Digital Holographic Microscopy by Mirau Interferometric Objective

Abstract

AbstractTypically Digital holographic microscopy (DHM) uses either a Michelson or Mach-Zehnder interferometers as an interferometric tool for attaining an in-line digital hologram. These interferometers need not only a well optical aligning in order to compensate the spherical aberration but also a special optical path difference compensation system when a low coherence illumination source is used. A Mirau interferometric objective appears as an alternative to overcome these difficult tasks and automatic reduction of quadratic aberration in DHM. A spatial averaging process of phase images reconstructed at different reconstruction distances is performed, with the reconstruction distance range being specified by the numerical focus depth of the optical system. An improved phase image is attained with a 46% of shot noise reduction. We use the integral of the angular spectrum as a reconstruction method to obtain a single-object complex amplitude that is needed to perform the averaging process. We also show the corresponding simulations and experimental results. The topography of a homemade TiO2 step wise of 100 nm high was measured and compared with the Atomic Force Microscope results. As far as we know, Mirau integrated on DHM has not been used.KeywordsPhase ImageShot NoiseReference WaveOptical Path DifferenceObject WaveThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.