Tunable homo- and hetero-atomic photonic molecules

We report on the achievement of a continuously tunable photonic molecule from an homoatomic to an heteroatomic condition. A complete control of the local mode tuning of two nominally identical photonic crystal microcavities on slab is obtained by a combination of different techniques. Homoatomic molecules are obtained by compensating the photonic disorder up to the standard condition of zero detuning between identical modes of the two cavities. Heteroatomic molecules are then realized by a large tuning of one of the two cavities, producing the condition of zero detuning between two modes of different polarization and spatial distribution. Clear modes anticrossing and hybridization is observed.