Search results for "2021"
showing 10 items of 516 documents
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 …
Self-Optimising Breather Ultrafast Fibre Laser
2021
We demonstrate the self-optimisation of the breather regime in an ultrafast fibre laser through an evolutionary algorithm. Depending on the specified merit function, single breathers with controllable breathing ratio and period, and breather molecular complexes with a controllable number of constituents can be obtained.
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.
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.
Offsetting Self-Phase Modulation in Optical Fibre by Sinusoidally Time-Varying Phase
2018
We report on our recent experimental and theoretical results on the use of a sinusoidally time-varying phase to suppress undesirable self-phase modulation of optical pulses propagating in fibre-optic systems.
High-quality 10 and 20 GHz repetition rate optical sources based on the spectral phase tailoring of a temporal sinusoidal phase modulation
2019
International audience; We theoretically introduce and experimentally demonstrate a new approach to generate high-quality, high repetition-rate pulse trains. This method is based on a temporal sinusoidal phase modulation combined with a triangular spectral phase shaping. Experimental results validate the concept at repetition rates of 10 and 20 GHz.
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…
All-optical fiber-based devices for ultrafast amplitude jitter magnification
2012
International audience; We propose two fiber-based architectures that enable the all-optical magnification of ultrafast amplitude fluctuations of picosecond or femtosecond pulse trains. An increase of the fluctuations by more than one order of magnitude is experimentally achieved.
High Order Harmonic Passive Mode-Locking In Double-Clad Fiber Laser
2009
We report passive mode-locking of a soliton erbium-doped double-clad fiber laser operating at the 322nd harmonic of the fundamental cavity frequency. Repetition rates scalable up to 3 GHz have been obtained with a pulse duration of about 1 ps and a pulse energy of about 18 pJ. The supermode suppression at the 322nd harmonic is better than 25 dB. The dynamics of emergence of this operating regime is also presented revealing a very long timescale.
Mitigation of self-phase modulation by sinusoidally time varying phase
2018
The propagation of intense ultra-short optical pulses in a Kerr medium such as an optical fibre remains a critical issue for many optical systems. This is because the self-phase modulation (SPM) of the propagating pulse usually causes a severe broadening of the pulse spectrum that is typically accompanied by an oscillatory structure. Several strategies have been proposed and successfully deployed to counteract the deleterious effects of SPM in fiber-optic systems, including spatial or temporal scaling to reduce the impact of nonlinearity. Other approaches rely on the exploitation of the peculiar properties of parabolic shaped pulses and self-similar evolution. However, none of these last te…