Structural characterization. Cross section SEM micrograph of a NAA rugate filter anodized for 300 cycles with an apodized sinusoidal current profile with a period of T = 200 s and a pore-widening post-treatment of tpw = 15 min. Inset shows the top view of the structure.
Macias et al. Nanoscale Research Letters 2014 9:315 doi:10.1186/1556-276X-9-315