TY - JOUR A1 - von Schmidsfeld, Alexander A1 - Nörenberg, Tobias A1 - Temmen, Matthias A1 - Reichling, Michael T1 - Understanding interferometry for micro-cantilever displacement detection JF - Beilstein Journal of Nanotechnology PY - 2016/// VL - 7 SP - 841 EP - 851 SN - 2190-4286 DO - 10.3762/bjnano.7.76 PB - Beilstein-Institut JA - Beilstein J. Nanotechnol. UR - https://doi.org/10.3762/bjnano.7.76 KW - displacement noise spectral density KW - interferometer KW - non-contact atomic force microscope (NC-AFM) KW - opto-mechanic effects N2 - Interferometric displacement detection in a cantilever-based non-contact atomic force microscope (NC-AFM) operated in ultra-high vacuum is demonstrated for the Michelson and Fabry–Pérot modes of operation. Each mode is addressed by appropriately adjusting the distance between the fiber end delivering and collecting light and a highly reflective micro-cantilever, both together forming the interferometric cavity. For a precise measurement of the cantilever displacement, the relative positioning of fiber and cantilever is of critical importance. We describe a systematic approach for accurate alignment as well as the implications of deficient fiber–cantilever configurations. In the Fabry–Pérot regime, the displacement noise spectral density strongly decreases with decreasing distance between the fiber-end and the cantilever, yielding a noise floor of 24 fm/Hz0.5 under optimum conditions. ER -