Abstract

In 1880, Alexander Graham Bell and his assistant, Sumner Tainter, unveiled a dramatic advance in optical communication technology, which they called “the photophone.” Without the benefit of lasers or modern detectors, the photophone could transmit a human voice hundreds of meters on a beam of light. The photophone was the world's first electro-optical system, and Bell and Tainter's experiments preceded wireless voice communication by radio by at least 19 years.