Characteristic Evaluation of Lenses for Ultrasonic Micro-Spectrometer

概要

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An ultrasonic micro-spectrometer (UMSM) was previously developed to measure the reflection coefficient of a solid specimen at a small spot on its surface. Lenses for the UMSM consist of a paired spherical transmitter and planar receiver, denoted as SPP lenses. In this paper, we show by both experiment and calculation that an acoustic field at the back focal plane of the spherical lens directly influences the incident angular dependence of the SPP lenses output. The acoustic field distribution depends strongly on the axial symmetry of the transducer in the spherical transmitter. Therefore, rapid variation of the field in the case of a circular transducer is successfully prevented by changing the transducer to a rectangular one, which is suitable for system normalization.
社団法人応用物理学会の論文
1993-05-30