Electromagnetically Induced Transparency and Slow Light with Optomechanics

TL;DR

This paper demonstrates electromagnetically induced transparency and tunable slow light in a nanoscale silicon optomechanical device, achieving significant optical delays and superluminal effects at cryogenic temperatures, with potential applications in quantum and classical optical signal processing.

Contribution

It presents the first experimental realization of EIT and tunable optical delays in a chip-scale silicon optomechanical system, combining optical and mechanical interactions for advanced light control.

Findings

Achieved 50 ns optical delay with near-unity transparency at 8.7 K.

Demonstrated superluminal light with 1.4 microseconds signal advance.

Showed potential for optical buffering, amplification, and filtering at room temperature.

Abstract

Controlling the interaction between localized optical and mechanical excitations has recently become possible following advances in micro- and nano-fabrication techniques. To date, most experimental studies of optomechanics have focused on measurement and control of the mechanical subsystem through its interaction with optics, and have led to the experimental demonstration of dynamical back-action cooling and optical rigidity of the mechanical system. Conversely, the optical response of these systems is also modified in the presence of mechanical interactions, leading to strong nonlinear effects such as Electromagnetically Induced Transparency (EIT) and parametric normal-mode splitting. In atomic systems, seminal experiments and proposals to slow and stop the propagation of light, and their applicability to modern optical networks, and future quantum networks, have thrust EIT to the forefront of experimental study during the last two decades. In a similar fashion, here we use the optomechanical nonlinearity to control the velocity of light via engineered photon-phonon interactions. Our results demonstrate EIT and tunable optical delays in a nanoscale optomechanical crystal device, fabricated by simply etching holes into a thin film of silicon (Si). At low temperature (8.7 K), we show an optically-tunable delay of 50 ns with near-unity optical transparency, and superluminal light with a 1.4 microseconds signal advance. These results, while indicating significant progress towards an integrated quantum optomechanical memory, are also relevant to classical signal processing applications. Measurements at room temperature and in the analogous regime of Electromagnetically Induced Absorption (EIA) show the utility of these chip-scale optomechanical systems for optical buffering, amplification, and filtering of microwave-over-optical signals.