Measurement of the spectral directivity of optoacoustic and ultrasonic transducers with a laser ultrasonic source
AUTOR(ES)
Conjusteau, André
FONTE
American Institute of Physics
RESUMO
Comprehensive characterization of wideband ultrasonic transducers and specifically optoacoustic detectors is achieved through the analysis of their frequency response as a function of the incident angle. The tests are performed under well-defined, repeatable operating conditions. Backillumination of a blackened, acoustically matched planar surface with a short laser pulse creates an acoustic impulse which is used as a wideband ultrasonic source. Upon illumination with a short laser pulse, the bandwidth of our source shows a −6 dB point of 12 MHz and a low-frequency roll-off around 300 kHz. Using proprietary software, we examine thoroughly the planarity of the emitted wave front within a specified amplitude cutoff and phase incoherence. Analysis of the angular dependence of the frequency response yields invaluable directivity information about the detector under study: a necessary component toward accurate optoacoustic image reconstruction and quantitative tomography. The laser ultrasonic source we developed is the main feature of our directivity measurement setup. Due to its simplicity, it can easily be adapted to various calibration devices. This paper focuses on the development and characterization of the flatness and the bandwidth of our wideband ultrasonic source.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=2766411Documentos Relacionados
- Volume and enthalpy changes after photoexcitation of bovine rhodopsin: laser-induced optoacoustic studies.
- RE: Ultrasonic Measurement of Testicular Tumors and the Correlation with Pathologic Specimen Sizes
- Ultrasonic measurement of coagulation and fibrinolysis
- Acoustic beam modeling of ultrasonic transducers and arrays using the impulse response and the discrete representation methods
- Analysis of 1-3 piezocomposite and homogeneous piezoelectric rings for power ultrasonic transducers