February 22, 2012

In the Footsteps of Heinrich Hertz – Commemorating the 155th Anniversary of the Physicist's Birth

Today, the 22 February, marks the 155th anniversary of the birth of the physicist Heinrich Hertz.
His work demonstrating the existence of electromagnetic waves forms the basis on which the evolution of telecommunications is built – radio and television, electronic data transmission and mobile communications. At the Fraunhofer Heinrich Hertz Institute even now scientists are still engaged with the results of his research.


Fiber Optics – World Record in Serial Data Transmission 
Take fiber optics, for instance, which are used as light wave carriers for optical data transmission. Single data bits are converted into pulses of light and sent through the fiber optic cables as electromagnetic waves. The current record held by Fraunhofer HHI for fiber optic data transmission is 10.2 Tbit/s – the staggering equivalent of 240 DVDs per second!
 

Or the terahertz – one trillion (1012) times the unit of frequency named after Heinrich Hertz. The terahertz (THz) lies in the 100 GHz to 10 THz frequency range between the infrared and microwave radiation bands and is particularly suitable for non-destructive inspection of the inside of materials as in control procedures for the manufacture and processing of plastics. Or for scanning letters and packets for biological weapons and explosives. Yet until only recently it was very difficult and expensive to generate and receive terahertz. Researchers at Fraunhofer HHI have now developed a chip based on components and technologies originally developed for fiber optic telecommunications that enables easy application of THz for practical purposes. This chip has opened up the way for use of THz technology in industrial applications –at reasonable costs too.


Heinrich Hertz 
Heinrich Hertz was born on 22 February 1857 in Hamburg. After studying mathematics and physics, he took his Ph.D. at the early age of 23. After a number of university teaching posts, in 1889 he became Professor of Physics at the Friedrich-Wilhelms-Universität Bonn. With the Hertz oscillator he didn't just prove the existence of electromagnetic waves but also discovered that these waves behave like light and propagate at the speed of light. In 1886 he finally succeeded in transmitting electromagnetic waves even though he had no idea of how these waves could be used for transmitting information. Yet in 1896 – just two years after Hertz's death – Guglielmo Marconi and Alexander Popow used them to transmit the words "Heinrich Hertz" over a distance of several hundred meters.