High-precision short-distance dual-comb ranging system without carrier-envelope-offset locking.

Area of Science:

• Optics and Photonics
• Metrology
• Precision Engineering

Background:

• Accurate short-distance measurement is crucial in various scientific and industrial applications.
• Existing methods like laser interferometry face limitations in precision and dynamic range.
• Dual-comb ranging (DCR) offers potential for high-resolution measurements but requires optimization.

Purpose of the Study:

• To develop a high-precision dual-comb ranging (DCR) method for short-distance measurement.
• To enhance the accuracy and dynamic distance resolution of DCR systems.
• To avoid complex carrier-envelope-offset locking in DCR systems.

Main Methods:

• Implementation of a high-precision dual-comb ranging (DCR) system.
• Introduction of cross-polarization detection to leverage interferogram coherence.
• Development of a carrier-wave phase difference (CPD) calculation algorithm using centroid extraction.

Main Results:

• Achieved a dynamic distance resolution of less than 10 nm at a 10 µm distance.
• Reduced the standard deviation of carrier-wave phase difference (CPD) by eight times compared to previous work.
• Demonstrated residual errors of less than ±40 nm when compared to a He-Ne laser interferometer over a 4.8 mm range.

Conclusions:

• The proposed DCR method offers superior precision and resolution for short-distance measurements.
• The novel CPD algorithm and cross-polarization detection significantly improve system performance.
• This technique provides a robust and accurate alternative to traditional interferometry for micro-scale metrology.