# High-Q nested resonator in an actively stabilized optomechanical cavity

## TL;DR

This paper introduces an actively stabilized nested resonator system in an optomechanical cavity that reduces environmental noise while maintaining vibration isolation, enhancing the stability and performance of micro- and nanomechanical resonators.

## Contribution

The study presents a novel active feedback method to stabilize a low-frequency nested resonator without losing vibration isolation in an optomechanical cavity.

## Key findings

- Active feedback minimizes resonator motion relative to the cavity mirror.
- The method stabilizes the cavity length effectively.
- Vibration isolation is preserved despite stabilization.

## Abstract

Experiments involving micro- and nanomechanical resonators need to be carefully designed to reduce mechanical environmental noise. A small scale on-chip approach is to add an additional resonator to the system as a mechanical low-pass filter. Unfortunately, the inherent low frequency of the low-pass filter causes the system to be easily excited mechanically. Fixating the additional resonator ensures that the resonator itself can not be excited by the environment. This, however, negates the purpose of the low-pass filter. We solve this apparent paradox by applying active feedback to the resonator, thereby minimizing the motion with respect the front mirror of an optomechanical cavity. Not only does this method actively stabilize the cavity length, but it also retains the on-chip vibration isolation.