Results from the CII-2006 campaign at the BIPM of the BIPM.L-K11 ongoing key comparison

Abstract

Lasers from five national metrological institutes (NMIs) were brought to the BIPM in November 2006 as part of the BIPM.L-K11 ongoing key comparison initiated by the Comité Consultative des Longueurs (CCL) 11th meeting in 2003. The absolute frequency of the f component of the R(127) 11-5 transition was measured for these lasers following the Protocol for BIPM.L-K11. The results of these measurements are compiled in the present paper. The comparison reports, as communicated by each participant, are included as Appendices.Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/.The final report has been peer-reviewed and approved for publication by the CCL, according to the provisions of the CIPM Mutual Recognition Arrangement (MRA).

Calibration of a Michelson-type laser wavemeter and evaluation of its accuracy

“…This laser meets all the recommendations (1983 and 1992) of the consultative committee for the definition of the meter [13]. Typically combined contribution to the frequency uncertainty from the parameter settings is 72.0 kHz [14]. Moreover, the He-Ne iodinestabilised laser intercomparisons from national laboratories undertaken by the BIPM (between 1993 and 2003) confirmed that the value of the laser uncertainty will not exceed 12 kHz if the laser's operating parameters are adjusted at the recommended values by the Consultative Committee of Length (CCL) as suggested in the BIPM Mise en Pratique [15].…”

Study of mode structure of a 612 nm He-Ne laser in a transverse magnetic field

“…(5). While determination of the type B uncertainty was rather different task in which we considered this uncertainty value as the difference in frequency between the hyperfine structure component f of the R(127) 11-5 transition of 127 I 2 emitted from the He-Ne Iodinestabilized laser which serves as the national length standard and at the same time, the most stable laser in the country when measured through international comparisons [9,10] and when measured by the wavemeter. These values where 473612353.6026 MHz and 473612523.0000 MHz respectively.…”