[[abstract]]What we believe to be a novel multipass, acoustically open photoacoustic detector designed for fast-response, high-sensitivity detection of trace gases and pollutants in the atmosphere is demonstrated. The acoustic pulses generated by the absorption of the light pulses of a tunable optical parametric oscillator by target molecules are detected by an ultrasonic sensor at 40 kHz. The photoacoustic signal is enhanced by an optical multipass arrangement and by concentration of the acoustic energy to the surface of the ultrasonic sensor. The detection sensitivity, estimated from CO2 measurements around a 2 μm wavelength, is ∼3.3×10−9 W cm−1.
展开▼
机译：[[摘要]]我们证明了一种新颖的多通道，声学开放式光声检测器，该检测器设计用于快速响应，高灵敏度检测大气中的痕量气体和污染物。由目标分子吸收可调光学参量振荡器的光脉冲产生的声脉冲由超声波传感器以40 kHz的频率检测。光声信号通过光学多通道布置以及声能在超声传感器表面的集中而得到增强。根据在2μm波长附近的CO2测量估算出的检测灵敏度约为3.3×10-9 W cm-1。
展开▼
