Search results for "POLARIZATION"
showing 10 items of 1884 documents
Record Phase Sensitive Extinction Ratio in a Silicon Germanium Waveguide
2015
A binary step-like phase response and phase-sensitive extinction ratio in excess of 28dB under CW pump operation was demonstrated in a 20mm-long low birefringence SiGe waveguide, using a polarization-assisted phase sensitive amplifier scheme.
Optical Imaging and Spectroscopy of Atomically Precise Armchair Graphene Nanoribbons
2019
We report the optical imaging and absorption spectroscopy on atomically precise armchair graphene nanoribbons (GNRs) on insulating fused silica substrates. This is achieved by controlling light polarization on macroscopically aligned GNRs which greatly enhances the optical contrast of the submonolayer GNRs on the insulating substrates. We measure the linear absorption spectra of 7-armchair and 9-armchair GNRs in this study, and the experimental data agree qualitatively with ab inito calculation results. The polarization spectroscopy technique enables an unambiguous optical identification of GNRs and provides a rapid tool to characterize the transferred film over a large area.
Experimental evidence of Brillouin-induced polarization wheeling in highly birefringent optical fibers
2009
International audience; We study the influence of Stimulated Brillouin Scattering on the polarization stabilization of a light beam propagating in a highly-birefringent optical fiber. In particular, due to a saturation effect, we find that the output polarization lies on a ring when the polarization is represented onto the Poincaré sphere.
Generation and characterization of 06-THz polarization domain-wall trains in an ultralow-birefringence spun fiber
2007
Polarization domain-wall (PDW) trains have been generated at a repetition rate of 0.6 THz in an ultralow-birefringence spun optical fiber and measured by use of an adapted frequency-resolved optical gating technique. Characterization of the intensity and the phase of the PDW train shows complete switching between adjacent domains of counterrotating circular polarizations and directly confirms predictions based on numerical simulations of the incoherently coupled nonlinear Schrödinger equations.
Managing Group and Phase Birefringence for Nonlinear Optics in Photonic Crystal Fibers
2006
A novel design of birefringent photonic crystal fibers with stress applying parts permits to manage the wavelength dependence of group and phase birefringence. Applications to vector frequency conversion and soliton polarization instabilities are discussed.
Linear and nonlinear fiber propagation of partially coherent fields exhibiting temporal correlations
2019
International audience; Using ultrafast photonic first-order differentiator applied on a partially coherent field, we report the generation of two correlated temporal waveforms and study their correlation properties upon linear and nonlinear propagation along the two orthogonal polarization axis of a dispersive optical fiber. Temporal correlations are maintained in linear propagation whereas Kerr nonlinearity generates anti-correlated temporal intensity patterns for both partially and uncorrelated fields. Experiments are in close agreement with the theoretical analysis.
Demonstration of polarization pulling using a fiber-optic parametric amplifier
2012
International audience; We report the observation of all-optical polarization pulling of an initially polarization-scrambled signal using parametric amplification in a highly nonlinear optical fiber. Broadband polarization pulling has been achieved both for the signal and idler waves with up to 25 dB gain using the strong polarization sensitivity of parametric amplifiers. We further derive the probability distribution function for the final polarization state, assuming a randomly polarized initial state, and we show that it agrees well with the experiments.
Demonstration of Stimulated-Raman-scattering suppression in optical fibers in a multifrequency pumping configuration
1999
International audience; We analyze the stimulated-Raman-scattering-(SRS) process induced by a linearly polarized multifrequency pump field in a normally dispersive single-mode fiber. We show, by theoretical analysis and numerical simulations, that the SRS process may be either controlled by switching all the generated Stokes radiations to the lowest-frequency pump or suppressed for all the frequency components of the pump field. The suppression process is achieved by an appropriate choice of the frequency separation between the pumps and a particular power distribution among the frequency components of the pump field. We present experimental spectra showing the effectiveness of this suppres…
phase-locked soliton pairs in a fiber ring laser
2002
We have experimentally observed the formation of stable pulse pairs with a π/2 phase difference in a passively mode-locked stretched-pulse fiber ring laser. We have developed a simplified theoretical model that, keeping the essential features of the experiment, reduces greatly the number of free parameters and solved it numerically. The agreement with the experimental results is excellent.
Fiber-based measurement of temporal intensity and phase profiles of an optical telecommunication pulse through self-phase modulation
2018
International audience; We propose and experimentally validate an all-fiber based approach to characterize the phase and intensity profiles of optical pulses. Based on three optical spectra affected by different levels of self-phase modulation, we were able to reconstruct the temporal details of pulses typical of optical telecommunications.