Ultrasonic Acoustic Probing Based on Gaussian Beam Analysis

By analyzing differences in phase and amplitude of a signal, information about differing acoustic contrast between materials can be quantified. Prior methods used a scanning acoustic microscope which allowed for phase shifts to be identified by reflections but could not quantify phase shifts besides 0° or 180°. The new method uses a continuous signal to identify more precisely the phase and amplitude to analyze the transmitted signal. We have utilized the knowledge that the acoustic signal used behaves as a Gaussian beam travelling through a material. As the beam comes into contact with a defect, it is theorized to split into multiple source waves on either side which interfere as they travel across the plate to the receiver. By keeping the transmitter stationary and probing the receiver, we examine how the phase and amplitude change as the distance between transducers varies (transverse profiles). This approach potentially has a biological application because the acoustic contrast between healthy cells and cancerous cells is difficult to identify using current ultrasonic methods. This testing method could potentially gather more precise data with respect to the slightly differing contrasts between the cells and help better identify the presence and location of unhealthy cells.