233 research outputs found
Quantum dot-cavity strong-coupling regime measured through coherent reflection spectroscopy in a very high-Q micropillar
We report on the coherent reflection spectroscopy of a high-quality factor
micropillar, in the strong coupling regime with a single InGaAs annealed
quantum dot. The absolute reflectivity measurement is used to study the
characteristics of our device at low and high excitation power. The strong
coupling is obtained with a g=16 \mueV coupling strength in a 7.3\mum diameter
micropillar, with a cavity spectral width kappa=20.5 \mueV (Q=65 000). The
factor of merit of the strong-coupling regime, 4g/kappa=3, is the current
state-of-the-art for a quantum dot-micropillar system
Noise investigation of a dual-frequency VECSEL for application to Cesium clocks
We theoretically and experimentally study the noise of a class-A
dual-frequency vertical external cavity surface emitting laser operating at
Cesium clock wavelength. The intensity noises of the two orthogonally polarized
modes and the phase noise of their beatnote are investigated. The intensity
noises of the two modes and their correlations are well predicted by a theory
based on coupled rate equations. The phase noise of the beatnote is well
described by considering both thermal effects and the effect of phase-amplitude
coupling. The good agreement between theory and experiment indicates possible
ways to further decrease the laser noises
Spatiotemporal chaos induces extreme events in an extended microcavity laser
Extreme events such as rogue wave in optics and fluids are often associated
with the merging dynamics of coherent structures. We present experimental and
numerical results on the physics of extreme events appearance in a spatially
extended semiconductor microcavity laser with intracavity saturable absorber.
This system can display deterministic irregular dynamics only thanks to spatial
coupling through diffraction of light. We have identified parameter regions
where extreme events are encountered and established the origin of this
dynamics in the emergence of deterministic spatiotemporal chaos, through the
correspondence between the proportion of extreme events and the dimension of
the strange attractor
Ultra-low threshold polariton lasing in photonic crystal cavities
The authors show clear experimental evidence of lasing of exciton polaritons
confined in L3 photonic crystal cavities. The samples are based on an InP
membrane in air containing five InAsP quantum wells. Polariton lasing is
observed with thresholds as low as 120 nW, below the Mott transition, while
conventional photon lasing is observed for a pumping power one to three orders
of magnitude higher.Comment: 4 pages, 3 figure
Fully-correlated pumping for dual-frequency VECSELs dedicated to cesium CPT clocks
We report a fully-correlated multi-mode pumping architecture optimized for
dramatic noise reduction of a class-A dual-frequency Vertical External Cavity
Surface Emitting Laser (VECSEL). Thanks to amplitude division of a laser diode,
the two orthogonally polarized modes emitted by the VECSEL oscillating at 852
nm are separately pumped by two beams exhibiting fully in--phase correlated
intensity noises. This is shown to lead to very strong and in-phase
correlations between the two lasing modes intensities. As a result, the phase
noise power spectral density of the RF beat note generated by the two modes
undergoes a drastic reduction of about 10 to 20 dB throughout the whole
frequency range from 10 kHz to 20 MHz and falls below the detection floor above
a few MHz. A good agreement is found with a model which uses the framework of
rate equations coupled by cross--saturation. The remaining phase noise is
attributed to thermal effects and additional technical noises and lies mainly
within the bandwidth of a phase-locked-loop
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