Precise measurements of CO2 concentrations using room temperature diode lasers

First results of a laboratory CO2 instrument using room temperature diode lasers are presented. Two different near infrared DFB-lasers, one working at 1.57 mu m and another one with an emission wavelength around 2.0 mu m, have been characterized. Both lasers have been used for measurements of CO2 concentrations. At ambient concentration levels a resolution of more than two orders of magnitude has been demonstrated at 1.57 mu m, at 2 mu m the precision is in the order of 0.1 ppm CO2, and for trace concentration determination a detection limit of 10 ppb will be obtained. The reported measurements demonstrate the applicability of near-infrared DFB-diode lasers to precise determination of CO2 concentrations as required for climatological, medical or industrial investigations.