Amar N. Ghosh | 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

Nanoimprinting and Tapering of Chalcogenide Photonic Crystal Fibers for Cascaded Supercontinuum Generation

Improved long-wavelength transmission and supercontinuum (SC) generation is demonstrated by anti-reflective (AR) nanoimprinting and tapering of chalcogenide photonic crystal fibers (PCF). Using a SC source input spanning from 1-4.2 μm, the total transmission of a 15 μm core diameter PCF was improved from ~53 % to ~74 % by nanoimprinting of AR structures on both input- and output facets of the fiber. Through a combined effect of reduced reflection and red-shifting of the spectrum to 5 μm, the relative transmission of light >3.5 μm in the same fiber was increased by 60.2 %. Further extension of the spectrum to 8 μm was achieved using tapered fibers. The spectral broadening dynamics and output power was investigated using different taper parameters and pulse repetition rates.

physics.optics↗