Fiber optic hydrophones for underwater monitoring

F. A. Bruno; M. Janneh; S. Guardato; G. P. Donnarumma; G. Iannaccone; G. Gruca; S. Werzinger; A. Gunda; N. Rijnveld; A. Cutolo; M. Pisco; A. Cusano

doi:10.1117/12.2678297

23 May 2023 Fiber optic hydrophones for underwater monitoring

F. A. Bruno, M. Janneh, S. Guardato, G. P. Donnarumma, G. Iannaccone, G. Gruca, S. Werzinger, A. Gunda, N. Rijnveld, A. Cutolo, M. Pisco, A. Cusano

Author Affiliations +

Proceedings Volume 12643, European Workshop on Optical Fibre Sensors (EWOFS 2023); 1264304 (2023) https://doi.org/10.1117/12.2678297
Event: European Workshop on Optical Fibre Sensors (EWOFS 2023), 2023, Mons, Belgium

Abstract

We report on the development and field test of fiber optic hydrophones (FOHs). In details, we focused on the development of acoustic hydrophones for towed arrays applications and seismic hydrophones for seismological monitoring applications. In both cases, the sensing configuration is based on a Michelson interferometer where a fiber coil is wrapped around a compliant mandrel acting as a sensitive element. For the first application, acoustic hydrophones were characterized in an instrumented tank at Leonardo Finmeccanica premises. The hydrophone exhibited a responsivity of about 19 nm/Pa in the frequency range 3÷10 kHz with a resolution down to 300μPa /√Hz. The same FOHs were used as a basic building block to develop a towed array with five elements. By using the same enabling technology, but tailoring the physical and geometrical properties of hydrophones, we developed seismic hydrophones. The sensing system was integrated in the seismologic monitoring system and installed at Campi-Flegrei caldera. During the field trials, we detected several earthquakes occurred in the area and compared the results with a reference piezoelectric hydrophone. The seismic sequence was used to retrieve the sensor responsivity in the frequency range 1-80Hz. The sensing system exhibited a responsivity of about 300nm/Pa and an average noise floor level down to 100μPa/√Hz. The reported field trials demonstrated the capability of FOHs to operate in relevant environments and realistic scenarios.

Citation Download Citation

F. A. Bruno, M. Janneh, S. Guardato, G. P. Donnarumma, G. Iannaccone, G. Gruca, S. Werzinger, A. Gunda, N. Rijnveld, A. Cutolo, M. Pisco, and A. Cusano "Fiber optic hydrophones for underwater monitoring", Proc. SPIE 12643, European Workshop on Optical Fibre Sensors (EWOFS 2023), 1264304 (23 May 2023); https://doi.org/10.1117/12.2678297

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available