The light source is a kind of object that can emit light autonomously, generally divided into natural light-emitting and artificial light-emitting. Sunlight is the most common type of natural light. Various types of light sources commonly used in laboratories, such as LED and laser, are artificial light-emitting bodies. The light source is a very important part in the optical system, and the research on the characteristics of various light sources is always an important content of optical research, such as spectral distribution, light intensity, optical power, color and etc.,