title: Piezoelectrical shear-force distance control in near-field optical microscopy for biological applications.
abstract: We present a piezoelectrical shear-force distance control setup for scanning near-field optical microscopy. The setup is compact and tip exchange is easy. The topographical sensitivity is comparable to optical feedback systems. With an acceptable vibration amplitude of 5-10 nm we obtained a topographical resolution of 5 pm/square root of Hz. Because there is no laser necessary for tip position feedback, there is no extraneous light to interfere with spectroscopic and other low-light level experiments. Our technique permits measurements of soft biological samples in aqueous solution, which opens up many possible applications of near-field optical microscopy in biology and medicine.
authors.affiliation: Abteilung Experimentelle Physik, Universität Ulm, Germany.
authors.forename: O
authors.initials: O
authors.lastname: Hollricher
authors.forename: R
authors.initials: R
authors.lastname: Brunner
authors.forename: O
authors.initials: O
authors.lastname: Marti
mesh_terms: D000818:Animals; D005336:Fiber Optic Technology; D006624:Hippocampus / Q000166:cytology; D008853:Microscopy / Q000295:instrumentation / Q000379:methods*; D008855:Microscopy, Electron, Scanning; D009474:Neurons / Q000648:ultrastructure; D051381:Rats; D012680:Sensitivity and Specificity; D014732:Vibration