Dynamic microforce measurement by distortion detection with a coupled-cavity laser displacement sensor stabilized in...

Area of Science:

• Physics
• Mechanical Engineering
• Optical Sensing

Background:

• Accurate measurement of small forces is crucial in various mechanical systems.
• Existing sensors may lack the sensitivity required for detecting minute dynamic variations.

Purpose of the Study:

• To develop a novel displacement sensor for dynamically measuring small forces.
• To achieve high sensitivity and mechanical stability in the sensor design.

Main Methods:

• Utilized a coupled-cavity laser configuration with a moving external mirror.
• Implemented a negative-feedback loop for mechanical stabilization of the lasing state.
• Maintained a constant external-cavity length for consistent performance.

Main Results:

• Achieved a minimum detectable displacement of 0.8 nm.
• Demonstrated sensitivity independent of the lasing wavelength.
• Successfully detected extremely small distortions in a stiff cantilever.

Conclusions:

• The developed sensor offers high sensitivity for dynamic force measurement.
• It is effective in reflecting transient variations in small friction forces.
• The sensor has significant applications in analyzing mechanical systems with high precision.