Figure 6

Generation of TESs by the SSH nanobeams with the same transverse spacing but different axial shift. (a) The field distribution \(H_{z}\) of the edge mode at \(\lambda_{2} = 1.624\;\upmu{\text{m}}\) when \(d_{2 } = 0.3\;\upmu{\text{m}}\) and \(d_{4 } = 0.4\;\upmu{\text{m}}.\) (b) The field distribution |E| of the edge mode at \(\lambda_{2} = 1.624\;\upmu{\text{m}}\) when \(d_{2 } = 0.3\;\upmu{\text{m}}\) and \(d_{4 } = 0\;\upmu{\text{m}}\). In the SSH structures, all the nanobeams have the same transverse spacing of \(d_{1 } = 0.6\;\upmu{\text{m}}\). The axial shift between the nanobeams \(j\) to \(j + 1\) (\(j = 1, 3, 5, 7, 9\)) is \(d_{2 }\), and the axial shift between the nanobeams j to \(j\) + 1 (\(j\) = 2, 4, 6, 8) is \(d_{4 }\), as depicted by the structure outline in (a). The other geometrical parameters of the nanobeams are the same as those in Fig. 5. The black and purple dotted lines indicate the central holes of the even and odd nanobeams, respectively. The spectra of the SSH nanobeams and the field distribution \(\left| {\mathbf{E}} \right|\) of the generated edge mode at the first resonance mode wavelength \(\lambda_{1}\) are given in Fig. S7 in Supplementary Information.