Standoff photoacoustic detection of explosives using quantum cascade laser has been studied. The laser beam has been focused on to the target molecules adsorbed on metallic surfaces. A 25 kHz microphone, a resonator cavity in form of a cylinder, and a parabolic acoustic reflector have been used to demonstrate the method. The experimental results have been compared with the theoretical calculations in three different experimental conditions. The photoacoustic signals have been found to decrease with increase in the standoff range. The sensitivity of 2.0 µg/cm² has been achieved at ~4.0 m.

中文翻译：

---

远程中红外光声光谱仪，用于检测爆炸物

研究了利用量子级联激光对爆炸物进行对峙光声检测。激光束已聚焦到吸附在金属表面的目标分子上。已使用25 kHz麦克风，圆柱体形式的谐振腔和抛物线声反射器来演示该方法。在三种不同的实验条件下，将实验结果与理论计算进行了比较。已经发现光声信号随着隔离范围的增加而减小。在约4.0 m处实现了2.0 µg / cm ²的灵敏度。