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We present experimental evidence for the different mechanisms driving the fluctuations of the local density of states (LDOS) in disordered photonic systems. We establish a clear link between the microscopic structure of the material and the frequency correlation function of LDOS accessed by a near-field hyperspectral imaging technique. We show, in particular, that short- and long-range frequency correlations of LDOS are controlled by different physical processes (multiple or single scattering processes, respectively) that can be--to some extent--manipulated independently. We also demonstrate that the single scattering contribution to LDOS fluctuations is sensitive to subwavelength features of the material and, in particular, to the correlation length of its dielectric function. Our work paves a way towards complete control of statistical properties of disordered photonic systems, allowing for designing materials with predefined correlations of LDOS. [ABSTRACT FROM AUTHOR]

We employ a far-field analysis of the angular emission pattern to experimentally assess the symmetry of localized modes in coupled photonic-crystal cavities. We demonstrate that the spatial distribution of localized modes in photonic-crystal nanocavities may change from a bonding to an antibonding orbital, a feature that is unusual in quantum mechanical coupled systems. Experimental data are confirmed by numerical calculations and interpreted in terms of the peculiar oscillatory behavior of the evanescent waves in photonic-crystal band gaps. [ABSTRACT FROM AUTHOR]

A revisited realization of the Young's double slit experiment is introduced to directly probe the photonic mode symmetry by photoluminescence experiments. We experimentally measure the far field angular emission pattern of quantum dots embedded in photonic molecules. The experimental data well agree with predictions from Young's interference and numerical simulations. Moreover, the vectorial nature of photonic eigenmodes results in a rather complicated parity property for different polarizations, a feature which has no counterpart in quantum mechanics.

We demonstrate the nonresonant magnetic interaction at optical frequencies between a photonic crystal microcavity and a metallized near-field microscopy probe. This interaction can be used to map and control the magnetic component of the microcavity modes. The metal coated tip acts as a microscopic conductive ring, which induces a magnetic response opposite to the inducing magnetic field. The resulting shift in resonance frequency can be used to measure the distribution of the magnetic field intensity of the photonic structure and fine-tune its optical response via the magnetic field components.

We report on the realization of a rewritable and local source inside a Si-based photonic crystal microcavity by infiltrating a solution of colloidal PbS quantum dots inside a single pore of the structure. We show that the resulting spontaneous emission from the source is both spatially and spectrally redistributed due to the mode structure of the photonic crystal cavity. The coupling of the quantum dot emission to the cavity mode is analyzed by mapping the luminescence signal of the infiltrated solution with a scanning near-field optical microscope at room temperature. Spectral characterization and the mode profile are in good agreement with a three-dimensional numerical calculation of the system.

We produce a quantum degenerate mixture composed by two Bose-Einstein condensates of different atomic species, 41K and 87Rb. We study the dynamics of the superfluid system in an elongated magnetic trap, where off-axis collisions between the two interacting condensates induce scissorlike oscillations.

We report on the achievement of simultaneous quantum degeneracy in a mixed gas of fermionic 40K and bosonic 87Rb. Potassium is cooled to 0.3 times the Fermi temperature by means of an efficient thermalization with evaporatively cooled rubidium. Direct measurement of the collisional cross-section confirms a large interspecies attraction. This interaction is shown to affect the expansion of the Bose-Einstein condensate released from the magnetic trap, where it is immersed in the Fermi sea.