Heterodyne multi-wavelength absolute interferometry based on a cavity-enhanced electro-optic frequency comb pair.

Area of Science:

• Optics and Photonics
• Metrology
• Precision Measurement

Background:

• Traditional interferometers face limitations in range and absolute distance measurement.
• Frequency combs offer potential for high-precision metrology but require sophisticated generation techniques.

Purpose of the Study:

• To demonstrate a heterodyne absolute distance interferometer with macroscopic range.
• To utilize synchronized cavity-enhanced electro-optic frequency comb generators for precise distance determination.
• To validate the system's performance against a reference interferometer.

Main Methods:

• Employing a heterodyne measurement principle with a frequency comb pair.
• Generating the frequency comb pair coherently using synchronized cavity-enhanced electro-optic frequency comb generators.
• Determining absolute distance from interferometric phases of distinct comb modes via a parallel digital lock-in scheme.

Main Results:

• Achieved absolute distance measurement with a macroscopic range.
• Demonstrated agreement within 15 μm compared to a reference HeNe incremental interferometer.
• Successfully operated the interferometer up to a range of 10 meters.

Conclusions:

• The developed heterodyne absolute distance interferometer offers a promising solution for long-range, high-accuracy measurements.
• The use of synchronized frequency comb generators is effective for absolute distance determination.
• The system shows excellent agreement with established interferometric techniques.