  In this paper, we present a novel concept for a multi-channel swept source
optical coherence tomography (OCT) system based on photonic integrated circuits
(PICs). At the core of this concept is a low-loss polarization dependent path
routing approach allowing for lower excess loss compared to previously shown
PIC-based OCT systems, facilitating a parallelization of measurement units. As
a proof of concept for the low-loss path routing, a silicon nitride PIC-based
single-channel swept source OCT system operating at 840 nm was implemented and
used to acquire in-vivo tomograms of a human retina. The fabrication of the PIC
was done via CMOS-compatible plasma-enhanced chemical vapor deposition to allow
future monolithic co-integration with photodiodes and read-out electronics. A
performance analysis using the results of the implemented photonic building
blocks shows a potential tenfold increase of the acquisition speed for a
multi-channel system compared to an ideal lossless single-channel system with
the same signal-to-noise ratio.
