slit. Because the wavefront is invisible, learners cannot clearly establish a physical image of the confined wavefront, making it difficult to fully understand the essential law underlying the diffraction phenomenon, namely the Huygens-Fresnel principle.

[0012] (4) The effect of demonstrating Poisson bright spots is poor.

[0013] Because the light-dark contrast of a Poisson spot strongly depends on the flatness of the circular shading area and the smoothness of the interface, traditional methods often use shading disks or small steel balls to conduct experiments. However, the shading disk's interface is not smooth enough; while the small steel balls have a smooth interface, their spherical structure introduces additional phase differences. Therefore, the light intensity of the central bright spot in traditional Poisson spot experiments is not strong enough to contrast with the surrounding area, requiring experiments to be conducted in a darkroom, and no light or dark fringes can be seen within the geometric shadow area.

[0014] (5) The existing experimental equipment scheme only allows students to "watch the demonstration experiment" stage.

[0015] While existing experimental protocols can be used for classroom demonstrations, since there's usually only one demonstration instrument, students lack the opportunity to conduct hands-on experiments. Consequently, students' learning of interference and diffraction is passive, unable to actively engage in experiments to enhance their learning interest and deepen their understanding. This makes it difficult for them to internalize this knowledge and translate it into practical problem-solving skills. Utility Model Content

[0016] The utility model provides a light interference and diffraction experimental device to solve the shortcomings of existing interference and diffraction experimental solutions.

[0017] The technical solution adopted by the utility model to solve the technical problem is as follows: the utility model provides a light interference and diffraction experimental device, which includes a laser transmitter and a first experimental part;

[0018] The laser emitter is used to emit a laser beam;

[0019] The first experimental part includes an interference apparatus and a diffraction apparatus;

[0020] The interference device is a thin sheet structure with uniform thickness, which can be placed on the propagation path of the laser beam and separate the laser beam incident on the interference device into two outgoing beams. The two outgoing beams have the same frequency, consistent vibration direction and constant phase difference, thereby observing the interference phenomenon of light;

[0021] The diffraction device can be placed on the propagation path of the laser beam and block half of the laser beam incident on the diffraction device, allowing the other half of the laser beam to form a spherical wave at the edge of the diffraction device, thereby observing the diffraction phenomenon of light.

[0022] Preferably, the interference device is a flat sheet of paper. Of course, the flat sheet of paper can also be replaced by a flat sheet of other materials.

[0023] Furthermore, the width of the flat paper sheet is between 0.3 cm and 1 cm, and the thickness is between 0.05 mm and 0.2 mm.

[0024] Preferably, the diffraction device is a folded paper sheet. Of course, the folded paper sheet can also be replaced by a folded sheet of other materials and with a substantially similar structure.

[0025] Furthermore, the folding paper sheet is formed by folding a paper sheet and has an L-shaped cross section, wherein the width of the folding paper sheet is between 0.6 cm and 2 cm, and the thickness is between 0.05 mm and 0.2 mm.

[0026] Preferably, the first experimental part further comprises one of the following:

[0027] Circular hole diffraction paper, wherein the circular hole diffraction paper is a paper with pinholes, and the pinholes are smooth circular holes with a diameter between 1 mm and 2 mm;

[0028] Cross diffraction paper, wherein the cross diffraction paper is a cross-shaped structure paper formed by crossing two pieces of paper, wherein the width of the two pieces of paper is between 0.3 cm and 1 cm, and the thickness of the two pieces of paper is between 0.05 mm and 0.2 mm;

[0029] A Poisson speckled glass sheet is a glass sheet with a smooth light-shielding disk formed in the middle.

[0030] Furthermore, the first experimental part also includes a stage; the interference device, diffraction device, circular hole diffraction paper and cross diffraction paper can be selectively placed on the stage to cooperate with the laser emitter to form corresponding optical phenomena;

[0031] The Poisson speckle glass sheet is placed at a predetermined position and can cooperate with the laser emitter to form a corresponding optical phenomenon.

[0032] Preferably, the experimental device further comprises a slide groove; the laser emitter can move back and forth along the slide groove to adjust the position of the laser beam emitted by the laser emitter.

