Visible light optical coherence microscopy imaging of the mouse cortex with femtoliter volume resolution

Conrad W. Merkle, Shau Poh Chong, Aaron M. Kho, Jun Zhu, Oybek Kholiqov, Alfredo Dubra, Vivek Srinivasan

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

Most flying-spot Optical Coherence Tomography (OCT) and Optical Coherence Microscopy (OCM) systems use a symmetric confocal geometry, where the detection path retraces the illumination path starting from and ending with the spatial mode of a single mode optical fiber. Here, we describe a visible light OCM instrument that breaks this symmetry to improve transverse resolution without sacrificing collection efficiency in scattering tissue. This was achieved by overfilling a 0.3 numerical aperture (NA) water immersion objective on the illumination path, while maintaining a conventional Gaussian mode detection path (1/e2 intensity diameter ∼0.82 Airy disks), enabling ∼1.1 μm full-width at half-maximum (FWHM) transverse resolution. At the same time, a ∼0.9 μm FWHM axial resolution in tissue, achieved by a broadband visible light source, enabled femtoliter volume resolution. We characterized this instrument according to paraxial coherent microscopy theory, and then used it to image the meningeal layers, intravascular red blood cell-free layer, and myelinated axons in the mouse neocortex in vivo through the thinned skull. Finally, by introducing a 0.8 NA water immersion objective, we improved the lateral resolution to 0.44 μm FWHM, which provided a volumetric resolution of ∼0.2 fL, revealing cell bodies in cortical layer I of the mouse brain with OCM for the first time.

Original languageEnglish (US)
Title of host publicationOptical Coherence Tomography and Coherence Domain Optical Methods in Biomedicine XXII
EditorsValery V. Tuchin, Valery V. Tuchin, James G. Fujimoto, Joseph A. Izatt
PublisherSPIE
Volume10483
ISBN (Electronic)9781510614512
DOIs
StatePublished - Jan 1 2018
EventOptical Coherence Tomography and Coherence Domain Optical Methods in Biomedicine XXII 2018 - San Francisco, United States
Duration: Jan 29 2018Jan 31 2018

Other

OtherOptical Coherence Tomography and Coherence Domain Optical Methods in Biomedicine XXII 2018
CountryUnited States
CitySan Francisco
Period1/29/181/31/18

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Keywords

  • cell bodies
  • meninges
  • mouse cortex
  • myelin
  • Optical coherence microscopy
  • optical coherence tomography
  • red blood cell
  • visible light

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Biomaterials
  • Atomic and Molecular Physics, and Optics
  • Radiology Nuclear Medicine and imaging

Cite this

Merkle, C. W., Chong, S. P., Kho, A. M., Zhu, J., Kholiqov, O., Dubra, A., & Srinivasan, V. (2018). Visible light optical coherence microscopy imaging of the mouse cortex with femtoliter volume resolution. In V. V. Tuchin, V. V. Tuchin, J. G. Fujimoto, & J. A. Izatt (Eds.), Optical Coherence Tomography and Coherence Domain Optical Methods in Biomedicine XXII (Vol. 10483). [104831X] SPIE. https://doi.org/10.1117/12.2292125