In many technical fields, as well as medicine, there is a need for measuring pressure shockwaves with high amplitudes and short duration. Classical hydrophones prove to be inadequate for such measurements, as their frequency response is too low. We therefore assembled an optical fiber hydrophone, whose functioning principle does not limit the frequency response. Such a hydrophone can measure pressure waves of amplitudes up to 100 MPa and sub-100 nanosecond duration. The hydrophone was tested in conjunction with a shockwave generation system based on absorption of Er:YAG laser light in water, via an optical fiber tip. The achieved measurable shockwave amplitude is 9 MPa, with a sensitivity of 0.97 mV/MPa. A method for measuring the laser induced cavitation bubble propagation speed is also proposed, as well as a method for detection and counting of the number of bubble collapses.
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