Friday, January 29, 2010

SEMINAR: "Crystals and ceramics for high power lasers andscintillation at the LCMCP-Paris" - Dr. Bruno Viana

"Crystals and ceramics for high power lasers and scintillation at the LCMCP-Paris"
Tuesday, February 23, 2010
2:30 PM - 3:30pm

Dr. Bruno Viana

In the field of solid state lasers, new directions are investigated to manage thermal effects. New crystals with very good thermal properties and/or new configuration are proposed. For instance Yb3+:CaGdAlO4 (CALGO) has a high thermal conductivity of about 7 W K−1m−1 allowing high-power diode pumping power. For this material, under 100W of incident power, thermal lenses effects are very small (temperature gradient in the crystal of only 20oC). In addition, this material has demonstrated generation of ultrashort laser pulses (<100fs). Other configurations (crystal composites, thin disks, crystalline fibers) are under progress within a French consortium. Transparent ceramics are also interesting and if we focused our attention on ytterbium doped CaF2 for laser applications, transparent sesquioxide Ln2O3 ceramics have been recently obtained for applications in scintillation. In medical imaging, careful control of the doping and point defects should be realized to optimize the optical properties and limit afterglow process. On the contrary materials with a long afterglow luminescence, also called persistent luminescence could be used for various applications (emergency signing, luminous painting, and lightning sources). We recently proposed this concept for a new tool in optical imaging.


Dr Bruno Viana is a specialist of the Optical Materials at the LCMCP-ENSCP in Paris. This research laboratory has developed several new lasers crystals in the last 15 years (borates BOYS or GdCOB, YCOB with non linear properties, silicates SYS, LSO and aluminates CALGO, or more recently transparent fluoride ceramic CaF2). Bruno Viana focused his works on rare earth doped laser materials (in particular for fs pulses generation) and high power lasers. He is in charge of the scintillation program (in form of crystals and transparent ceramics) and of the development of materials for medical imaging at the LCMCP-ENSCP.

For More Information:

Michael Bass, Professor Emeritus, CREOL
Tel: 407-823-6977
FAX: 407-823-6880

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