Optical frequency comb stabilization using cascaded injection locking for DAS applications in ISAC systems

Coherent and narrow-linewidth OFCs can serve as independent lasers for ISAC systems supporting both DAS systems and coherent optical communications in WDM links. In this study, we investigate the effects of cascaded injection locking in a two-stage optical injection system. The cascaded injection locking effectively stabilizes Phase-Locked Period-One-based OFC (PPOFC) signals with at least 10 coherent comb lines, each exhibiting an optical linewidth of less than 10 kHz. Furthermore, each comb line of the PPOFC signals can function as an independent laser for a DAS system, enabling the retrieval of driving acoustic waves with a SNR greater than 30 dB.