1. Light travels fastest in vacuum, and its speed depends on the frequency of the light source. In a medium, light travels slower than in a vacuum. Generally speaking, the propagation speed of light is inversely proportional to the refractive index of the medium. The greater the refractive index, the slower the propagation speed of light. This phenomenon is widely used in optical and physical experiments, such as optical prisms and lenses.
2. Light will interfere and diffract during its propagation. Interference phenomenon means that when two or more coherent light waves are superimposed at a certain point in space, their amplitudes are added, and the light intensity is proportional to the square of the amplitude.
Diffraction refers to the phenomenon that when light encounters obstacles in the process of propagation, light waves will continue to propagate around the edges of obstacles. These phenomena are widely used in optics and physics to study the structure and properties of matter.
3. Light will be reflected and refracted during its propagation. When light meets an opaque object or mirror, it will be reflected. The reflected light forms a certain angle with the incident light, and the reflection angle is equal to the incident angle.
When light enters another medium from one medium, it will be refracted, that is, the propagation direction of light will change. The greater the refractive index, the greater the degree of light deflection. These phenomena are widely used in optical imaging, reflection, spectral analysis and other fields.
4. Light will also be affected by absorption, scattering and absorption of substances during its propagation. The absorption of light by matter is due to the reaction of electrons in matter to external photons, while scattering refers to the phenomenon that light is collided by tiny particles in the atmosphere and changes its propagation direction. These phenomena have different effects on the propagation of light and the performance of optical instruments.
Application of light:
1. Lighting: The most basic application of light is lighting. In a dark environment, we need light to see things around us. From the earliest candlelight, to incandescent lamps, fluorescent lamps, and now to LED lamps, lighting technology continues to develop, making our lives brighter. At the same time, in order to improve the efficiency and quality of lighting, various control and optimization algorithms have also been applied to lighting equipment, such as intelligent lighting system.
2. Optical instruments: Optical instruments are widely used in scientific research and daily life. For example, a microscope can help us observe tiny objects; Telescopes can help us observe distant stars; Spectrometer can help us analyze the structure and composition of substances. These optical instruments all use some characteristics of light to achieve their goals.
3. Optical communication: In the field of communication, the transmission speed of light is very fast, so optical fiber communication is widely used. Optical signals transmitted through optical fibers can transmit a large amount of information in a short time. Now, most of the Internet data used in our daily life are transmitted through optical fiber communication.
4. Laser: Laser is a new invention in 1960s. It uses the principle of stimulated radiation of matter to produce light with better directivity, higher brightness and purer color. Laser is widely used in medical treatment, scientific research, industry and other fields. For example, laser scalpel can reduce bleeding and infection during surgery; Laser is used to study the characteristics of matter in scientific research; Laser is used for marking and cutting in industry.