Fiber-top and ferrule-top cantilevers for atomic force microscopy and scanning near field optical microscopy

Abstract

Fiber-top and ferrule-top cantilevers (FTC) are a new generation of all optical, monolithic, self-aligned microdevices. They are obtained by carving a cantilever on the cleaved end of an optical fiber (fiber-top) or on a ferrule terminated fiber (ferrule-top). FTCs rely on Fabry-Perot interferometry to measure the deflection of the cantilever with subnanometer deflection sensitivity. FTCs specially developed for scanning probe microscopy are equipped with a sharp tip that has the dual function of probing the topography and collecting/emitting light. We perform the scanning probe microscopy using these probes in air, liquid and at low temperature (12°K). The light emission/collection functionality of FTC probes also allows one to combine scanning near field optical microscopy (SNOM) and optical transmission microscopy with contact and non-contact mode atomic force microscopy (AFM). This makes FTCs ideal for AFM+SNOM on soft samples, polymers and biological specimen, where bent fiber probes and tuning fork based systems would not be recommended because of the high stiffness of those probes. We demonstrate here the capability of fiber-top cantilevers to measure deflection and collect near field optical signal, and also the capability of ferrule-top cantilevers for simultaneous optical transmission microscopy and topography of SNOM gratings. Thanks to their unique features, FTCs also open up possibilities for UV nanolithography and on-demand optical excitation at nanoscale.