Temporal reflection in nonlinear optical fibers provides a powerful framework for manipulating light. In this work, we theoretically and experimentally demonstrate a novel, to the best of our knowledge, mechanism for wave trapping induced by the dynamical evolution of a single high-order soliton pulse. Experimental measurements performed in a 5-km-long nonlinear dispersion-shifted fiber confirm the coexistence of reflected, transmitted, and trapped components, in excellent agreement with theoretical predictions. These results establish a simple and versatile route toward dynamic temporal waveguiding using a single optical pulse, opening new opportunities for all-optical control and manipulation of ultrafast signals.

We unveil a family of dissipative solitons with composite structure, consisting of a central body sandwiched between two sets of sidelobes. The strongest sidelobes allow for long-range interactions with other solitons, and their composite phase structure allows for the generation of soliton molecules on demand.

We report the observation of classical light thermalization to the negative temperature Rayleigh-Jeans (RJ) equilibrium states. We extend theoretically these equilibrium states to the Bose-Einstein quantum regime (BE) through the analysis of the thermodynamic properties.

We present theoretical and experimental evidence of high-gain far-detuned nonlinear frequency conversion, extending towards both the visible and the mid-infrared, in a few-mode graded-index silica fiber pumped at 1.064 μm, and more specifically achieving gains of hundreds of dB per meter below 0.65 μm and beyond 3.5 μm. Our findings highlight the potential of graded-index fibers in terms of strong modal confinement over an ultrabroad spectral range for enabling high-gain wavelength conversion. Such advancements require an accurate interpretation of intramodal and intermodal four-wave mixing processes.

In this paper, we introduce an all-fibered dual-comb spectrometer based on a new design of highly nonlinear fiber to efficiently convert frequency combs from 1.55 micron to 2 micron We show that our spectrometer can be used to measure absorption profiles of rovibrational transitions of CO2 and N2O molecules, and especially their collisional self-broadening coefficients. The results show very good agreement with the HITRAN database and thus further measurements have been performed on a mixture CO2 /N2O to measure the broadening of the CO2 absorption lines resulting from the presence of N2O.

We address the challenge of configuring a fiber laser cavity to enable efficient access to multi-pulse structures such as dissipative soliton molecules. We theoretically compare multi-pulsing routes in the parameter space of the laser. By using a two-dimensional parameter space, we experimentally demonstrate an important reduction in the laser pumping power required to form soliton molecules.

Abstract We present theoretical and experimental evidence of high-gain far-detuned nonlinear frequency conversion, extending towards both the visible and the mid-infrared, in a few-mode graded-index silica fiber pumped at 1.064 $$\upmu \hbox {m}$$ μ m , and more specifically achieving gains of hundreds of dB per meter below 0.65 $$\upmu \hbox {m}$$ μ m and beyond 3.5 $$\upmu \hbox {m}$$ μ m . Interestingly, our findings highlight the potential of graded-index fibers for enabling high-gain wavelength conversion into the strong-loss spectral region of silica. Such advancements require an accurate interpretation of intramodal and intermodal four-wave mixing processes.

We experimentally study the spatial beam profile and the spectral broadening at the output of a multimode air-silica microstructure fiber taper, used along the direction of an increasing fiber diameter. By using a laser pump at 1064 nm emitting 60 ps Gaussian beam pulses, we observed a competition between Raman beam cleanup and Kerr beam self-cleaning: the multimode frequency conversion process permits to generate spectral sidebands with frequency detuning from the pump that are difficult to obtain in standard graded-index multimode fibers. The generated supercontinuum spans from 500 nm up to 2.5 µm.

We demonstrate experimentally, the generation of an intense broadband comb-like spectrum spontaneously built up through stimulated Raman scattering in a low-pressure CO2-filled hollow-core photonic crystal fiber pumped by a single infrared pump.

We present both theoretical and experimental evidence of far-detuned nonlinear wavelength conversion towards the mid-infrared, namely beyond 3500 nm, in a few-mode graded-index silica fiber pumped at 1064 nm. Intramodal and intermodal four-wave mixing processes are carefully analyzed by means of the frequency-dependent propagation constants.

