Bigeng Chen

Abstract Ultra-high extinction ratio (ER) optical modulation is crucial for achieving high-performance fiber-optic distributed acoustic sensing (DAS) for various applications. Bulky acousto-optical modulators (AOM) as one of the key devices in DAS have been used for many years, but their relatively large volume and high power consumption are becoming the bottlenecks to hinder the development of ultra-compact and energy-efficient DAS systems that are highly demanded in practice.

The integration of a FNW into a typical silicon photonic circuit is illustrated schematically in Fig. 1a, where a FNW is used to bridge the two SWs via side-by-side near-field optical coupling. On-chip SWs were fabricated with a silicon-on-insulator (SOI) wafer by the processes of E-beam lithography and subsequent dry-etching (see Methods section).