Efficient Mid-Infrared Soliton Self-Frequency Shift and Dispersive Wave in a Chalcogenide Fiber

We present a numerical investigation of soliton self-frequency shift in the mid-infrared (MIR) region and the generation of redshifted dispersive waves in a chalcogenide microstructured optical fiber, with the use of femtosecond pulses well within the anomalous dispersion regime. The fiber’s structural parameters were carefully optimized to establish two zero-dispersion wavelengths at 2.12 and
$4.09~\mu \text{m}$
, facilitating the generation of tunable solitons with wavelength shifts of up to
$3.67~\mu \text{m}$
. A
$2.8~\mu \text{m}$
pump laser, featuring a 200-fs duration and a peak power not exceeding 1 kW, was employed in this investigation. The redshifted dispersive wave, generated at approximately
$5~\mu \text{m}$
, exhibited a high spectral density, characterized by a 3 dB bandwidth of 11 nm and a signal-to-noise ratio of 20 dB. The fiber exhibited a notable power proportion of 66.2% within the critical 3-
$5~\mu \text{m}$
range, indicating its potential for crucial applications in the MIR region. These findings highlighted the significance of effective dispersion and nonlinearity control in the fiber to enable efficient MIR wavelength generation.