Direct measurement of a light induced attractive force between two metal bodies seperated by a subwavelength slit

In this work the improved nanonewton force facility of the Physikalisch-Technische Bundesanstalt (PTB), the German national metrology laboratory, and its possibility of measuring a theoretical predicted negative light pressure between two metallic plates with subwavelength distance is presented. The work includes presentation of upgrades to the existing nanonewton force facility for the realization of the experiment, the measuring methods and the first results obtained with the experimental setup together with comparisons to theoretical calculations.