Design and experimental demonstration of optomechanical paddle nanocavities

TL;DR

This paper reports the design, fabrication, and initial testing of paddle nanocavities that combine optical and mechanical resonances, demonstrating promising properties for sensing and nonlinear optomechanics.

Contribution

It introduces a novel paddle nanocavity design with tunable optical and mechanical properties, and provides initial experimental characterization under ambient conditions.

Findings

Optical mode with Q factor ~6000 at 1550 nm

Mechanical resonances at 12-64 MHz with Q factors 44-327

Effective masses around 350-650 fg

Abstract

We present the design, fabrication and initial characterization of a paddle nanocavity consisting of a suspended sub-picogram nanomechanical resonator optomechanically coupled to a photonic crystal nanocavity. The optical and mechanical properties of the paddle nanocavity can be systematically designed and optimized, and key characteristics including mechanical frequency easily tailored. Measurements under ambient conditions of a silicon paddle nanocavity demonstrate an optical mode with quality factor $Q_o$ ~ 6000 near 1550 nm, and optomechanical coupling to several mechanical resonances with frequencies $\omega_m/2\pi$ ~ 12-64 MHz, effective masses $m_\text{eff}$ ~ 350-650 fg, and mechanical quality factors $Q_m$ ~ 44-327. Paddle nanocavities are promising for optomechanical sensing and nonlinear optomechanics experiments.