Characterization of ultrasonic transducers using a fiberoptic sensor.
The PVDF (polyvinylidene fluoride) hydrophones, commonly used to measure the characteristics of ultrasonic transducers, suffer from a number of drawbacks. They disturb the field distribution to be measured and cause spatial averaging effects because of their finite aperture. In addition, they are very delicate and susceptible to damage. To overcome some of these problems, the authors previously proposed the use of an optical fiber-based probe to measure the ultrasonic fields. In this paper, this fiberoptic ultrasonic sensor is used to measure the characteristics of six transducers, focused as well as unfocused, covering a frequency range of 2.25 MHz to 20 MHz. Results obtained using the fiberoptic sensor are compared with those obtained using a calibrated PVDF needle hydrophone with an effective diameter of 0.5 mm. The temporal responses as well as the beam profiles of the transducers measured using the fiberoptic sensor show excellent agreement with the results obtained using the PVDF needle hydrophone.
Wu
Y Q
YQ
Biomedical Engineering and Science Institute, Drexel University, Philadelphia, PA 19104.
Shankar
P M
PM
Lewin
P A
PA
D005336:Fiber Optic Technology; D055100:Optical Fibers; D014159:Transducers; D014465:Ultrasonics