High-precision absolute distance and vibration measurement with frequency scanned interferometry

Area of Science:

• Optical Physics
• Metrology
• Instrumentation

Background:

• Accurate distance and vibration measurements are crucial in various scientific and engineering fields.
• Traditional interferometry methods face limitations in precision and applicability for dynamic measurements.

Purpose of the Study:

• To develop a high-precision measurement system for absolute distance and vibration analysis.
• To demonstrate the capabilities of frequency scanned interferometry (FSI) using optical fibers.

Main Methods:

• Utilized frequency scanned interferometry with a pair of single-mode optical fibers.
• Employed a high-finesse Fabry-Perot interferometer to precisely track laser frequency changes during scanning.
• Developed two novel multiple-distance-measurement analysis techniques.

Main Results:

• Achieved absolute distance measurement precision of approximately 50 nm for distances between 0.1 to 0.7 m.
• Successfully extracted vibration frequencies from 0.1 to 100 Hz with amplitudes as small as a few nanometers.
• Demonstrated vibration measurement capability without requiring a priori knowledge of vibration parameters.

Conclusions:

• Frequency scanned interferometry with optical fibers offers a robust method for high-precision metrology.
• The developed analysis techniques significantly enhance the capabilities for both static distance and dynamic vibration measurements.
• This approach provides a versatile tool for applications requiring sensitive and accurate nanoscale measurements.