Positioning assembly for positioning the tip of an optical fiber

The main application of a positioning assembly for positioning a tip of an optical fiber is to operate an open Fabry-Perot fiber cavity. This is an optical resonator, which enables enhanced light-mat ter interaction useful for quantum technologies and ultrasensitive microscopy. The cavity is formed by two mirrors: one is a macroscopic planar mirror onto which samples can be deposited, and the other is on the tip of the fiber, which can be scanned over the planar mirror to locate the samples. By such a setup, ultrasensitive scattering microscopy to detect single nanoparticles can be performed. Due to the resonant nature of the cavity, even weak scattering of light from the sample results in a large variation of the optical power of the obtained signal. Furthermore, by such a setup the emission obtained from a quantum emitter located in the cavity can be enhanced through the Purcell effect.The present invention relates to a positioning assembly for positioning a tip of an optical fiber, a fiber nanopositioner comprising the positioning assembly and an optical system comprising the fiber nanopositioner