Important ongoing research on mode-locked fiber lasers aims at developing new types of multisoliton regimes, such as soliton molecules, molecular complexes, or soliton crystals. The on-demand generation of such multi -pulse structures is a major challenge, whereas experiments generally involve a tedious trial-and-error adjustment of the laser parameters. Here we present an approach based on a gradual and calibrated adjustment of the system configuration, which employs efficient parameter routes to reach well-defined multipulse regimes. Our numerical simulations show that once the mode-locking threshold is reached, we can adjust the laser parameters gradually to force the evolution of the laser dynamics towards multipulse structures with fewer distortion in their intensity profiles, which are accessible at reduced pump power levels.

In this paper, we present a new method to reach the multi-pulse regime in mode-locked fibre laser. This approach allows us to generate distortion free pulses while reducing the required pumping power. Our experimental results, in good agreement with our simulations, confirm the usefulness of this method.

Nonlinear random waves exhibit a phenomenon of irreversible thermalization, in analogy with the thermalization of a classical gas system. This irreversible process of thermalization to the Rayleigh-Jeans equilibrium distribution has been recently observed experimentally in multimode optical fibers. Here we discuss a recent progress along two different directions. Firstly, we report the observation of thermalization to negative temperature equilibrium states, in which high-order fiber modes are more populated than low-order modes. Secondly, we analyze the impact of disorder inherent to light propagation in multimode fibers. We identify an unexpected regime in which strong random coupling among non-degenerate modes leads to a nonequilibrium process of Rayleigh-Jeans thermalization.

Since the first proof-of-principle experiments 25 years ago, quantum metrology has matured from fundamental concepts to versatile and powerful tools in a large variety of research branches, such as gravitational-wave detection, atomic clocks, plasmonic sensing, and magnetometry. At the same time, two-photon interferometry, which underpins the possibility of entanglement to probe optical materials with unprecedented levels of precision and accuracy, holds the promise to stand at the heart of innovative functional quantum sensing systems. We report a novel quantum-based method for measuring the frequency dependence of the velocity in a transparent medium, i.e, the chromatic dispersion (CD). This technique, using energy-time entangled photons, allows straightforward access to CD value from the visibility of two-photon fringes recorded in a free evolution regime. In addition, our quantum approach features all advantages of classical measurement techniques, i.e, flexibility and accuracy, all in a plug-and-play system.

Nous montrons que la spectroscopie à double peignes électro-optiques permet de mesurer le rapport isotopique 13 C/ 12 C avec une précision meilleure que 2‰ pour un temps d’enregistrement de quelques dizaines de secondes. Les résultats sont compatibles avec des mesures obtenues à l’aide d’un spectromètre de masse.

We present theoretical as well as experimental evidence of far-detuned nonlinear wavelength conversion towards the mid-infrared, namely beyond 3.5 µm, in a few-mode graded-index silica fiber pumped at 1.064 µm. We take into account the full frequency-dependence of the propagation constants, which allows us to obtain excellent agreement of theoretical predictions with experimental observations and provides new and accurate interpretation of intramodal and intermodal four-wave mixing processes in few-mode fibers.

We experimentally demonstrate a stabilized single-frequency Brillouin fiber laser operating at 1.06 µm by means of a passive highly nonlinear fiber (HNLF) ring cavity combined with a phase-locking loop scheme. The stimulated Brillouin scattering efficiency is first investigated in distinct single-mode germanosilicate core fibers with increasing G e O 2 content. The most suitable fiber, namely, 21 mol.% G e O 2 core fiber, is used as the Brillouin gain medium in the laser cavity made with a 15-m-long segment. A Stokes lasing threshold of 140 mW is reported. We also show significant linewidth narrowing (below 1 kHz) as well as frequency noise reduction compared to that of the initial pump in our mode-hop free Brillouin fiber laser.

We report on a stabilized single-frequency Brillouin fiber laser operating at 1.06 µm by means of a passive highly nonlinear fiber ring cavity combined with a phase-locking loop scheme. We show significant linewidth narrowing (below 1-kHz) as well as frequency noise reduction compared to that of the initial pump in our mode-hop free Brillouin fiber laser.