Insight into refractive index modulation as route to enhanced light coupling in semiconductor nanowires

Recent developments in chemical processes to prepare single-crystalline nanowire (NW) superlattices (SLs) have discovered a range of unique nanophotonic properties. In particular, diameter-modulated silicon NW geometric SLs (GSLs) have shown their ability to produce complex interference effects through which enhanced light manipulation is achieved. Here, we re-imagine the origin of the complex interference effects occurring in shallow-modulated GSLs and present a refractive index modulation as a key deciding factor. We introduce the design of a NW refractive index SL (ISL), a hypothetical uniform-diameter NW in which the refractive index is periodically modulated, and explain the coupling effect between Mie resonance and bound guided state. We apply the ISL concept to other NW SL systems and suggest potential routes to bring substantial enhancements in lasing activities. (c) 2023 Optica Publishing Group

Automated summary

Recent developments in chemical processes have discovered unique nanophotonic properties in the preparation of single-crystalline nanowire superlattices. Particularly, diameter-modulated silicon nanowire geometric superlattices have shown the capability of enhanced light manipulation through complex interference effects. This study re-imagines the origin of the complex interference effects and identifies refractive index modulation as a key deciding factor. The concept of a nanowire refractive index superlattice is introduced, and its application to other nanowire superlattice systems is suggested to potentially enhance lasing activities.