PFMCal: Photonic force microscopy calibration extended for its application in high-frequency microrheology

The present document is an update of the previously published MatLab code for the calibration of optical tweezers in the high-resolution detection of the Brownian motion of non-spherical probes. In this instance, an alternative version of the original code, based on the same physical theory, but focused on the automation of the calibration of measurements using spherical probes, is outlined. The new added code is useful for high-frequency microrheology studies, where the probe radius is known but the viscosity of the surrounding fluid maybe not. This extended calibration methodology is automatic, without the need of a user’s interface. A code for calibration by means of thermal noise analysis is also included; this is a method that can be applied when using viscoelastic fluids if the trap stiffness is previously estimated. The new code can be executed in MatLab and using GNU Octave. The previous version of this program (AEXH_v1_0) may be found at http://dx.doi.org/10.1016/j.cpc.2015.06.024