Efficient thallium photodissociation laser

We report on an atomic thallium laser at 535.0 and 377.6 nm which is pumped by the photodissociation of TlI with the 193-nm output of an ArF laser. High-resolution Fabry-Perot scans of the 535.0-nm line have shown a structure in the laser spectrum which depends on the Tl inversion density. The energy efficiency for conversion of the pump into thallium laser emission has been measured to be 14±3%.