Third harmonic imaging contrast from tubular structures in the presence of index discontinuity

Research output: Contribution to journalResearch articleContributedpeer-review

Contributors

  • Joséphine Morizet - , Ecole Polytechnique, University of St Andrews (Author)
  • Nicolas Olivier - , Ecole Polytechnique (Author)
  • Pierre Mahou - , Ecole Polytechnique (Author)
  • Arthur Boutillon - , Clusters of Excellence PoL: Physics of Life, Chair of Tissue Dynamics (CMCB), Ecole Polytechnique (Author)
  • Chiara Stringari - , Ecole Polytechnique (Author)
  • Emmanuel Beaurepaire - , Ecole Polytechnique (Author)

Abstract

Accurate interpretation of third harmonic generation (THG) microscopy images in terms of sample optical properties and microstructure is generally hampered by the presence of excitation field distortions resulting from sample heterogeneity. Numerical methods that account for these artifacts need to be established. In this work, we experimentally and numerically analyze the THG contrast obtained from stretched hollow glass pipettes embedded in different liquids. We also characterize the nonlinear optical properties of 2,2 -thiodiethanol (TDE), a water-soluble index-matching medium. We find that index discontinuity not only changes the level and modulation amplitude of polarization-resolved THG signals, but can even change the polarization direction producing maximum THG near interfaces. We then show that a finite-difference time-domain (FDTD) modeling strategy can accurately account for contrast observed in optically heterogeneous samples, whereas reference Fourier-based numerical approaches are accurate only in the absence of index mismatch. This work opens perspectives for interpreting THG microscopy images of tubular objects and other geometries.

Details

Original languageEnglish
Article number7850
JournalScientific reports
Volume13
Issue number1
Publication statusPublished - Dec 2023
Peer-reviewedYes

External IDs

PubMed 37188736

Keywords

ASJC Scopus subject areas