Architecture for microcomb-based GHz-mid-infrared dual-comb spectroscopy

Area of Science:

• Spectroscopy
• Quantum Optics
• Infrared Technology

Background:

• Dual-comb spectroscopy (DCS) provides high sensitivity and broad spectral coverage.
• Mid-infrared (mid-IR) spectroscopy is crucial for analyzing molecular signatures.
• Existing DCS systems can be complex and require bulky components.

Purpose of the Study:

• To demonstrate GHz-resolution mid-IR DCS using a simplified, chip-based architecture.
• To achieve rapid spectral measurements of gases like methane and ethane.
• To explore the potential for on-demand spectral resolution tuning.

Main Methods:

• Utilized counter-propagating (CP) soliton microcombs.
• Employed interleaved difference frequency generation to create mid-IR combs.
• Integrated all optical components onto a single microcavity for stability and reduced complexity.

Main Results:

• Achieved GHz-resolution mid-IR DCS spectra of methane and ethane.
• Demonstrated rapid measurements within 0.5 ms intervals.
• Showcased tunable spectral resolution capabilities.

Conclusions:

• The developed system offers a simplified, compact architecture for mid-IR DCS.
• This advancement is a significant step towards chip-based mid-IR gas sensors.
• Potential applications include chemical threat detection, breath analysis, and environmental monitoring.