Oblique illumination holographic OCT for improving resolution, reducing speckle and objectively correcting aberrations

Full-field Fourier-domain optical coherence tomography (FF-FD-OCT) is an emerging OCT variant characterized by its high acquisition speed and phase stability. Like all OCT techniques, it suffers from speckle noise and aberrations and shows lower lateral resolution compared to confocal OCT. Here, we demonstrate an oblique illumination FF-FD-OCT that overcomes these limitations. The effective resolution is increased and the oblique illumination helps to reduce speckle noise. Compared to standard adaptive optics OCT, it uniquely allows for an objective determination of aberrations that can be corrected computationally. We demonstrate the enhanced image quality of the technique and show its potential for future in vivo applications.