Three dimensional spatiotemporal nano-scale position retrieval of the confined diffusion of nano-objects inside optofluidic microstructured fibers

Understanding the dynamics of single nano-scale species at high spatiotemporal resolution is of utmost importance within fields such as bioanalytics or microrheology. Here we introduce the concept of axial position retrieval via scattered light at evanescent fields inside a corralled geometry using optofluidic microstructured optical fibers allowing to unlock information about diffusing nano-scale objects in all three spatial dimensions at kHz acquisition rate for several seconds. Our method yields the lateral positions by localizing the particle in a wide-field microscopy image. In addition, the axial position is retrieved via the scattered light intensity of the particle, as a result of the homogenized evanescent fields inside a microchannel running parallel to an optical core. This method yields spatial localization accuracies