Demonstration of Pressure Wave Observation by Acousto-Optic Sensing Using a Self-Mixing Interferometer.

Area of Science:

• Optics and Photonics
• Fluid Dynamics
• Acousto-optics

Background:

• Characterizing shock waves is crucial for understanding dynamic pressure phenomena.
• Traditional methods for shock wave measurement can be complex and expensive.
• Self-mixing interferometry offers a sensitive technique for detecting optical path length variations.

Purpose of the Study:

• To demonstrate a compact and inexpensive interferometric sensor for shock wave characterization.
• To utilize the self-mixing effect in a laser cavity for dynamic refractive index measurements.
• To validate the sensor's performance using a shock tube and compare results with acousto-optic models.

Main Methods:

• Development of a dynamic sensor architecture based on self-mixing interferometry.
• Design and implementation of an experimental setup incorporating a shock tube.
• Measurement of refractive index changes induced by shock waves with a pressure amplitude of 5 bar.

Main Results:

• Successful demonstration of a compact, low-cost self-mixing interferometric sensor for shock wave detection.
• Acquisition of experimental data for shock waves with a 5 bar pressure amplitude.
• Interpretation of measurements aligned with established acousto-optic models.

Conclusions:

• The self-mixing interferometric sensor is a viable and cost-effective tool for shock wave characterization.
• The sensor effectively measures refractive index variations caused by shock waves.
• This technique provides valuable data for validating theoretical models in acousto-optics and fluid dynamics.