As-anodized rugate filter response to methylamine. Reflectance spectra for an as-anodized PSi rugate filter measured before and after 5-min exposure to 10.7% (volume) of methylamine vapor (a). The change in the reflective peak position plotted as a function of exposure and recovery time (b). The instantaneous blueshift indicates rapid oxidation of the PSi optical filter.
Jalkanen et al. Nanoscale Research Letters 2012 7:311 doi:10.1186/1556-276X-7-311