Optical Sciences

Biomolecules and nanostructures

The Optical Sciences group studies the interaction of light and matter. Our current focus is on detection and sensing/imaging with an emphasis on the development of integrated photonics. We are part of Twente University's Department of Science and Technology and member of the MESA+ institute.


Atomic steps with tuning-fork-based noncontact atomic force microscopy

(full pdf)

Rensen WHJ, van Hulst NF, Ruiter AGT, West PE
vol 75 issue 11: p1640-p1642 SEP 13 1999

Tuning forks as tip-sample distance detectors are a promising and versatile alternative to conventional cantilevers with optical beam deflection in noncontact atomic force microscopy (AFM). Both theory and experiments are presented to make a comparison between conventional and tuning-fork-based AFM. Measurements made o­n a Si(111) sample show that both techniques are capable of detecting monatomic steps. The measured step height of 0.33 nm is in agreement with the accepted value of 0.314 nm. According to a simple model, interaction forces of 30 pN are obtained for the tuning-fork-based setup, indicating that, at the proper experimental conditions, the sensitivity of such an instrument is competitive to conventional lever-based AFM. (C) 1999 American Institute of Physics. [S0003- 6951(99)05337-1].
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