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Integrating high-precision and fringe-scale displacement sensing using heterodyne cavity-tracking
Optics Express
|August 13, 2025
Summary
We developed a compact interferometer for highly sensitive displacement measurements. This novel technique achieves sub-femtometer sensitivity and a wide dynamic range, advancing precision sensing capabilities.
Area of Science:
- Optics and Photonics
- Metrology
- Precision Engineering
Background:
- High-sensitivity displacement sensing is crucial for various scientific and industrial applications.
- Existing interferometric techniques often face limitations in terms of size, sensitivity, or dynamic range.
Purpose of the Study:
- To present a novel heterodyne stabilized cavity-based interferometer scheme.
- To demonstrate a compact and high-sensitivity displacement sensor with a fringe-scale operating range.
Main Methods:
- Utilizing a heterodyne stabilized cavity-based interferometer.
- Probing a length-actuated cavity to measure displacement.
Main Results:
- Achieved a sensitivity of 260 fm/Hz at 1 Hz and 46 fm/Hz at 130 Hz.
- Demonstrated a dynamic range of six orders of magnitude for displacement measurement.
- Reached a maximum motion of 0.15 μm, with potential for sub-femtometer noise floor.
Conclusions:
- The developed interferometer scheme offers a compact and highly sensitive displacement sensing solution.
- The technique shows promise for reaching sub-femtometer noise floors and wide dynamic ranges.
- Future improvements can extend the tracking bandwidth and displacement range by addressing signal digitization limitations.
