Scattering of a cross-polarized linear wave by a soliton at an optical event horizon in a birefringent nanophotonic waveguide

The scattering of a linear wave on an optical event horizon, induced by a cross polarized soliton, is experimentally and numerically investigated in integrated structures. The experiments are performed in a dispersion-engineered birefringent silicon nanophotonic waveguide. In stark contrast with co-polarized waves, the large difference between the group velocity of the two cross-polarized waves enables a frequency conversion almost independent on the soliton wavelength. It is shown that the generated idler is only shifted by 10 nm around 1550 nm over a pump tuning range of 350 nm. Simulations using two coupled full vectorial nonlinear Schr\"odinger equations fully support the experimental results

Generation of ultra broadband coherent supercontinuum in tapered and dispersion managed silicon nanophotonic waveguides

Tapered and dispersion managed (DM) silicon nanophotonic waveguides are investigated for the generation of optimal ultra broadband supercontinuum (SC). DM waveguides are structures showing a longitudinally dependent group velocity dispersion that results from the variation of the waveguide width with the propagation distance. For the generation of optimal SC, a genetic algorithm has been used to find the best dispersion map. This allows for the generation of highly coherent supercontinuums that span over 1.14 octaves from 1300 nm to 2860 nm and 1.25 octaves from 1200 nm to 2870 nm at -20 dB level for the tapered and DM waveguides respectively, for a 2 $\mu$m, 200 fs and 6.4 pJ input pulse. The comparison of these two structures with the usually considered optimal fixed width waveguide shows that the SC is broader and flatter in the more elaborated DM waveguide, while the high coherence is ensured by the varying dispersion.Comment: arXiv admin note: substantial text overlap with arXiv:1610.0566

Observation of an optical event horizon in a silicon-on-insulator photonic wire waveguide

We report on the first experimental observation of an optical analogue of an event horizon in integrated nanophotonic waveguides, through the reflection of a continuous wave on an intense pulse. The experiment is performed in a dispersion-engineered silicon-on-insulator waveguide. In this medium, solitons do not suffer from Raman induced self-frequency shift as in silica fibers, a feature that is interesting for potential applications of optical event horizons. As shown by simulations, this also allows the observation of multiple reflections at the same time on fundamental solitons ejected by soliton fission.SCOPUS: ar.jhttp://www.opticsexpress.org/abstract.cfm?URIinfo:eu-repo/semantics/publishe

Physical origin of higher-order soliton fission in nanophotonic semiconductor waveguides

Supercontinuum generation in Kerr media has become a staple of nonlinear optics. It has been celebrated for advancing the understanding of soliton propagation as well as its many applications in a broad range of fields. Coherent spectral broadening of laser light is now commonly performed in laboratories and used in commercial white light sources. The prospect of miniaturizing the technology is currently driving experiments in different integrated platforms such as semiconductor on insulator waveguides. Central to the spectral broadening is the concept of higher-order soliton fission. While widely accepted in silica fibers, the dynamics of soliton decay in semiconductor waveguides is yet poorly understood. In particular, the role of nonlinear loss and free carriers, absent in silica, remains an open question. Here, through experiments and simulations, we show that nonlinear loss is the dominant perturbations in wire waveguides, while free-carrier dispersion is dominant in photonic crystal waveguides

Dispersive wave emission and supercontinuum generation in a silicon wire waveguide pumped around the 1550 nm telecommunication wavelength

We experimentally and numerically study dispersive wave emission, soliton fission and supercontinuum generation in a silicon wire at telecommunication wavelengths. Through dispersion engineering, we experimentally confirm a previously reported numerical study [1] and show that the emission of resonant radiation from the solitons can lead to the generation of a supercontinuum spanning over 500 nm. An excellent agreement with numerical simulations is observed.Comment: 4 pages, 4 figure

Observation of two-photon absorption induced soliton fission

info:eu-repo/semantics/publishe

Depletion-limited Kerr solitons in singly-resonant optical parametric oscillators

We analyze the impact of pump depletion in the generation of cavity solitons in a singly-resonant parametrical oscillator that includes a $\chi^{(3)}$ nonlinear section. We find an analytical expression that provides the soliton existence region using variational methods, study the efficiency of energy conversion, and compare it to a driven Kerr resonator modeled by the Lugiato-Lefever equation. At high walk-off, solitons in singly-resonant optical parametric oscillators are more efficient than those formed in a Kerr resonator driven through a linear coupler.Comment: 5 pages, 4 figure

Supercontinuum generation assisted by dispersive waves trapping in dispersion-managed integrated silicon waveguides

Compact chip-scale comb sources are of significant interest for many practical applications. Here, we experimentally study the generation of supercontinuum (SC) in an axially varying integrated waveguide. We show that the local tuning of the dispersion enables the continuous blue shift of dispersive waves thanks to their trapping by the strongly compressed pump pulse. This mechanism provides new insight into supercontinuum generation in a dispersion varying integrated waveguide. Pumped close to 2.2 $\mu$m in the femtosecond regime and at a pulse energy of $\sim$ 4 pJ, the output spectrum extends from 1.1 $\mu$m up to 2.76 $\mu$m and shows good coherence properties. Octave-spanning SC is also observed at input energy as low as $\sim$ 0.9 pJ. We show that the supercontinuum is more robust against variations of the input pulse parameters and is also spectrally flatter in our numerically optimized waveguide than in fixed-width waveguides. This research demonstrates the potential of dispersion varying waveguides for coherent SC generation and paves the way for integrated low power applications, such as chip-scale frequency comb generation, precision spectroscopy, optical frequency metrology, and wide-band wavelength division multiplexing in the near-infrared