Search results for "Shaping"
showing 10 items of 128 documents
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.
Transition dynamics in optical fiber amplifiers operating in the normal dispersion regime
2011
Over the past decade there has been large interest in ultrafast optical fiber amplifiers operating in the normal dispersion regime because of the discovery that, high-energy pulses with a parabolic intensity profile and linear frequency chirp are the asymptotic solution to the system for arbitrary initial conditions [1]. These so-called “similariton” solutions propagate in a self-similar manner, holding certain relations (scaling) between pulse power, duration, and chirp parameter. While the asymptotic similariton features seem now well understood [1], the physics of the transition to this solution from arbitrary initial pulses has not been fully explored yet (most of the previous attempts …
Spectral phase reconstruction of femtosecond laser pulse from interferometric autocorrelation and evolutionary algorithm
2021
International audience; We report on the complete temporal characterization of femtosecond laser pulses from second-order interferometric autocorrelation and laser spectrum measurements. The method exploits a newly developed autocorrelator based on a two photon-absorption signal produced directly within a camera sensor so as to provide a single-shot interferometric autocorrelation of great reliability and robustness. Interferometric autocorrelation trace and laser spectrum are exploited for a spectral phase retrieval via an evolutionary algorithm. The quality of the reconstruction for highly modulated spectral phases imprinted by a pulse shaper confirms the reliability of the method. The au…
Nonlinear Sculpturing of Optical Pulses in Fibre Systems
2019
The interplay among the effects of dispersion, nonlinearity and gain/loss in optical fibre systems can be efficiently used to shape the pulses and manipulate and control the light dynamics and, hence, lead to different pulse-shaping regimes [1,2]. However, achieving a precise waveform with various prescribed characteristics is a complex issue that requires careful choice of the initial pulse conditions and system parameters. The general problem of optimisation towards a target operational regime in a complex multi-parameter space can be intelligently addressed by implementing machine-learning strategies. In this paper, we discuss a novel approach to the characterisation and optimisation of …
Optical waveform tailoring in passive and laser cavity fibre systems
2019
International audience; The interplay among the effects of dispersion, nonlinearity and gain/loss in optical fibres is a powerful tool to generate a broad range of pulse shapes with tuneable properties. Here we propose a method to optimise the systems parameters for a given pulse target. By reducing the system complexity and applying machine-learning strategies, we show that it is possible to efficiently identify the sets of parameters of interest. Two configurations are numerically investigated: pulse shaping in a passive normally dispersive fibre and pulse generation in a dual-pump nonlinear-amplifying-loop-mirror mode-locked fibre laser.
Parabolic pulse generation and applications
2009
Parabolic pulses in optical fibers have stimulated an increasing number of applications. We review here the physics underlying the generation of such pulses as well as the results obtained in a wide-range of experimental configurations.
Parabolic pulse formation and applications
2009
Parabolic pulses in optical fibers have stimulated an increasing number of applications. We review here the physics underlying the generation of such pulses as well as the results obtained in a wide-range of experimental configurations.
Experimental parabolic pulse generation with an active dispersion decreasing fiber
2008
We experimentally demonstrate the use of an hybrid configuration to generate parabolic pulses. We combine dispersion decrease with distributed gain. This leads to several benefits on the parabolic generated pulses compared with a passive configuration.
Kerr Beam Self-Cleaning in Multimode Fibers
2018
We overview recent experimental results of beam self-cleaning observed in various types of multimode fibers. We analyze the output spatial beam shapes and their connection with the refractive index profile of the fibers.
Nonlinear sculpturing of optical pulses with normally dispersive fiber-based devices
2018
International audience; We present a general method to determine the parameters of nonlinear pulse shaping systems based on pulse propagation in a normally dispersive fiber that are required to achieve the generation of pulses with various specified temporal properties. The nonlinear shaping process is reduced to a numerical optimization problem over a three-dimensional space, where the intersections of different surfaces provide the means to quickly identify the sets of parameters of interest. We also show that the implementation of a machine-learning strategy can efficiently address the multi-parameter optimization problem being studied.