arXiv subjects

Carlos Mas Arabí

Publications and source records attributed to Carlos Mas Arabí.

10 recordsLinked to original sources

arXiv2025

Adiabatic and Deterministic Routes to Soliton Combs in Non-Hermitian Kerr Cavities

We present a cardinal solution for the long-standing and fundamental problem associated with the adiabatic, reversible, and controlled excitation of both dark and bright solitons in Kerr micro-resonators with normal group velocity dispersion. Our findings stem from the inclusion of a localised non-Hermitian potential, which we use to drastically reshape the characteristic collapsed snaking structure associated with such solitons. Consequently, we demonstrate a novel snaking-free bifurcation landscape where solitons of all possible widths are continuously connected via the dynamic change of the cavity detuning, and hence dissipative localised states of unprecedentedly high pump-to-comb conversion efficiencies can be excited in an adiabatic, deterministic, and reversible fashion. Our fundamental discovery has practical implications of paramount importance for frequency comb generation in all-normal dispersion cavities, which are key to comb generation in most spectral regions away from the telecom bands.

physics.optics↗

arXiv2025

Dual-mode phonon dynamics and lasing in optomechanical cavities

We use the full nonlinear bifurcation theory as a powerful methodology to thoroughly classify and predict the phonon lasing dynamics in optomechanical cavities. We exemplify its scope in the very relevant and so far vaguely explored dynamics of dual-mode phonon lasing when two independent mechanical modes are directly coupled to one optical field. We uncover a plethora of different lasing regimes in a fixed and realistic cavity geometry, including single- and dual-mode lasing, perfect synchronization of different mechanical modes, and quasiperiodic time crystals. All dynamical regimes are unambiguously associated with bifurcations of different natures, which may exhibit both super and sub-critical natures characterizing the often hysteretic behavior of the systems when they are externally driven by a time-varying laser source. Our results, generalizable to any other optomechanical system, open unprecedented pathways to understand and control the formation and dynamics of optomechanical frequency combs.

physics.optics↗

arXiv2025

Self-modulated multimode silicon cavity optomechanics

Multimode cavity optomechanics, where multiple mechanical degrees of freedom couple to optical cavity modes, provides a rich platform for exploring nonlinear dynamics and engineering complex interactions. In this work, we investigate the interplay between two mechanical modes with similar characteristics and a self-induced nonlinear modulation of intra-cavity power (self-pulsing) driven by free-carrier dispersion and thermo-optic effects in silicon. Notably, the self-pulsing dynamics adapts to the optomechanically induced perturbations from both mechanical modes, enabling simultaneous synchronous pumping and driving them into a stable state characterized by high-amplitude, self-sustained, and coherent oscillations. This result effectively overcomes the strong mode competition typically observed in modes with similar spatial distributions and frequency scales. Remarkably, this regime is achieved even when the mechanical frequencies do not satisfy a harmonic relation, leading to quasi-periodic or chaotic intra-cavity power dynamics, while the mechanical modes maintain coherent, high-amplitude oscillations. These results, supported by a numerical model that accurately predicts the dynamics of the system, open new pathways for the generation and control of multi-phonon coherent sources in chip-integrated silicon platforms.

physics.optics↗

arXiv2024

Temporal solitons in a coherently driven active resonator

Optical frequency combs are lightwaves composed of a large number of equidistant spectral lines. They are important for metrology, spectroscopy, communications and fundamental science. Frequency combs are most often generated by exciting dissipative solitons in lasers or in passive resonators, both of which suffer from significant limitations. Here, we show that the advantages of each platform can be combined. We introduce a novel kind of soliton, called active cavity soliton, hosted in coherently driven lasers pumped below the lasing threshold. We use an active fibre resonator and measure high peak power solitons on a low power background, in excellent agreement with simulations of a generalized Lugiato-Lefever equation. Moreover, we find that amplified spontaneous emission has negligible impact on the soliton's stability. Our results open up novel avenues for frequency comb formation by showing that coherent driving and incoherent pumping can be efficiently combined to generate a high-power ultra-stable pulse train.

