{"id":11465,"date":"2025-12-10T11:07:45","date_gmt":"2025-12-10T10:07:45","guid":{"rendered":"https:\/\/soliton-gmbh.de\/?post_type=product&p=11465"},"modified":"2026-09-11T16:47:44","modified_gmt":"2026-09-11T14:47:44","slug":"fiber-optic-hydrophone-of-the-hfo-series","status":"publish","type":"product","link":"https:\/\/soliton-gmbh.de\/en\/produkt\/faseroptisches-hydrofon-der-hfo-serie\/","title":{"rendered":"HFO-690 \u2013 Fiber-optic hydrophone measurement technology for high-power ultrasound"},"content":{"rendered":"

HFO-690 \u2013 Fiber-optic hydrophone measurement technology for high-power ultrasound<\/h2>\n

The Onda HFO-690 Fiber Optic Hydrophone<\/strong> was specially developed for the measurement of high-intensity ultrasound fields. Unlike conventional piezoelectric hydrophones, the HFO-690 operates with an optical fiber tip, making it suitable for sound pressures of up to 500 MPa<\/strong>.<\/p>\n

A typical application area is the characterization of High Intensity Focused Ultrasound (HIFU)<\/strong>. In addition to the acoustic pressure, the system can simultaneously Temperature<\/strong> captures and thus enables a comprehensive investigation of high-intensity ultrasound fields.<\/p>\n

High bandwidth and spatial resolution<\/h2>\n

The HFO-690 offers an exceptionally wide frequency range of 3 kHz to 150 MHz<\/strong> and a spatial resolution of 100 \u00b5m<\/strong>. This also makes it possible to investigate complex and highly focused ultrasonic fields with high spatial resolution.<\/p>\n

The nominal acoustic sensitivity is 6 mV\/MPa<\/strong>. Bandwidth limiting filters allow adaptation to the respective measurement task while reducing the noise equivalent pressure.<\/p>\n

Simultaneous sound pressure and temperature measurement<\/h2>\n

A special feature of the HFO-690 is the possibility to, to measure acoustic pressure and temperature simultaneously<\/strong>. The temperature measurement offers a sensitivity of 10 mV\/\u00b0C; Onda specifies operation in water in the temperature range of 5 to 95 \u00b0C<\/strong>.<\/p>\n

Especially in HIFU applications, this combination is interesting because, in addition to the acoustic field distribution, thermal effects can also play a significant role.<\/p>\n

Robust against extreme ultrasonic fields<\/h2>\n

Conventional piezoelectric hydrophones can be damaged at very high acoustic intensities. In contrast, the fiber-optic measurement principle of the HFO-690 enables measurements at sound pressures up to 500 MPa<\/strong>, with Onda pointing out that the allowable load depends on the frequency content of the signal.<\/p>\n

Furthermore, the optical probe is immune to electrical or electromagnetic interference<\/strong>. Ambient light is optically filtered so that interfering stray light has as little influence on the measurement as possible.<\/p>\n

Simple alignment and handling<\/h2>\n

The HFO-690 is designed as a fully integrated measuring system and features a Touchscreen user interface<\/strong>. A visible light source facilitates the alignment of the fiber tip within the measurement setup.<\/p>\n

Damaged fiber tips can be restored within a short time using a simple cleaving process. In addition, the system features a simple calibration routine for practical measurement use.<\/p>\n

Typical applications<\/h2>\n

The HFO-690 is particularly suitable for measurement tasks where high sound pressure levels, a wide bandwidth, or a very small measurement area are required:<\/p>\n