# A controllable two-membrane-in-the-middle cavity optomechanical system

## TL;DR

This paper introduces a highly controllable optomechanical system with two dielectric membranes inside a Fabry-Perot cavity, demonstrating tunable resonances and potential for quantum dynamical studies.

## Contribution

It presents a novel two-membrane-in-the-middle cavity system with independent control over membrane positions, angles, and vibrational frequencies, extending possibilities for multimode optomechanics.

## Key findings

- Measured cavity resonant frequencies showing band-structure-like diagrams
- Achieved independent tuning of membrane positions and angles
- Demonstrated individual vibrational frequency control via piezoelectricity

## Abstract

We report an optomechanical system with two dielectric membranes inside a Fabry-Perot cavity. The cavity resonant frequencies are measured in such a two-membrane-in-the-middle system, which show an interesting band-structure-like diagram. This system exhibits great controllability on the parameters of the system. The positions and angles of each membrane can be manipulated on demand by placing two membranes inside the cavity separately. The eigenfrequencies of the vibrational modes of the membranes can also be tuned individually with piezoelectricity. This scheme could be straightforwardly extended to multiple-membrane-in-the-middle systems, where more than two membranes are involved. Such a well controllable multiple membrane optomechanical system provides a promising platform for studying nonlinear and quantum dynamical phenomena in multimode optomechanics with distinct mechanical oscillators.