Broadband lasing and nonlinear conversion of radiation from LiF : F2+ and LiF : F2- colour centre lasers

Broadband LiF : F₂⁺ and LiF : F₂^- colour centre lasers are studied theoretically and experimentally. The cavities of these lasers ensure spatial wavelength selection. The lasers generate nanosecond pulses in the near-infrared range with a spectrum wider than 1300 cm^-1. As a result of optimisation of the optical layout and selection of proper nonlinear crystals, the broadband laser radiation with a spectral width of more than 1300 cm^-1 is efficiently and simultaneously converted into the second harmonic in a nonlinear LiIO₃ crystal and into the fourth harmonic, in a nonlinear BBO crystal.