Brick-Based Silicon Optomechanical Cavity Sensor for Nanoparticles Mass Detection

Nanophotonics Technology Center, Universitat Politècnica de València, 46022 Valencia, Spain

^* Corresponding author: agramar1@ntc.upv.es

Published online: 31 October 2024

Abstract

A novel design for an optomechanical cavity consisting of a series of rectangular silicon nanobricks, with each brick acting as an independent mechanical resonator but all coupled to a same optical field, is proposed, and numerically demonstrated. Each brick is placed on top of a thin silica pillar that provides mechanical support whilst isolates the individual mechanical resonances. The mass sensing capabilities of this cavity are studied through numerical simulations, proving that a point mass approximation can be used for silica nanoparticles with radius smaller than 100 nm, and that different nanoparticles can be measured independently but simultaneously.