Coupled-resonator optical waveguides doped with nanocrystals

Microsphere resonators doped with semiconductor nanocrystals are explored as building blocks for coupled-resonator optical waveguides (CROWs). The evolution of individual cavity modes into coherently coupled waveguide modes is studied using polarization-sensitive microphotoluminescence spectroscopy. To demonstrate the formation of multisphere photon states, we use a bent linear array of microresonators and probe the properties of the cavity photon field by the spatially and spectrally resolved measurement of the nanocrystal emission. Photon mode coupling is evidenced by the observed mode splitting and emission intensity distributions along the CROW structure.