Summary
- In development between 1874-1876 and commercially available from 1880, the photophone was a telecommunications device invented by Alexander Graham Bell that used light to transmit sound.
- It was Bell’s “favorite” invention, even though the device was obsolete by the 1920s due to the limitations of relying on sunlight and the inability to transmit sound beyond line of sight.
- Using a laser as a coherent light source, modern hobbyist Nick Bild has recreated the ancient wireless telephone, showing that it is still possible to have a conversation using just light (assuming the person you are talking to is also in line of sight and there are no clouds).
- Bild also highlights the simplicity of the transmitter, which consisted of little more than a vibrating mirror attached to a tube and the receiver, which contained a selenium cell.
bells labs invented the laser. Just sayin.