Absolute frequencies of the methane-stabilized HeNe laser (3.39μm) and the CO2, R(32) stabilized laser (10.17μm)

The frequencies of two infrared lasers stabilized by molecular absorption lines have been measured by using a frequency-synthesis chain extending down to the caesium frequency standard. The measured values are 29,477,160,852+or-16 kHz for the R(32), 10.17 mu m transition of CO2 and 88,376,181,608+or-43 kHz for the F2(2) component of the P(7) transition in the nu 3 band of methane. These values are in good agreement with previous determinations and are obtained using the value 32,176,079,482 kHz measured previously for a stabilized CO2 laser operating on the R(12), 9.3 mu m transition.