1, the law of refraction was discovered by a Dutch mathematician with a sneer, and it is the law that determines the direction of refracted light in the phenomenon of light refraction. The refracted ray lies in the plane determined by the incident ray and the normal of the interface; Refracted light and incident light are on both sides of the normal respectively; For two kinds of media with certain refractive index, the ratio of sine of incident angle I to sine of refraction angle I' is constant.
2. When light enters from a medium with high light speed into a medium with low light speed, the refraction angle is smaller than the incident angle; The refraction angle is greater than the incident angle when entering the medium with high light speed from the medium with low light speed.
First, the concept of principle.
1, the law of refraction was discovered by a Dutch mathematician with a sneer, and it is the law that determines the direction of refracted light in the phenomenon of light refraction. When the light enters the second medium (refractive index n2) from the first medium (refractive index n 1), a part of the light will be refracted on the smooth interface after entering the second medium from the first medium.
Second, the experiment pointed out that:
The refracted ray lies in the plane determined by the incident ray and the normal of the interface; Refracted light and incident light are on both sides of the normal respectively; For two kinds of media with certain refractive index, the ratio of sine of incident angle I to sine of refraction angle I' is constant. When light enters from a medium with high speed of light into a medium with low speed of light, the refraction angle is smaller than the incident angle; The refraction angle is greater than the incident angle when entering the medium with high light speed from the medium with low light speed.
Third, the scope of application
This law is the basic experimental law of geometric optics. It is suitable for homogeneous and isotropic media. The principle of optical path structure of various optical instruments used for controlling optical path and imaging is mainly based on the laws of refraction and reflection of light. This law can also be derived from the concept of light waves, so it can also be applied to the refraction of radio waves and sound waves. The refraction law of light only applies to the static interface composed of isotropic media.
Four. detail
1, the law of refraction is also called Snell's law. When light refracts through the interface between two media, it is one of the basic laws of geometric optics to determine the relationship between the propagation direction of incident light and refracted light. The plane formed by the incident light and the interface normal passing through the incident point is called the incident plane, and the included angles between the incident light and the refracted light and the normal are called the incident angle and the refraction angle, respectively, which are expressed as θ 1 and θ2.
2. The law of refraction is expressed as follows: ① The refracted light is in the incident plane. ② The sine ratio of incident angle and refraction angle is a constant, which is expressed by n2 1, that is, n2 1 is called the relative refractive index of the second medium to the first medium.