Dressed states of molecules and state focusing

The state-focusing properties of the dressed states of a molecule in a strong microwave field are studied through molecular-beam microwave–microwave double-resonance spectroscopy. The state-focusing properties can be easily obtained through the dressed state formalism using a sudden approximation for the transition between field-free and dressed molecular states. Using this formalism, the transition moment and state-focusing properties of dressed states can be predicted by considering the component molecular states in the molecule-field eigenstates. By carefully constructing the molecule-field eigenstates, powerful double-resonance capabilities can be obtained by borrowing state-focusing character from other molecular states.