[0033] Preferably, the experimental device further comprises a second experimental part, which comprises a vernier caliper, wherein two outer measuring jaws of the vernier caliper form a single slit with adjustable width for quantitatively studying Fraunhofer single-slit diffraction.

[0034] Furthermore, the second experimental part also includes a demonstration board, on which at least one of a double slit, a triple slit, a grating, a rotatable polarizer, a triangular hole and a rectangular hole is provided.

[0035] The beneficial effects of the utility model are as follows:

[0036] The first experimental part of the experimental device of the present invention belongs to the special experimental part, and the second experimental part belongs to the conventional experimental part. Among them, the conventional experimental part integrates commonly used optical elements into a set of multifunctional wave optics demonstration experimental instruments to meet the quantitative research of Young's double-slit experiment and Fraunhofer single-slit diffraction experiment, so as to meet the students' learning of basic interference and diffraction knowledge. The special experimental part can provide students with deeper learning content, that is, the teacher explains and demonstrates the essence of interference and diffraction to the students, and guides the students to conduct independent exploration of interference and diffraction, so as to achieve the purpose of in-depth mastery of the laws of interference and diffraction, and use them to analyze and solve practical problems. In other words, the special innovation of the present invention is that the special experimental part can reproduce Young's double-slit interference experiment and Fraunhofer single-slit diffraction experiment by only using paper without the need for double slits and single slits, and can also intuitively display physical mechanisms such as wavefront division and wavefront confinement, so as to promote learners to have a deep understanding of the Huygens-Fresnel principle. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 This is a front view of the light interference and diffraction experimental device provided by the preferred embodiment of the utility model;

[0038] Figure 2 yes Figure 1 dorsal view of;

[0039] Figure 3 This is a principle diagram and the pattern formed when using a flat paper sheet to conduct an interference experiment in the present invention, wherein (a) is the principle diagram and (b) is the pattern formed;

[0040] Figure 4 This is a principle diagram and the pattern formed when using folded paper to conduct diffraction experiments in the present invention, wherein (a) is the principle diagram and (b) is the pattern formed;

[0041] Figure 5 The figure is a schematic diagram of the structure of the circular hole diffraction paper in the present invention and the pattern formed when the Fraunhofer circular hole diffraction experiment is carried out, wherein (a) is a schematic diagram of the structure and (b) is a pattern formed;

[0042] Figure 6 The schematic diagram of the structure of the cross diffraction paper in the present invention and the pattern formed when the cross diffraction experiment is performed, wherein (a) is a schematic diagram of the structure and (b) is a pattern formed;

[0043] Figure 7 This is a schematic diagram of the structure of the Poisson bright spot glass sheet in the present invention and the pattern formed when conducting the Poisson bright spot experiment, wherein (a) is a schematic diagram of the structure, and (b) is the pattern formed;

[0044] Components marked in the diagram are: 1 - Base, 2 - Laser emitter, 3 - Slide, 4 - Bracket. 5 - Vernier caliper, 6 - Second adjustment knob, 7 - Demonstration board, 8 - Poisson speckle glass, 9 - Stage, 10 - First adjustment knob, 11 - Flat paper, 12 - Folded paper, 13 - Circular hole diffraction paper, 14 - Cross diffraction paper. DETAILED DESCRIPTION

[0045] The present invention will be further described in detail below with reference to specific embodiments, but the implementation manner of the present invention is not limited thereto.

[0046] The utility model provides a light interference and diffraction experimental device, which comprises a laser emitter 2 and a first experimental part.

[0047] The laser emitter 2 is used to emit a laser beam. The focal length of the laser beam is adjustable, and the light spot is a perfect circle. Of course, the light spot can also be non-circular, but in this case, the laser emitter must first be irradiated vertically onto a small circular hole to filter the laser emitter's output light spot.

[0048] The first experimental part belongs to the special experimental part, which includes an interference device, a diffraction device and a stage 9.

[0049] The interference device is a flat sheet of paper 11 of uniform thickness. When conducting an interference experiment, the flat sheet of paper 11 is placed on the stage 9. The laser emitter 2 is then adjusted to a suitable position so that the flat sheet of paper 11 is located in the propagation path of the laser beam. The laser beam incident on the flat sheet of paper 11 is then split into two outgoing beams. This allows the two outgoing beams to have the same frequency, consistent vibration direction, and constant phase difference to form a light interference phenomenon, leaving an interference pattern on the light screen. Figure 3 Middle (b).

