Optical sensing based on phase interrogation with a Young's interference hologram using a digital micromirror device.

We propose a new holographic interferometric technique of phase interrogation for nanophotonic sensors, allowing to reach low phase noise and fluctuation by using a digital micromirror device spatial light modulator. With the spatial light modulator, both beam shaping and phase shifting interferometry can be simultaneously managed, hence enabling the interrogation of nanophotonic devices with a common-path heterodyne Young's interference experiment. The efficiency of the technique is illustrated in the particular case of temperature sensing using Tamm plasmon photonic crystals. The hologram sensor allows to probe resonant structures with deep attenuation at resonance, such as resonant structures at critical coupling or with phase singularities.

Polariton condensation in photonic molecules.

We report on polariton condensation in photonic molecules formed by two coupled micropillars. We show that the condensation process is strongly affected by the interaction with the cloud of uncondensed excitons and thus strongly depends on the exact localization of these excitons within the molecule. Under symmetric excitation conditions, condensation is triggered on both binding and antibinding polariton states of the molecule. On the opposite, when the excitonic cloud is injected in one of the two pillars, condensation on a metastable state is observed and a total transfer of the condensate into one of the micropillars can be achieved. Our results highlight the crucial role played by relaxation kinetics in the condensation process.

Interactions in confined polariton condensates.

We investigate the effect of interactions in zero-dimensional polariton condensates. The shape of the condensate wave function is shown to be modified by repulsive interactions with the reservoir of uncondensed excitons. In large micropillar cavities, when uncondensed excitons are located at the center, the condensate is ejected toward the pillar edges. The same effect results in the generation of optical traps in wire cavities. Once polariton condensates are spatially separated from the excitonic reservoir, spectral signatures of polariton-polariton interactions within the condensate are evidenced.

Surface emitting microlaser based on 2D photonic crystal rod lattices.

2D photonic crystal (2D PC) structures consisting in a square lattice of Indium Phosphide (InP) microrods bonded on a Silicon/Silica Bragg mirror are experimentally investigated. We focus on slow Bloch modes above the light line, especially at the Gamma-point where a vertical emission can be obtained. Stimulated emission around 1.5 microm is demonstrated in such structures, at room temperature, for the first time. In addition the achieved threshold power lies within the range reported for surface emitting devices based on conventional lattices of holes. It is shown that the laser mode is laterally confined by a carrier induced refractive index change, under pulsed excitation. It is also demonstrated that this type of 2D PC is well suited for sensors integrated in microfluidic systems.