Mid-infrared laser absorption spectrometers based upon all-diode laser difference frequency generation and a room temperature quantum cascade laser for the detection of CO, N2O and NO

作者：Kasyutich V L^*; Holdsworth R J; Martin P A

来源：Applied Physics B: Lasers and Optics , 2008, 92(2): 271-279.

DOI：10.1007/s00340-008-3097-0

We describe the performance of two mid-infrared laser spectrometers for carbon monoxide, nitrous oxide and nitric oxide detection. The first spectrometer for CO and N2O detection around 2203 cm(-1) is based upon all-diode laser difference frequency generation (DFG) in a quasi-phase matched periodically-poled lithium niobate (PPLN) crystal using two continuous-wave room-temperature distributed feedback diode lasers at 859 and 1059 nm. We also report on the performance of a mid-infrared spectrometer for NO detection at similar to 1900 cm(-1) based upon a thermoelectrically-cooled continuous-wave distributed feedback quantum cascade laser (QCL). Both spectrometers had a single-pass optical cell and a thermoelectrically cooled HgCdZnTe photovoltaic detector. Typical minimum detection limits of 2.8 ppmv for CO, 0.6 ppmv for N2O and 2.7 ppmv for NO have been demonstrated for a 100 averaged spectra acquired within 1.25 s and a cell base length of 21 cm at similar to 100 Torr. Noise-equivalent absorptions of 10(-5) and 10(-4) Hz(-1/2) are typically demonstrated for the QCL and the DFG based spectrometers, respectively.

• 出版日期2008-8