Nanophotonic nonlinear and laser devices exploiting bound states in the continuum

Abstract

The quality factor (Q), describing the rate of energy loss from a resonator, is a defining performance metric for nanophotonic devices. Suppressing cavity radiative losses enables strong nonlinear optical responses or low-power operation to be achieved. Exploiting long-lived, spatially-confined bound states in the continuum (BICs) has emerged from the numerous approaches considered as a promising route to boost nanophotonic Q factors. Initial research explored the formation mechanisms of various types of BICs, drawing parallels to topological physics. With these fundamentals now established, we review the recent application of BICs in passive and active nanophotonic devices.

Active control of an electromagnetically induced transparency analogue in a coupled dual bound states in the continuum system integrated with graphene

“…Recently, bound states in the continuum (BIC) has emerged as a promising way to address these challenges. 15–18 BIC represents a captivating and counterintuitive phenomenon in wave physics. Initially conceptualized in quantum mechanics, despite being within the radiative spectrum of open systems, BIC states are not coupled to an external wave and thus exhibit an infinite Q -factor.…”

Recent advances in strongly resonant and gradient all-dielectric metasurfaces

“…Recently, metasurfaces have been pushed to the extreme in search of enhanced performance and new application regimes. The emergence of metasurfaces supporting bound states in the continuum (BIC) 7–9 has provided a pathway towards achieving a strongly resonant response and an ultra-narrow temporal bandwidth. BIC metasurfaces can offer extreme frequency selectivity and the ability to profoundly enhance the local fields and boost light–matter interaction.…”

A universal and stable metasurface for photonic quasi bound state in continuum coupled with two dimensional semiconductors

“…A BIC in a lossless system has an infinite quality factor, with no radiative loss to the environment. BICs are broadly classified into be relevant for numerous applications in the development of nanoscale light sources [6,7], sensors [8][9][10] and nonlinear optical devices [11][12][13].…”