All-optical dynamic modulation of spontaneous emission rate in hybrid optomechanical emitter-cavity systems

Abstract

Optomechanics is the study of the interaction between nano-objects and light fields through radiation pressure. Recent sophisticated optomechanical systems consist of strongly coupled mechanical and optical resonators and are made using semiconductor nanofabrication techniques. Although the optomechanical systems have exhibited their powerful capability of controlling photons, they are scarcely used to control the solid-state artificial atoms that emit photons. The main reason is that an efficient coupling mechanism remains unexplored. Here, we hybridize a silicon-integrated optomechanical resonator with two-level atom-like emitters to demonstrate an optomechanical cavity quantum electrodynamic (cQED) effect. With this system and the effect, we realize the dynamic modulation of the spontaneous emission rate. We choose copper dopants in silicon as the emitters for its narrow linewidth (0.3 nm) and long lifetime ( ∼ 30 n s ). Our judiciously designed coupled-nanobeam optomechanical resonator achieves a strong Purcell effect and high cavity-modulation performances. The optical cavity of the optomechanical resonator is dynamically coupled to the emission line and, as a result, on-demand sharp pulses (up to 9.5-fold intensity enhancement and 3.5 ns in duration, which is one ninth of the emission lifetime) appear along the photoluminescence decay. These experimental results are exactly explained with an analytical model that combines optomechanical and cQED theories. Considering that dopants in silicon are highly competitive qubits, we believe that our optomechanical cQED technology will find important applications in the quantum era.