Photo radiation pressure at resonance of frequency modulated micro cantilever

Abstract

We demonstrated high-sensitivity measurement of photo-radiation pressure by applying frequency modulation (FM) detection for the resonance phenomenon of the micro-cantilever structure. We constructed a system to detect minute displacements using the optical-lever method and achieved a noise density of approximately 1pm/√Hz from the thermal vibration measurement. The resonance frequency shift was positive, which meant repulsive forces acted on the metal surface by way of the force generated due to incidence of the laser beam on the stainless-steel (SS) cantilever. For an incident light of 1mW intensity, a vibration amplitude of 0.687 nm and a radiation pressure of 0.378µN were measured experimentally.