Chalcogenide-glass polarization-maintaining photonic crystal fiber for mid-infrared supercontinuum generation

TL;DR

This paper presents the design, fabrication, and experimental demonstration of a chalcogenide-glass polarization-maintaining photonic crystal fiber that generates a broad mid-infrared supercontinuum, with results matching numerical simulations.

Contribution

It introduces a novel highly birefringent, polarization-maintaining chalcogenide photonic crystal fiber for mid-infrared supercontinuum generation, including fabrication, experimental validation, and polarization dependence analysis.

Findings

Supercontinuum spans from 3.1 to 6.02 μm with femtosecond pumping.

The fiber exhibits high birefringence of 6×10^{-4} at 4.5 μm.

Supercontinuum bandwidth depends on input pump polarization angle.

Abstract

In this paper, we report the design and fabrication of a highly birefringent polarization-maintaining photonic crystal fiber (PM-PCF) made from chalcogenide glass, and its application to linearly-polarized supercontinuum (SC) generation in the mid-infrared region. The PM fiber was drawn using the casting method from As38Se62 glass which features a transmission window from 2 to 10 $\mu m$ and a high nonlinear index of 1.13.10$^{-17}$m$^{2}$W$^{-1}$. It has a zero-dispersion wavelength around 4.5 $\mu m$ and, at this wavelength, a large birefringence of 6.10$^{-4}$ and consequently strong polarization maintaining properties are expected. Using this fiber, we experimentally demonstrate supercontinuum generation spanning from 3.1-6.02 $\mu m$ and 3.33-5.78 $\mu m$ using femtosecond pumping at 4 $\mu m$ and 4.53 $\mu m$, respectively. We further investigate the supercontinuum bandwidth versus the input pump polarization angle and we show very good agreement with numerical simulations of the two-polarization model based on two coupled generalized nonlinear Schr\"odinger equations.