• The first drawing is a close up of the inside of a fiber optic cable. Each optical fiber has a core and an outer layer that is made from glass. These are both protected by the sheath.
• The second diagram details how a TV signal is transmitted via fiber optics. They are sent along the optical cables in the form of light. The camera produces an electrical signal which the transmitter turns into a digital code. This digital code is sent along cables in the form of rapid pulses of light. The receiver decodes the signal and converts it from a digital code back into an electrical signal, which then forms a picture on the TV.
• Optical fibers are also being used in medicine. Photos show two surgeons using an endoscope to look at the internal organs of a patient.
• The last picture is a close up of the eye of a needle with a single optical fiber passing through it to show how thin each strand of ultra-pure glass is that is used to make optical fibers.