Extended Data Fig. 4: Y-Polarized Transmittance Spectra for w1 and l2 Sweeps.
From: Optical control of resonances in temporally symmetry-broken metasurfaces
(a) Transmittance spectra for y-polarized light (inset for reference) in analogy to the x-polarized spectra of the two gradient metasurfaces in Fig. 2h: on the left for varying w1 with fixed \({l}_{1}={l}_{2}=175\,{\rm{nm}}\) and \({w}_{2}=95\,{\rm{nm}}\); on the right for varying l2 with fixed \({w}_{1}=185\,{\rm{nm}}\), \({w}_{2}=95\,{\rm{nm}}\), and \({l}_{1}=175\,{\rm{nm}}\). In the w1 sweep (left), the Mie 1 and Mie 2 modes discussed in Fig. 3 are not visible for small w1 and appear as w1 increases. In the l2 sweep (right), there is almost no change in the transmittance spectra, indicating the mode’s independence from the size parameters along the off-polarization axis. This allows us to use the same optimized pump wavelength of 720 nm, as it remains resonant with Mie 1 across the entire l2 gradient. This is confirmed in (b) by the transmittance spectra at the RSP-BIC condition with \({l}_{2}^{{\rm{R}}{\rm{S}}{\rm{P}}}=226\,{\rm{n}}{\rm{m}}\) (shown in Fig. 3a) and with \({l}_{2}=236\,{\rm{nm}}\) (the structure used in Fig. 3e,f), which both feature almost identical Mie 1 modes.
