The formula for the relationship between light intensity and amplitude is I=kA? When the radiation of the light source is uniform, the light intensity is I=F/Ω, Ω is the stereo angle, the unit is the degree of spherical (sr), F is the luminous flux, the unit is lumens, for the point light source I=F/(4π).
Light propagation is characterized by high speed, wave-particle duality, interference and diffraction, reflection and refraction.
1, light travels fastest in a vacuum, and the value of its speed depends on the frequency of the light source. In a medium, light will travel slower than in a vacuum. In general, 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 optics and physics experiments, such as optical prisms and lenses.
2, light in the propagation process will occur interference and diffraction. Interference is the phenomenon that when two or more coherent light waves are superimposed at a point in space, their amplitudes add up, and the light intensity is proportional to the square of the amplitude.
Diffraction is the phenomenon that when light encounters an obstacle in its propagation, the light wave continues to propagate around the edge of the obstacle. These phenomena are widely used in optics and physics to study the structure and properties of matter.
3, light in the propagation process will occur reflection and refraction phenomenon. When light encounters opaque objects or mirrors, light will be reflected, reflected light and incident light at a certain angle, and the angle of reflection is equal to the angle of incidence.
When light enters another medium from one medium, the phenomenon of refraction occurs, that is, the direction of propagation of light will change. The greater the refractive index, the greater the degree of deflection of light. These phenomena are widely used in optics in areas such as imaging, reflection, and spectral analysis.
4, light in the propagation process will also be affected by the material absorption, scattering and absorption. Substance absorption of light is due to the reaction of the electrons in the substance to foreign photons, and scattering refers to the light in the propagation process by the collision of tiny particles in the atmosphere and change the direction of propagation of the phenomenon. These phenomena have different effects on the propagation of light and the performance of optical instruments.
Applications 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 and fluorescent lamps, and now LED lights, lighting technology continues to develop, making our lives brighter. At the same time, various control and optimization algorithms have been applied to lighting devices, such as intelligent lighting systems, in order to improve the efficiency and quality of lighting.
2. Optical instruments: In scientific research and daily life, optical instruments are used in large quantities. For example, microscopes can help us observe tiny objects; telescopes can help us observe distant stars; spectrometers can help us analyze the structure and composition of substances. All of these optical instruments utilize certain properties of light to achieve their purposes.
3, optical communication: in the field of communication, the transmission speed of light is very fast, so fiber optic communication is widely used. Optical signals transmitted through optical fiber can transmit a large amount of information in a short period of time. Nowadays, most of the Internet data we use in our daily life is transmitted through fiber-optic communication.
4, laser: laser is a new invention in the 1960s. It makes use of the principle of excited radiation of matter to produce light with better direction, higher brightness and purer color. Laser has a wide range of applications in medical, scientific research, industry and other fields. For example, laser knives can reduce bleeding and infection in surgery; lasers are used in scientific research to study the properties of matter; and lasers are used in industry for marking and cutting.