Search results for "Silicon"
showing 10 items of 1391 documents
Nanobox array for silicon-on-insulator luminescence enhancement at room temperature
2006
We report the light extraction enhancement obtained at room temperature from a square lattice of crystalline silicon nanoboxes etched in a silicon-on-insulator substrate. Luminescence spectra recorded under optical pumping show a 125 times emission enhancement as compared with the reference unpatterned silicon-on-insulator emission. In light of band diagram calculations, it is demonstrated that the emission enhancement partially results from the coupling between electron-hole recombination inside the silicon boxes and low group velocity optical modes of the array. Moreover, it is observed that these modes present different decoupling lengths and that a complete extraction of luminescence ca…
Si and Si-rich silicon-nitride waveguides for optical transmissions and nonlinear applications around 2 µm
2019
We show that cm-long silicon and silicon-rich silicon nitride waveguides with subwavelength transverse dimensions can efficiently sustain high-speed transmissions at 2 μm. We report the transmission of a 10 Gbit/s signal with negligible power penalty. Parametric conversion in both continuous and pulsed pump regimes is also demonstrated, as well as the spectral broadening of picosecond pulses.
Bloch mode coupling investigation in silicon-on-insulator W1 photonic crystal waveguide
2004
We report in this paper the study of a W1 photonic crystal waveguide which supports two Bloch modes having different parity. A monomode ridge waveguide etched in a Silicon-On-Insulator substrate and connecting to the photonic crystal waveguide allows us to excite the even Bloch mode. Transmission measurements, performed on a broad spectral range, evidence the even mode propagation along the defect line and experimental spectrum is discussed in light of band diagram and FDTD calculations. Then spectrally resolved near-field patterns obtained by using a scanning near field optical microscope in collection mode for wavelengths inside and outside the multimode region of the photonic crystal wav…
Near-field control of optical bistability in a nanocavity
2009
Micro- and nanocavities allow for strong light confinement in very small volume [1]. They give opportunities for new experiments such as cavity quantum electrodynamics, waveguiding, light slowing or trapping…[2] The increase of the electromagnetic (EM) field in the cavity enhances the interaction between light and matter, resulting in the possible observation of nonlinear effects [3]. Several studies have recently been published on the observation and characterisation of nonlinear silicon cavities [4]. As a step further, we propose and demonstrate the feasibility of an innovative way to mechanically control the bistable operating regime of a nanovavity. Using a near-field tip, we switch the…
Data Transmissions at 1.98 µm in cm-long SiGe Waveguides
2017
International audience; We demonstrate an error-free transmission of 10-Gbit/s optical signals along a SiGe waveguide at a wavelength of 1.98 μm. Bit error rate measurements confirm the absence of penalty during the transmission through a 2.5-cm long waveguide having a width of 2.2 μm.
Integrated low drive voltage electro-optic Bragg modulator using a, periodically poled lithium niobate
2017
Periodically poled lithium niobate (PPLN) is currently used for frequency conversions using quasi-phase-matching, thanks to its high nonlinear coefficients and mature poling process. PPLN can also be attractive for electro-optic (EO) applications. Several studies have been conducted on PPLN-based EO deflectors, and recent realizations have lower the required applied voltage under hundred volts [1]. Indeed, for practical EO applications drive voltages as low as 5 V are usually required. For this purpose, we use a recent technique to realize high-quality isolated crystalline film out of LN [2] to implement an EO Bragg deflector with a drive voltage below 10 V. In this work we present an effic…
Demonstration of a reef knot microfiber resonator.
2009
We propose a new way to realize a microfiber optical resonator by implementing the topology of a reef knot using two microfibers. We describe how this structure, which includes 4 ports and can serve as an add-drop filter, can be fabricated. Resonances in an all-silica reef knot are measured and good fits are obtained from a simple resonator model. We also show the feasibility of assembling a hybrid silica-chalcogenide reef knot structure.
Substitutional carbon defects in silicon: A quantum mechanical characterization through the infrared and Raman spectra
2020
EUROfusion Enabling Research Project, Grant/Award Number: ENR‐MFE19.ISSP‐UL‐02; GENCI, Grant/Award Number: 2018‐[A0050810537] (Ph. D'Arco) Access to the HPC resources of CINES/IDRIS/TGCC obtained thanks to the grant 2018-[A0050810537]
Photonic crystal intermediate reflector in micromorph tandem solar cells
2011
Experimental and numerical evidences are presented which show that the efficiency of silicon based tandem solar-cells can be increased by incorporating a three-dimensional photonic crystal as an intermediate reflector.
Changes in surface stress, morphology and chemical composition of silica and silicon nitride surfaces during the etching by gaseous HF acid
2007
International audience; HF acid attack of SiO2 and Si3N4 substrates is analyzed to improve the sensitivity of a sensor based on inicrocantilever. Ex situ analysis of the etching using XPS, SIMS and AFM show significant changes in the anisotropy and the rate of the etching of the oxides on SiO2 and Si3N4 surface. Those differences influence the kinetic evolution of the plastic bending deflection of the cantilever coated with SiO2 and Si3N4 layer, respectively. The linear dependence between the HF concentration and the Si3N4 cantilever bending corresponds to a deep attack of the layer whereas the nonlinear behavior observed for SiO2 layer can be explained by a combination of deep and lateral …