A New Kind of Laser Microphone for Photoacoustic Applications

We present in this paper a new kind of laserbased microphone device capable of detecting minute displacements of the microphone diaphragm, leading to drastically improved sensitivity in detecting the impinging pressure waves like acoustic waves and water waves over existing state-of-the-art laser and fiber-optic microphones. The drastically improved sensitivity in detecting diaphragm surface displacements of the novel laser microphone leads to niche applications including the photoacoustic detection of molecules and compounds with long standoff detection distances as well as highly sensitive technology for monitoring submarine activities. Preliminary experimental demonstration of the novel laser microphone technology is presented, validating the theoretical modeling that is also presented.