Papers by Author: T.L. Chen

Abstract: A prototype all-coil electromagnetic force balance has been designed and built. This measurement system compares the mechanical force to an SI realization of electromagnetic force, which is driven from interaction of currents in radial coil set and levitation coil. The preliminary measurement results demonstrate that the magnetic field distribution and magnetic force output are consistent with the results by simulation.

Abstract: This investigation presents a fibre-optic Fabry-Perot interferometer as a displacement sensor in an atomic force microsope (AFM). A simple model of light wave transmission between two fibres with the same core diameter is proposed to determine the theoretical equation of light intensity of interference fringes from the fibre-optic Fabry-Perot interferometer. By replacing an AFM cantilever with a movable reflective mirror, the variations of relative light intensity of the interference fringes with the spacing between the fibre and the mirror were recorded. The theoretical equation for the light intensity of interference fringes was close to those obtained experimentally. Finally, a fibre-optic Fabry-Perot interferometer was operated in an AFM to image a two-dimensional phase array with a pitch of 4 µm and a depth of 150 nm.