Real-time dual-wavelength digital holographic microscopy for MEMS characterization

Jonas Kühn*, Tristan Colomb, Frédéric Montfort, Florian Charrière, Yves Emery, Etienne Cuche, Pierre Marquet, Christian Depeursinge

*Corresponding author for this work

Research output: Chapter in Book/Report/Conference proceedingConference contributionpeer-review

7 Scopus citations

Abstract

We present a method to achieve real-time dual-wavelength digital holographic microscopy (DHM) measurements of micro-electro-mechanical systems (MEMS) with a single camera acquisition. Indeed, while DHM is a technique of choice for MEMS investigation, thanks to its high-speed full-field complex wavefront reconstruction compatible with stroboscopic or pulsed operation modes, the nanometer-resolved phase information available suffers from a so-called phase ambiguity when the optical path length (OPL) induced by the sample is larger than the laser wavelength (typically 400-700nm in the visible range). This measurement range limitation is due to the periodic nature of the phase and, although unwrapping algorithms may be used in some cases, it represents an obstacle to widen DHM applications range. Here we introduce a technique for two-wavelengths DHM, extending the technology field of applications to the micro-meter range, and this with a single hologram acquisition to stay compatible with the exclusive DHM high-speed capabilities described above. Examples of investigation on a 1Hz moving micro-mirror at video frequency are shown to demonstrate the interest of the method for MEMS monitoring.

Original languageEnglish (US)
Title of host publicationOptomechatronic Sensors and Instrumentation III
Volume6716
DOIs
StatePublished - 2007
Externally publishedYes
EventOptomechatronic Sensors and Instrumentation III - Lausanne, Switzerland
Duration: Oct 8 2007Oct 10 2007

Other

OtherOptomechatronic Sensors and Instrumentation III
CountrySwitzerland
CityLausanne
Period10/8/0710/10/07

Keywords

  • Digital holography
  • Dual-wavelength
  • Interferometry
  • MEMS
  • MOEMS
  • Phase microscopy

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Computer Science Applications
  • Applied Mathematics
  • Electrical and Electronic Engineering

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