Interference-modulated photon statistics in whispering-gallery-mode microresonator optomechanics

Abstract

Whispering-gallery-mode (WGM) microresonator optomechanical systems that can attain high quality factors, exhibit small optical mode volume, and can be excited through their evanescent field are versatile platforms for both theoretical and experimental studies in quantum and nonlinear optics. Investigating photon statistical properties in WGM microresonator optomechanical systems is an important avenue to understand their inner interaction mechanism. Here, the interference-modulated photon statistics in a three-mode coupling, i.e., a pair of counterpropagating optical cavity modes and a mechanical mode, in WGM microresonator optomechanical systems is studied. In the case that one optical mode is driven by an external field, strong antibunching photon statistics can be observed in the presence of mode coupling. When the two cavity modes are driven simultaneously, it is found that the photon statistical properties can be well steered by modulating the interference between different transition paths with the help of the amplitudes of the two input fields and their relative phase. Especially, we show in detail that the antibunching photon statistics can be optimized within the weak optomechanical coupling regime by properly adjusting the relative phase. We also find that it is necessary to prepare the mechanical resonator near to the ground state to eliminate the detrimental effect of thermal phonon number on the photon statistical properties. This investigation can deepen our understanding of the interaction between clockwise or counterclockwise light and mechanical motion as well as be useful for the construction of integrated on-chip single-photon sources.