Thin-film ring laser with waveguide pumping

A waveguide-pumped thin-film ring laser, using rhodamine 6G as the active substance, was constructed and investigated. Measurements were made of the threshold pump power (22 W), radiation directionality coefficient (2–50), emission wavelength (580–600 nm), and width of emission line (0.6–1 nm). The gain was calculated for two models of an organic dye amplifier with an exponential distribution of the pump intensity along the amplifier. An estimate was obtained of the minimum pump power necessary for the excitation of the investigated thin-film ring laser.