arXiv subjects

Bernard Ségard

Publications and source records attributed to Bernard Ségard.

20 records · Page 2Linked to original sources

arXiv2006

Pulse Normalisation in Slow-Light Media

We analytically study the linear propagation of arbitrarily shaped light-pulses through an absorbing medium with a narrow transparency-window or through a resonant amplifying medium. We point out that, under certain general conditions, the pulse acquires a nearly Gaussian shape, irrespective of its initial shape and of the spectral profile of the line. We explicitly derive in this case the pulse parameters, including its skewness responsible for a deviation of the delay of the pulse maximum from the group delay. We illustrate our general results by analysing the slow-light experiments having demonstrated the largest fractional pulse-delays

physics.optics↗

arXiv2005

Optimal superluminal systems

We demonstrate that significant effects in the "superluminal propagation"of light-pulses cannot be observed without involving systems whose gain explodes outside the pulse spectrum. We explicitly determine the minimum norm of the gain to attain given superluminal effects and the transfer function of the corresponding optimal system. The gain-norms which would be required with the most efficient systems considered up to now (dispersive media, photonic barriers) to attain the same effects are shown to exceed the minimum by several orders of magnitude. We finally estimate the largest superluminal advances which could be attained in a realistic experiment.

physics.optics↗