A novel system has been developed for the direct measurement of acoustic displacement at a liquid–solid interface which is useful in the observation of leaky wave and related beam‐shift phenomena. Theory predicts that under certain conditions the acoustic field configuration is sensitive to material characteristics such as grain structure and hence assessment of this sensitivity is relevant to ultrasonic surface evaluation. The system utilizes a scanning laser probe together with knife‐edge detection; it permits rapid data acquisition, is remarkedly stable and easy to align, and provides linear maps of field intensity with minimal corruption even with acoustic transducer electrical input levels in the submilliwatt range.