High-fluence infrared filters

Brandon Wood, Vince Lordi

The National Ignition Facility (NIF), housed at LLNL, is the world’s most powerful laser. Using a nonlinear optical KDP crystal, it converts low-frequency infrared light into higher-frequency ultraviolet light before target illumination. In order to improve the efficiency of NIF operation, scientists at LLNL are working to develop an effective filter for selective blocking of leaked low-frequency light. This is made much more difficult because of the extremely high fluences present.
To assist in selecting suitable materials for selective-frequency infrared absorption of high-fluence optics, we have been performing excited-state optical absorption studies of ion-doped solutions and optical glasses. The simulations are designed to probe the relationship between local dopant environment, chemistry, and optical properties. We work hand-in-hand with synthesis and characterization experts at NIF to test predictions and provide valuable feedback.
Figure: Lowest unoccupied molecular orbital of a Cu2+ candidate dopant atom solvated in a neutral aqueous environment.