Axial sub-nanometer accuracy in digital holographic microscopy

J. Kühn*, F. Charrière, T. Colomb, E. Cuche, F. Montfort, Y. Emery, P. Marquet, C. Depeursinge

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

107 Scopus citations

Abstract

We present state-of-the-art dual-wavelength digital holographic microscopy (DHM) measurement on a calibrated 8.9 nm high chromium thin step sample and demonstrate sub-nanometer axial accuracy. By using a modified DHM reference calibrated hologram (RCH) reconstruction method, a temporal averaging procedure and a specific dual-wavelength DHM arrangement, it is shown that specimen topography can be measured with an accuracy, defined as the axial standard deviation, reduced to at least 0.9 nm. Indeed for the first time to the best of our knowledge, it is reported that averaging each of the two wavefronts recorded with real-time dual-wavelength DHM can provide up to 30% spatial noise reduction for the given configuration. Moreover, the presented experimental configuration achieves a temporal stability below 0.8 nm, thus paving the way to Angström range for dual-wavelength DHM.

Original languageEnglish (US)
Article number074007
JournalMeasurement Science and Technology
Volume19
Issue number7
DOIs
StatePublished - Jul 1 2008
Externally publishedYes

Keywords

  • Digital holography
  • Non-contact
  • Optical metrology
  • Phase imaging
  • Real-time

ASJC Scopus subject areas

  • Instrumentation
  • Applied Mathematics

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