Broadband Coherent Mid-Infrared Supercontinuum Generation in All-Chalcogenide Microstructured Fiber With All-Normal Dispersion

Abstract

We demonstrated numerically the generation of broadband, coherent supercontinuum (SC) spectra in the mid-infrared region using dispersion-engineered all-chalcogenide microstructured fibers (MOFs). The 1-cm-long hexagonal fiber can be made with Ge11.5As24S64.5 glass as a low-refractive-index material embedded in a Ge11.5As24Se64.5 glass matrix. By optimizing the structural parameters, we determined a broad and flat all-normal-dispersion characteristic up to 14 μm. A highly coherent broadband SC with an intensity greater than −3 dB in the range from 5973 to 8695 nm is obtained when the fiber is pumped by a 7 μm laser with pulse duration of 50 fs and peak power of 6 kW. Flat-top SC of −30 dB level can be observed utilizing identical pump pulse parameters, covering wavelengths from 3823 to 13577 nm (>1.5 octaves). This broadband coherent MIR SC source can be applied in frequency metrology, optical coherence tomography, biomedical imaging, and few-cycle pulse compression.

Fabrication of Step−Index Fluorotellurite Fibers with High Numerical Aperture for Coherent Mid—Infrared Supercontinuum

“…Fluoride, chalcogenide, and tellurite glass fibers with high transmittance and ANDi in the mid−infrared range are promising nonlinear mediums to generate highly coherent MIR SC. Recently, Xiao et al proposed a microstructured chalcogenide fiber with ANDi for coherent MIR SC generation, and the SC spectrum is from 3823 nm to 13,577 nm based on a 1 cm long fiber [17]. Zhang et al fabricated step−index chalcogenide fiber with ANDi, and coherent MIR SC from 1.7-12.7 µm was generated from the fiber pumped at 5 µm [18].…”