Abstract We report on mid-infrared gas spectroscopy measurements by means of the supercontinuum (SC) absorption method. developed a 80 MHz-repetition-rate SC light source with an average power 40 mW generated through nonlinear propagation 200 fs pulses in 10 cm-long segment step-index tellurite fiber. A compact multipass cell is used for analyzing CO 2 and CH 4 gases their mixture 2–3.5 µ m spe...