physics.optics↗

arXiv2024

Manipulation and control of temporal cavity solitons with trapping potential

Temporal cavity solitons (CSs) are stable, localized particle-like objects in the form of optical pulses that circulate indefinitely in coherently driven nonlinear resonators. In the spectral domain, they form highly coherent frequency combs. Owing to their remarkable stability, they are attracting attention for applications in sensing, metrology, or optical signal synthesis. In this work, we report on the dynamics of CSs interacting with a trapping potential. We demonstrate that this interaction provides a powerful means to control their properties such as position, speed, and central frequency. Our theoretical analysis predicts fundamental limitations on the spectral shift of CSs relative to the driving frequency. Specifically, it reveals that within a broad range of detunings, frequency-shifted CSs encounter destabilization through a Hopf bifurcation. Moreover, we find that with periodic potentials, the Kelly sidebands emitted by trapped solitons undergo Bloch oscillations. In our experiments, we use an intracavity phase modulator to create the equivalent of an external real potential. We observe stable blue- and red- shifted solitons up to a limit close to our theoretical predictions. We then show theoretically and experimentally that this unprecedented level of control over the CS spectrum can be leveraged to cancel the Raman-induced self-frequency shift and even to stabilize CSs beyond the limitation imposed by stimulated Raman scattering. Our results provide valuable insights for applications requiring robust and potentially rapid tunable control over the cavity soliton properties.

physics.optics↗

arXiv2023

High peak-to-background-ratio solitons in a coherently-driven active fiber cavity

We demonstrate that the peak-to-background ratio of driven solitons can be greatly improved by harnessing the cavity detuning. We use a driven fiber laser pumped below the lasing threshold to increase the finesse and excite solitons in a very wide region of detunings. When driving a 50 m long fiber cavity close to the anti-resonance condition, we excite sub-800 fs solitons with a peak-to-background ratio over 30000. The experimental results are in good agreement with simple theoretical models describing the soliton peak power and the background power.

physics.optics↗

arXiv2022

Mode-locking induced by coherent driving in fiber lasers

The generation of stable short optical pulses in mode-locked lasers is of tremendous importance for many applications. Mode-locking is a broad concept that encompasses different processes enabling short pulse formation. It typically requires an intracavity mechanism that discriminates between single and collective mode lasing, which can be complex and sometimes adds noise. Moreover, known mode-locking schemes do not guarantee phase stability of the carrier wave. Here we theoretically propose that injecting a detuned signal seamlessly leads to mode-locking in fiber lasers. We show that phase-locked pulses, akin to cavity solitons, exist in a wide range of parameters. In that regime the laser behaves as a passive resonator due to the non-instantaneous gain saturation.

physics.optics↗

arXiv2021

Self-Pulsing in driven-dissipative photonic Bose-Hubbard dimers

We experimentally investigate the nonlinear dynamics of two coupled fiber ring resonators, coherently driven by a single laser beam. We comprehensively explore the optical switching arising when scanning the detuning of the undriven cavity, and show how the driven cavity detuning dramatically changes the resulting hysteresis cycle. By driving the photonic dimer out-of-equilibrium, we observe the occurrence of stable self-switching oscillations near avoided resonance crossings. All results agree well with the driven-dissipative Bose-Hubbard dimer model in the weakly coupled regime.

physics.optics↗

arXiv2021

Parametrically driven Kerr cavity solitons

Temporal cavity solitons are optical pulses that propagate indefinitely in nonlinear resonators. They are currently attracting a lot of attention, both for their many potential applications and for their connection to other fields of science. Cavity solitons are phase locked to a driving laser. This is what distinguishes them from laser dissipative solitons and the main reason why they are excellent candidates for precision applications such as optical atomic clocks. To date, the focus has been on driving Kerr solitons close to their carrier frequency, in which case a single stable localised solution exists for fixed parameters. Here we experimentally demonstrate, for the first time, Kerr cavity solitons excitation around twice their carrier frequency. In that configuration, called parametric driving, two solitons of opposite phase may coexist. We use a fibre resonator that incorporates a quadratically nonlinear section and excite stable solitons by scanning the driving frequency. Our experimental results are in excellent agreement with a seminal amplitude equation, highlighting connections to hydrodynamic and mechanical systems, amongst others. Furthermore, we experimentally confirm that two different phase-locked solitons may be simultaneously excited and harness this multiplicity to generate a string of random bits, thereby extending the pool of applications of Kerr resonators to random number generators and Ising machines.

physics.optics↗

arXiv2017

Geometric parametric instability in periodically modulated GRIN multimode fibers

We present a theoretical and numerical study of light propagation in graded-index (GRIN) multimode fibers where the core diameter has been periodically modulated along the propagation direction. The additional degree of freedom represented by the modulation permits to modify the intrinsic spatiotemporal dynamics which appears in multimode fibers. More precisely, we show that modulating the core diameter at a periodicity close to the self-imaging distance allows to induce a Moiré-like pattern, which modifies the geometric parametric instability gain observed in homogeneous GRIN fibers.

physics.optics↗