Tag: Sandro Perrone

Enhanced Detection Range for PFM published in Rev. Sci. Instrumen.

10-fold detection range increase in quadrant-photodiode position sensing for photonic force microscope

10-fold detection range increase in quadrant-photodiode position sensing for photonic force microscope
Sandro Perrone, Giovanni Volpe & Dmitri Petrov
Review of Scientific Instruments 79(10), 106101 (2008)
DOI: 10.1063/1.2993177

We propose a technique that permits one to increase by one order of magnitude the detectionrange of position sensing for the photonic force microscope with quadrant photodetectors(QPDs). This technique takes advantage of the unavoidable cross-talk between output signals of the QPD and does not assume that the output signals are linear in the probe displacement. We demonstrate the increase in the detection range from 150 to 1400 nm for a trapped polystyrene sphere with radius of 300 nm as probe.

Stochastic Resonant Damping published in Phys. Rev. E

Stochastic resonant damping in a noisy monostable system: Theory and experiment

Stochastic resonant damping in a noisy monostable system: Theory and experiment
Giovanni Volpe, Sandro Perrone, J. Miguel Rubi & Dmitri Petrov
Physical Review E 77(5), 051107 (2008)
DOI: 10.1103/PhysRevE.77.051107

Usually in the presence of a background noise an increased effort put in controlling a system stabilizes its behavior. Rarely it is thought that an increased control of the system can lead to a looser response and, therefore, to a poorer performance. Strikingly there are many systems that show this weird behavior; examples can be drawn form physical, biological, and social systems. Until now no simple and general mechanism underlying such behaviors has been identified. Here we show that such a mechanism, named stochastic resonant damping, can be provided by the interplay between the background noise and the control exerted on the system. We experimentally verify our prediction on a physical model system based on a colloidal particle held in an oscillating optical potential. Our result adds a tool for the study of intrinsically noisy phenomena, joining the many constructive facets of noise identified in the past decades—for example, stochastic resonance, noise-induced activation, and Brownian ratchets.