Illustrates term total internal reflection in fiber optics?

Total internal reflection in fiber optics:

The field of fiber optics depends onto the total internal reflection of light rays traveling by tiny optical fibers. There fibers are so small which once the light is introduced in the fiber along with an angle within the boundaries of the numerical aperture of the fiber, this will carry on to reflect almost lossless off the walls of the fiber and therefore can travel long distances into the fiber. Bundles of these fibers can accomplish imaging of or else inaccessible areas.