Using the principle of total reflection of light, light is transmitted through optical fibers. The angle of incidence of the incident light and the angle of reflection of the reflected light follow the law of refraction. When the angle of incidence increases, so does the angle of reflection. When the angle of incidence increases to 90°, the incident light returns to the original medium. This phenomenon is very light. Total reflection. Therefore, when the angle between the light incident on the fiber core and the optical axis is less than a certain value, the light is reflected at the interface. At this point, the light bends along a zigzag path in the core, but does not leave the cladding. Optical fibers have the ability to bind and transmit from infrared to the visible light region, and also have sensing capabilities. Optical fibers can transmit signals such as the brightness of light, changes in light spots, etc., to the other end. The above information is provided by the fiber closure manufacturer, and it is hoped that the knowledge of how fiber optic works can benefit more people.