TITANIA - A 1020 W CM(-2) ULTRAVIOLET-LASER

The Titania laser system, based around a 42 cm e-beam pumped KrF ampli fier, is currently being installed at the Rutherford Appleton Laborato ry and will come on line as a user facility in 1996. Like Sprite, its predecessor, it will operate in both CPA (249 nm) and Raman (268 nm) s hort-pulse modes, delivering up to 10 TW to target in high-quality bea ms. With brightness expected to reach 10(21) W cm(-2) sterad(-1), it w ill be the world's brightest ultraviolet laser. The design of the Tita nia system includes a number of novel features. The multi-pass Ti:sapp hire front-end amplifier uses an unusual beam-folding scheme. The Rama n system will involve the first application of Raman multiplexing, com bining high KrF efficiency with low transport cost. Reflective coating s with very high damage thresholds are being developed for the CPA com pressor gratings and the UV transport optics. A windowless configurati on for the final Raman amplifier is presently under analysis, to allow the performance of this maximally stressed component to be extended s ubstantially. Finally the design of the Titania e-beam machine, featur ing novel split-cathode diodes, has resulted in unusually high efficie ncy of electron transport into the laser gas. The laser's infrastructu re has involved sophisticated mechanical and electrical design, and a computerized diagnostic, control and safety package is being developed to allow one-man operation of the whole 1000 m(2) installation.