Figure 4From: 1-D nanoporous anodic alumina rugate filters by means of small current variations for real-time sensing applicationsReflectance and transmittance characterization of the NAA rugate filters. (a) Reflectance and (b) transmittance spectra of NAA rugate filters anodized for 300 cycles, with an apodized sinusoidal current profile with a period time of T = 200 s.Back to article page