Polarization-multiplexed, dual-beam swept source optical coherence tomography angiography

TL;DR

This paper introduces a polarization-multiplexed dual-beam OCTA system that captures wider retinal images simultaneously by splitting and coding two orthogonal-polarized beams, enabling faster, larger field-of-view imaging.

Contribution

It presents a novel dual-beam setup using polarization multiplexing and frequency coding to expand OCTA imaging field of view and reduce acquisition time.

Findings

Achieved simultaneous 5x5 mm² angiograms in 4 seconds.

Montaged images expanded FOV to approximately 5x9.2 mm².

Demonstrated effective separation and coding of dual-beam OCTA signals.

Abstract

A polarization-multiplexed, dual-beam setup is proposed to expand the field of view for a swept source optical coherence tomography angiography (OCTA) system. This method used a Wollaston prism to split sample path light into two orthogonal-polarized beams. This allowed two beams to shine on the cornea at an angle separation of ~ 14 degrees, which led to a separation of ~ 4.2 mm on the retina. A 3-mm glass plate was inserted into one of the beam paths to set a constant path length difference between the two polarized beams so the interferogram from the two beams are coded at different frequency bands. The resulting OCTA images from the two beams were coded with a depth separation of ~ 2 mm. 5x5 mm2 angiograms from the two beams were obtained simultaneously in 4 seconds. The two angiograms then were montaged to get a wider field of view (FOV) of ~ 5x9.2 mm2.