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Q: Quantenoptik

Q 28: Quantum Effects III

Q 28.2: Talk

Thursday, April 5, 2001, 17:45–18:00, H 3010

Superluminal information transfer in near field optics — •Alfons Stahlhofen — Inst. f. Physik, Rheinau 1, D-56075 Koblenz

Mathematical ideal signals as analyzed by Sommerfeld/Brillouin are frequency band unlimited. Such signals have a well defined front obeying the well known speed limit given by the vacuum velocity of light. Physical real signals, by comparison, are frequency band limited, do not have a well defined front and the very notion of a front velocity looses its meaning. The information in real signals is encoded in the halfwidth of the signal. These facts, well documented in any handbook on telecommunications (but not in any textbook of physics) are used to analyze the information transfer in photonic tunneling. It is shown, that in these experiments superluminal information transfer did indead take place without putting the causality-principle into jeopardy.