SD OCT
Spectral Domain OCT
Fourier Domain OCT

OCT allows fast, non-invasive volumetric measurements of the surface and sub-surface structure at a resolution of microns for objects which are moderately absorbing in the IR. The technique relies on interferometry with a singular depth profile (A-scan) being reconstructed from the measured spectrum. By scanning the illumination spot across the object, a 3D or 2D virtual cross section of the object's stratigraphy can be collected over a small region. In OCT virtual cross sections, contrast is provided by variations in the material refractive index with bright regions corresponding to boundaries (interfaces) between structures. This enables measurements of structures like layers and scattering sites. 2D OCT virtual cross-sections (B-scans) are usually presented as convenient cross-sectional views, similar to microscopic images of sample cross-sections extracted from the object. 3D information of an entire volume (a cube) may be also collected by combining a sequence of 100 to 1000 B-Scan cross-sections across the surface.

Optical coherence tomography (oct)

Analysis Method

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