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Updated: Jun 6, 2026

Characterizing Far-infrared Laser Emissions and the Measurement of Their Frequencies
Published on: December 18, 2015
A novel laser wavelength meter based on the measurement of synthetic wavelength
Liping Yan1, Benyong Chen, Wanfu Yang
1Nanometer Measurement Laboratory, Zhejiang Sci-Tech University, Hangzhou 310018, China.
Abstract:
The accuracy of the current wavelength meter using optical interferometry is limited by the numbers of fringe counted. To solve this problem, a novel laser wavelength meter based on the measurement of synthetic wavelength is proposed. The unknown wavelength is obtained by measuring the value of synthetic wavelength produced by the unknown and reference wavelengths, and half of this value corresponds to 2π variation of the phase difference between the interference signals of the unknown and reference wavelengths. The optical configuration of the wavelength meter is designed and the measurement principle is analyzed theoretically. To verify its feasibility, three helium-neon lasers' wavelengths were determined experimentally, and a relative uncertainty on the unknown wavelength of the order of 10(-8) was realized. Accuracy analysis shows that this wavelength meter has the advantage of high accuracy when the unknown wavelength is around the standard laser wavelength recommended by CIPM.
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