- ABOUT US
Sunnyvale, CA – June 6, 2012 - Onda is proud to present at the 2012 ISTU in Heidelberg, Germany on the following topic:
Characterization of a New Fiber-Optic Hydrophone for High Intensity Acoustic Fields
Samuel M. Howard, Ph.D, Xi Chen, Ph.D., and Claudio I. Zanelli, Ph.D.
Background: Fiber-optic hydrophones present a rugged means of detecting high intensity acoustic fields directly. Key parameters are signal-to-noise ratios, highest pressure detectable, detector effective size, and bandwidth. Bare fiber designs normally have low signal-to-noise ratios but can withstand high pressures and can be re-used after cleaving. Fabri-Perot devices offer higher sensitivity, have simultaneous temperature sensing, have limited pressure range, and are not repairable by the user. One characteristic common to both is the use of infrared light, which presents a health hazard and requires eye protection.
Methods: A fiber-optic hydrophone recently developed to measure high intensity acoustic fields has been characterized in terms of its acoustic response and simultaneous temperature measurement capability. The system uses visible light, making it safer than previous designs, while maintaining the flexibility of cleavable and exchangeable fibers. Results: We show the effect of finite piston deconvolution, as well as the time vs noise tradeoff in its temperature response. Using 105 diameter micron fibers, we show response sensitivity over a 150MHz bandwidth. Temperature measurements show a noise of about +/- 2 deg C (using a 0.2 second integration time) can be improved by extended averaging, in detriment of response time.
Conclusion: This development represents a significant alternative to measure high intensity fields directly, at a relatively low cost and with increased safety.