Peter M. Moselund | Searcharxiv

arXiv2020

Cross-Phase Modulation Instability in PM ANDi Fiber-Based Supercontinuum Generation

We demonstrate broadband supercontinuum generation in an all-normal dispersion polarization-maintaining photonic crystal fiber and we report the observation of a cross-phase modulation instability sideband that is generated outside of the supercontinuum bandwidth. We demonstrate this sideband is polarized on the slow axis and can be suppressed by pumping on the fiber's fast axis. We theoretically confirm and model this nonlinear process using phase-matching conditions and numerical simulations, obtaining good agreement with the measured data.

physics.optics↗

arXiv2019

Ultra-low-noise supercontinuum generation with a flat near-zero normal dispersion fiber

A pure silica photonic crystal fiber with a group velocity dispersion ($β_2$) of 4 ps$^2$/km at 1.55 $μ$m and less than 7 ps$^2$/km from 1.32 $μ$m to the zero dispersion wavelength (ZDW) 1.80 $μ$m was designed and fabricated. The dispersion of the fiber was measured experimentally and found to agree with the fiber design, which also provides low loss below 1.83 $μ$m due to eight outer rings with increased hole diameter. The fiber was pumped with a 1.55 $μ$m, 125 fs laser and, at the maximum in-coupled peak power (P$_0$) of 9 kW, a 1.34$-$1.82 $μ$m low-noise spectrum with a relative intensity noise below 2.2\% was measured. The numerical modeling agreed very well with the experiments and showed that P$_0$ could be increased to 26 kW before noise from solitons above the ZDW started to influence the spectrum by pushing high-noise dispersive waves through the spectrum.

physics.optics↗