Comb-locked frequency-swept synthesizer for high precision broadband spectroscopy

Area of Science:

• Spectroscopy
• Optical Metrology
• Laser Technology

Background:

• Frequency combs have advanced optical metrology and trace gas sensing.
• Current comb spectrometers face a trade-off between frequency precision and spectral coverage.
• Limitations exist in achieving both high sensitivity and broad bandwidth simultaneously.

Purpose of the Study:

• To introduce a novel comb-locked frequency-swept optical synthesizer.
• To overcome the limitations of existing comb spectrometers by enabling precise, broadband measurements.
• To enhance capabilities in trace gas sensing and optical metrology.

Main Methods:

• Development of a frequency-swept optical synthesizer phase-locked to a frequency comb.
• Utilizing a continuous-wave laser swept over terahertz spectral ranges in seconds.
• Implementing the synthesizer for both single-line precision measurements and broadband spectral acquisition.

Main Results:

• Achieved line center frequency determination with 30 kHz absolute uncertainty.
• Acquired absorption spectra over >3 THz with sensitivity of a few 10^-10 cm^-1.
• Demonstrated versatility for both high-precision and broadband spectroscopic applications.

Conclusions:

• The comb-locked frequency-swept optical synthesizer offers unprecedented versatility in spectroscopy.
• This technology enables simultaneous high precision and broad spectral coverage.
• The synthesizer is a promising tool for breakthroughs in terahertz metrology and coherent laser ranging.