Light and technology: how does optical fiber transmit light?
Since the first quartz filament was pulled out in 1930, we have truly entered the era of optical fiber. So far, we already have various types of optical fibers, such as multi-mode optical fiber G.651, single-mode optical fiber G.652, G.653, G.654, G.655 and so on. These fibers form the basis of our entire optical communications. So how is light transmitted in an optical fiber? Say we want to shine a flashlight beam down a long, straight hallway at the other end, just point the beam straight down the hallway, the light travels in a straight line, and we know it's fine. What if the corridor has a bend? At this time, a mirror can be placed at the corner to reflect the beam at the corner. What if the hallway is very winding, with multiple bends? It is also possible to line the walls with mirrors and angle the beam of light so that it bounces from side to side along the hallway. This is exactly what happens when light travels through an optical fiber, but the light is to...