Figure 4From: Thermally promoted addition of undecylenic acid on thermally hydrocarbonized porous silicon optical reflectorsEffect of surface modification on reflectance spectra. The effect of thermal hydrosilylation of undecylenic acid (a) and the UnTHC treatment (b) on the reflectance spectra of PSi-based graded-index microcavities. The solid red line represents spectra for as-anodized samples, and the dashed black line is the spectrum recorded after modification. The inset shows the anodization current profile as a function of anodization time. The constant current region results in a cavity layer that is created between two rugate filters. Full width at half maximum (FWHM) values of the cavity resonance, determined from a Lorentzian fit to experimental data, show values in the order of a few nanometers (c).Back to article page