  A systematic method to fabricate porous silicon one dimensional photonic
crystals has been engineered to have a photonic bandwidth up to 2000nm. The
observation of the tailorability of the photonic bandgap (PBG) underscores the
requirement of the large refractive index contrast for making broad PBG
structures. In this letter, we present the fabrication and characteristics of
such structures that may be promising structures for a large variety of
applications.
