Light is a natural phenomenon that can be seen everywhere in life. Scientific research defines light as an electromagnetic wave with a certain frequency. Its essence is an electromagnetic wave visible to the human eye. Light is also known as the visible spectrum, which is composed of tens of thousands of photons, possessing both particle and wave properties. Human research on light can be traced back to ancient Greece. At that time, humans had a certain understanding of the generation, propagation, and application of light. However, due to the combination of natural science and religious beliefs at that time, people’s understanding of light stagnated until the nineteenth century when the research results of Scottish physicist James Clerk Maxwell appeared. Physicists gained a deeper understanding of the laws of light, and then began to further study the properties and applications of light. People’s understanding of the essence of light has become clearer with these studies. Nowadays, the research on the properties and applications of light is still a hot direction in various scientific research fields, including aerospace, weapons development, material processing, medical equipment, ranging, analytical detection, photography, daily lighting, etc.