Opt Express. 2021 Jan 18;29(2):2204-2226. doi: 10.1364/OE.403432.
Optical coherence tomography (OCT) is a powerful technique for cross-sectioning imaging. However, the lateral resolution may be degraded by optical aberrations originating from the sample or the setup. We present an extensive quantitative study of the impact of aberrations in time-domain en-face full-field OCT (FFOCT). Using an adaptive optics loop integrated in an FFOCT setup, a deformable mirror is used to introduce low-order calibrated aberrations. The experimental analysis of both the line spread functions (SF) and the complex object images has allowed us to measure the loss in contrast and the impact on lateral spatial resolution. We demonstrate that the frequency content of FFOCT image spectra in terms of signal-to-noise ratio and cutoff frequency is degraded by aberrations but remains much higher than in conventional incoherent images. Line SF profiles in conventional imaging display widening, whereas in FFOCT they display oscillations, leading to the possible perception of preserved resolution. Nevertheless, for complex objects, the aberration image blurring is strong due to the convolution process by the point SF, resulting in a significant filtering of the image spatial spectrum.
光学相干断层扫描（OCT）是一种用于横截面成像的强大技术。然而，来自样本或设置的光学像差可能会降低横向分辨率。我们对时域面内全场 OCT（FFOCT）中的像差的影响进行了广泛的定量研究。使用集成在 FFOCT 设置中的自适应光学环，使用变形镜引入低阶校准像差。对线扩展函数（SF）和复杂物体图像的实验分析使我们能够测量对比度的损失以及对横向空间分辨率的影响。我们证明了像差会降低 FFOCT 图像光谱的频率内容（以信噪比和截止频率表示），但仍然比传统非相干图像高得多。传统成像中的线 SF 轮廓显示变宽，而在 FFOCT 中显示振荡，导致可能感知到分辨率保持。然而，对于复杂物体，由于点 SF 的卷积过程，像差的图像模糊很强，导致图像空间频谱的显著滤波。
