Patent ID: 6057927
Filing Date: 2000-05-02
Classification: G01B,G01K,G01N

Abstract:
An apparatus comprising:generating means for applying a radiation pulse from a pulsed source of radiation to an object to generate elastic waves therein;detecting means for optically detecting the elastic waves generated in the object by said generating means, wherein said detecting means comprises an interferometer for optically detecting the elastic waves; andanalyzing means for analyzing the elastic waves optically detected in the object by said detecting means, said analyzing means comprising shear resonance identifying means for identifying at least one shear resonance in the object in accordance with the elastic waves optically detected in the object by said detecting means,wherein the elastic waves are generated in the object without frequency sweeping, andwherein the radiation pulse generates a broadband ultrasonic pulse in the object, whereby said generating means simultaneously excites a broad frequency spectrum of elastic waves in the object.