Frank Jülicher

Frank Jülicher coauthored a calibration method for optical tweezers that combines the trapped particle's thermal fluctuations with its response to a controlled sinusoidal motion. These two measurements determine position and force scales without taking the particle's drag coefficient as an independently known input. The experiment tested the method both near and far from surfaces. Its physical advantage is to separate detector calibration from uncertain particle size, viscosity and wall-dependent drag.^[ref]