Multimode optomechanical weighing of a single nanoparticle

Abstract

We demonstrate multimode optomechanical sensing of individual nanoparticles\nwith radius of a hundred of nanometers. A semiconductor optomechanical disk\nresonator is optically driven and detected under ambient conditions, as\nnebulized nanoparticles land on it. Multiple mechanical and optical resonant\nsignals of the disk are tracked simultaneously, providing access to several\nphysical informations about the landing analyte in real-time. Thanks to a fast\ncamera registering the time and position of landing, these signals can be\nemployed to weigh each nanoparticle with precision. Sources of error and\ndeviation are discussed and modeled, indicating a path to evaluate the\nelasticity of the nanoparticles on top of their mere mass. The device is\noptimized for future investigation of biological particles in the high\nmegadalton range, such as large viruses.\n