| 摘要 |
The present invention relates to a method and apparatus for providing a magnified image of a zone of a specimen. The method comprises the steps of generating acoustic waves having different frequencies and focussing on the zone the acoustic waves wherein different points on the zone receive and reflect acoustic waves having different frequencies, the frequency of a wave received by a given point being function of the position of the point in the zone. The method further comprises the steps of analyzing the reflected waves to generate signals representative of the physical structure of the zone at the points and establishing a correspondance between the signals and the positions of the points in the zone from the frequencies of the reflected waves and, forming from the signals a magnified representation on a display of the physical structure of the zone to construct an image of the zone. The invention also relates to the use of the same technique to obtain quantitative information on the acoustic properties of specimens on a microscopic scale. These properties, which include sound velocity and attenuation as a function of position, direction and frequency can be derived directly from the property of different emitted frequencies corresponding to different positions in the lens assembly. This property can also be used to obtain images for different incidence angles either independently or in any desired combination. |
