Modernization of Koesters interferometer and high accuracy calibration gauge blocks

8th Brazilian Congress on Metrology

França, R.S.^1 ; Silva, I.L.M.^1 ; Couceiro, I.B.^1 ; Torres, M.A.C.^1 ; Bessa, M.S.^1 ; Costa, P.A.^1 ; Oliveira, W.^1 ; Grieneisen, H.P.H.^1

National Institute of Metrology, Quality and Technology, Inmetro Optical Metrology Division - Diopt, Brazil^1

关键词: Frequency stabilized lasers;    Gauge block;    High accuracy calibration;    Interferometric techniques;    Optical Metrology;    Spectral line;    Time and frequencies;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/733/1/012059/pdf
DOI  :  10.1088/1742-6596/733/1/012059

来源: IOP

【 摘 要 】

The Optical Metrology Division (Diopt) of Inmetro is responsible for maintaining the national reference of the length unit according to International System of Units (SI) definitions. The length unit is realized by interferometric techniques and is disseminated to the dimensional community through calibrations of gauge blocks. Calibration of large gauge blocks from 100 mm to 1000 mm has been performed by Diopt with a Koesters interferometer with reference to spectral lines of a krypton discharge lamp. Replacement of this lamp by frequency stabilized lasers, traceable now to the time and frequency scale, is described and the first results are reported.