Absolute angular position measurement by dual-comb spectroscopy of an autocollimation diffracted beam

Area of Science:

• Optics and Spectroscopy
• Metrology

Background:

• Dual-comb spectroscopy enables ultrahigh-resolution, fast broadband spectral measurements.
• Industrial inspection and scientific research require precise angular-position determination.

Purpose of the Study:

• To propose and experimentally demonstrate an absolute angular-position measurement method based on dual-comb spectroscopy.
• To achieve high-precision angular measurements with a simple experimental setup.

Main Methods:

• Utilizing the dual-comb spectroscopy technique for spectral measurements.
• Employing autocollimation diffracted beams from a target grating to determine absolute angular position.
• Leveraging traceable and wide-amplitude spectra for accurate positioning.

Main Results:

• Experimental demonstration of an absolute angular-position measurement method.
• Achieved precision of 0.12 arcsec within a dynamic range of approximately 6660 arcsec.
• Comparison residuals within ±0.3 arcsec against a commercial autocollimator over 1000 arcsec.

Conclusions:

• The proposed dual-comb spectroscopy method offers a simple yet effective approach for absolute angular-position measurement.
• The technique provides high precision and a wide dynamic range suitable for demanding applications.
• Demonstrated performance validates the method's potential for industrial and scientific use.