Bimodal Resonance Phenomena—Part II: High/Low-Contrast Grating Resonators

Abstract

Several groups are currently working on integrated optical resonators. In this context, one of the most interesting implementations is based on high-contrast gratings, featuring high-Q Fano resonances. Mastering these phenomena can potentially open up the possibility to exploit such devices for the implementation of vertical-coupled filters or compact monolithic lasers. To this aim, in this paper the novel analytic framework introduced in Part I is applied to complement the design guidelines present in the literature. Through explicit expressions of the loop gain eigenvalues it is possible to predict the positions and quality factors of resonances in crossing and anticrossing points. Moreover, a quantitative connection between these points and Fano resonances is established. The framework presented in this paper has been useful for identifying, in a low-contrast grating, resonance features similar to those well known in highcontrast structures.

Bound states in the continuum and high-Q resonances supported by a dielectric ridge on a slab waveguide

“…This expression is used as the dispersion equation in the theory of the so-called matrix Fano resonances of high-contrast gratings [39]. A similar study of high-contrast gratings was presented in [40], where the authors used the concept of generalized Fabry-Pérot interferometers [41].…”

Plasmons in ultra-thin gold slabs with quantum spill-out: Fourier modal method, perturbative approach, and analytical model

“…In the FMM, which is also referred to as rigorous coupled wave analysis (RCWA), the eigenmodes are expanded using a Fourier basis. The FMM has been used widely for investigating gratings [23][24][25][26][27][28], since the Fourier basis is particularly suitable for periodic structures. Nonetheless, by introducing perfectly matched layers (PMLs) at the boundaries of simulation domains, the FMM has been successfully employed for studying various non-periodic structures such as dielectric waveguides [20,29,30], photonic crystals waveguides [31,32], finite gratings [33], microdisks [34,35], and vertical cavities [36,37].…”