[0050] The diffraction device is a folded paper sheet 12. When conducting a diffraction experiment, the folded paper sheet 12 is placed on the stage 9, and then the laser emitter 2 is adjusted to a suitable position so that the folded paper sheet 12 is located on the propagation path of the laser beam. Half of the laser beam incident on the folded paper sheet 12 is blocked, and the other half of the laser beam forms a spherical wave at the edge of the folded paper sheet 12, thereby forming a diffraction phenomenon of light and leaving a diffraction pattern on the light screen, see Figure 4 Middle (b).

[0051] The width of the flat paper sheet 11 is between 0.3 cm and 1 cm, and the thickness is between 0.05 mm and 0.2 mm. Generally, the flat paper sheet 11 can be obtained by cutting ordinary A4 printing paper, and the thickness of ordinary A4 printing paper is about 0.1 mm. For example, a paper sheet with a width of 0.5 cm and a suitable length is cut from A4 printing paper, and then the paper sheet is clamped in a gap on the upper surface of a fixing base (such as Figure 2 As shown), when performing interference experiments, the fixing seat can be placed between the two clamping plates of the stage 9.

[0052] The folding paper sheet 12 is formed by folding a paper sheet and has an L-shaped cross section. The width of the folding paper sheet is between 0.6 cm and 2 cm, and the thickness is between 0.05 mm and 0.2 mm. Generally, the folding paper sheet 12 can also be obtained by cutting ordinary A4 printing paper. For example, a paper sheet with a width of 1 cm and a suitable length is cut from A4 printing paper, and then the paper sheet is folded at a right angle along the fold line to form a structure with two sides with a width of 0.5 cm and an L-shaped cross section, thus forming the folding paper sheet 12. The folding paper sheet 12 is then clamped in a gap on the upper surface of a fixed seat (such as Figure 1 As shown), when conducting a diffraction experiment, the fixing seat can be placed between the two clamping plates of the stage 9.

[0053] Typically, a clean white wall can be used as the light screen when conducting experiments. Alternatively, a concave lens can be added after the light path where interference and diffraction occur to disperse the interference and diffraction images, making it easier to observe on a closer light screen.

[0054] In some embodiments, in addition to performing interference experiments using a flat paper sheet 11 and diffraction experiments using a folded paper sheet 12, the first experimental section may also include some extended experiments. Specifically, the first experimental section may also include at least one of a circular hole diffraction paper sheet 13, a cross diffraction paper sheet 14, and a Poisson speckle glass sheet 8.

[0055] For example Figure 1 In the example shown, the first experimental part also includes the above three, namely, the circular hole diffraction paper 13, the cross diffraction paper 14 and the Poisson bright spot glass sheet 8.

[0056] The circular hole diffraction paper 13 can be used to perform a Fraunhofer circular hole diffraction experiment. The circular hole diffraction paper 13 is a piece of paper with a pinhole, and the pinhole is a smooth circular hole with a diameter between 1 mm and 2 mm. When making the circular hole diffraction paper 13, you can first cut out a piece of paper with a width of 1 cm and a suitable length, then use a pin to poke a smooth circular hole with a diameter of 1-2 mm on the paper, and then clamp the circular hole diffraction paper 13 in the gap on the upper surface of a fixing base (such as Figure 1 When conducting a Fraunhofer circular aperture diffraction experiment, the holder is placed between the two clamping plates of the stage 9. Then, the position is adjusted so that the incident laser beam passes through the circular hole on the circular aperture diffraction paper 13. Then, the Fraunhofer circular aperture diffraction pattern can be observed on the light screen. Figure 5 Middle (b).

[0057] The cross diffraction paper sheet 14 can be used for cross diffraction experiments. The cross diffraction paper sheet 14 is a cross-shaped structure paper sheet formed by cross-bonding two paper sheets, wherein the width of the two paper sheets is between 0.3cm and 1cm, and the thickness is between 0.05mm and 0.2mm. When making the cross diffraction paper sheet 14, you can first cut out two paper sheets with a width of 0.5cm and a suitable length, and then use scissors to cut a 50% width incision in the center of each of the two paper strips, and cross-bond the incisions of the two paper strips into a cross-shaped structure, that is, forming the above-mentioned cross diffraction paper sheet 14, and then clamp the cross diffraction paper sheet 14 in the gap on the upper surface of a fixed seat (such as Figure 1 When conducting a cross diffraction experiment, the holder is placed between the two clamping plates of the stage 9, and then the position is adjusted so that the incident laser beam hits the center of the cross structure of the cross diffraction paper 14. The cross diffraction pattern can be observed on the screen, see Figure 6 Middle (b).

