Plasma-Induced Asymmetric Self-Phase Modulation and Modulational Instability in Gas-Filled Hollow-Core Photonic Crystal Fibers

Abstract

We study theoretically the propagation of relatively long pulses with ionizing intensities in a hollow-core photonic crystal fiber filled with a Raman-inactive noble gas. Because of photoionization, an extremely asymmetric self-phase modulation and a new kind of "universal" plasma-induced modulational instability appear in both normal and anomalous dispersion regions. We also show that it is possible to spontaneously generate a plasma-induced continuum of blueshifting solitons, opening up new possibilities for pushing supercontinuum generation towards shorter and shorter wavelengths.

PHz-Wide Spectral Interference Through Coherent Plasma-Induced Fission of Higher-Order Solitons

“…Instead, the pulse experiences asymmetric spectral broadening [10], caused by the combined effects of the optical Kerr nonlinearity and plasma-induced phasemodulation (Fig. 4(a)).…”

“…The tight confinement of high-intensity femtosecond pulses in a single spatial mode with precisely controllable anomalous dispersion allows established soliton dynamics to be extended into the strong-field regime [6], opening up unique possibilities. For the first time, it has been possible to study how optical solitons interact with plasmas over long pathlengths and broad frequency ranges in a well-controlled environment, as well as effects such as plasma-induced blue-shifting [7,8], adiabatic soliton compression [9] and modulational instability (MI) [10].In previous work, soliton-plasma interactions were mainly studied in the regimes of low and very high soliton order. Here we investigate high-intensity ultrashort solitons of intermediate order, and demonstrate novel coherent plasma-induced fission, leading to pulse splitting and the production of robust pulse pairs of PHz bandwidth that co-propagate phase-locked over cm-long distances.…”

“…The tight confinement of high-intensity femtosecond pulses in a single spatial mode with precisely controllable anomalous dispersion allows established soliton dynamics to be extended into the strong-field regime [6], opening up unique possibilities. For the first time, it has been possible to study how optical solitons interact with plasmas over long pathlengths and broad frequency ranges in a well-controlled environment, as well as effects such as plasma-induced blue-shifting [7,8], adiabatic soliton compression [9] and modulational instability (MI) [10].…”

Free-carrier-driven spatiotemporal dynamics in amplifying silicon waveguides

“…Taking full account of FC generation and recombination, we calculate the stationary nonlinear CWs of the system and we investigate their stability. We find that, analogously to gas-filled HCPCFs [10], stationary CWs are universally unstable in both normal and anomalous dispersion regimes. However, due to the inherent non-conservative nature of our system, modulational instability (MI) does not generate a shower of solitons as in Ref.…”

“…In this interesting and rather unexplored operating regime, free-carriers (FCs) directly interact with the optical field and introduce novel nonlinear effects [8]. A quite similar scenario happens in gas-filled hollow core photonic crystal fibers (HCPCFs) in the ionization regime, where accelerating solitons [9] and universal modulational instability [10] have been recently observed. In this case, the free plasma generated through ionization is responsible for an intense blueshift of several hundreds of nanometers of the optical pulse [11].…”