We report a mid-infrared quartz-enhanced photoacoustic sensor for highly sensitive nitrous oxide (N₂O) detection using a 4.56 µm quantum cascade laser (QCL) with a butterfly package type. This new type of QCL features a compact size (30 mm × 12.7 mm × 13 mm), low threshold current (< 120 mA) at room temperature, and relatively high emission power (> 100 mW), which are suitable for portable trace gas sensor development. In this work, the QCL beam is directly coupled to the QEPAS detection module by using only one focusing lens. By measuring N₂O mixtures with different concentrations (120 ppb to 3.16 ppm), the developed sensor shows a good linearity (R-square value of 0.999) and a minimum detection limit of below 1 ppb. The sensor has been successfully deployed for ambient air measurement, demonstrating the applicability and promising potential of using this QCL with butterfly package for various gas sensing applications.

我们报告了一种中红外石英增强光声传感器，使用蝶形封装的 4.56 µm 量子级联激光器 (QCL) 进行高灵敏度一氧化二氮 (N _{2 O) 检测。}这种新型QCL具有紧凑的尺寸（30 mm × 12.7 mm × 13 mm）、室温下较低的阈值电流（< 120 mA）和相对较高的发射功率（> 100 mW），适用于便携式痕量气体传感器开发。在这项工作中，仅使用一个聚焦透镜将 QCL 光束直接耦合到 QEPAS 检测模块。通过测量不同浓度（120 ppb 至 3.16 ppm）的 N ₂ O 混合物，所开发的传感器表现出良好的线性度（R 方值为 0.999）和低于 1 ppb 的最低检测限。该传感器已成功部署用于环境空气测量，证明了使用带有蝶形封装的 QCL 来实现各种气体传感应用的适用性和广阔前景。