Multichannel Detection of Photoacoustic Signals: Preliminary Results

Abstract

In a typical photoacoustic measurement system, signal detection is usually implemented with a single microphone or another pressure sensor. A solution presented in this paper consists of an array of 14 MEMS microphones equipped with dedicated and individually controllable signal paths, based on programmable gain amplifiers and analog-to-digital converters. Further, digital signal processing and recording are implemented in an FPGA-based hardware system. Use of multiple microphones increases the signal amplitude and the signal-to-noise ratio and allows for measurements of pressure-field distribution inside the photoacoustic cell.