This work presents a significant advancement towards in vivo ophthalmic optical coherence tomography (OCT) and angiography on a photonic integrated chip. Arrayed waveguide gratings (AWGs) on photonic integrated circuits replace the diffraction gratings used in spectral-domain OCT (SD-OCT). Two AWG designs with 256 channels were tested, enabling the first chip-based OCT and angiography for in vivo three-dimensional human retinal measurements. Design 1 achieved 91 dB sensitivity (830 µW) and 10.7 µm axial resolution (22 nm bandwidth), while Design 2 achieved 90 dB sensitivity (480 µW) and 6.5 µm axial resolution (48 nm bandwidth). The silicon nitride-based waveguides were fabricated with a fully CMOS-compatible process, enabling monolithic co-integration on a silicon chip. Tomogram comparisons with a commercial SD-OCT system demonstrated the clinical potential of this chip-based OCT system.

Elisabet A. Rank, Ryan Sentosa, Danielle J. Harper, Matthias Salas, Anna Gaugutz, Dana Seyringer, Stefan Nevlacsil, Alejandro Maese-Novo, Moritz Eggeling, Paul Muellner, Rainer Hainberger, Martin Sagmeister, Jochen Kraft, Rainer A. Leitgeb, Wolfgang Drexler