Theoretical and experimental determination of the confocal function of OCT systems for accurate calculation of sample optical properties.

The attenuation coefficient of biological tissue could serve as an indicator of structural and functional changes related to the onset or progression of disease. Optical coherence tomography (OCT) provides cross sectional images of tissue up to a depth of a few millimeters, based on the local backscatter properties. The OCT intensity also depends on the confocal function, which needs to be characterised to determine correctly the exponential decay of the intensity based on Lambert-Beer.

Confocal corrected attenuation coefficient imaging in phantoms and using chromatic focal shift calibration.

Optical coherence tomography (OCT) is conventionally used for structural imaging of tissue. Calibrating the intensity values of OCT images can give information on the tissue's inherent optical properties, such as the attenuation coefficient, which can provide an additional parameter to quantify possible pathological changes. To obtain calibrated intensity values, the focus position and Rayleigh length of the incident beam need to be known.