3-ring-CROW, 2D, schematically
Short coupled resonator optical waveguide,
a configuration with three identical micro-rings, coupled to two straight access channels. Parameters: refractive indices 1.0 (background) and 1.5 (cores), bus waveguide width 0.6µm, gap distance 0.3 µm, cavity radius 7.5 µm (outer rim), cavity core width 0.75 µm.  

2-D simulations for TE-polarization, the principal electric field component Ey is perpendicular to the x-z-plane of the computational window.

Transmission properties
Unidirectional HCMT model (hybrid analytical/numerical coupled mode theory), based on the guided slab modes of the access channels, together with bend modes supported by the cavity cores; transmittance T and dropped optical power D as functions of the vacuum wavelength λ of the exciting guided mode.

1.555 µm 1.5597 µm 1.561 µm 1.5627 µm 1.5649 µm 1.5664 µm 1.57 µm

The links at the positions indicated by the bold upper tick marks lead to animations of the time harmonic electric field, and of the field modulus. Note that these features relate to one single resonance of a similar one-ring filter (free spectral range 36 nm).