Fabrication and tuning of high quality porous silicon microcavities

We have made a number of high quality porous silicon microcavities operating in the visible and near infrared regions with a FWHM of less than 2 nm. This is achieved through the low temperature anodic oxidation of highly doped p-type silicon wafers. Reduced interface fluctuations and very large porosity modulations are responsible for the improvement of the quality of the optical structure. We have also demonstrated thermally induced, post-fabrication tuning of the cavity resonance, which leads to non-permanent and repeatable changes in the cavity mode.