Porous silicon free-standing coupled microcavities

We report the experimental characterization of porous silicon free-standing coupled microcavities. We have grown free-standing structures of up to 109 stacked layers. Free-standing structures are interesting because reflectance spectra can be measured on both sides of the samples. The comparison of reflectance spectra from the front and back side indicates that the porous silicon anodization process has a natural drift along the growth direction. However, we demonstrate that this drift can be compensated, showing a homogeneous structure of ten coupled microcavities, in which all ten resonance peaks are resolved in both transmission and reflection measurements. (C) 2003 American Institute of Physics.