Fourier-domain full-field optical coherence tomography with real-time axial imaging

Fourier-domain full-field optical coherence tomography (FD-FF-OCT) is a fast interferometric imaging technique capable of volumetric sample imaging. However, half of the backscattered light from a sample is lost as it passes through a 50/50 beam splitter, which is at the heart of almost every interferometer. Here, it is demonstrated that this light could be extracted by spatially splitting the illumination pupil plane and detecting it with a separate camera. When a line camera is used to detect the recovered signal, it enables real-time axial imaging of the human cornea in vivo, which serves as a useful visual feedback for aligning a patient for imaging.