ACS Chemistry for Life

If modern communications are considered to be a web, then optical fibers are the silk that makes the connections possible. Optical fibers are tiny strands of glass that work by the principle of internal reflectance. When the surface of the fiber is clad with a transparent material that has a lower index of refraction, then the glass fiber acts as a pipe for light; light does not exit the fiber when it hits a wall, it is refracted, or bounces back to continue along the length of the strand. 

The potential for this technology was demonstrated long ago, in the 1840’s, but it was not until 1970 that Corning Glass Works produced the first fibers with the ability to maintain enough intensity of the transmitted light to allow the fibers to be used for long distance communication.

Optical fibers have numerous advantages over their predecessor, copper wires. Compared to copper, optical fibers are smaller and lighter with a higher signal carrying capacity. Fiber optics are less expensive, have less signal degradation, and are ideal for carrying digital signals. Because fiber optic cables transmit data via light pulses, rather than electronic pulses, they are also much more resistant to interference from electromagnetic noise due to radios, motors, or other cables.

In addition to transforming our world’s communication network, fiber optics are used extensively in the medical field.  Previously, if a doctor needed to examine an internal area of concern in a patient, extensive surgery often had to be done.  Now, endoscopy allows doctors to insert a probe with flexible, optical fibers into a narrow incision in the patient’s body, which allows him to view the medical problem directly, and thus minimize invasive surgery.

More background on fiber optics is available at http://www.arcelect.com/fibercable.htm

This topic was adapted from the technology milestones project of 2001 ACS President Attila Pavlath.