Absolute frequency measurement of a 1.5-microm acetylene standard by use of a combined frequency chain and femtosecond comb.
We have developed and characterized a pair of Doppler-free acetylene-stabilized diode laser frequency standards as optical communications references. The Allan deviation sigma/f of an individual system reaches a minimum of 4 x 10(-14) at a sampling time of 5000 s, and the long-term lock-point repeatability is found to be 0.4 kHz (one standard uncertainty), corresponding to a fractional uncertainty of 2 x 10(-12). Using a combination of a frequency chain and a self-referenced femtosecond comb, we have measured the frequency of line P(16) of the v1 + v3 overtone band of 13C2H2 to be 194,369,569,385.9 (3.0) kHz. The uncertainty of this number is limited solely by the reproducibility of the standards.
Edwards
Christopher S
CS
National Physical Laboratory, Queens Road, Teddington, Middlesex TW11 0LW, UK. christopher.edwards@npl.co.uk
Margolis
Helen S
HS
Barwood
Geoffrey P
GP
Lea
Stephen N
SN
Gill
Patrick
P
Huang
Guilong
G
Rowley
William R C
WR