Suppression of quantum-radiation-pressure noise in an optical spring

TL;DR

This paper proposes a method to enhance the effective quality factor of mechanical resonators using optical spring effects and feedback control, enabling quantum-limited measurements by suppressing radiation-pressure noise.

Contribution

It introduces a novel approach to increase mechanical Q and suppress quantum radiation pressure noise in optomechanical systems using optical springs and feedback.

Findings

Effective Q can be increased via optical stiffening.

Quantum radiation pressure noise can be evaded with sensing and feedback.

Method is feasible with current technology and improves quantum optomechanics performance.

Abstract

Recent advances in micro- and nanofabrication techniques have led to corresponding improvement in the performance of optomechanical systems, which provide a promising avenue towards quantum-limited metrology and the study of quantum behavior in macroscopic mechanical objects. One major impediment to reaching the quantum regime is thermal excitation, which can be overcome for sufficiently high mechanical quality factor Q. Here, we propose a method for increasing the effective Q of a mechanical resonator by stiffening it via the optical spring effect exhibited by linear optomechanical systems, and show how the associated quantum radiation pressure noise can be evaded by sensing and feedback control. In a parameter regime that is attainable with current technology, this method allows for realistic quantum cavity optomechanics in a frequency band well below that which has been realized thus far.