Holographic interferometric vibration measurement based on photorefractive crystal in diffusion mode

Area of Science:

• Optics and Photonics
• Vibration Analysis
• Materials Science

Background:

• Traditional vibration measurement systems can be complex and pose safety risks.
• High-frequency vibration detection requires sensitive and accurate methodologies.

Purpose of the Study:

• To develop and validate a dynamic holographic vibration measurement system.
• To enable simultaneous measurement of in-plane and out-of-plane vibrations.
• To achieve sensitive and linear demodulation of vibration signals.

Main Methods:

• Theoretical and experimental investigation of a holographic system using a bismuth silicon oxide (BSO) photorefractive crystal.
• Utilizing diffuse mode operation without an external electric field.
• Adjusting reference beam polarization to introduce a π/2 phase shift for enhanced sensitivity.

Main Results:

• The system successfully measures high-frequency (MHz level) vibrations with sub-micron accuracy.
• Demonstrated simultaneous measurement of in-plane and out-of-plane vibrations.
• Confirmed system practicality, safety, and superior performance compared to high-voltage drift mode operations.

Conclusions:

• The developed holographic system offers a safe and effective method for dynamic vibration measurement.
• The system's sensitivity and accuracy are suitable for detecting subtle, high-frequency movements.
• Further analysis identified factors influencing measurement sensitivity.