| 摘要 |
<p>METHOD AND APPARATUS FOR STRUCTURAL ANALYSIS Apparatus for the non-destructive structural analysis of a solid object, the apparatus comprising: a laser pulse generating device to generate a laser beam pulse at a selected frequency for application to an input surface of an object to be analysed to generate an elastic wave pattern in the object; a scanning electron microscope for scanning at a frequency which is a multiple of the laser beam pulse frequency, the generated wave pattern over an output surface of the object to provide an output signal; a control device for controlling operation of the scanning electron microscope in relation to the laser beam pulse to progressively vary the phase difference between the scanning frequency and the laser beam pulse frequency, and a processing device for processing such an output signal to allow generation of a representative signal representative of such a wave pattern at a preselected time instant; generating means for generating a composite signal from such a representative signal and from a reference signal derived from the laser pulse frequency; and a digital computer for processing such a composite signal to provide reconstruction means in the form of a digital hologram for reconstructing a representation of the object. The invention further extends to a corresponding method.</p> |
