CN102840841A - Grating position adjusting device - Google Patents

Abstract

The grating position adjustment device includes a grating, a grating clamp, a door-type fixing frame, a spring, a horizontal adjustment screw, and a vertical adjustment screw. Horizontal adjustment screw (5) makes the incident light perpendicular to the grating notch distribution direction. Adjust the screw (1) vertically so that the grating notches are parallel to the light source slits. The requirements for the position of the grating in the grating experiment are: the vertical line of the grating notch is parallel to the dial, the vertical line of the grating notch is perpendicular to the slit of the incident light source, and the plane of the grating is not required to be perpendicular to the plane of the dial. The diffraction angle is the smallest when it is normal incidence, and the diffraction angle is larger than normal incidence when it is oblique incidence. The grating position adjustment device is mainly used in the grating experiment. In the grating experiment, since the position of the grating has a relatively large impact on the diffracted light, in order to ensure the correctness and uniformity of the results, the position of the grating needs to be adjusted accurately.

Description

Grating position adjustment device

technical field

The device is used to adjust the position of the grating in the grating experiment, to ensure that the vertical line of the grating notch (the distribution direction of the grating notch) is perpendicular to the incident light and the grating notch is parallel to the incident light slit.

Background technique

Gratings are often used in optical experiments or optical applications. The position of the grating has a relatively large impact on the diffracted light. In order to ensure the correctness and uniformity of the results, the position of the grating needs to be adjusted accurately. In the university grating experiment, the light source is a small long slit, which passes through a lens to form parallel light incident on the grating, and the diffracted light enters the eye for observation after passing through a telescope, and the diffracted light seen by the eye is still a slit ( referred to as diffraction fringes).

The grating experiment requires the position of the grating: the vertical line of the grating notch is parallel to the dial, the vertical line of the grating notch is perpendicular to the incident light, and the plane of the grating is not required to be perpendicular to the dial. However, in the current university physics experiments, it is observed whether the grating is perpendicular to the dial by adjusting the self-collimating cross image reflected by the stage screw from the grating. Since the grating is light-transmitting, the reflection image is relatively shallow, and the observation is difficult. Students often This step takes a lot of time; in addition, even if the grating plane is perpendicular to the dial plane, it cannot guarantee that the grating notch in the grating plane is perpendicular to the dial, so that the measured diffraction angle is too small.

Contents of the invention

The invention can omit the adjustment of the stage, and adjust the position of the grating by using the characteristics of the diffracted light.

The technical solution of the present invention is: the device mainly includes a grating, a grating clip, a door-shaped fixing frame, a horizontal adjustment spring and screws, and a vertical adjustment screw. By adjusting the spring and screw horizontally, ensure that the incident light is perpendicular to the vertical direction of the grating notch; by adjusting the vertical screw, make the vertical line of the grating notch parallel to the dial.

The beneficial effects of the invention are: the diffracted light is relatively bright and easy to observe; by changing the adjustment of the stage to the adjustment of the horizontal direction and the vertical direction of the grating, the horizontal adjustment and the vertical adjustment are independent of each other, and the adjustment efficiency is improved.

Description of drawings

Figure 1 is a schematic diagram of the grating.

In the figure 1. grating notch, 2. vertical direction of grating notch (distribution direction of grating notch).

Figure 2 is a schematic diagram of grating normal incidence and oblique incidence.

In the figure, 1. Parallel incident light, 2. Grating (the distribution direction of grating marks), 3. Zero-order fringes, 4. Diffraction fringes, the angle between zero-order fringes and diffraction fringes is the diffraction angle. Normal incidence: The incident parallel light is perpendicular to the distribution direction of the grating grooves, and the diffraction angle is the minimum at this time. Oblique incidence: the incident parallel light is not perpendicular to the distribution direction of the grating grooves, and the diffraction angle is larger than the normal incidence at this time.

Figure 3 is a diagram of the experimental setup.

In the figure 1. Vertical adjustment screw, 2. Grating, 3. Door type fixing frame, 4. Spring, 5. Horizontal adjustment screw, 6. Grating fixing clip.

specific implementation plan

In the grating experiment, the telescope moves parallel to the angle dial, and the diffraction fringes are observed through the telescope to measure the diffraction angle.

Parallel light is incident on the grating, and the diffraction angle at this time is the smallest. Adjust the screw (5) to pull the grating (2) to move under the action of the spring, so that the diffraction fringes observed in the telescope move to the zero-order fringes. When the diffraction fringes are no longer toward When the zero-order fringe moves and is about to move in the opposite direction, stop the adjustment screw (5), and the incident light is now incident on the grating.

The distribution of the diffraction fringes is in the same direction as the distribution of the grating notches, so it must be ensured that the distribution direction of the grating notches is parallel to the moving plane of the telescope. When the notch of the grating is not parallel to the slit of the light source, what is measured at this time is the projection of the diffraction angle on the moving plane of the telescope, and the result will be too small. At this time, adjust the screw (1), and the diffraction fringes observed in the telescope, etc. When it is high, stop adjusting. At this time, the grating marks are parallel to the light source slit, and the distribution direction of the grating marks is parallel to the dial.

Claims (1)

1. The grating position adjustment device is mainly composed of a grating, a grating clip, a door-shaped fixing frame, a spring, a horizontal adjustment screw, and a vertical adjustment screw. It is characterized in that the distribution direction of the grating marks and the incident parallel light are adjusted by the spring and the horizontal adjustment screw Vertically, adjust the vertical adjustment screw so that the distribution direction of the grating marks is parallel to the dial.

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