Efficient coupling of nanoemitters to photonic or plasmonic structures requires the control of the orientation of the emitting dipoles. Nevertheless controlling the dipole orientation remains an experimental challenge. Many experiments rely on the realization of numerous samples, in order to be able to statistically get a well aligned dipole to realize an efficient coupling to a nanostructure. In order to avoid these statistical trials, the knowledge of the nature of the emitter and its orientation is crucial for a deterministical approach. We developed a method , relying on the combination of polarimetric measurement and emission diagram which gives fine information both on the emitting dipolar transition involved and on the dipolar orientation
We analyse by this method square and rectangle single colloidal CdSe/CdS nanoplatetelets. We demonstrate that their emission can be described by just by two orthogonal dipoles lying in the plane of the platelets. More surprisingly the emission of the square nanoplatelets is not polarised whereas the rectangle one is. We demonstrate that this polarized emission is due to the rectangular shape anisotropy by a dielectric effect.
 C. Lethiec, et al, Three-dimensional orientation measurement of a single fluorescent nanoemitter by polarization analysis, Phys. Rev. X 4, 021037 (2014),
 C. Lethiec et al, Polarimetry-based analysis of dipolar transitions of single colloidal CdSe/CdS dot-inrods, New Journal of Physics 16, 093014 (2014)
 S. Ithurria et al, colloidal nanoplatelets with 2 dimensional electronic structure, Nature Materials 10, 936 (2011)
Plasmonic nano-antennas provide broadband spontaneous emission control by confining light on highly sub-wavelength volumes. We realize a plasmonic patch antenna by positioning a emitter within a ultrathin slab of dielectric limited by an optically thick gold layer and a thin gold patch. A single CdSe/CdS colloidal quantum dot is deterministically located just in the center of the antenna by an original in situ optical lithography protocol . Depending on the dimension of the patch antenna and the emitter orientation, different Purcell factors could be achieved leading to different optical properties. For moderate Purcell factors, patch nanoantennas are plasmonic directive single photon sources. For higher Purcell factors, the spontaneous emission acceleration makes the multiexciton radiative recombination more efficient than Auger non radiative recombination. Emission of photons due to multiexcitons recombination could be observe at very short time scale. Such antennas can be very efficiently excited. Such antenna appear to be extremely bright as their luminescence exceed by more than one order of magnitude the one of single nanocrystals.
 Dousse, A. et al. Controlled light-matter coupling for a single quantum dot embedded in a pillar microcavity using far-field optical lithography. Phys. Rev. Lett. 101, 267404 (2008).
 C. Belacel, B. Habert, F. Bigourdan, F. Marquier, J-P. Hugonin, S. Michaelis de Vasconcellos, X. Lafosse, L. Coolen, C. Schwob, C. Javaux, B. Dubertret, J-J. Greffet, P. Senellart, A. Maître, Controlling spontaneous emission with plasmonic optical patch antennas, Nanoletters 13 1516 (2013)
As they allow the control of light propagation, photonic crystals find many fields of application. Among them, self-assembled 3D-photonic crystals are ordered at the nanometric scale over centrimetric areas. Furthermore, self-assembly allows the design of complexes structures leading, for example, to the controlled disruption of the crystal periodicity (called defect) and the appearance of permitted optical frequency bands within the photonic bandgap. Light frequencies included in the corresponding passband are then localized in the defect allowing manipulation of nano-emitters fluorescence. We present the fabrication and the optical characterization of a heterostructure composed of a sputtered silica layer sandwiched between two silica opals. We show by photoluminescence measurements than this structure strongly modifies the transmitted fluorescence of nanocrystals.
Efficient coupling of nanoemitters to photonic or plasmonic structures requires the control of the orientation of the
emitting dipoles related to the emitter. Nevertheless the knowledge of the dipole orientation remains an experimental
challenge. Many experiments rely on the realization of large sets of samples, in order to be able to get one nanostructure
coupled to a well aligned dipole. In order to avoid these statistical trials, the knowledge of the nature of the emitter
(single or double dipole) and its orientation are both crucial for a deterministic approach. Based on the theoretical
development of the point-dipole emission, we propose in this paper to determine the nature and the polarization of two
types of nanoemitters (spherical nanocrystals and dot-in-rod) by the analysis of their emission polarization [1,2]. The
nanoemitters we considered in this study are colloidal semiconductor (CdSe/CdS) nanocrystals with different sizes and
aspect ratio, allowing us to establish a relationship between the geometry of a nanoemitter and the nature and orientation
of its associated radiating dipole.
The visibility and quality of optical images is ultimately limited not by diffraction but by the quantum noise affecting each pixel of a detector. Multimode non-classical states of light, characterized by spatial quantum correlation or local reduced quantum noise, permit in principle to go beyond the standard quantum limit and therefore to improve transverse optical resolution. It has been predicted that Optical Parametric Oscillators (OPO) operating simultaneously on many transverse modes are good candidates for generating multimode non-classical states of light. We perform an experiment showing that a c.w. confocal OPO above threshold emits such states. Below threshold, the OPO is turned to a multimode optical parametric amplifier.
The quantum nature of light imposes a limit to the detection of all properties of a laser beam. We show how we can reduce this limit for a measurement of the position of a light beam on a quadrant detector, simultaneously in two tranverse directions. This quantum laser pointer can measure the beam direction with greater precision than a usual laser. We achieve this by combining three beams, one intense coherent and two vacuum squeeezed beams, with minimum losses into one spatially multimode beam optimized for this application.