We present a method to design a finite decay rate for excited rotational
states in polar molecules. The setup is based on a hybrid system of polar
molecules with atoms driven into a Rydberg state. The atoms and molecules are
coupled via the strong dipolar exchange interaction between two rotation levels
of the polar molecule and two Rydberg states. Such a controllable decay rate
opens the way to optically pump the hyperfine levels of polar molecules and it
enables the application of conventional laser cooling techniques for cooling
polar molecules into quantum degeneracy.Comment: 4+ pages, 1 figur