Vernier spectrometer using counterpropagating soliton microcombs.

Area of Science:

• Photonics and Optical Engineering
• Spectroscopy
• Quantum Optics

Background:

• High-resolution laser frequency determination is crucial for applications in sensing, spectroscopy, and communications.
• Conventional methods often rely on complex dual-frequency comb systems.

Purpose of the Study:

• To demonstrate a single microresonator system for rapid and broadband optical frequency measurement.
• To achieve relative frequency precision comparable to conventional dual-frequency comb systems.
• To characterize laser tuning dynamics and spectral features with high accuracy.

Main Methods:

• Utilized dual-locked counterpropagating solitons with slightly different repetition rates.
• Implemented a vernier spectrometer configuration within a single microresonator.
• Applied the system to measure high laser tuning rates (up to 10 THz/s), step-tuned lasers, multiline spectra, and molecular absorption lines.

Main Results:

• Achieved rapid and broadband measurement of optical frequencies with high resolution.
• Demonstrated relative frequency precision comparable to established dual-frequency comb systems.
• Successfully characterized fast laser tuning, broadly step-tuned lasers, multiline spectra, and molecular absorption.

Conclusions:

• The dual-locked soliton microresonator offers technical simplification and enhanced measurement capabilities for arbitrarily tuned sources.
• This approach paves the way for chip-scale spectrometers with performance exceeding current tabletop grating and interferometer-based devices.
• The technology holds significant promise for advancing optical frequency metrology and related fields.