  In this work we identify and study the presence of extremely intense surface
resonances that frustrate the coupling of photons into a photonic crystal over
crucial energy ranges. The practical utility of photonic crystals demands the
capability to exchange photons with the external medium, therefore, it is
essential to understand the cause of these surface resonances and a route to
their elimination. We demonstrate that by modifying the surface geometry it is
possible to tune the optical response or eliminate the resonances to enable
full exploitation of the photonic crystal.
