  We design photonic structures embedding different functional molecular
systems of photochromic switching and lasing. We study the light absorption of
two photochromic molecules and of 4,4'-bis[(N-carbazole)styryl]biphenyl
(BSB-Cz) with density functional theory. For the photochromic diarylethene we
derivate the refractive index with Kramers-Kronig relations and we design
multilayer photonic structures alternating diarylethene with either poly vinyl
carbazole or fluorine indium co-doped cadmium oxide (FICO) nanoparticlebased
layers. For BSB-Cz we design a one-dimensional photonic crystal alternating
BSB-Cz layers with $SiO_{2}$ layers and a microcavity embedding BSB-Cz between
indium tin oxide (ITO) / FICO nanoparticle-based multilayers.
