Spectra of electron-beam pumped XeF lasers.

An analysis is presented of the lasing spectrum of the rovibronic XeF(B-X) transition as observed in an electron-beam pumped laser. The intricate spin-split rotational and vibrational structure in the 35.1- and 353-nm lasing emission is investigated, and insight is gained on the processes responsible for the vibrational, rotational, and spin inhomogeneities manifested in the spectra. Explanations of the data are developed in terms of near-resonant vibration-rotation energy transfer, rotational relaxation rate differences in the B and X states, rapid dissociation of the rotational resonances near the dissociation limit of the ground state, relatively slow collisional spin relaxation, and optical coupling of spin states. The implications for narrowband extraction in the 351- and 353-nm bands are noted. The rotational relaxation rates of the X and B states of XeF are estimated in the Appendix.