Fig. 2.
Reflectivity spectra of a bifunctional porous Si rugate film. The green solid trace is obtained from the side of the film that contained a mirror etched by using a sinusoidal current varying between 11.5 and 34.6 mA/cm2. This side of the porous mirror then was hydrosilylated with 1-dodecene. The red dashed trace is obtained from the side of the film that contained a second mirror, etched by using a sinusoidal current varying between 11.5 and 34.6 mA/cm2 and then removed from the Si substrate. This side of the porous mirror was thermally oxidized. The total thickness of the porous Si film is ≈100 μm. The optical reflectivity spectra were obtained by using an Ocean Optics SD2000 charge-coupled device spectrometer fitted with focusing optics and by using tungsten light illumination. arb, arbitrary.