Full-field mapping of ultrasonic field by light-source-synchronized projection
A simple method for imaging ultrasonic fields in clear media was introduced. A modulated laser source was used to project the ultrasonic field onto a CCD camera. By use of the source-synchronized lock-in detection scheme, 2D images of the amplitude and phase distributions can be determined simultaneously. This technique was experimentally demonstrated with a 1-MHz ultrasonic transducer operated in continuous-wave mode. This method is very straightforward to implement and can be combined with the traditional tomographic reconstruction technique to obtain the 3D distribution of an ultrasonic field.