[0058] The Poisson bright spot glass sheet 8 can be used to conduct the Poisson bright spot experiment. The Poisson bright spot glass sheet 8 is a glass sheet with a smooth light-shielding disk formed in the middle. When making the Poisson bright spot glass sheet 8, it can be made on a transparent glass sheet. First, remove the tip of the signature pen, then drop black ink on the glass sheet, and then let the black ink solidify naturally to form a light-shielding disk with a flat surface and a smooth interface, thereby improving the light and dark contrast of the Poisson bright spot when conducting the Poisson bright spot experiment. The prepared Poisson bright spot glass sheet 8 can be fixed at a specific position on the experimental device. When conducting the Poisson bright spot experiment, adjust the incident light spot of the laser beam so that it is slightly larger than the light-shielding disk, and ensure that the light-shielding disk is illuminated from the back of the glass sheet (that is, the laser beam first passes through the glass sheet and then illuminates the light-shielding disk with a flat surface and a smooth circular interface). The pattern of the Poisson bright spot can be observed on the light screen, see Figure 7Typically, a plurality of light-shielding disks can be made on the glass sheet, for example, four light-shielding disks with diameters of 0.5 mm, 1 mm, 1.5 mm, and 2.0 mm can be made.

[0059] Preferably, see Figure 1 The experimental device of the present invention also includes a base 1 and a bracket 4. The bracket 4 is vertically fixed to the base 1 and has a light-transmitting hole at an appropriate position. A slide groove 3 is provided on the front side of the bracket 4 and is fixed to the upper surface of the base 1. The laser emitter 2 is fixed to a support that can move left and right along the slide groove 3. The stage 9 is provided on the rear side of the bracket 4 and fixed to the base 1. The stage 9 is equipped with a first adjustment knob 10 that adjusts the spacing between the two clamping plates of the stage 9. The Poisson's speckle glass sheet 8 is fixed to the bracket 4. During the experiment, the relative position of the laser emitter 2 and the experimental equipment on the stage 9 can be adjusted by moving the support of the laser emitter 2 along the slide groove 3, so that the incident laser beam is perpendicular to the paper or glass sheet and at the same height as the position of the device, such as the small hole, the center of the cross, or the black light-blocking disk. In the above experiment, the distance between the laser emitter 2 and the paper should be between 1 cm and 2 cm, and the distance between the paper and the light screen is usually 3 m to 4 m (without using a concave lens to disperse the interference and diffraction images).

[0060] In some embodiments, the experimental device of the present invention further includes a second experimental part, which belongs to the conventional experimental part.

[0061] Specifically, the second experimental part includes a vernier caliper 5 and a demonstration board 7. The vernier caliper 5 is fixed on the bracket 4, and the two outer measuring claws of the vernier caliper 5 form a single slit with adjustable width, which is used to quantitatively study Fraunhofer single-slit diffraction. Preferably, the vernier caliper 5 adopts a digital display vernier caliper, and the side of the vernier caliper 5 is equipped with a second adjustment knob 6, which can conveniently adjust the distance between the two outer measuring claws of the vernier caliper 5, thereby adjusting the width of the single slit. The demonstration board 7 is a conventional instrument currently used in optical experiments and can be purchased directly from the market. The demonstration board 7 is fixed on the bracket 4, and is provided with double slits, triple slits, a grating, a rotatable polarizer, a triangular hole and a rectangular hole.

