Imitrines. I. A new class of laser dyes in the visible range

Laser action has been achieved in solutions of imidazotriazine (imitrine) dyes excited by the third (355 nm) and fourth (266 nm) harmonics of a neodymium laser. The widths of the free-lasing spectra of the dyes were 40-50 nm and covered the 475-580 nm range. The threshold pump intensity and lasing efficiency were measured. The prospects for using imitrines in lasers in the visible range are discussed.