Acoustic Sensing

We capture acoustic information beyond human perception and reveal acoustic events invisible to conventional sensors.

XARION Acoustic Sensing enables contactless measurement and analysis of airborne acoustic signals in industrial and scientific applications. Main application fields include sound-field characterization of ultrasonic sources, and process monitoring in applications such as pulsed laser drilling, laser powder bed fusion, ultrasonic welding, and acoustic crack or anomaly detection.

At the core of the system is XARION's Optical Microphone. It detects sound pressure optically and without moving mechanical parts. This enables broad measurement bandwidth, fast temporal response, and robust signal acquisition in environments where conventional microphones or piezoelectric sensors may be limited.

  • The Optical Microphone from XARION covers a very wide frequency range that includes both low and very high-frequency acoustic signals. Depending on the Optical Microphone model, the bandwidth can range from 10 Hz to 1 MHz, 50 kHz to 2 MHz, or 50 kHz to 4 MHz.

  • Model selection depends mainly on frequency range and expected sound pressure level. Eta450 and Eta600 are suitable for weaker, high-frequency ultrasonic signals. Eta250 is a general-purpose process-monitoring model. Eta100 is better suited for very high sound pressure levels.

  • Typical applications include pulsed processes such as laser drilling, laser ablation, laser cleaning, LPBF, ultrasonic welding (wire-to-terminal welding, foil-to-tab welding), and crack detection. Acoustic signatures can be correlated with process stability, parameter changes, defect formation, or other process deviations depending on the application.

  • XARION provides different system options depending on the application and level of integration required. For process monitoring applications, XARION offers a Process Monitoring Bundle including, aside from the Optical Microphone, a dedicated FPGA-based industrial PC performing real-time spectrogram calculations at a rate of up to 30,000 spectra / s (HF-MES). For industrial production environments, XARION can provide application-specific systems for integration into existing machines or production lines. The acquired data are processed in real time. Based on trained in reference values system provides OK/NOK signals for direct feedback to the production process.

  • Signals can be acquired digitally and analyzed in real time. Typical methods include filtering, time-domain evaluation, FFT/spectrogram analysis, energy curves, event detection, thresholding, and feature extraction for statistical or data-driven models. The XARION PM Bundle includes the Optical Microphone, acquisition hardware, and real-time analysis tools.

  • The Optical Microphone offers an unmatched bandwidth for airborne sound measurements, up to 4 MHz depending on the model. It has no moving membrane, avoids mechanical resonance effects, and is insensitive to electromagnetic interference. Compared with piezoelectric AE sensors, it does not require mechanical coupling to the part or machine structure.

  • Yes, XARION offers the possibility to evaluate the technical feasibility of an application in advance through measurement and trial days. Measurements can be carried out either in XARION’s test laboratories or directly at the customer’s site especially for processes or installations that cannot be reproduced in a lab environment. If you are interested in a trial day, please contact: This email address is being protected from spambots. You need JavaScript enabled to view it..

  • By continuously capturing acoustic signals, process deviations can be detected at an early stage, often before visible defects occur. This supports early quality control and process optimization.

  • Yes, Optical Microphones can generally also be used for acoustic measurements in water. For this application area, XARION offers dedicated Optical Hydrophones specifically designed for acoustic measurements in liquids.