Figure 5.

Reflectance spectra of PSRFs and C-PSRFs. PSRFs' reflectance spectra (upper curve) etched with single periods of (a) 3.105, (b) 3.45, and (c) 4.14 s, respectively, and reflectance spectrum of C-PSRFs (lower curve) with three peaks etched with the coupled current density of three single periods of (a₁) 3.105, (b₁) 3.45, and (c₁) 4.14 s. In both cases, the sinusoidal current varied between 10 and 50 mA cm^-2 and was cycled 30 times.