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一种新研制成功便携式以室温半导体激光器为基础的中红外气体敏感器用于测量空气中甲烷浓度。这种气体敏感器由波长为８１０ｎｍ的单极性半导体激光器和波长为１０８３ｎｍ的分布反馈式半导体激光器作为泵浦光并通过周期性极化的磷酸锂晶体产生了在３３μｍ连续差频光。通过调谐单极性半导体激光器使差频光调谐在３０４５～３１７０波数之间。外场测量空气中的甲烷得到的灵敏度为１８ｐｐｂｍ／Ｈｚ１／２，探测灵敏度主要受激光强度噪声所限制。
A newly developed portable, ambient temperature semiconductor laser-based mid-infrared gas sensor is used to measure the concentration of methane in the air. The gas sensor consisted of a unipolar semiconductor laser of wavelength 810 nm and a distributed feedback semiconductor laser of wavelength 1083 nm as pump light and produced 3 .3 μm continuous difference frequency light with periodically poled lithium phosphate crystals. Difference frequency light is tuned between 3045 and 3170 wavenumbers by tuning a unipolar semiconductor laser. The field measurement of methane in the air gives a sensitivity of 18ppbm / Hz1 / 2, and the detection sensitivity is mainly limited by the laser intensity noise.