Absolute shape measurement of high NA focusing microobjects in digital holographic microscope with arbitrary spherical wave illumination

作者：Kozacki Tomasz^*; Lizewski Kamil; Kostencka Julianna

来源：Optics Express, 2014, 22(14): 16991-17005.

DOI：10.1364/OE.22.016991

In this paper a new high NA shape measurement technique working with an arbitrary spherical wave illumination is presented. The main contribution of this work are formulas, derived from exact reflection and refraction laws for both the reflection and the transmission configurations, which enable accurate shape calculations in systems with an arbitrary location of the illuminating point source. The proposed algorithms permit measurement of multiple samples of arbitrary shapes using a single hologram. An accuracy of this method is confirmed with numerical simulations, which show superiority of this approach over a standard procedure utilizing paraxial approximation. The method is validated experimentally using a reflective measurement of a microlens topography, whose NA in reflection is 0.7. Furthermore, a new measurement configuration is presented that extends the capabilities of transmission systems for characterization of high gradient shapes.

• 出版日期2014-7-14