Central wavelength calibration of NAA rugate filters. (a) Reflectance spectra of NAA rugate filters anodized with a period of T = 200, 250, and 300 s for 50 cycles and (b) central wavelength position of the resonance band as a function of period time. The squares represent the central position of the resonance band, and the error bars correspond to the bandwidth.
Macias et al. Nanoscale Research Letters 2014 9:315 doi:10.1186/1556-276X-9-315