Swept-Source Optical Coherence Tomography System with an On-Chip K-Clock Based on Silicon Photonics

The paper presents the design of a photonic integrated circuit (PIC), which represents a key step towards a fully integrated swept-source optical coherence tomography (SS-OCT) system. In addition to the on-chip interferometer and reference arm, the PIC includes an optical clock implemented through a tunable unbalanced Mach-Zehnder interferometer and a balanced detection scheme. The chip is developed based on a silicon-on-insulator platform and operates in a 1300 nm wavelength range suitable for tissue and inner organ diagnostics. The simulation results in the Ansys Lumerical software show the good performance of the proposed SS-OCT device beyond the zero-delay point. The implementation of the optical part of the OCT circuit on PIC can provide a trade-off between miniaturization, cost, and system performance, which can unlock new perspectives for its application.