Tunable optomechanically induced transparency by controlling the dark-mode effect

TL;DR

This paper explores how controlling the dark-mode effect in multi-mechanical-mode optomechanical systems enables tunable transparency windows and enhanced sideband efficiency, with potential applications in optical communication.

Contribution

It introduces a phase-dependent phonon-exchange interaction to control dark modes, leading to multiple tunable transparency windows and improved optomechanical effects in multi-mode systems.

Findings

Dark-mode control enables double transparency windows.

Second-order sideband efficiency is enhanced when dark-mode is broken.

Number of mechanical modes influences linewidth amplification proportionally.

Abstract

We study tunable optomechanically induced transparency by controlling the dark-mode effect induced by two mechanical modes coupled to a common cavity field. This is realized by introducing a phase-dependent phonon-exchange interaction, which is used to form a loop-coupled configuration. Combining this phase-dependent coupling with the optomechanical interactions, the dark-mode effect can be controlled by the quantum interference effect. In particular, the dark-mode effect in this two-mechanical-mode optomechanical system can lead to a double-amplified optomechanically induced transparency (OMIT) window and a higher efficiency of the second-order sideband in comparison with the standard optomechanical system. This is because the effective mechanical decay rate related to the linewidth of the OMIT window becomes a twofold increase in the weak-coupling limit. When the dark-mode effect is broken, controllable double transparency windows appear and the second-order sideband, as well as the light delay or advance, is significantly enhanced. For an N-mechanical-mode optomechanical system, we find that in the presence of the dark-mode effect, the amplification multiple of the linewidth of the OMIT window is nearly proportional to the number of mechanical modes, and that the OMIT with a single window becomes the one with N tunable windows by breaking the dark-mode effect. The study will be useful in optical information storage within a large-frequency bandwidth and multichannel optical communication based on optomechanical systems.