Novel Polycrystalline Ceramic Laser for RF Guns

79411S Lasers perform a critical role in injectors of high quality (low emittance and high phase-space brightness) electron beams to linear accelerators. Radio frequency (RF) photoinjectors (in which electrons packed tightly in phase-space are produced from a photocathode surface properly embedded in a high electromagnetic field inside a radio frequency cavity and subjected short pulse laser irradiation for photo-emission) have been under intensive development for more than a decade. For these photoinjectors, diode-pumped solid state lasers, typically Nd:YAG, impinge ultra-fast pulses on the photocathode surface to generate electron bunches. For future RF photoinjector guns, improvements in laser speed, power, and brightness will be needed. Advances in ceramic powders and processing methods are enabling the development of transparent, polycrystalline ceramic lasers with performance equivalent to, and sometimes exceeding that of, single crystal solid state lasers. In this project, high purity nanopowders will be used in conjunction with the latest powder ceramic processing methods to produce a new polycrystalline laser material with significant potential as a new DPSS (Diode Pumped Solid State) laser for RF photoinjector guns. In Phase I, high purity starting materials, along with a cubic ceramic nanopowder that has high levels of a rare earth lasing dopant, will be fabricated into highly transparent specimens. Optical measurements and microstructural analysis will be used to vary and refine the experimental processing protocols, in order to achieve the highest possible optical quality. Commercial Applications and Other Benefits as described by the awardee: In addition to the application to high energy physics, faster, higher power solid state ceramic lasers should have application in industrial, medical, and aerospace markets. The use of solid state ceramic lasers in ultra fast laser machining, materials processing, medical diagnostics and therapeutics, entertainment, image recording, and remote sensing applications should grow dramatically in the next few years. Another potentially large market for these lasers is in collision avoidance systems for automobiles.