A number of experimental and theoretical schemes have been employed to perform time resolved investigations on diatomic molecules. Laser excitation of the molecule in question is the common ground in the cases discussed. The experimental technique used in a particular case is dependent on the availability of laser sources and the various difficulties encountered when producing and exciting the molecule. In particular, a novel way of utilizing the fast current scanning effect in a diode laser in lifetime measurements is described and, in order to handle saturation effects when deconvoluting lifetime data in a two photon excitation experiment a dynamical three level modelfunction is used as a model fitting function to extract the lifetime data. A treatment of the two cases when, (i): the molecules of interest escape out of the field of view either due to diffusion (collisional escape) or, (ii), if the escape mechanism is non collisional direct escape, have been performed in order to determine which escape model to assume under a particular set of experimental conditions.