Single quantum dots for slow and fast light in a planar photonic crystal

Abstract

We theoretically investigate slow and fast light propagation and pulse velocity control in a nanocavity containing a single quantum dot side-coupled to a planar-photonic-crystal waveguide. We demonstrate that low coupling strength (i.e., the weak coupling regime) between a cavity and a dot, under on-resonance condition, can lead to delays of about $+90\mathrm{ps}$ for a pulse $1∕e$-width of $280\mathrm{ps}$. The group delay dependence on the various coupling parameters suggests achievable delays of $+300\mathrm{ps}$ and consequently very slow light speeds of around $5000\mathrm{m}∕\mathrm{s}$ in a $1.5\mu \mathrm{m}$ cavity-waveguide section. We also show that under off-resonant condition one can achieve significant pulse advancement of $-60\mathrm{ps}$.

© 2007 Optical Society of America