Light source refers to an object or device used to emit light, and it is a device that converts energy in the form of electric energy, thermal energy and chemical energy into light energy. Light source is widely used in the fields of lighting, display, communication, medical treatment and scientific research, which has important economic and social significance. According to the principle of generating light, light sources can be divided into two categories: spontaneous radiation type light sources and excitation radiation type light sources.
Spontaneous emission light source refers to the light source that can emit light without external excitation, such as sun, flame, filament, etc. The spectrum produced by this light source is continuous and the light intensity is uniform, but its spectral characteristics and stability are limited by the material and temperature of the light source itself, so it is difficult to meet the requirements of high precision and long-term stability.
Excitation radiation light source refers to the light source that needs external excitation to emit light, such as semiconductor laser, fluorescent lamp, LED, etc. The light produced by this light source has a narrow spectrum, high intensity and high power density. Through accurate design and control, different wavelength, light intensity and color characteristics can be obtained to meet various application requirements.
Based on different physical principles and working modes, excitation radiation light sources can be divided into many types, such as semiconductor lasers, gas discharge light sources, optical fiber light sources, phosphors and light-emitting diodes. These light sources have their specific advantages and limitations, and they are widely and important in different fields and applications.
In a word, light source is a device that converts other forms of energy into light energy, which is widely used in lighting, display, communication, medical treatment, scientific research and other fields. According to the different principles of light generation, light sources can be divided into spontaneous radiation type and excitation radiation type, and the latter includes many types. Different types of light sources have different characteristics and application scope, so it is necessary to choose suitable light sources for different fields and application scenarios.