Non-square rectangular microresonators,
2D simulation of two configurations with the following specification: background refractive index nb = 1.0, refractive index of the guiding regions ng = 3.2, waveguide width w = 0.2 µm, gap width g = 0.29 µm, the resonator dimensions are as given below. All calculations are meant for TE polarization, i.e. Ey is the single nonvanishing component of the electrical field.

Spectral response of the resonator elements:
The devices are excited in port A by the guided mode of the lower waveguide with the specified vacuum wavelength λ. PB - PD and PA are the relative power transmissions to ports B, C, and D, and the relative power reflected into port A. Note that the curves related to PA, PC, and PD are almost superimposed. The links at the positions indicated by the the blue tick marks lead to illustrations of the time dependent electric field, and of the local electromagnetic energy density, respectively.

Cavity aspect ratio 2:1,
resonator dimensions L = 3.08 µm, W = 1.54 µm, the waveguides run along the long sides of the cavity:

1.3587 µm 1.3847 µm 1.4347 µm 1.472 µm 1.517 µm 1.5687 µm 1.608 µm 1.65 µm 1.6813 µm

Cavity aspect ratio 1:2,
resonator dimensions L = 1.54 µm, W = 3.08 µm, the waveguides run along the shorter sides of the cavity:

1.3073 µm 1.344 µm 1.3707 µm 1.3987 µm 1.4347 µm 1.4393 µm 1.452 µm 1.506 µm 1.5107 µm 1.5163 µm 1.5693 µm 1.5893 µm 1.6087 µm 1.6213 µm 1.6587 µm 1.678 µm