Non-destructive Monitoring of Molecular Vibrational Transitions

Transition frequency measurement by monitoring a phase shift requires no cycling transition and appears to be applicable to molecular vibrational transitions. We estimated the attainable signal-to-noise ratio SNR, and found that this method can be used to observe the one-photon E1 transition of more than 100 molecules. This method can also be used to observe the two-photon transition of more than 104 molecules in an optical lattice. This method is likely to be particularly useful for observing the (v,N,J,F)=(0,1,1/2,0)→(1,1,1/2,0) transition frequency of CaF molecules.