An Optical Frequency Comb Tied to GPS for Laser Frequency/Wavelength Calibration

Area of Science:

• Metrology
• Optical Physics
• Precision Engineering

Background:

• Optical frequency combs offer broad spectral coverage for calibrating laser frequencies and vacuum wavelengths.
• Traceable standards are crucial for length measurements, with typical relative uncertainties of 10⁻⁸ to 10⁻¹².
• The Global Positioning System (GPS) provides a reliable frequency reference for metrology applications.

Purpose of the Study:

• To describe NIST's procedures for comb-based laser wavelength calibration.
• To detail ancillary measurements, including mode order determination.
• To ensure traceable standards for length metrology.

Main Methods:

• Utilizing optical frequency combs for laser wavelength calibration.
• Employing Global Positioning System (GPS) as a traceable frequency reference.
• Characterizing measurement errors in GPS-based comb systems.

Main Results:

• Established procedures for comb-based laser wavelength calibration at NIST.
• Demonstrated the effectiveness of GPS as a frequency reference for achieving traceable standards.
• Developed techniques for comprehensive error characterization in comb systems.

Conclusions:

• Comb-based calibration provides traceable standards for length measurement with high accuracy.
• GPS integration enhances the reliability and traceability of comb-based metrology.
• Thorough error characterization ensures confidence in measurement results.