We have determined the absolute frequencies of the R(0) and Q(1) transitions of the 2ν3 band of 12CH4 in the 1.66-μm region to be 180.345 065 08(37) and 180.021 253 10(61) THz. The numbers in parentheses are the standard deviations in units of the last digit of the quoted frequencies. We have used the 1.54-μm saturated absorption line of 13C2H2 as a frequency reference and an optical frequency comb generator for bridging the frequency difference of 14 THz between the 1.66- and 1.54-μm radiations.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Atomic and Molecular Physics, and Optics
- Physical and Theoretical Chemistry
- Electrical and Electronic Engineering