Ultrahigh-resolution, high-speed, Fourier domain optical coherence tomography and methods for dispersion compensation

TLDR

Ultrahigh‑resolution OCT uses broadband light to achieve micron‑scale axial resolution, and Fourier‑domain detection boosts imaging speed and sensitivity while providing direct access to the optical spectrum. The study presents a general technique for automatic numerical dispersion compensation applicable to both spectral‑domain and swept‑source Fourier‑domain OCT. Automatic numerical dispersion compensation is performed using the Fourier‑domain spectrum, enabling ultrahigh‑resolution imaging. The system achieves 2.1 µm axial resolution and 16,000 axial scans per second, providing a ~100‑fold speed increase over time‑domain OCT and enabling in‑vivo retinal imaging.

Abstract

Ultrahigh-resolution optical coherence tomography uses broadband light sources to achieve axial image resolutions on the few micron scale. Fourier domain detection methods enable more than an order of magnitude increase in imaging speed and sensitivity, thus overcoming the sensitivity limitations inherent in ultrahigh-resolution OCT using standard time domain detection. Fourier domain methods also provide direct access to the spectrum of the optical signal. This enables automatic numerical dispersion compensation, a key factor in achieving ultrahigh image resolutions. We present ultrahigh-resolution, high-speed Fourier domain OCT imaging with an axial resolution of 2.1 ìm in tissue and 16,000 axial scans per second at 1024 pixels per axial scan. Ultrahigh-resolution spectral domain OCT is shown to provide a ~100x increase in imaging speed when compared to ultrahigh-resolution time domain OCT. In vivo imaging of the human retina is demonstrated. We also present a general technique for automatic numerical dispersion compensation, which is applicable to spectral domain as well as swept source embodiments of Fourier domain OCT.