Publications de Romuald Houdré

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Superfluidity, the ability of a quantum fluid to flow without friction, is one of the most spectacular phenomena occurring in degenerate gases of interacting bosons. Since its first discovery in liquid helium-4 (refs 1, 2), superfluidity has been observed ...

A quantum fluid passing an obstacle behaves differently from a classical one. When the flow is slow enough, the quantum gas enters a superfluid regime, and neither whirlpools nor waves form around the obstacle. For higher flow velocities, it has been predi ...

Recently there has been a growing amount of attention devoted to tuneable photonic crystals (PhCs) where the optical response of PhC structures can be dynamically modified. We will show how infiltrating planar PhCs with a synthetic organic material allows ...

The bacterial ecosystem is naturally balanced by viruses known as bacteriophages. Accordingly, they represent an emerging adjuvant to antibiotics to fight bacterial infections. However, the interaction of a single bacterium with bacteriophages remains poor ...

Photonic crystals (PhCs) act on light in two different ways: confinement and modification of propagation. Both phenomena rely on the complex interplay between multiply scattered waves that can form what is known as a Bloch mode. Here, we present a techniqu ...

A convenient approach for slowing down light in integrated optical circuits is by utilizing a set of coupled microcavities in a photonic crystal lattice. While this provides for flexibility in dispersion engineering, light transport is influenced by a comb ...

The authors present a statistical study of residual disorder in nominally identical planar photonic crystal waveguides operating in the slow light regime. The focus is on the role played by the subnanometer scaled residual disorder inherent to state-of-the ...

We show a technique that images the intensity distribution and local state of polarization of the optical field of high-quality factor optical modes confined in dielectric planar photonic crystal nanocavities. Based on energy-loss spectroscopy of swift ele ...

Compact semiconductor light sources with high performance continuous-wave (CW) and single mode operation are highly demanded for many applications in the terahertz (THz) frequency range. Distributed feedback (DFB) and photonic crystal (PhC) quantum cascade ...

Second-harmonic generation in nonlinear materials can be greatly enhanced by realizing doubly resonant cavities with high quality factors. However, fulfilling such doubly resonant condition in photonic crystal (PhC) slab cavities is a long-standing challen ...

In this paper, we present a systematic study of the effect of growth parameters on the structural and optical properties of InAs quantum dot (QD) grown under Stranski-Krastanov mode by molecular beam epitaxy. The dot density is significantly reduced from 1.9x10(10) to 0.6x10(10) cm(-2) as the growth rate decreases from 0.075 to 0.019 ML/s, while the island size becomes larger. Correspondingly, the emission wavelength shifts to the longer side. By increasing the indium fraction in the InGaAs capping layer, t

We report on nonlinear frequency conversion from the telecom range via second harmonic generation (SHG) and third harmonic generation (THG) in suspended gallium nitride slab photonic crystal (PhC) cavities on silicon, under continuous-wave resonant excitat ...

We retrieve the dispersion properties of photonic crystal waveguides near the band edge with high experimental accuracy. The dispersion diagram of the waveguide modes in the complex-valued plane is directly measured in the far ﬁeld by using a Fourier space ...

The phenomenological approach introduced by Benisty et al. [Appl. Phys. Lett. 76, 532 (2000)] to model out-of-plane radiation losses in planar photonic crystals with a low vertical refractive index contrast is extended to the case of in-plane disorder. The ...

Antimicrobial resistance poses a significant threat to human health. The resistance arises from factors such as natural bacterial mutations and the widespread misuse of antibiotics in both agronomical and medical practices. Traditional antimicrobial suscep ...

Integrated switching devices comprise the building blocks of ultrafast optical signal processing(1,2). As the next stage following intensity switching(1,3,4), circular polarization switches(5-9) are attracting considerable interest because of their applica ...

We present a far-ﬁeld optical technique allowing measurements of the dispersion relation of electromagnetic ﬁelds propagating under the light cone in photonic nanostructures. It relies on the use of a one-dimensional grating to probe the evanescent tail of ...

We report on the experimental investigation of the Floquet-Bloch modes propagation inside photonic crystal (PhC) structures as well as their emission from the structures with far-field optics. We demonstrate that far-field optical experiments can be used t ...

We are progressively approaching the physical limits of microcavity LEDs (MC-LEDs) for high brightness, high efficiency LEDs. They are promising high efficiency devices and they offer the very attractive prospect of full planar fabrication process. However, to compete with other high efficiency LED schemes, they need to approach or surpass the 50 % efficiency mark. We first explore the limits of planar MC-LEDs in both the GaAllnAsP and GaInAlN materials systems, and show that the single-step extraction limi

We demonstrate a resonant optical trapping mechanism based on two-dimensional hollow photonic crystal cavities. This approach benefits simultaneously from the resonant nature and unprecedented field overlap with the trapped specimen. The photonic crystal s ...

Romuald Houdré

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Superfluidity of polaritons in semiconductor microcavities

Polariton Superfluids Reveal Quantum Hydrodynamic Solitons

Tuning the optical properties of planar photonic crystals by liquid crystal infiltration

Monitoring of Single-Cell Bacterial Lysis by Phages Within Integrated Optical Traps

Exploring light propagating in photonic crystals with Fourier optics

Influence of Disorder and Finite-Size Effects on Slow Light Transport in Extended Photonic Crystal Coupled-Cavity Waveguides

Statistical analysis of subnanometer residual disorder in photonic crystal waveguides: Correlation between slow light properties and structural properties

Imaging of high-Q cavity optical modes by electron energy-loss microscopy

Continuous-wave vertically emitting photonic crystal terahertz laser

Doubly resonant second-harmonic generation of a vortex beam from a bound state in the continuum

Tuning InAs/GaAs quantum dot properties under Stranski-Krastanov growth mode for 1.3 mu m applications

Efficient continuous-wave nonlinear frequency conversion in high-Q gallium nitride photonic crystal cavities on silicon

Influence of residual disorder on the anticrossing of Bloch modes probed in k space

Disorder-induced losses in planar photonic crystals

Photonic Crystal Cavities for Ultrafast Antimicrobial Susceptibility Testing at the Single-Bacterium Level

Exciton-polariton spin switches

Grating-assisted superresolution of slow waves in Fourier space

Characterisation of photonic crystal and nanophotonics devices with Fourier optics

Recent results and latest views on microcavity LEDs

Single particle detection, manipulation and analysis with resonant optical trapping in photonic crystals