Numerical analysis of spectroscopic studies using supercontinuum generated by noise-like pulses

Abstract

Multiple Supercontinuum (SC) spectra generated by noise-like pulses (NLPs) were subjected to numerical analysis to assess their viability for gas detection. The numerical setup employed for this study was a figure-eight fiber laser using a mode-locking configuration. This configuration included a nonlinear optical loop mirror, which functions as an amplitude filter, and a double-clad erbium-ytterbium fiber, which serves as the active element. The absorption spectrum of the gas C₂H₂ in the near-infrared region, obtained from the HITRAN database, was analyzed for the proposed numerical setup. The analysis revealed distinct outcomes in terms of sensitivity, depending on the type of NLP generated through polarization manipulation. Some spectra maintained most of the gas rovibrational lines and frequency components, thus facilitating the proper gas identification. Simulations were also performed for CH₄, showing a visible absorption spectrum, thereby substantiating that these sources powered by NLPs can detect various gases with a high degree of selectivity.