The polarization of light refers to the vibration of electric field intensity in one direction during the propagation of light waves, and the asymmetry of this direction relative to the propagation direction of light is called the polarization of light.

When a light wave propagates in a medium, its electric field intensity can vibrate in different directions. If the electric field intensity of a light wave vibrates in a certain direction, we say that the light wave is polarized. This particular direction is called the polarization direction or the main polarization direction.

In natural light, all light waves vibrate in different directions. However, for some specific optical phenomena, such as reflection and refraction, only when the incident light is polarized light will there be some special behaviors.

Thanks to the Scottish physicist David Brewster and his collaborators, the polarization of light was discovered in the early19th century. They discovered the polarization phenomenon in crystals, and thus won the Nobel Prize in Physics from 65438 to 0839. Since then, the polarization of light has been an important field of optical research.

Examples of polarization applications of light;

1, liquid crystal display (LCD): In this type of display, polarized light is used to control the brightness and contrast of images. A special polarizer is used to filter out polarized light in a certain direction, thus controlling the bright and dark areas of the image.

2. Optical interference and optical measurement: In interference measurement, the interference mode of polarized light can provide additional information. For example, by observing the interference pattern of polarized light, parameters such as the thickness and optical constant of the material can be determined.

3. Optical communication: In optical fiber communication, the polarization of light is used to improve the speed and reliability of data transmission. By using polarized light, more data can be transmitted in parallel, while reducing the attenuation and interference of optical signals.

4. Optical radar: This kind of radar uses polarized light to measure particles in the atmosphere. By analyzing the returned polarized light, the composition and structure of the atmosphere can be determined.

5. Sunglasses and anti-glare glasses: These glasses use polarizers to reduce glare and reflect light, thus improving visual comfort and clarity. In the sun, polarized sunglasses can eliminate the reflection of water and glass and provide a clearer vision.

6. Photography: In photography, polarization filters are used to control reflected light and glare, thus improving the color saturation and contrast of the picture. Polarizing filter allows the photographer to control the direction of light entering the camera, thus optimizing the effect of the picture.

7. Medical treatment: In the medical field, the polarization of light is used for spectral analysis and diagnosis. For example, by analyzing the polarization state of the reflected light of the diseased tissue, the nature and degree of the lesion can be determined.