arXiv:physics/0512149

Note on saturable absorption and 'slow light'

Adrian C. Selden

Published Dec 16, 2005• 0 citations

Abstract

Quantitative evaluation of some recent 'slow light' experiments shows that they can be interpreted as saturable absorption phenomena and therefore do not necessarily demonstrate a reductuion in the group velocity of light

Related papers

Benchmark tests of slow light in saturable absorbers

Adrian C. Selden

A series of benchmark tests of slow light in saturable absorbers is proposed. Stage I concerns experimental tests of saturable absorption, which can mimic slow light in saturable media. Stage II outlines the more demanding requirements for practical observation of spectral hole-burning in the absorption line, which is responsible for the reduction in group velocity.

arXiv:0904.4780Apr 30, 20090 citations

Open Letter to the OSA Topical Meeting "Slow and Fast Light"

Evgenii B. Aleksandrov, Valerii S Zapasskii, G. G. Kozlov +1 more

The question is raised about whether the pulse delay in a saturable absorber has anything to do with the "slow light" and group velocity reduction. We also wonder why the 40-years-old trivial interpretation of the effect remains so far ignored.

arXiv:0806.2732Jun 17, 20081 citation

Slow Light: Underlying Controversies

Valerii S Zapasskii, G. G. Kozlov, Evgenii B. Aleksandrov

We show that some experimental observations on ‘slow’ and ‘fast’ light can be interpreted in terms of simple models of classical nonlinear optics without attracting the idea of steep-dispersion-based modification of group velocity of light.

Jan 1, 20070 citations

Direct observation of signal evolution of slow and fast light in media with saturated and reverse saturated absorption

Hai Wang, Yezhuo Zhang, He Tian +3 more

Applied Physics BJul 25, 20087 citations

Slow light and saturable absorption

Adrian C. Selden

Quantitative analysis of slow light experiments utilising coherent population oscillation (CPO) in a range of saturably absorbing media, including ruby and alexandrite, Er 3+ :Y 2 SiO 5 , bacteriorhodopsin, semiconductor quantum devices and erbium-doped optical fibres, shows that the observations may be more simply interpreted as saturable absorption phenomena. A basic two-level model of a saturable absorber displays all the effects normally associated with slow light, namely phase shift and modulation gain of the transmitted signal, hole burning in the modulation frequency spectrum and power broadening of the spectral hole, each arising from the finite response time of the non-linear absorption. Only where hole-burning in the optical spectrum is observed (using independent pump and probe beams), or pulse delays exceeding the limits set by saturable absorption are obtained, can reasonable confidence be placed in the observation of slow light in such experiments. Superluminal (“fast light”) phenomena in media with reverse saturable absorption (RSA) may be similarly explained.

Optics and SpectroscopyJun 1, 200920 citations

Saturable absorption or slow light?

Adrian C. Selden

Quantitative analysis of slow light experiments utilising coherent population oscillation (CPO) in a range of saturably absorbing media, including ruby and alexandrite, Er3+:Y2SiO5, bacteriorhodopsin, semi-conductor quantum devices and erbium doped optical fibres, shows that the observations may be more simply interpreted as saturable absorption phenomena. A basic two-level model of a saturable absorber displays all the effects normally associated with slow light, namely phase shift and modulation gain of the transmitted signal, hole burning in the modulation frequency spectrum and power broadening of the spectral hole, arising from the finite response time of the non-linear absorption. Only where hole-burning in the optical spectrum is observed (using independent pump and probe beams), or pulse delays exceeding the limits set by saturable absorption are obtained, can reasonable confidence be placed in the observation of slow light in such experiments. Superluminal ('fast light') phenomena in media with reverse saturable absorption (RSA) may be similarly explained.

arXiv:0812.3076Dec 16, 20081 citation