Title :
Fast Light and the Speed of Information Transfer in the Presence of Detector Noise
Author :
Feng, Michael Z. ; Sorin, Wayne V. ; Tucker, Rodney S.
Author_Institution :
ARC Special Res. Centre for Ultra-Broadband Inf. Networks, Univ. of Melbourne, Melbourne, VIC, Australia
Abstract :
The phenomenon of fast-light pulse propagation has seen renewed interest in recent years, but its relationship to the speed of information transfer is still being debated. In this paper, we define the speed of information transfer as the propagation speed of a point of constant signal-to-noise ratio (SNR) on the leading edge of a signal pulse. We use standard telecommunication analysis to include the effects of noise so that the bit-error rate (BER) can be calculated as a function of a variable decision time. We introduce the concept of a time-dependent Q-factor so that pulse arrival times can be compared at equivalent BERs. We show that when receiver noise is included in a gain-assisted fast-light system, the measured speed of information transfer can exceed the speed of light for an equivalent pulse travelling through a vacuum.
Keywords :
Q-factor; error statistics; light propagation; optical communication; optical noise; bit-error rate; detector noise; fast-light pulse propagation; gain-assisted fast-light system; receiver noise; signal-to-noise ratio; speed of information transfer; time-dependent Q-factor; Bit error rate; Fast light; Gain measurement; Noise measurement; Optical propagation; Pulse measurements; Q factor; Signal to noise ratio; Telecommunication standards; Velocity measurement; Fast light; Q-factor; information transfer; pulse advancement;
Journal_Title :
Photonics Journal, IEEE
DOI :
10.1109/JPHOT.2009.2031684
