Figure 2

SEM image and transmission spectra of the ideal and fabricated devices. ( a) SEM image of the fabricated device with the thicknesses of the Si walls denoted by numbers. Transmission spectra of the predicted ideal triple-defect device (black line) and the fabricated device (red line) operating within ( b) the first order SB with d_Si = 325 nm, (c) the second order SB with d_Si = 360 nm and (d) the third order SB with d_Si = 486 nm. The structural deviations for the fabricated device are: (b) ± δ d_Si = 10.8% (35 nm), (c) 5.6% (20 nm) and (d) 4% (20 nm). The refractive index of allcavities is $n_{\text{def}}^{(\mathbf{2}\mathbf{,}\mathbf{4}\mathbf{,}\mathbf{6})}=1.63$.