[0062] In the present invention, the second experimental part belongs to the conventional experimental part, which is similar to the instruments used in the conventional interference diffraction experimental devices currently on the market, except that a vernier caliper 5 is used to replace the conventional single-slit instrument; during the experiment, by moving the laser emitter 2 and allowing the laser beam to vertically irradiate the corresponding elements of the second experimental part, the following conventional experiments can be completed: (1) Using the single slit with adjustable width formed by the two outer measuring claws of the digital display vernier caliper, the Fraunhofer single-slit diffraction can be quantitatively studied; (2) Using the double slit of the purchased demonstration board 7, the Young double-slit interference experiment can be quantitatively studied; (3) Using the purchased demonstration board 7, optical experiments such as double-slit and triple-slit interference, grating diffraction, polarization phenomenon, triangular hole diffraction and rectangular hole diffraction can also be demonstrated.

[0063] The first experimental part of the present invention is a special experimental part, which uses instruments completely different from the conventional experimental devices currently on the market to carry out interference and diffraction experiments, as follows.

[0064] In the above-mentioned special experimental part, when conducting the interference experiment, there is no need to make a double slit. It is only necessary to place a flat paper 11 in the center of the laser beam propagation path and let the flat paper 11 evenly split the incident laser beam into two outgoing beams. This incident laser beam splitting scheme intuitively presents the physical mechanism of wavefront separation, that is, the two outgoing beams are separated from the incident beam, which fully meets the three basic conditions of interference (i.e., the same frequency, consistent vibration direction and constant phase difference), thereby achieving self-coherence and finally achieving the corresponding results of reproducing Young's double-slit interference experiment. The experimental principle and results are shown in Figure 2 and Figure 3 respectively. Figure 3 (a) and Figure 3 Middle (b).

[0065] In the diffraction experiment of the above-mentioned special experiment, it is not necessary to make a single slit. Instead, a paper sheet needs to be folded into a right angle to form the folded paper sheet 12, which is then placed in the center of the laser beam propagation path. The right-angled folded paper sheet 12 blocks half of the incident beam, resulting in the outgoing beam being only half of the incident beam. In this way, the wavefront of the incident beam is restricted by the folded paper sheet 12, so the outgoing beam forms a spherical wave at the edge of the folded paper sheet 12. According to the Huygen-Fresnel principle, the same result as Fraunhofer single-slit diffraction will be produced. The experimental principle and results are shown in [1] and [2], respectively. Figure 4 (a) and Figure 4 Middle (b).

[0066] In addition, the above-mentioned special experiment part can also demonstrate Fraunhofer circular hole diffraction through the circular hole diffraction paper 13. The structure of the circular hole diffraction paper 13 and the pattern formed are shown in FIG. Figure 5 (a) and Figure 5In addition, the special experiment part can also demonstrate cross diffraction through the cross diffraction paper 14. The structure of the cross diffraction paper 14 and the pattern formed are shown in FIG. Figure 6 (a) and Figure 6 In addition, the featured experiment part can also demonstrate Poisson bright spot through Poisson bright spot glass sheet 8. The structure of Poisson bright spot glass sheet 8 and the pattern formed are shown in FIG. Figure 7 (a) and Figure 7 Middle (b).

[0067] The basic use process of this experimental device is as follows: (1) The teacher uses the laser transmitter 2, demonstration board 7 and vernier caliper 5 in the device to demonstrate the conventional double-slit and single-slit experiments, and the teacher and students jointly summarize the interference and diffraction laws. (2) The teacher conducts special experiments Figure 3 and Figure 4 (3) Students conduct independent experimental research, such as conducting experiments in or outside the classroom. Figure 5-Figure 7 The experiment shown.

[0068] The experimental device of this utility model has two main functions. First, it can be used to conduct conventional interference and diffraction experiments, allowing students to understand the interference and diffraction laws of light. More importantly, this experimental device also provides students with deeper learning content. That is, teachers guide students to explore the nature of interference and diffraction through special experimental demonstrations, encourage students to conduct independent experiments, thereby enhancing their learning interest and achieving a deep understanding of the interference and diffraction laws. The key innovations of this utility model are mainly reflected in the special experimental part, as follows:

[0069] (1) Achieving interference without a double slit. Using only a piece of paper (i.e., the flat paper 11) to split the incident light beam can not only reproduce the results of Young's double-slit interference experiment, but also intuitively demonstrate the physical mechanism of wavefront splitting.

[0070] (2) Achieving diffraction without a single slit. Simply by using a piece of paper folded at a right angle (i.e., the folded paper 12) to confine the incident light beam, the results of Fraunhofer single-slit diffraction can be reproduced, while also visually demonstrating the physical mechanism of wavefront confinement.

