Development of an index-matching epoxy-based collimator for reducing multipath artifacts in multimodal intravascular optical coherence tomography

We developed a novel collimator with an expanded, index-matched cladding for double-clad fiber-based multimodal intravascular optical coherence tomography (OCT) systems. The proposed design mitigates multipath artifacts by reducing cladding-to-core coupling at fiber discontinuities, resulting in an improvement in signal-to-noise ratio. This enhancement effectively suppresses image artifacts and improves overall OCT image quality, thereby enabling more accurate diagnostic assessment in multimodal intravascular imaging.