Highly Coherent Supercontinuum Generation in Circular Lattice Photonic Crystal Fibers Using Low-power Pulses

TL;DR

This paper proposes two circular lattice photonic crystal fiber designs using Ge-Sb-Se material for highly coherent broadband supercontinuum generation in the mid-infrared with low-power pulses, demonstrating broad spectral coverage and structural robustness.

Contribution

The study introduces novel fiber structures with high nonlinearity and low confinement loss, enabling efficient supercontinuum generation at low power levels with good fabrication tolerance.

Findings

Supercontinuum spanning 0.45-5.3 μm and 0.48-6.5 μm achieved

High nonlinear coefficients of 22.01 and 17.99 W^{-1}m^{-1}

Structures exhibit low confinement loss and high structural tolerance

Abstract

Two structures of circular lattice Photonic Crystal Fibers (PCFs) based on $Ge_{20}Sb_{15}Se_{65}$ (GSS) material have been proposed for a highly coherent broadband supercontinuum generation (SCG) in the mid-infrared region. Numerical studies on both structures show that the fundamental modes are well confined in the core while the confinement losses are very low. Also, the high nonlinear coefficient of 22.01 $W^{-1}m^{-1}$ and 17.99202 $W^{-1}m^{-1}$ for the two structures ensure that these structures can accomplish a high nonlinear activity. It has been found that broadband supercontinuum (SCs) spanning from 0.45 $\mu$m to 5.3 $\mu$m and 0.48 ${\mu}$m to 6.5 ${\mu}$m can be generated using a hyperbolic secant pulse of 0.5 kW. The proposed structures also show very good structural tolerance to optical properties that prevent any radical shift in SC spectra owing to potential fabrication mismatch.