Wideband Mid-Infrared Comb for Biomedical Applications

Abstract

Since there are many so-called finger print absorption spectra of molecular gas species, the mid-infrared (MIR) region is critical especially for spectroscopy. We developed a highly sensitive, high-resolution spectroscopy system in the MIR region using cavity ring-down spectroscopy (CRDS) with a MIR comb. We developed a wideband wavelength-tunable MIR comb source based on a high-power, Yb-doped fiber laser and the difference frequency generation (DFG) process. We successfully observed the absorption spectra of 14CO2 using our developed system, which is useful for such field applications, as pharmacology, biology, medicine, agriculture, and environmental monitoring.