Lawrence Livermore National Laboratory



Laser Gain Materials Development

Laser gain materials with proper pumping profiles and efficient spectral filtering ability are critical to high peak power laser systems. Transition metal complexes can meet the desired requirements for spectral filtering when the oxidation states of dopant ions are precisely controlled. By tightly integrating experimental observations with first-principles simulations, fundamentally new insights into the specific factors that control the redox chemistry and the emission and absorption characteristics in model inorganic systems are revealed. By transferring the knowledge to manufacturing industry, a pathway is being developed toward fabricating large aperture optics capable of efficiently absorb unwanted transmission with minimal losses for the must-pass light in high peak power laser systems.

People

Selected Publications

S.G. Demos, P.R. Ehnnann, S.R. Qiu, K.I. Schaffers, T.I. Suratwala, "Dynamics of defects in Ce3+ doped silica affecting its performance as protective filter in ultraviolet high-power lasers", Optics Express 22 (2014) 28798


High reflective coatings by e-beam physical vapor deposition

High-dielectric constant multilayer coating films produced by e-beam physical vapor deposition are used on high reflective mirrors for high peak power laser systems. Coating inclusions, surface contaminations and substrate surface-flaws often limit thin film performance and lifetime by creating damage under laser irradiation. Mitigation strategies and process protocol are being developed based on FDTD simulations of E-field intensification and femtosecond laser machining. Recent studies are extended to understand the impact of laser-contaminate interaction on the performance of thin films and its dependence on geometrical shapes of particulates, the oblique angles of irradiance and thermal mechanical properties of the protective layer.

People

High reflectance mirrors at 1053 nm made from multilayer coating thin film by e-beam physical vapor deposition.

Selected Publications

S.R. Qiu, J.E. Wolfe, A.M. Monterrosa, M.D Feit, T.V. Pistor, C.J. Stolz, "Searching for optimal mitigation geometries for laser-resistant multilayer high-reflector coatings", Applied Optics, 50 (2011) C373

J.E. Wolfe, S.R. Qiu, C.J. Stolz, "Fabrication of mitigation pits for improving laser damage resistance in dielectric mirrors by femtosecond laser machining", Applied Optics, 50 (2011) C457


Optical Gratings and Diffractive Optics

PLS researchers serve as critical members of the Advanced Optical Components and Technologies  program that develops, creates and provides critical optical components for laser-based missions at LLNL. The group also designs and fabricates a variety of custom gratings  and diffractive optics  for researchers worldwide. This group has been awarded several R&D100 Awards.

Multilayer dielectric diffraction gratings up to 1 meter in diameter are manufactured entirely at LLNL and optimized for a diffraction efficiency of greater than 90 percent.

People

Selected publications

JA Britten, SN Dixit, M DeBruyckere, D Steadfast, J Hackett, B Farmer, G Poe, B Patrick, PD Atcheson, JL Domber, and A Seltzer. "Large-aperture fast multilevel Fresnel zone lenses in glass and ultrathin polymer films for visible and near-infrared imaging applications," Applied Optics (2014) 53, 2312-2316.

JA Britten, HT Nguyen, SF Falabella, BW Shore, MD Perry, DH Raguin. "Etch-stop characteristics of Sc2O3 and HfO2 films for multilayer dielectric grating applications," Journal of Vacuum Science & Technology A—Vacuum Surfaces and Films (1996) 14, 2973-2975