Nonlinear radiation pressure dynamics in an optomechanical crystal

TL;DR

This paper explores nonlinear radiation pressure effects in a silicon nanobeam optomechanical crystal, demonstrating control over mechanical self-oscillation through optical pumping and an analytical thermo-optic model.

Contribution

It introduces a method to steer the system to a stable attractor using modulated optical pumping and develops an analytical model including thermo-optic effects.

Findings

Observation of highly nonlinear mechanical motion at 10K

Successful steering to a stable attractor with red-detuned pump

Analytical model accurately predicts experimental behavior

Abstract

Utilizing a silicon nanobeam optomechanical crystal, we investigate the attractor diagram arising from the radiation pressure interaction between a localized optical cavity at $\lambda = 1552$nm and a mechanical resonance at $\omega/2\pi = 3.72$GHz. At a temperature of $T \approx 10$K, highly nonlinear driving of mechanical motion is observed via continuous wave optical pumping. Introduction of a time-dependent (modulated) optical pump is used to steer the system towards an otherwise inaccessible dynamically stable attractor in which mechanical self-oscillation occurs for an optical pump red-detuned from the cavity resonance. An analytical model incorporating thermo-optic effects due to optical absorption heating is developed, and found to accurately predict the measured device behavior.