Theory and modeling of gaseous diffractive optics elements

Acousto-optics consists of launching acoustic waves in a medium to modulate its refractive index and create a tunable optical grating. Here, we will present the theoretical basis of a new scheme to generate acousto-optics in a gas, where the acoustic waves are initiated by the localized absorption (and thus gas heating) of spatially-modulated UV light. Our theoretical and numerical analysis encompasses the physical chemistry of UV absorption by ozone and subsequent chemical reactions, the hydrodynamics of the waves launched by the heat deposition and the diffraction properties of the resulting optical elements. Our model shows good agreement with experiments and suggests future directions for the applications of these optical elements, like for the final optics of inertial fusion energy facilities. Work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344, and funded by the LDRD Program at LLNL under Project Tracking Code No. 24-ERD-001.