DOYENNETTE , Laetitia

Excitons in nitride quantum wells (QWs) are naturally indirect due to the strong internal electric field: electron and hole within such excitons are spatially separated, leading to strong dipole moments and long radiative lifetimes. The physics of indirect excitons (IXs) has been extensively studied in GaAs-based heterostructures: they can...

Excitons in wide nitride Quantum Wells (QWs) are naturally indirect due to the strong internal electric field: within such excitons the electron and the hole are spatially separated, resulting in strong dipole moments and long radiative lifetimes. These properties offer the possibility to explore the collective exitonic phases with complex...

Excitons in nitride quantum wells (QWs) are naturally indirect due to the strong built-in electric field: electron and hole within such excitons are spatially separated, leading to strong dipole moments and long radiative lifetimes. The physics of indirect excitons (IXs) has been extensively studied in GaAs-based heterostructures: they can...

The slab waveguide geometry is attracting more and more interest in the field of polaritonics. Waveguide polaritons are obtained when an excitonic transition and a slab guided mode are brought in the strong coupling regime, in strong analogy with cavity polaritons in Fabry-Perot resonators. Waveguide polaritons have been first demonstrated in...

Exciton-photon coupling in a waveguide geometry is attracting more and more interest in the field of polaritonics. Waveguide polaritons are obtained when the exciton and the guided mode of a photonic waveguide are brought in the strong coupling regime, in strong analogy with cavity polaritons in Fabry-Perot resonators. One of the first...

We experimentally demonstrate the difference between a ridge polariton laser and a conventional edge-emitting ridge laser operating under electron-hole population inversion. The horizontal laser cavities are 20-60µm long GaN etched ridge structures with vertical Bragg refectors. We investigatethe laser threshold under optical pumping and assess...

Following the demonstration of polariton lasing in GaN ridge polariton lasers [1,2], the polaritonic analog to conventional semiconductor diode lasers, we here analyse and model the laser dynamics in the interesting case of waveguide polaritons. The laser cavities are GaN etched ridge structures with DBRs operating under strong coupling [3] up...

Low-threshold lasing under pulsed optical pumping is demonstrated at room temperature for III-nitride microdisks with InGaN/GaN quantum wells on Si in the blue spectral range. Thresholds in the range of 18 kW/cm 2 have been achieved along with narrow linewidths of 0.07 nm and a large peak to background dynamic of 300. We compare this threshold...

On-chip microlaser sources in the blue constitute an important building block for complex integrated photonic circuits on silicon. We have developed photonic circuits operating in the blue spectral range based on microdisks and bus waveguides in III-nitride on silicon. We report on the interplay between microdisk-waveguide coupling and its...

We investigate the demonstration and quantification of the strong coupling between excitons and guided photons in a GaN slab waveguide. The dispersions of waveguide polaritons are measured from T = 6 to 300 K through gratings. They are carefully analyzed within four models based on different assumptions, in order to assess the strong-coupling...

The waveguide geometry is a new playground for the physics of polariton fluids. The exciton and guided photons can be brought to the strong coupling regime, in analogy with vertical microcavities. The low waveguide losses allow for long propagation distances, up to hundreds of microns. Recent achievements with waveguide polaritons include the...

The polariton emission in a microcavity is usually measured from the surface, and little is known about the actual role of guided modes below the light cone in air; these can couple to the exciton transition and give rise to additional polaritons branches, creating thereby a polaritons leak channel, and can further collect part of the...

Ultraviolet microdisk lasers are integrated monolithi-cally into photonic circuits using a III-nitride on silicon platform with gallium nitride (GaN) as the main waveguiding layer. The photonic circuits consist of a microdisk and a pulley waveguide terminated by out-coupling gratings. We measure quality factors up to 3500 under continuous-wave...

The main interest of group-III-nitride nanophotonic circuits is the integration of active structures and laser sources. A photonic platform of group-III-nitride microdisk lasers integrated on silicon and emitting in the blue spectral range is demonstrated. The active microdisks are side-coupled to suspended bus waveguides, and the coupled...

Nanophotonic circuits using group III-nitrides on silicon are still lacking one key component: efficient electrical injection. In this paper we demonstrate an electrical injection scheme using a metal microbridge contact in thin III-nitride on silicon mushroom-type microrings that is compatible with integrated nanophotonic circuits with the...

For our last research, we concentrated our studies on the quality factor and the room temperature lasing threshold of microdisk cavities. But, electrical injection requires an improved device configuration in order to reduce losses which are intrinsically higher compared to optical pumping. The gain-loss problematic is the key point to achieve...

The integration of nitride semiconductors on a silicon platform is a very promising field for nanophotonic applications in the UV-blue spectral range. Efficient sources are a main topic that can be achieved by compact microlasers based on GaN/AlN and InGaN/GaN multiple quantum wells (MQW) grown on a silicon substrate. The epitaxy of these...