New ion laser transitions in He-Au mixtures

We have observed 20 new laser transitions when exciting a helium discharge in a gold-plated hollow cathode. The new ion laser transitions span the wavelength region from 253 to 763 nm. The behavior of laser power as a function of helium pressure and discharge current is presented. In general, the transitions have low threshold currents (<4 A), and the output power does not saturate at the limit of the discharge current. Multiline output power of 125 mW has been demonstrated in the 250–290-nm region.