Measurements comparing the linearly propagated field using an effective apodization and the nonlinearly generated second harmonic field

摘要

We have previously introduced the concept of an "effective apodization" as a linear description of the nonlinearly generated harmonic components of a finite amplitude ultrasonic field. The objective of the present work is to examine the seemingly unlikely possibility that an approach based solely on the linear back-propagation of measured data from the focal plane can accurately describe the nonlinearly generated field over a very wide range of depths.