Defocus test and defocus correction in full-field optical coherence tomography.

We report experimental evidence and correction of defocus in full-field optical coherence tomography of biological samples owing to mismatch of the refractive index of biological tissues and water. Via a metric based on the image quality, we demonstrate that we are able to compensate this index-induced defocus and to recover a sharp image in depth. (C) 2009 Optical Society of America