Optical-optical double resonance process in free-jet supersonic expansion of van der Waals molecules: characteristics of the expansion, number of excited molecules and emitted photons

Basic characteristics of a free-jet supersonic expansion beam are presented along with an estimation of a number of expanding CdAr and ZnAr molecules that are excited in the free-jet in optical-optical double resonance (OODR) process. The estimation is demonstrated for laser excitation from the ground, via respective A30+(53P1) or C11(41P1) intermediate, to the E31(63S1) or 11(41D2) Rydberg state of CdAr or ZnAr, respectively. A number of subsequently emitted and collected photons is also predicted.