Long distance measurement by dynamic optical frequency comb.

Area of Science:

• Optics and Photonics
• Metrology
• Precision Measurement

Background:

• Traditional absolute distance measurement methods often rely on stable frequency comb spacing.
• Existing techniques can be limited by bulky phase-locking circuits and finite non-ambiguity ranges.

Purpose of the Study:

• To propose and validate a new method for absolute distance measurement.
• To overcome limitations of conventional techniques by sweeping frequency comb repetition frequency.
• To achieve an infinitely expandable non-ambiguity range for distance measurements.

Main Methods:

• Utilizing the slope of the inter-mode beat phase by sweeping the repetition frequency of a frequency comb.
• Developing a simplified measurement setup without requiring bulky phase-locking circuits.
• Conducting distance experiments in laboratory and outdoor environments.

Main Results:

• Experimental results demonstrate high accuracy in absolute distance measurements.
• Achieved differences within 25 µm at 65 m in a laboratory setting.
• Achieved differences within 100 µm at 219 m in an outdoor setting.

Conclusions:

• The proposed method offers a robust and simplified approach to absolute distance measurement.
• The technique effectively expands the non-ambiguity range, enabling measurements over extended distances.
• This advancement has significant implications for metrology and precision engineering applications.