What does a prism look like?

The prism is a transparent body with a triangular optical cross section.

Structure of prism

Prism, referred to as prism for short, is a triangular cylinder formed by the intersection of the planes of the glass transparent body. Generally, the main section is triangular, and its structure is divided into face, edge, vertex, bottom and bottom top line.

1, refractive surface: most ophthalmic prisms are very thin, and their two inclined surfaces are used as light-transmitting surfaces, which are called refractive surfaces.

2. Edge (main edge): The edge is the intersection of the two refractive surfaces of the prism, also known as the top.

3. Vertex angle: Vertex angle refers to the angle formed by the intersection of two refraction surfaces.

4. Bottom: The side opposite to the edge is called the bottom.

5. Main section: The section perpendicular to the main edge is called the main section.

6. Bottom top line: The bottom top line refers to a straight line passing through the top and perpendicular to the bottom.

7. Deflection angle: The included angle between incident light and emergent light is called the deflection angle of prism.

Prism principle

Sunlight is polychromatic light with different frequencies of red, orange, yellow, green, indigo and purple. These have different refractive indexes for the same medium, so a beam of light will be refracted at different deflection angles after entering the prism (the law of refraction of light).

Prism effect

White light is polychromatic light composed of various monochromatic lights; The refractive index of the same medium for different colors of light is different; Different colors of light travel at different speeds in the same medium. Because the refractive index of the same medium is different for various monochromatic lights, the deflection angle of each monochromatic light passing through the prism is also different. So white light passing through the prism will separate each monochromatic light, that is, dispersion.