Influence of separation distance on the spectral response

In Section 3.4 we analyzed the effect of changes in the separation distance on the coupler performance. In this section, we investigate its influence on the spectral response of the entire resonators. Three types of changes of $g$ and $\tilde{g}$ are discussed viz. changing both separation distances identically, changing only one of the separation distances while keeping the other constant, and changing both separation distances with $g + \tilde{g}$ = constant (i.e. shifting the cavity between fixed port waveguides).

The simulations are carried out for the resonator configurations of Figure 4.5 (ring resonators) and Figure 4.8 (disk resonators), and the spectrum evaluation procedure by quadratic interpolation is employed.