Pictoral representation showing a sample with a source transducer capable of emitting a signal unidirectional in the direction in the frame at ; and a laser vibrometer receiver measuring the components in the frame at .
Experimental setup. The DLV used to obtain the in-plane components is mounted on a rotational stage in order to measure the and components individually. The DLV and normal LV are focused coincidently and synced to obtain in-plane and out-of-plane components simultaneously. For the experiments reported here , the unit vectors for which are shown.
Numerical simulations of the selective focusing after reciprocal TR of individual particle velocity components and of various combinations. The simulations are performed for a cube of fused silica, and for with excitation in the plane, reception in the plane. Left column specifies the scalar input information supplied to the source for rebroadcasting at position . Right column displays the subsequent recording of the three particle velocity components at location .
Experimentally obtained signals during the reciprocal TR focusing process. (a) & (b) Respectively, the normal and in-plane component signals recorded during the broadcast of ; note the high amplitude focusing that occurs in the component and is absent in the (also absent in , not shown). (c) & (d) The and component signals recorded during the broadcast of ; note the focusing now seen in the component, not in the or (not shown). (e) & (f) The and component signals recorded during the broadcast of ; note the focusing now seen in both components. The reduced amplitude of each focus is due to the conservation of energy in that one transducer is only capable of emitting a finite amount of energy into the system.
Three component focusing with . Model (top row) and experimental (bottom row) results. Magnitude of the three velocity components of motion , and . The color scales are normalized to the maximum amplitude in each respective component. Note the near identical focal structure for each component.
Single component focusing with . Model (top row) and experimental (bottom row) results. Three velocity components of motion , and . The color scales are normalized to the maximum amplitude in each respective component to illustrate the full structure of the vector wave field. Note the in-plane dipole motion seen in the and components around the focal location due to the Poisson effect.
Single component focusing with . Model [(a) & (c)] and experimental [(b) & (d)] results. (a) & (b) Out of plane and (c) & (d) in-plane magnitudes, i.e., and , respectively. Each column uses the same color scale to accurately depict the relative amplitudes of the in-plane and out of plane components at the time of focus. The Poisson effect is manifest in the in-plane components around the focal location, however, these amplitudes, while higher than the background, are still small with respect to the focal amplitude along (out of plane).
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