Rapidly tunable synthetic wavelength ranging with an RFSoC

Area of Science:

• Optics and Photonics
• Metrology
• Interferometry

Background:

• Accurate optical range and time-of-flight measurements are vital for advanced technologies.
• Existing optical measurement techniques often involve trade-offs between precision, accuracy, and system complexity.

Purpose of the Study:

• To introduce a novel continuous-wave synthetic wavelength interferometry technique.
• To demonstrate dynamic synthetic wavelength sweeping and absolute optical range measurement using digitally tunable electro-optic frequency combs.

Main Methods:

• Utilized digitally tunable electro-optic frequency combs for synthetic wavelength generation.
• Employed a software-defined radio for dynamic wavelength sweeping and control.
• Implemented continuous-wave interference principles for measurement.

Main Results:

• Achieved better than 60 nm (0.2 fs) precision over a 1 m free-space optical delay line.
• Demonstrated 15 µm precision (50 fs, 2×10⁻¹⁰ m/m fractional error) over a 40 km fiber link.
• Validated the digital approach for absolute optical range measurement.

Conclusions:

• The presented technique offers a simplified and digitally controlled method for high-precision optical range measurements.
• The system's reliance on continuous-wave interference reduces overall complexity.
• This digital synthetic wavelength interferometry shows promise for various high-precision applications.