Numerical determination of the signal velocity in dispersive pulse propagation
Abstract
The signal velocity of a unitstepfunctionmodulated signal with a constant carrier frequency (wc) that is propagating in a linear dispersive medium with absorption (the Lorentz medium) is determined through numerical simulation and compared with that predicted by rigorous asymptotic theory. The exceptional agreement between these purely numerical results and the asymptotic theory, including the bifurcation of the signal velocity at carrier frequencies well above the medium resonance frequency, serve to validate completely both the description of the signal arrival afforded by the asymptotic theory and the physical propriety of this velocity measure in dispersive pulse propagation for input pulses with an instantaneous turnon time.
 Publication:

Journal of the Optical Society of America A
 Pub Date:
 September 1989
 DOI:
 10.1364/JOSAA.6.001430
 Bibcode:
 1989JOSAA...6.1430O
 Keywords:

 Asymptotic Methods;
 Electromagnetic Wave Transmission;
 Plane Waves;
 Propagation Velocity;
 Signal Transmission;
 Step Functions;
 Carrier Frequencies;
 Lorentz Transformations;
 Refractivity;
 Saddle Points;
 Sommerfeld Approximation;
 Physics (General)