25 June 2003 Tailoring ultrasonic beams with optoacoustic holography
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Proceedings Volume 4969, Laser Resonators and Beam Control VI; (2003) https://doi.org/10.1117/12.483648
Event: High-Power Lasers and Applications, 2003, San Jose, CA, United States
Abstract
A combination of laser-induced ultrasound generation and ultrasonic holography for spatial control of the generated ultrasonic pulse is presented. Ultrasound is produced by absorption of laser pulses at an absorbing layer in a water tank via the optoacoustic effect. In order to produce a defined ultrasonic frequency in the MHz range, the laser pulses are harmonically time-modulated using an acousto-optic modulator (AOM). Additionally, the laser intensity is spatially controlled. This is realized with a high resolution liquid crystal spatial light modulator (LCD). A computer generated pattern is displayed at the LCD and projected by the expanded laser beam to an absorptive layer in the water tank. As a result, the emitted ultrasonic wave emerges in a predetermined way, which is an acoustical analogue to the effect of a "diffractive optical element" in laser optics. The flexible method of optical ultrasound generation and diffractive steering promises new applications in medical and technical ultrasound diagnostics.
© (2003) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Alex Meyer, Alex Meyer, Stefan Josef Gspan, Stefan Josef Gspan, Stefan Bernet, Stefan Bernet, Monika Ritsch-Marte, Monika Ritsch-Marte, } "Tailoring ultrasonic beams with optoacoustic holography", Proc. SPIE 4969, Laser Resonators and Beam Control VI, (25 June 2003); doi: 10.1117/12.483648; https://doi.org/10.1117/12.483648
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