Photonic molecules defined by SU-8 photoresist strips on a photonic crystal waveguide

We present experimental and numerical investigations of photonic molecules obtained from laser patterned SU-8 photoresist strips on photonic crystal waveguides. Properties of cavities defined by a single strip are investigated and we show that two adjacent strips on a waveguide form a pair of optically coupled cavities. Simulation results and micro-photoluminescence mapping measurements demonstrate that the coupling strength is tunable by controlling the separation between the strips. Confocal mapping with decoupled collection and excitation points is used to explicitly show coupling between two cavities of a photonic molecule.