Application Cases

With the continuous development of technology, sonar technology has become increasingly important, and fiber-optic hydrophones are a key component of sonar technology. In the experiment, fiber-optic hydrophones were fabricated using gold-coated stainless steel and quartz thin films as reflective strain films, which have the advantages of small size, high sensitivity, and low cost. To verify the performance indicators of the fiber-optic hydrophones, a test system was built around the power amplifier in the experiment to detect their responses to static and dynamic pressures, aiming to provide valuable research results for the development of fiber-optic hydrophone technology.

The Aigtek ATA-1200C broadband amplifier, with a maximum output voltage of 30 Vpp and a bandwidth range of DC to 25 MHz, features low distortion and high stability, providing strong support for driving ultrasonic transducers.

Experiment Name: Development of a Dynamic Pressure Testing System for Fiber-Optic Hydrophones

Experiment Principle:

The signal generator, combined with the power amplifier, drives the ultrasonic transducer to produce sound waves. The fiber-optic hydrophone works by sending light from the light source through the fiber into the modulator, where the underwater acoustic signal to be measured interacts with the light entering the modulation zone. This interaction causes changes in the optical properties of the light (such as intensity, frequency, phase, etc.), forming a modulated signal light. Then, by utilizing the influence of the measured quantity (i.e., the underwater acoustic signal) on the transmission characteristics of the light, the modulated optical signal is transmitted through the fiber to the signal processing system.

Experimental Block Diagram:

Experimental Photograph:

Experimental Process:

For static testing, the hydrophone is placed in a graduated cylinder, while for dynamic testing, the hydrophone is placed in a water tank (later changed to a round bucket) along with a ceramic piezoelectric transducer. After the signal generator produces a signal, it is amplified by the power amplifier to drive the transducer to emit sound. The fiber-optic hydrophone placed in the water tank controls the vibration intensity of the reflective film by absorbing the sound pressure, thus causing changes in the intensity of the reflected light. After reflection, the light is converted into an electrical signal. In dynamic testing, an RC filter circuit is added. The signal is displayed on an oscilloscope and finally processed with a MATLAB narrowband bandpass filter function.

Experimental Results:

The measured results of the gold-coated quartz film hydrophone match well with the theory. It has a larger diameter and higher sensitivity but a smaller detection range. The measured results of the stainless steel film hydrophone deviate significantly from the ideal values. The sound pressure range shows good linearity. The gold-coated quartz film hydrophone has better sensitivity and a lower detection limit than other comparisons. Hydrophones with different diameters of gold-coated quartz films perform accordingly within their respective frequency ranges, while the resonant frequency of the stainless steel film hydrophone deviates significantly from the theoretical value.

Application Directions: Communication Engineering, Environmental Monitoring, Military Field, Biomedical

Application Scenarios: Acoustic Measurement and Testing, Sonar System Testing

Product Recommendation: ATA-1000 Series Broadband Amplifiers

Figure: Performance Parameters of the ATA-1000 Series Broadband Amplifiers

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