Development Of Scanning Photoacoustic Spectroscopy (PAS) Using A Novel Optical/Laser Microphone For The Remote Detection Of Explosives

We propose to develop a scanning photoacoustic spectroscopic (PAS) system fitted with a novel laser microphone for the remote scanning of targeted molecules and chemical compounds. By leveraging the acoustic signatures emitted by the target molecules, the proposed PAS technology offers better detection sensitivity in identifying the presence and concentrations of targeted molecules compared to conventional photo-spectroscopic techniques like LIBS, Raman spectroscopy, and terahertz radiations. Further boosting the performance of the proposed PAS technology is the adoption of a novel, highly sensitive laser microphone capable of detecting the minute displacements of the diaphragm caused by the acoustic signatures emitted by the targeted molecules. The excellent sensitivity of the proposed PAS technology with novel laser microphone is expected to offer standoff detection distances in the 50 –100 meters range at the end of its development. We also propose to study the deployment of arrayed microphones to perform cancellation of common background noise, leading thus to even better sensitivity in trace gas detection and further lengthening of the standoff distances. Scanning mechanisms and the related opto-mechanical system architectures of the proposed PAS technology is also to be conducted to support rapid scanning of desired areas at the standoff distance.