Towards absorption spectroscopy by means of mid-infrared supercontinuum generation in a step index tellurite fiber

Abstract

Abstract We report on mid-infrared gas spectroscopy measurements by means of the supercontinuum (SC) absorption spectroscopy method. We developed a 80 MHz-repetition-rate mid-infrared SC light source with an average power of 40 mW generated through nonlinear propagation of 200 fs pulses in a 10 cm-long segment of step-index tellurite fiber. A compact multipass cell is used for analyzing absorption of CO2 and CH4 gases and their mixture in the 2–3.5 µm spectral range. Experimental results are compared to the HITRAN database.