Quartz-enhanced photoacoustic spectroscopy employing a distributed feedback-quantum cascade laser array for nitrous oxide and methane broadband detection

摘要

We report on a quartz-enhanced photoacoustic (QEPAS) sensor employing a monolithic distributed-feedbackquantum cascade laser array operating in a pulsed mode as a light source. The array consists of 32 quantumcascade lasers emitting in a spectral range from 1190 cm~(-1) to 1340 cm~(-1), which covers two absorptionbranches of nitrous oxide (N_2O) and several absorption features of (CH_4). The versatility of the QEPAStechnique combined with the rapid wavelength tuning provided by the ultra-compact, low-power consuminglaser source allowed the detection of N_2O and CH_4 with detection sensitivities below a part-per-million atatmospheric pressure.