Long-range, high-precision absolute distance measurement based on two optoelectronic oscillators

Area of Science:

• Optoelectronics
• Metrology
• Precision Measurement

Background:

• Accurate distance measurement is crucial in various scientific and engineering fields.
• Traditional methods face limitations in long-range precision and environmental interference.
• Optoelectronic oscillators offer potential for advanced metrology applications.

Purpose of the Study:

• To demonstrate a new scheme for long-range, high-precision absolute distance measurement.
• To convert distance information into frequency information using optoelectronic oscillators.
• To leverage self-referencing and accumulative magnification for enhanced accuracy.

Main Methods:

• Utilizing two coupled optoelectronic oscillators (OEOs) for distance measurement.
• Employing frequency detection to translate distance into measurable frequency shifts.
• Applying accumulative magnification theory to reduce measurement error.

Main Results:

• Achieved micro-meter level accuracy over a distance of approximately 3.35 km.
• Demonstrated a maximum error of ±1.5 μm, including environmental drift.
• Attained a highest relative measurement precision of 4.5×10⁻¹⁰.

Conclusions:

• The proposed two-OEO system enables unprecedented long-range, high-precision absolute distance measurement.
• The self-referencing design and error reduction techniques significantly improve measurement fidelity.
• This technology holds promise for applications demanding extreme measurement accuracy.