Alex Fontana and Ludovic Bellon, Phys. Rev. Applied 22, 014044 (2024)
[article] doi: 10.1103/PhysRevApplied.22.014044
[dataset] doi: 10.5281/zenodo.11110783
Optical beam deflection is a popular method to measure the deformation of micro-mechanical devices. As it measures mostly a local slope, its sensitivity depends on the location and size of the optical spot. We present a method to evaluate precisely these parameters, using the relative amplitude of the thermal noise induced vibrations. With a case study of a micro-cantilever, we demonstrate the accuracy of the approach, as well as its ability to fully characterize the sensitivity of the detector, and the parameters (mass,
stiffness) of the resonator.