FIBER OPTIC 101

Consider a ray of light passing between two media of different refractive indexes n1 and n2 as shown in figure 3. If n1> n2 the light ray as it passes from one media to the next will bend away from an imaginary line (the normal) perpendicular to the media’s mating surface. Conversely if n1 < n2 then the ray will bend towards the normal. Total internal reflection occurs when n1 > n2 and the incident ray of light makes an angle, Θc, such that it does not enter the adjacent medium but travels along the interface. At angles greater than Θc the ray will be reflected back into medium 

Total Internal Reflection

As we has discuss o, fiber optic is a glass or plastic fiber that carries light along its length. Fiber optics is the overlap of applied science and engineering concerned with the design and application of optical fibers. Fiber-optic communication is a method of transmitting information from one place to another by sending light through an optical fiber. The light forms an electromagnetic carrier wave that is modulated to carry information. Standard optical fibers are made by first constructing a large-diameter pre-form, with a carefully controlled refractive index profile, and then pulling the pre-form to form the long, thin optical fiber. The pre-form is commonly made by three chemical vapor deposition methods which is inside vapor deposition, outside vapor deposition, and vapor axial deposition.