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We describe a high-resolution, vacuum-ultraviolet spectroscopic technique based on a tunable, narrow-band, VUV, spontaneous anti-Stokes light source. The technique was used to measure the absolute energies of the ls2s ISo states of 3 He... more
Recent advances in the design of high dynamic range (HDR) monitors enable the display of images having a large dynamic range, close to that encountered in the real world. As their usage will increase, we will be confronted with the... more
We present a tone mapping algorithm that is derived from a model of retinal processing. Our approach has two major improvements over existing methods. First, tone mapping is applied directly on the mosaic image captured by the sensor,... more
This note introduces the concept of pre-coherence as a missing structural stage in the standard theory of Bose-Einstein condensation. Current models (Gross-Pitaevskii, Bogoliubov, kinetic and stochastic extensions) lack a theoretical... more
Matrix mechanics describes the spectral emissions of hydrogen gas, but quantum mechanics concerns the emission and absorption of radiation by single atoms. To obtain the spectral emissions of a single hydrogen atom we reformulate matrix... more
A method to extract the complex refractive index of spherical particles from a polydisperse suspension at concentrations where multiple light scattering effects are significant, is presented. The optical constants are estimated from total... more
Optical measurement of fruit quality is challenging due to the presence of a skin around the fruit flesh and the multiple scattering by the structured tissues. To gain insight in the lighttissue interaction, the optical properties of... more
The inversion of multiple-scattered light measurements to extract the optical constant (complex refractive index) is computationally intensive. A significant portion of this time is due to the effort required for computing the single... more
The transformation of circularly polarized Laguerre-Gauss optical vortex beams with topological charge ℓ 1 = focused through a cascade of two identical biaxial crystals along their optical axes is considered. For such an arrangement, the... more
We describe a number of methods that have been pursued to develop superconducting nanowire single-photon detectors (SNSPDs) with attractive overall performance, including three systems that operate with >70% system detection efficiency... more
We measured the optical absorptance of superconducting nanowire single photon detectors. We found that 200-nm-pitch, 50%-fillfactor devices had an average absorptance of 21% for normally-incident front-illumination of 1.55-µm-wavelength... more
A photon-number-resolving detector based on a four-element superconducting nanowire single photon detector is demonstrated to have sub-30-ps resolution in measuring the arrival time of individual photons. This detector can be used to... more
Many-body exciton interactions shape the optoelectronic response of atomically thin transition-metal dichalcogenides, yet optical control of these interactions remains largely unexplored. To date, modulation of exciton–exciton... more
An investigation into the effects of varying levels of chromatic dispersion on a Mode-Locked Laser Diode optical clock recovery process is presented. Results demonstrate that this technique is invariant to input dispersion varying between... more
Circular harmonic expansion-based carrier frequency offset estimation is investigated for optical MQAM communication systems. The proposed method, combined with a gradient-descent algorithm, shows better performance compared to already... more
HAL is a multi-disciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or... more
All-optical nonlinear phase noise reduction using an InP-over-SOI PhC nanocavity is experimentally demonstrated for 20-Gbit/s NRZ-QPSK signals. The phase-preserving intensitylimiting function results in an OSNR penalty reduction of 3.5 dB... more
HAL is a multi-disciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or... more
The use of multiple-quantum-well saturable absorbers in all optical sampling of high repetition rate pulse trains is presented. Measurements of a 40GHz pulse train were made using a device with a response time of 5ps.
HAL is a multi-disciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or... more
HAL is a multi-disciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or... more
We report on a novel quantum well saturable absorber device whose measured response time of 1.5 psec and contrast of at least 4 dB make it suitable for all-optical extinction ratio enhancement at 160 Gbitls.
HAL is a multi-disciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or... more
HAL is a multi-disciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or... more
We demonstrate a fast photodetector (f 3dB > 40GHz) integrated into a high-index contrast photonic crystal platform. Device design, fabrication and characterization are presented.
We present a simple alternative method for the compensation of quadrature imbalance in optical quadrature phase-shift-keying (QPSK) coherent systems. The method is based on the determination and the compensation of the phase mismatch by... more
HAL is a multi-disciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or... more
HAL is a multi-disciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or... more
We report on all-optical wavelength conversion of a 56 Gb/s differential quadrature phase shift keying signal and a 42.7 Gb/s on-off keying signal. Wavelength conversion is based on four-wave mixing effect in a 1 m-long highly nonlinear... more
We report on the investigation of four-wave mixing (FWM) in a long (1.3 mm) dispersion-engineered Gallium Indium Phosphide (GaInP) photonic crystal (PhC) waveguide. A comparison with a non-engineered design is made with respect to... more
Al 2 O 3 :Er 3+ waveguide amplifier to investigate its potential application in high-speed photonic integrated circuits. Net internal gain of up to 11 dB was measured for a continuous-wave 1532 nm signal under 1480 nm pumping, with a... more
We report on the experimental and theoretical study of a selfphase-modulation-based regenerator at 42.6 Gbit/s with a return-to-zero 33% format. We point out some detrimental effects such as intrachannel interactions and Brillouin... more
We numerically investigate the 2R-regeneration technique utilizing self-phase modulation and off-center filtering. Our numerical simulations take into account the incoherent nature of noise through its spectral representation. This... more
In this work, we numerically investigate the performances of optical regenerators based on self-phase modulation and spectral offset filtering at 40 Gbit/s. We outline the different effects affecting the device performances and explain... more
We propose and demonstrate a non-destructive method for loss measurement in optical guided structures. In the proposed approach, the device under test does not require connectors at its ends, thus making this technique available for both... more
HAL is a multi-disciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or... more
HAL is a multi-disciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or... more
We report on the use of an InP/SOI hybrid photonic crystal nanocavity for the realization of a phase-preserving alloptical power limiter. This function is experimentally demonstrated with 20-Gbit/s NRZ-QPSK signals. Histogrambased... more
HAL is a multi-disciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or... more
HAL is a multi-disciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or... more
We report on the impact of the sampling-source extinction ratio (ER) in a linear optical sampling system. To this effect, an analytical model is developed and contrasted with experimental data and numerical simulation, to determine the... more
HAL is a multi-disciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or... more
Absorber (SA). The 1 potential of the device to perform WDM regeneration is firstly demonstrated through the first pigtailed saturable absorber chip implemented with 8 independent fibres using a cost effective coupling technique. The... more
A quantum dash Fabry-Perot actively mode locked laser module is tested as part of a 42.7 Gbit/s transmitter with more than 10 nm wavelength tunability. Its low chirp level is also assessed through chromatic dispersion tolerance... more
Ultrafast switching with low energies is demonstrated using InP photonic crystal nanocavities embedding InGaAs surface quantum wells heterogeneously integrated to a silicon on insulator waveguide circuitry. Thanks to the engineered... more
We investigate the cascadability of a microcavity-saturable-absorber-based phase-preserving amplitude regenerator for RZ-DPSK signals. The results show that the tolerance of phase-encoded signals to nonlinear phase noise is increased. A... more
There is an important need for improvement in both cost and efficiency of photovoltaic cells. For improved efficiency a better understanding of solar cell performance is required. In this paper we propose an analytical kinetic model of... more