Dual-comb spectroscopy for in-plane angle measurement using OAM vortex light.

Area of Science:

• Optics and Photonics
• Metrology
• Spectroscopy

Background:

• Dual-comb spectroscopy (DCS) is a powerful tool for high-resolution spectral measurements.
• Optical vortices possess orbital angular momentum (OAM) and a helical phase structure.
• Integrating DCS with optical vortices has not been previously explored for dimensional expansion.

Purpose of the Study:

• To propose and demonstrate a novel measurement concept, dual-vortex-comb spectroscopy (DVCS).
• To extend dual-comb spectroscopy into angular dimensions.
• To explore the potential of optical vortices in enhancing metrological capabilities.

Main Methods:

• Combining dual-comb spectroscopy with optical vortices carrying orbital angular momentum.
• Utilizing the helical phase structure of optical vortices to encode angular information.
• Performing a proof-of-principle experiment to measure in-plane azimuth angles.

Main Results:

• Demonstrated in-plane azimuth-angle measurements with an accuracy of approximately 0.1 mrad after cyclic error correction.
• Verified the origin of cyclic errors through simulation.
• Showcased that the measurable angle range can be controlled by the topological number of optical vortices.

Conclusions:

• Achieved the first demonstration of dimensional conversion between in-plane angle and dual-comb interferometric phase.
• Established DVCS as a viable technique for angular metrology.
• This work significantly expands the applicability of optical frequency comb metrology into new dimensions.