Numerical analysis of low-RI WGM resonators excited by a periodically arranged multilayer dielectric planar waveguide

[摘要] In the applications of whispering gallery mode (WGM) resonators, especially those with low refractive indices (RIs), optical excitation is always a critical issue due to the lack of suitable and matching waveguide materials. The Bloch surface wave (BSW) can facilitate achieving an effective coupling, resulting from its field distribution extending a large portion of its mode energy around the external surface and its easy adjustment of the effective refractive index. In this paper, a BSW waveguide platform for adaptive excitation of spherical WGM resonators is proposed, designed, and numerically analyzed. The simulation results show that the WGM resonator stimulated by BSW exhibits a resonance depth (RD) as large as -98% and a high total quality factor Qtotal -3.13x104 which is in the same order of magnitude as its intrinsic value Q;tt,;ot;o of 5.8x104. Moreover, less limited by its constitutive materials, this BSW-WGM platform is robust and especially suitable for fully integrated applications.

[发布日期] 2021-12-15

[关键词] Integrated optics device;BSW planar waveguide;Whispering gallery mode resonance;Optical coupling