[0071] (3) Realize diffraction such as Poisson bright spot. The experimental device can also demonstrate Fraunhofer circular aperture diffraction, cross diffraction and Poisson bright spot, and can significantly improve the light and dark contrast of Poisson bright spot, and can observe light and dark rings in geometric shadow areas.

[0072] (4) Achieve a shift from "watching demonstration experiments" to "doing demonstration experiments." Students can conduct independent research experiments at low cost, requiring only a laser pen to serve as the laser transmitter 2. The experiment is not limited by time or space, and does not require darkroom conditions; it can be completed in an ordinary room. The experimental plan is simple and easy to implement, and does not require the use of any specialized equipment for component processing. All high school students and above can complete the above experimental content independently.

[0073] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that the present invention is susceptible to various modifications and variations. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A light interference and diffraction experimental device, characterized in that: It includes a laser transmitter (2) and a first experimental part; The laser emitter (2) is used to emit a laser beam; The first experimental part includes an interference apparatus and a diffraction apparatus; The interference device is a thin sheet structure with uniform thickness, which can be placed on the propagation path of the laser beam and separate the laser beam incident on the interference device into two outgoing beams. The two outgoing beams have the same frequency, consistent vibration direction and constant phase difference, thereby observing the interference phenomenon of light; The diffraction device can be placed on the propagation path of the laser beam and block half of the laser beam incident on the diffraction device, allowing the other half of the laser beam to form a spherical wave at the edge of the diffraction device, thereby observing the diffraction phenomenon of light.

2. The light interference and diffraction experimental device according to claim 1, characterized in that: The interference device is a flat paper sheet (11).

3. The light interference and diffraction experimental device according to claim 2, characterized in that: The width of the flat paper sheet (11) is between 0.3 cm and 1 cm, and the thickness is between 0.05 mm and 0.2 mm.

4. The light interference and diffraction experimental device according to claim 1, characterized in that: The diffraction device is a folded paper sheet (12).

5. The light interference and diffraction experimental device according to claim 4, characterized in that: The folding paper sheet (12) is formed by folding a paper sheet and has an L-shaped cross section, wherein the width of the folding paper sheet is between 0.6 cm and 2 cm, and the thickness is between 0.05 mm and 0.2 mm.

6. The light interference and diffraction experimental device according to claim 1, characterized in that: The first experimental part also includes one of the following: A circular hole diffraction paper sheet (13), wherein the circular hole diffraction paper sheet (13) is a paper sheet with pinholes, and the pinholes are smooth circular holes with a diameter between 1 mm and 2 mm; A cross diffraction paper sheet (14), wherein the cross diffraction paper sheet (14) is a cross-shaped structured paper sheet formed by cross-bonding two paper sheets, wherein the width of the two paper sheets is between 0.3 cm and 1 cm, and the thickness of the two paper sheets is between 0.05 mm and 0.2 mm; A Poisson speckle glass sheet (8) is a glass sheet with a smooth light-shielding disk formed in the middle.

7. The light interference and diffraction experimental device according to claim 6, characterized in that: The first experimental part also includes a stage (9); the interference device, the diffraction device, the circular hole diffraction paper (13) and the cross diffraction paper (14) can be selectively placed on the stage (9) to cooperate with the laser emitter (2) to form corresponding optical phenomena; The Poisson speckle glass sheet (8) is placed at a predetermined position and can cooperate with the laser emitter (2) to form a corresponding optical phenomenon.

8. The light interference and diffraction experimental device according to claim 1, characterized in that: The experimental device further comprises a slide groove (3); the laser emitter (2) can move back and forth along the slide groove (3) to adjust the position of the laser beam emitted by the laser emitter (2).

9. The light interference and diffraction experimental device according to claim 1, characterized in that: The experimental device also includes a second experimental part, which includes a vernier caliper (5). Two outer measuring jaws of the vernier caliper (5) form a single slit with adjustable width for quantitatively studying Fraunhofer single-slit diffraction.

10. The light interference and diffraction experimental device according to claim 9, characterized in that: The second experimental part further comprises a demonstration board (7), on which at least one of a double slit, a triple slit, a grating, a rotatable polarizer, a triangular hole and a rectangular hole is arranged.

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