Knowledge Bank

The pump/probe microwave optical double resonance (PPMODR) technique utilizes the sensitivity of optical LIF detection and the resolution of molecular beam microwave spectroscopy. It has been primarily used in the study of neutral atomic and molecular compounds which could be readily produced in effusive oven $sources1$. It is the optical analog of a molecular beam magnetic resonance $experiment2$ where the state selecting and detecting magnetic fields have been replaced with laser radiation for depletion and LIF detection. Here we report on the adaptation of this technique for the study of refractory metal containing compounds generated in a supersonic laser ablation/reaction source. The technique appears to be quite general having been applied to the microwave and millimeter wave study of SrOH, YO, YF, CaOH, TiO and TiN. The linewidths are typically kHz (FWHM) and are satisfactorily modelled using the Rabi two level $formula2$. The advantages of PPMODR method over other microwave techniques include the ability to rapidly perform long spectral searches and the requirement of low microwave intensity (typically W/cm for electric dipole allowed transitions).