Nonlinear optical properties and memory effects of the azo polymers carrying different substituents

The third-order nonlinear optical properties and electric memory behavior of azobenzene polymers were influenced by different substituents. The nonlinear optical coefficients of polymer films measured using the Z-scan technique revealed that the polymers with different substituents exhibited different nonlinear absorption. The reversibility of sandwich memory devices based on the azobenzene polymers was dependant on the terminal substituent on the azobenzene chromophore. Polymers with electron-accepting terminal moieties in the azobenzene pendant showed write-once-read-many-times memory whereas the polymer that contained electron-donating moieties displayed a FLASH-type (rewritable) memory.