| 摘要 |
First 101 and second 102 pulsed waves are transmitted along first and second transmit beams and the transmit timing between said first and second pulsed waves are selected so that the pulsed wave fronts overlap in an overlap region R(r,t) that propagates along at least one measurement or image curve Î (r) in the material object 103 . The scattered signal produced by nonlinear interaction between said first and second waves in the overlap region is received and processed to form a nonlinear interaction scattering image signal along Î (r). The measurement or image curve can be scanned laterally by changing the relative transmit timing between the first and second waves or the direction of at least one of the first and second transmit beams, or both. The methods are applicable to imaging nonlinear scattering sources for both electromagnetic and elastic or acoustic waves, and combinations of these. Imaging micro-bubbles and micro-calcifications, detecting fish and characterising borehole formations are potential applications. |
