Xenon and hydrogen gas mixtures as laser active media

Abstract

Nonlinearities and hysteretic behaviours of piezoelectric actuators used in scanning probe microscopes (SPM) lead to uncertain position determinations of the moving probe in all directions. Therefore, probes must be controlled with nanometre resolution and the three dimensions must be traceable to the unit of length for metrological investigations. Many positioning systems exist but only a few are implementable into SPM or have unsatisfying dynamic properties as well as Abbe errors.A hybrid implementation of a capacitive and a novel three-dimensional interferometric position measurement system has been developed to overcome these problems. The theory and technique of this holographic interferometry are given and the characteristics of the components used for implementation in the final set-up are analysed. A realized SPM head including this technique, in addition to a capacitive position system, as well as its properties are discussed.