Recent Experiments Leading to the Characterization of the Performance of Portable (He-Ne)/CH₄Lasers: Part II: Results of the 1986 LPTF Absolute Frequency Measurements

Abstract

Comparison of the VNIIFTRI and LPTF frequency multiplication chains has been carried out through the measurement of the frequency of a portable VNIIFTRI (He-Ne)/CH4 laser. Agreement is within 100 Hz (1.1 parts in 1012) and is secured by the very good medium-term frequency repeatability of the (He-Ne)/CH4 VNIIFTRI portable laser (a few parts in 1013). On the same occasion a measurement of the frequency of the BIPM (He-Ne)/CH4 reference laser (B.3) has been performed at LPTF. Other experiments carried out on the BIPM laser show that the reproducibility of the (He-Ne)/CH4 system could be improved by a systematic study and then by a better control of the various perturbing factors which influence the shape of the methane-saturated absorption peak.

Practical realization of the definition of the metre, including recommended radiations of other optical frequency standards (2001)

“…five times the reported measured uncertainty of 4 Hz, giving a relative standard uncertainty of 6.9 × 10 −13 . This value is linked to the earlier recommended transition, R(12) (00 0 1)-(10 0 0) laser line in 12 C 16 O 2 , resonant with OsO 4 [62][63][64][65].…”

Horloge à réseau optique à atomes de mercure

“…À ce titre, le LNE-SYRTE est impliqué de longue date dans la métrologie ultraprécise des fréquences optiques [10][11][12]. Depuis 2000, ces activités incluent le dé-veloppement d'étalons de fréquence optique à atomes de strontium (Sr).…”

Absolute frequency measurement of mid-infrared secondary frequency standard at BNM-LPTF

“…(1) L2 = 29 053 488 000 000 + 7B1 + B2 ? B3 Hz (2) where B1, B2 and B3 are the readings of counters 1, 2 1n 3 of Fig. 1.…”