Abstract

The Photonic Force Microscope is a novel scanning probe microscope based on optical tweezers to hold a probe, which fluctuates in its position due to thermal noise. The three-dimensional position of the probe is detected with high temporal resolution and spatial precision by analyzing the interference of unscattered and forward scattered light. We present the theoretical framework of the optical forces acting on the probe, as well as of the detection signal due to coherent scattering and describe thermal noise position fluctuations by a Brownian dynamics simulation. As an application we simulate the temporal and spatial behavior of a probe tethered to the coverslip (according to the molecular kinesin/microtubule system) at different laser powers and different anchor positions.

© 2001 OSA/SPIE