The principle of refraction law of light was discovered by Dutch mathematician Snitch, and it is the law that determines the direction of light refraction 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.
Experiments show that:
(1) The refracted ray lies in the plane determined by the incident ray and the interface normal;
(2) The refracted ray and the incident ray are on both sides of the normal respectively;
(3) 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.
Simply put, 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.
The formula of refraction law of light is 1. Refracted light and incident light are separated on both sides of the normal (the normal is in the middle and perpendicular to the interface).
2. Refracted light, incident light and normal are in the same plane. (Three lines, two points and one side)
3. The ratio of sine of refraction angle to sine of incident angle is constant (refraction law).
When light inclines from the air into other media, the refraction angle is smaller than the incident angle.
4. When light enters the air obliquely from other media, the refraction angle is greater than the incident angle. (The above two items are summarized as: whoever is faster is bigger. That is to say, in which substance light propagates fast, then both the angle of refraction and the angle of incidence are large, and the angle in vacuum is always the largest)
5. Under the same conditions, the refraction angle increases (decreases) with the increase (decrease) of the incident angle.
6. The angle between the refracted light and the normal is called the refraction angle.
7. When light is obliquely incident from air into water or other media (except in vacuum, because light cannot be deflected in vacuum), the refracted light is deflected to the normal direction, and the refraction angle is smaller than the incident angle.
8. When light is vertically injected into water or other media from the air, its propagation direction remains unchanged.