Application Cases

Acoustic Field Reconstruction holds significant importance across multiple domains. However, traditional methods, such as sensor array techniques, present various limitations. Optical methods, characterized by non-contact operation and high precision, are rapidly advancing. This experiment, based on the principle of beam deflection, investigates acousto-optic interaction models and tomographic reconstruction theory. By integrating reconstruction methods that account for the physical properties of sound waves with acousto-optic holography algorithms incorporating gradient fields, we designed an underwater acousto-optic sensing platform for experimental validation. This approach aims to achieve the joint reconstruction of sound pressure and gradient fields, overcoming the shortcomings of conventional methods and providing novel insights for acoustic field reconstruction.

Aigtek's ATA-4051C High-Voltage Power Amplifier, known for its low distortion and high stability, offers robust support for driving ultrasonic transducers.

Experiment Name: Measurement of Underwater Acoustic Field Sound Pressure and Gradient

Experimental Principle:
The experiment utilizes the beam deflection principle. A laser beam is projected vertically into a water tank containing an ultrasonic transducer. When the transducer emits sound, it alters the water's refractive index, modulating the laser beam. The modulated beam is then captured by a position-sensitive detector. Leveraging the acousto-optic effect, information about the sound pressure gradient is derived by measuring the beam's deflection. Tomographic imaging techniques are employed, using Radon transform and inverse transform principles alongside projection data from various angles to reconstruct the acoustic field. Concurrently, compressive sensing theory is applied, capitalizing on the sparsity of the acoustic field's divergence to reduce data volume, thereby enhancing reconstruction efficiency and accuracy, ultimately achieving the joint reconstruction of sound pressure and gradient fields.

Experimental Block Diagram:

Experimental Setup Photo:

Experimental Procedure:
Prior to the experiment, the optical path was aligned to ensure the laser beam entered the water tank vertically and was centered on the four-quadrant detector. A signal generator produced a pulsed signal, which was amplified by a power amplifier to drive the underwater acoustic transducer. The transducer-generated acoustic waves changed the water's refractive index, causing the laser beam to deflect. The four-quadrant detector recorded the beam position, and its output signal was transmitted to a data acquisition unit after high-frequency noise removal via a low-pass filter. A translation stage controlled the transducer's movement, enabling multi-angle scanning to obtain beam deflection data from different positions and angles for subsequent acoustic field reconstruction and analysis.

Experimental Results:
The experiment analyzed the time-domain and frequency-domain characteristics of the beam deflection signal, confirming the feasibility of quantitatively calculating sound pressure and sound pressure gradient from the deflection angle. The results indicate that gradient field reconstruction based on beam deflection can effectively capture sound pressure and gradient information of the acoustic field. The reconstruction method based on Kirchhoff integral demonstrated higher accuracy than the traditional angular spectrum method and enabled the separate reconstruction of single-sided and double-sided sound sources.

Application Areas: Communication Engineering, Environmental Monitoring, Military Applications, Biomedical

Application Scenarios: Acoustic Measurement and Testing, Ultrasonic Testing, Underwater Target Detection

Product Recommendation: ATA-4000 Series High-Voltage Power Amplifier

Figure: ATA-4000 Series High-Voltage Power Amplifier Specifications

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