Bulk phase error correction by smart-integration-path method for phase-sensitive signal processing of optical coherence tomography

Bulk phase error (BPE) caused by environmental fluctuations will be a crucial problem for complex numerical processing of optical coherence tomography (OCT). We established a fully numerical phase stabilization method so-called smart-integration-path (SIP) method, which first estimates the vectorial gradient of BPE from a volumetric OCT data, then computes BPE from the gradient, and finally corrects BPE. The performance of SIP was subjectively evaluated by computational refocusing performance of ex vivo samples. The performance was also objectively evaluated by the standard deviations of spatial frequency spectra of en face OCT images. Both analyses showed positive effects of the BPE correction.