Traceability of the optical wavelength 633 nm calibration at SNSU-BSN

Abstract

Measurement traceability is the critical aspect in metrology area. As national metrology institute in Indonesia, National Measurement Standard Laboratory-National Standardization Agency of Indonesia, SNSU-BSN, maintains the recommended stabilized laser as primary standard of length, i.e., 633 nm iodine stabilized He-Ne laser (KIM-1) with expanded uncertainty (Ur) 63.4×10−12, was obtained from International Laboratory Comparison as a part of CCL-K11 key comparison of the optical frequency standards. Two calibration methods have been applied to create the traceability link from the length measurement device to KIM-1. The accuracy of KIM-1 transferred to stabilized and non-stabilized He-Ne lasers concerning beat frequency method and direct measurement method using wavelength meter. Laser head Agilent 5519B with dual frequency mode was used as DUT in beat frequency experiment. As calibration result, the optical wavelength of DUT is (632.991 371 061±1.9×10−9) nm and (632.991 374 729±2.6×10−9) nm, respectively for 1st and 2nd polarized beam. In case of direct measurement method, calibration result was obtained by using Laser Head Polytec OPV-503 as DUT, the result is (632.9913±0.0026) nm. Best measurement capability was reached 1.3×10−10 in relative value (Hz/Hz) for beat frequency method and 2.6×10−3 nm for direct measurement method.