Fibre optics wavemeters calibration using a self-referenced optical frequency comb

Area of Science:

• Metrology
• Optical Engineering
• Telecommunications

Background:

• Optical frequency combs offer high-accuracy frequency measurements, approaching atomic clock precision (<10^-13 s).
• Accurate laser frequency measurement is crucial for optical communication systems.
• Wavemeters are essential for calibrating and verifying laser frequencies in the optical communication window.

Purpose of the Study:

• To present a technique for measuring laser frequencies using self-referenced optical frequency combs.
• To apply this technique for calibrating two wavemeters within the 1.5 μm optical communication band.
• To analyze the long-term stability and temperature dependence of a high-resolution wavemeter.

Main Methods:

• Utilizing self-referenced optical frequency combs for laser frequency metrology.
• Applying the technique to calibrate two distinct wavemeters operating at 1.5 μm.
• Conducting a 750-hour continuous operation test for a high-resolution wavemeter.
• Investigating the impact of temperature variations on wavemeter performance.

Main Results:

• Achieved calibration uncertainties of 12 MHz and 59 MHz for the two wavemeters.
• Observed a measurement dispersion of 7.72 MHz for the high-resolution wavemeter over 750 hours.
• Reduced wavemeter dispersion to 2.15 MHz by analyzing and compensating for temperature dependence.
• Demonstrated no significant temporal deviations in wavemeter measurements after temperature analysis.

Conclusions:

• Self-referenced optical frequency combs provide a robust method for calibrating wavemeters in optical communication bands.
• The developed calibration technique significantly enhances the accuracy and reliability of optical frequency measurements.
• Temperature compensation is critical for achieving high precision and long-term stability in wavemeter operation.