"Slow Light" and "Slow Current"

TL;DR

This paper explains the phenomena of slow light and slow current in nonlinear media through a unified framework based on intensity spectrum and susceptibility, supported by an analog electric circuit model.

Contribution

It provides a comprehensive interpretation of slow light and slow current effects using the concept of intensity spectrum and susceptibility, including an analog circuit demonstration.

Findings

Hole-burning effects can be understood via intensity spectrum analysis.

The analog circuit demonstrates the equivalence of optical and electrical slow effects.

Unified interpretation simplifies understanding of nonlinear medium responses.

Abstract

It is shown that the effect of hole-burning under conditions of coherent population oscillations as well as the light pulse delay in a saturable absorber (a modification of the "slow light" effect) can be interpreted, in a comprehensive way, in terms of {\it intensity spectrum} of the light and {\it intensity-related susceptibility} of the non-linear medium. The physical content of these effects is illustrated by a simple electric circuit with a non-linear resistor which realizes a full analog of the saturable absorber. In this case the effect of hole-burning in the absorption spectrum of the medium is converted in to the effect of hole-burning in the frequency dependence of resistance of the non-linear resistor and the effect of "slow light" -- in to the effect of "slow current".