Experimental Study of a Sensor System Using an Optoelectronic Oscillator to Measure Acoustic Impact Intensity

Sensor systems that utilize an optoelectronic oscillator (OEO) have demonstrated their effectiveness in applications requiring high accuracy and rapid polling speeds. The OEO-based interrogation approach demonstrates distinct advantages compared to alternative fiber-optic sensing technologies. While plasmonic sensors and photonic crystal cavities can achieve higher sensitivity, the OEO system provides direct frequency-domain readout in the microwave range (GHz), eliminating the need for complex optical spectrum analysis. This paper presents the results of an experimental study to determine the sensitivity of an OEO-based sensor system used for measuring the intensity of acoustic impacts. The results achieved at a controlled temperature of 40°C to eliminate any influence of temperature variations on the system’s performance. The demonstrated sensitivity of 33.94 MHz/dBA and detection threshold of 84.8 dBA position this system as a complementary approach for acoustic emission monitoring, particularly suited for applications requiring high-speed interrogation and integration with microwave signal processing infrastructure. Compared to conventional FBG interrogation systems limited by the sensor’s quality factor, the OEO architecture leverages its own high-Q microwave oscillation, enabling enhanced resolution.