Search results for "nonlinear optics"
showing 10 items of 482 documents
High-order Kerr nonlinearity of air calibrated with transient molecular alignment
2009
Talk given by O. Faucher; International audience; Nonlinear electronic Kerr index of the major air constituents has been measured up to high order terms using transient molecular alignment as a reference. Sign reversal associated to negative nonlinearity is observed above a pulse intensity of 26 TW/cm^2.
Shaping Light in Nonlinear Optical Fibers
2017
International audience; This book is a contemporary overview of selected topics in fiber optics. It focuses on the latest research results on light wave manipulation using nonlinear optical fibers, with the aim of capturing some of the most innovative developments on this topic. The book’s scope covers both fundamentals and applications from both theoretical and experimental perspectives, with topics including linear and nonlinear effects, pulse propagation phenomena and pulse shaping, solitons and rogue waves, novel optical fibers, supercontinuum generation, polarization management, optical signal processing, fiber lasers, optical wave turbulence, light propagation in disordered fiber medi…
All-fibered high-quality low duty-cycle 160-GHz femtosecond pulse source
2008
International audience; In this paper, we report the experimental demonstration of an all-optical fiber-based 160-GHz femtosecond pulse source exhibiting a duty cycle as low as 1/17. The 380-fs wellseparated Gaussian pulses are generated thanks to the strong temporal compression of an initial beat-signal propagating into three distinct segments of optical fiber. Experimental results are supported by numerical simulations based on the generalized nonlinear Schrödinger equation. (© 2008 by Astro Ltd., Published exclusively by WILEY-VCH Verlag GmbH & Co. KGaA)
Sub-nanosecond nonlinear pulse shaping in microfiber resonators
2009
Thanks to their small size and large index contrast allowing for tight field confinement, optical microfibers are of great interest in nonlinear optics. Their properties have recently been exploited in various devices for supercontinuum generation, pulse compression [1] and third-harmonic generation [2]. Combining field confinement and field enhancement in a loop or knot resonator can result in low-threshold non-linear microfibre devices, in which pulse shaping effects and bistability can be obtained. Such a behaviour has already been observed at a power level of ten milliwatts with millisecond time response, in the case of thermally-induced non-linearity in silica microfibres [3]. In contr…
Parabolic pulse generation through passive reshaping of gaussian pulses in a normally dispersive fiber
2007
We numerically and experimentally demonstrate that a Gaussian pulse can be reshaped into a pulse with a stable parabolic intensity profile during propagation in normally dispersive nonlinear fibers.
Titanium dioxide waveguides for supercontinuum generation and optical transmissions in the near-and mid-infrared
2019
International audience; We report the development of titanium dioxide-based waveguides for applications in the near-and mid-infrared. Thanks to embedded metal grating couplers, we demonstrate error free 10 Gbit/s optical transmissions at 1.55 and 2 µm. With additional management of the dispersion profile, we also demonstrate octave spanning supercontinuum in cm-long TiO2 waveguides.
Slow and fast nonlinearities in microfiber resonators
2008
Nonlinear optical properties of microfiber resonators are investigated. First, a miniature optical resonator standing in air is realized out of a silica microfiber, and measurements of the intensity transfer function show a wide variety of hysteresis cycles obtained at low scanning frequency of the input power. The results are satisfactorily interpreted through the action of thermally-induced nonlinear phase shifts. Secondly, we discuss the conditions under which the fast Kerr nonlinearity can be used efficiently in microfiber resonators under pulsed optical operation.
Nonlinear femtosecond pulse propagation in all-solid photonic bandgap fiber
2009
Nonlinear femtosecond pulse propagation in all-solid photonic bandgap fiber is investigated experimentally and numerically for both the photonic bandgap guiding in the central silica core and the total internal reflection in germanium doped inclusions.
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.
Self-polarization of light in optical fibers
2015
The second performs the first experimental demonstration of the polarization domain walls which cancel the effects which degrade the intensity and spectral profile of a telecom signal during propagation. This phenomenon comes from non-linear coupling between the two orthogonal polarization modes of light propagating in a Kerr medium in normal dispersion regime, and causes a modulation in phase opposition of the two modes along the fiber. It is possible to lock two optical pulse trains complementary intensity so that the pulses do not suffer the effects of distortion occurring in the fiber in order to maintain the information to be transmitted. And a distortion-free propagation was achieved …