Full field OCT, the principle behind LLTech devices, performs non-invasive high-resolution optical slicing beneath the tissue surface.
An incoherent light source illuminates the whole field of the microscope objectives. Due to the low temporal coherence of the source, interference occurs only when the optical path lengths of the two arms of the interferometer are identical within 1µm.
When a biological sample is placed under the microscope objective in the sample arm, the light reflected by the reference mirror interferes with the light reflected or backscattered by the sample structures contained in a limited volume. The Light-CT fine slicing ability allows depth exploration and high-quality 3D imaging.
For further details, scientific publications are available here.
Light-CT captures “en face” images directly using a megapixel camera and a pair of microscope objectives.
Light-CT derives from low coherence interference microscopy. The interferometer can be displaced to step the focal plane through different depths beneath the surface to create a 3D tomographic image. “En face” capture allows Light-CT to operate with high lateral resolution (typically ~1µm) using medium or large aperture microscope objectives.
The FFOCT image displays in gray scale the static optical contrast of the region of interest. Hihgly backscattering content like different fibrous structures (collagen, axons, etc.) appears white while weakly backscattering content like cells appears dark gray or black.