Optomechanically induced transparency
(Jul 4, 2010)Abstract
Coherent interaction of laser radiation with multilevel atoms and molecules
can lead to quantum interference in the electronic excitation pathways. A
prominent example observed in atomic three-level-systems is the phenomenon of
electromagnetically induced transparency (EIT), in which a control laser
induces a narrow spectral transparency window for a weak probe laser beam. The
concomitant rapid variation of the refractive index in this spectral window can
give rise to dramatic reduction of the group velocity of a propagating pulse of
probe light. Dynamic control of EIT via the control laser enables even a
complete stop, that is, storage, of probe light pulses in the atomic medium.
Here, we demonstrate optomechanically induced transparency (OMIT)--formally
equivalent to EIT--in a cavity optomechanical system operating in the resolved
sideband regime. A control laser tuned to the lower motional sideband of the
cavity resonance induces a dipole-like interaction of optical and mechanical
degrees of freedom. Under these conditions, the destructive interference of
excitation pathways for an intracavity probe field gives rise to a window of
transparency when a two-photon resonance condition is met. As a salient feature
of EIT, the power of the control laser determines the width and depth of the
probe transparency window. OMIT could therefore provide a new approach for
delaying, slowing and storing light pulses in long-lived mechanical excitations
of optomechanical systems, whose optical and mechanical properties can be
tailored in almost arbitrary ways in the micro- and nano-optomechanical
platforms developed to date.