Simplified phase-stable dual-comb interferometer for short dynamic range distance measurement.

Area of Science:

• Optical Metrology
• Interferometry

Background:

• Accurate absolute distance measurement is crucial in various scientific and industrial applications.
• Traditional interferometric techniques often face challenges with dynamic range and precision.

Purpose of the Study:

• To propose a simplified phase-stable dual-comb interferometer for absolute distance measurement.
• To achieve high precision and a practical measurement dynamic range.

Main Methods:

• Development of a simplified phase-stable dual-comb interferometer.
• Utilizing a time delay of 2000 ns for stable phase-difference information and reduced timing jitter.
• Linking time-of-flight (TOF) and carrier-wave interferometric (CWI) results.

Main Results:

• Stable phase-difference information and lower timing jitter were experimentally verified.
• Direct linking of TOF and CWI results achieved in an average of 20 ms.
• Demonstrated nanometer-level precision (2 nm) within 0.5 s averaging time.
• Achieved millimeter-scale measurement dynamic range without additional noise suppression.

Conclusions:

• The proposed simplified dual-comb interferometer offers a robust method for absolute distance measurement.
• The technique provides high precision and a practical dynamic range, suitable for various stand-off distances.
• This approach enhances the efficiency and accuracy of optical metrology systems.