An infrared version of the Multiplexed Two‐Wave Mixing (MTWM) Interferometer system using a long pulse laser system as the source has been developed at Northwestern University. This infrared version has higher optical power which makes it possible to build large array laser ultrasonic detectors. A 16‐element laser ultrasonic array detector and its imaging applications using surface acoustic waves and bulk waves are reported. © 2004 American Institute of Physics