Computational aberration correction in spatiotemporal optical coherence (STOC) imaging

TL;DR

This paper introduces a computational aberration correction method for spatiotemporal optical coherence imaging, enhancing image clarity and revealing detailed retinal structures by leveraging phase modulation and coherent averaging.

Contribution

It demonstrates that phase modulation combined with coherent averaging enables effective aberration correction in STOC imaging, improving retinal imaging resolution.

Findings

Coherent averaging preserves lateral phase stability.

Computational phase correction compensates for geometrical aberrations.

Reveals photoreceptor mosaic in human retina.

Abstract

Spatiotemporal optical coherence (STOC) imaging is a new technique for suppressing coherent crosstalk noise in Fourier-domain full-field optical coherence tomography (FD-FF-OCT). In STOC imaging, the timevarying inhomogeneous phase masks modulate the incident light to alter the interferometric signal. Resulting interference images are then processed as in standard FD-FF-OCT and averaged incoherently or coherently to produce crosstalk-free volumetric OCT images of the sample. Here, we show that coherent averaging is suitable when phase modulation is performed for both interferometer arms simultaneously. We explain the advantages of coherent over incoherent averaging. Specifically, we show that modulated signal, after coherent averaging, preserves lateral phase stability. This enables computational phase correction to compensate for geometrical aberrations. Ultimately, we employ it to correct for aberrations present in the image of the photoreceptor layer of the human retina that reveals otherwise invisible photoreceptor mosaic.