Optical Nyquist pulse generation in mode-locked fibre laser
International audience
Robustness of 40 Gb/s ASK modulation formats in the practical system infrastructure.
In this work, we analyzed by means of numerical and laboratory experiments the resilience of 40 Gb/s amplitude shift keying modulation formats to transmission impairments in standard single-mode fiber lines as well as to optical filtering introduced by the optical add/drop multiplexer cascade. Our study is a pre-requisite to assess the implementation of cost-effective 40 Gb/s modulation technology in next generation high bit-rate robust optical transport networks. © 2006 Optical Society of America.
Temporal and Spectral Nonlinear Pulse Shaping Methods in Optical Fibers
The combination of the third-order optical nonlinearity with chromatic dispersion in optical fibers offers an extremely rich variety of possibilities for tailoring the temporal and spectral content of a light signal, depending on the regime of dispersion that is used. Here, we review recent progress on the use of third-order nonlinear processes in optical fibers for pulse shaping in the temporal and spectral domains. Various examples of practical significance will be discussed, spanning fields from the generation of specialized temporal waveforms to the generation of ultrashort pulses, and to stable continuum generation.
Testing and extrapolating the nonlinear robustness of modulation formats
The comparison of the robustness of modulation formats in fiber transmission systems facing nonlinear impairments and noise is carried out experimentally using a test link. Special techniques may be necessary when extrapolating by numerical simulations.
New fiber laser architecture with transform-limited nonlinear spectral compression
International audience; We numerically demonstrate a new fiber laser architecture supporting spectral compression of negatively chirped pulses in passive normally dispersive fiber. Such a process is beneficial for improving the energy efficiency of the cavity as it prevents narrow spectral filtering from being highly dissipative. The proposed laser design provides an elegant way of generating transform-limited picosecond pulses.
Random walks and random numbers from supercontinuum generation
International audience; We report a numerical study showing how the random intensity and phase fluctuations across the bandwidth of a broadband optical supercontinuum can be interpreted in terms of the random processes of random walks and L´evy flights. We also describe how the intensity fluctuations can be applied to physical random number generation. We conclude that the optical supercontinuum provides a highly versatile means of studying and generating a wide class of random processes at optical wavelengths.
Performance optimisation of dual-pump NALM fibre laser using machine learning inference
We apply predictive regression to find optimum operating regimes in a recently proposed layout of a flexible Figure-8 laser having two independently pumped segments of active fibre in its bidirectional ring.
Amplifier similariton fiber laser with nonlinear spectral compression
International audience; We propose a new concept of a fiber laser architecture supporting self-similar pulse evolution in the amplifier and nonlinear spectral pulse compression in the passive fiber. The latter process allows for transform-limited picosecond pulse generation, and improves the laser's power efficiency by preventing strong spectral filtering from being highly dissipative. Aside from laser technology, the proposed scheme opens new possibilities for studying nonlinear dynamical processes. As an example, we demonstrate a clear period-doubling route to chaos in such nonlinear laser system.
Performance analysis of dual-pump nonlinear amplifying loop mirror mode-locked all-fibre laser
We numerically characterise, in the three-dimensional space of adjustable cavity parameters, the performance of a recently reported layout of a flexible figure-8 laser having two independently pumped segments of active fibre in its bidirectional ring (Smirnov et al 2017 Opt. Lett. 42 1732–5). We show that this optimisation problem can be efficiently addressed by applying a regression model based on a neural-network algorithm.
In-Cavity Transformations for New Nonlinear Regimes of Pulse Generation in Mode-Locked Fibre Lasers
International audience; We review recent progress in the research on nonlinear mechanisms of pulse generation in passively mode-locked fibre lasers. These include parabolic self-similar pulse mode-locking, a mode-locking regime featuring pulses with a triangular distribution of the intensity, and spectral compression arising from nonlinear pulse propagation. We also report on the possibility of achieving various regimes of advanced temporal waveform generation in a mode-locked fibre laser by inclusion of a spectral filter into the laser cavity.
Multi-parameter optimisation of dual-pump NALM fibre laser using machine-learning approaches
Recently, a new design of a model-locked all-fibre Figure-8 laser employing a nonlinear amplifying loop mirror (NALM) with two active fibre segments and two independently controlled pump-power modules has been proposed and experimentally demonstrated. This laser layout combines the reliability and robustness of conventional Figure-8 lasers with the flexibility of nonlinear-polarisation-evolution (NPE) lasers, providing access to a variety of generation regimes with a relatively wide adjustment range of the pulse parameters. Moreover, it enables reliable and reproducible live electronic adjustment of the lasing regimes, which is practically impossible to do by adjusting fibre-based polarisat…
Nonlinear pulse shaping and polarization dynamics in mode-locked fiber lasers
International audience; We review our recent progress on the study of new nonlinear mechanisms of pulse shaping in passively mode-locked fiber lasers. These include a mode-locking regime featuring pulses with a triangular distribution of the intensity, and spectral compression arising from nonlinear pulse propagation. We also report on our recent experimental studies unveiling new types of vector solitons with processing states of polarization for multi-pulse and tightly bound-state soliton (soliton molecule) operations in a carbon nanotube (CNT) mode-locked fiber laser with anomalous dispersion cavity.
Amplifier similariton fibre laser with nonlinear spectral compression
We propose and numerically demonstrate a new concept of fibre laser architecture supporting self-similar pulse evolution in the amplifier and nonlinear pulse spectral compression in the passive fibre. The latter process is beneficial for improving the power efficiency as it prevents strong spectral filtering from being highly dissipative.