Computational multiheterodyne spectroscopy.

Area of Science:

• Spectroscopy
• Quantum Optics
• Metrology

Background:

• Dual-comb spectroscopy (DCS) offers high-resolution, broad-bandwidth spectral measurements.
• Coherent integration in DCS typically requires a phase reference, necessitating complex stabilization or correction of phase and timing errors.
• Current methods limit the applicability and complexity of DCS systems.

Purpose of the Study:

• To demonstrate a computational approach for extracting phase and timing information in multiheterodyne spectra.
• To eliminate the need for external phase references and optical elements in DCS.
• To simplify dual-comb systems and broaden the applicability of multiheterodyne techniques.

Main Methods:

• Developed computational algorithms to extract phase and timing signals directly from the multiheterodyne spectrum.
• Reconceptualized frequency combs based on the temporal structure of phase noise rather than frequency stability.
• Validated the method's viability even when relative linewidths exceed the repetition rate difference.

Main Results:

• Successfully extracted phase and timing signals computationally from multiheterodyne spectra.
• Demonstrated that the technique is effective without additional measurements or optical components.
• Showcased the method's robustness even with significant relative linewidths.

Conclusions:

• Computational extraction of phase and timing signals significantly simplifies dual-comb spectroscopy systems.
• This approach expands the scope and accessibility of multiheterodyne spectroscopy techniques.
• Reconceptualizing phase noise in frequency combs unlocks new possibilities for optical measurements.