Contactless ultrasonic wave optical receiver - is multidirectional and uses segmented optical receiver and directionally sensitive signal delay structure

摘要

The method and arrangement are for contactless optical reception of ultrasonic waves incident obliquely on a test surface (3) and involve illumination of the surface and reception of the modulated light in a multiple section light receiver (6) after it has passed through an interferometer (5). Ultrasonic waves incident from different directions can be analysed simply without changing the light beam distance. The surface region of the test object which is deflected by the ultrasound is illuminated uniformly. The segment (600-932) output signals are delayed and summed by adders (74-76). The signal delays are selected to ensure that signal maximal occur at the outputs of corresp. adders when ultrasonic wavefronts of predefined shape and direction occur at the test surface.