Lamb dip of a Quadrupole Transition in H_2

The saturated absorption spectrum of the hyperfine-less S(0) quadrupole line in the (2-0) band of H_2 is measured at \lambda=1189 nm, using the NICE-OHMS technique under cryogenic conditions (72~K). It is for the first time that a Lamb dip of a molecular quadrupole transition is recorded. At low (150-200 W)... Show more