Maximum imaging depth comparison in porcine vocal folds using 776-nm vs. 1552-nm excitation wavelengths

Murat Yildirim, Onur Ferhanoglu, James B. Kobler, Steven M. Zeitels, Adela Ben-Yakar

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


Vocal fold scarring is one of the major causes of voice disorders and may arise from overuse or post-surgical wound healing. One promising treatment utilizes the injection of soft biomaterials aimed at restoring viscoelasticity of the outermost vibratory layer of the vocal fold, superficial lamina propria (SLP). However, the density of the tissue and the required injection pressure impair proper localization of the injected biomaterial in SLP. To enhance treatment effectiveness, we are investigating a technique to image and ablate sub-epithelial planar voids in vocal folds using ultrafast laser pulses to better localize the injected biomaterial. It is challenging to optimize the excitation wavelength to perform imaging and ablation at depths suitable for clinical use. Here, we compare maximum imaging depth using two photon autofluorescence and second harmonic generation with third-harmonic generation imaging modalities for healthy porcine vocal folds. We used a home-built inverted nonlinear scanning microscope together with a high repetition rate (2 MHz) ultrafast fiber laser (Raydiance Inc.). We acquired both two-photon autofluorescence and second harmonic generation signals using 776 nm wavelength and third harmonic generation signals using 1552 nm excitation wavelength. We observed that maximum imaging depth with 776 nm wavelength is significantly improved from 114 μm to 205 μm when third harmonic generation is employed using 1552 nm wavelength, without any observable damage in the tissue.

Original languageEnglish
Title of host publicationMultiphoton Microscopy in the Biomedical Sciences XIII
Publication statusPublished - 2013
Externally publishedYes
EventMultiphoton Microscopy in the Biomedical Sciences XIII - San Francisco, CA, United States
Duration: 3 Feb 20135 Feb 2013

Publication series

NameProgress in Biomedical Optics and Imaging - Proceedings of SPIE
ISSN (Print)1605-7422


ConferenceMultiphoton Microscopy in the Biomedical Sciences XIII
Country/TerritoryUnited States
CitySan Francisco, CA


  • Healthy porcine vocal folds
  • Maximum imaging depth
  • Second-harmonic generation
  • Third-harmonic generation
  • Two-photon autofluorescence
  • Ultrafast fiber laser
  • Vocal fold scarring


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