Amplifying Sommerfeld precursors and producing a discontinuous index of refraction with gains and losses.
We show that for specially designed linear dispersive media with one absorption line and one gain line the Sommerfeld precursors of a pulse can be amplified leading to an earlier detection of the signal. Also, we show that in some systems with one strong absorption line, a carefully placed gain resonance must induce a discontinuity in the imaginary part of the frequency dependent index of refraction and in the first derivative of its real part.
Ribeiro
F J
FJ
Department of Physics, University of California, Berkeley, California 94720, USA.
Cohen
M L
ML