A NEW FOCUSING ULTRASONIC TRANSDUCER AND 2 FOCI ACOUSTIC LENS FOR ACOUSTIC MICROSCOPY

The textured piezoelectric film of a new organic-based material produc ed by vapor deposition was used as an active element of a focusing ult rasonic transducer. The transducer exhibits, near theoretical lateral and axial resolution, unipolar pulse response to a step voltage, and 3 0 dB insertion losses in octave frequency band, The transducer is acou stically transparent over a wide frequency range and can be fabricated on a concave spherical surface of the standard acoustic lens. The res ulting double transducer and two foci acoustic lens are capable of imp roving the quality of the surface structure imaging or of being used i n continuous wave reflection acoustic microscopy.