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The conservation of spectral asymmetry is a fundamental feature of the ideal four‐wave mixing process as it exists in a medium combining quadratic chromatic dispersion and third‐order nonlinearity. The robustness of this invariant in an experimental configuration where the excitation conditions of an optical fiber are sequentially updated, mimicking infinite propagation is tested in this paper. This theoretical and experimental study reveals the high sensitivity of the asymmetry to very slight deviations from the ideal case, and the idealized system behaves as an intermediate case between the ideal case of noncascaded four‐wave mixing and propagation in a system governed by the nonlinear Schrödinger equation is shown. [ABSTRACT FROM AUTHOR]

We show using numerical simulations that data driven discovery using sparse regression can be used to extract the governing differential equation model of ideal four-wave mixing in a nonlinear Schrödinger equation optical fibre system. Specifically, we consider the evolution of a strong single frequency pump interacting with two frequency detuned sidebands where the dynamics are governed by a reduced Hamiltonian system describing pump-sideband coupling. Based only on generated dynamical data from this system, sparse regression successfully recovers the underlying physical model, fully capturing the dynamical landscape on both sides of the system separatrix. We also discuss how analysing an ensemble over different initial conditions allows us to reliably identify the governing model in the presence of noise. These results extend the use of data driven discovery to ideal four-wave mixing in nonlinear Schrödinger equation systems. [ABSTRACT FROM AUTHOR]

We propose and numerically validate an all‐optical scheme to generate a train of optical pulses. Modulation of a continuous wave with a periodic binary temporal phase pattern followed by a spectral phase shaping enables us to obtain ultrashort pulse trains. An ideal step phase profile as well as a profile arisen from a bandwidth‐limited device is investigated. Analytical guidelines describing pulse train formation and their characteristics are provided. Pulses with a duration of a few picoseconds at a repetition rate of 10 GHz can be expected for realistic experimental conditions. [ABSTRACT FROM AUTHOR]

We theoretically and experimentally demonstrate the generation of high-quality low duty-cycle pulse trains at repetition rates of 28 GHz, 56 GHz and 112 GHz. Starting from a continuous wave we benefit from phase modulations in the temporal and spectral domains by applying a sinusoidal profile and a set of well-chosen $\pi $ shifts, respectively, to generate a train of modified besselons at doubled repetition rate. With further nonlinear spectral expansion in a normally dispersive fiber followed by dispersion compensation we achieve subpicosecond durations and a duty cycle as low as 0.025 at 28 GHz. Spectral cancelation of one component over two or four enables to further double or quadruple the repetition rate. [ABSTRACT FROM AUTHOR]

Correction to: I Scientific Reports i https://doi.org/10.1038/s41598-022-16586-5, published online 26 July 2022 In the original version of the Article, Figure 4 (C) was a duplication of Figure 6 (C). (a) Typical noisy data input to SINDy showing ( ) and ( ) evolution for initial conditions 0 = 0.87, 0 = 1.2 (b) Histogram showing the number of returned terms from applying SINDy to 100 data sets. [Extracted from the article]