Spatiotemporal Optical Coherence (STOC) Manipulation Improves Imaging with Full-Field Swept-Source OCT

Abstract

Full-field swept-source optical coherence tomography (FF-SS-OCT) achieves high-resolution high-speed images of the sample by parallel interferometric detection. However, the image quality is very susceptible to the cross-talk-generated noise [1]. This issue results from the so-called signal degrading speckles [2], and can be reduced, if the spatially incoherent light source (thermal lamp or LED) is employed [1] but reduces the imaging speed. Recently, it was demonstrated that, the PSF of the FF-OCT with spatially incoherent illumination is almost insensitive to low-order geometrical aberrations, e.g. defocus [3]. These results lead to a hypothesis that the cross-talk-generated noise and low-order geometrical aberrations can be overcome by damping the spatial coherence of the incident light beam. Here, we present a novel method, in which the cross-talk-generated noise is suppressed with the spatiotemporal optical coherence (STOC) manipulation. In STOC, the phase of incident light is modulated in time with a set of phase patterns displayed sequentially on the spatial light modulator (SLM). Light modulation is synchronized with light acquisition to effectively control the spatial coherence of the detected light.