Solid-State Micro-ball for Optical Limiters

A Phase I SBIR program is proposed to develop crystalline materials for optical limiters. Crystals will be fabricated into micro-balls and suspended in an index matched glass for use in practical applications. The materials development portion of the program will involve studies of the use of photoionization, color center formation, charge trapping and transfer, and combinations of these processes for ions in crystalline materials. The general approach is to use a two step process in which the first step allows for the absorption of high intensity laser radiation and the second step provides the recovery mechanism for the material. The first step will involve the photoionization of transition metal ions to create absorbing color centers in an appropriate host lattice. The second step will be the reduction of a second dopant ion removing the color centers.