The ultrasound equivalent of a laser could lead to important new discoveries in materials science by providing researchers with a non-destructive way to detect even the subtlest of changes, such as phase transitions deep in their samples. Now, researchers at the University of Illinois at Urbana-Champaign and at the University of Missouri-Rolla have built just such an ultrasound analogue of the laser – the uaser, pronounced way-zer.
Light amplification by stimulated emission of radiation devices, lasers, are well known, but a sonic analogue had until now not been developed. Richard Weaver and his colleagues set out to change that and to develop a device that would induce ultrasound amplification by stimulated emission of radiation to produce coherent ultrasonic waves of a single frequency. “A sonic laser has been possible for some time now,” Weaver told us, “our method could have been done earlier. I tend to think it wasn’t for two reasons: first no-one saw an application and second few people are expert at both laser physics and ultrasonics.”