Photonic Crystals are considered to day as the « must » for the ultimate control of light in spatial and spectral domains (trapping of light in the photonic band gap regime, slowing down of photons in the slow Bloch mode regime). This seminar concentrates on two dimensional Photonic Crystals (2DPC): it is shown that they provide unmatched tools for the ultimate engineering of electromagnetic field which is required in nanophotonic devices of quantum information. Special emphasis is put on devices where light control is provided by slow Bloch mode confinement scheme.