Fourier domain mode-locked (FDML) lasers at 1050 nm and 202,000 sweeps per second for OCT retinal imaging

Abstract

Retinal imaging ranks amongst the most important clinical applications for optical coherence tomography (OCT) [1, 2]. The recent demonstration of increased sensitivity [3-6] in Fourier Domain detection [7, 8] has opened the way for dramatically higher imaging speeds, up to axial scan rates of several tens of kilohertz. However, these imaging speeds are still not sufficient for high density 3D datasets and a further increase to several hundreds of kilohertz is necessary. In this paper we demonstrate a swept laser source at 1050 nm with a sweep rate of 202 kHz. The laser source provides ~10 mW average output power, up to 60 nm total sweep range and a sensitivity roll off of less than 10 dB over 4 mm. In vivo 2D and 3D imaging of the human retina at a record axial scan rate of 101 kHz is demonstrated. These results suggest that swept source OCT has the potential to significantly outperform spectral/Fourier domain OCT for ophthalmic imaging applications in the future.